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How to properly insulate a ceiling made of boards. Subtleties of ceiling insulation in a house with a cold roof. Sequence of work for different insulation options

In winter, at least 25% of the heat is lost through the roof of an uninsulated building; the losses are compensated by increased heating. Of course, heating entails increased energy consumption. Budget method solution to the problem - insulating the ceiling in a private house, the attic remains cold. Less overlap roof slopes in terms of area, hence the savings. Our task is to tell you how to properly insulate a ceiling by first selecting the appropriate materials.

The age-old question - to insulate from the inside or outside

Any external fence separating a living space from the street should be sheathed with thermal insulation on the outside. Accordingly, the ceiling insulation is top floor of a private house is done from the attic side. Causes:

1. Installation is physically simplified, which is important when doing the work yourself. No need to do hanging frame or hem the insulation from below to the ceiling.
2. A layer of insulation 10-20 cm thick (depending on the region of residence) will not reduce the height of the rooms. This is an important plus for old buildings and “Khrushchev” buildings with low ceilings.
3. In a lived-in house or apartment, you won’t have to redo the renovations.
4. If you do not follow the internal thermal insulation technology, the surface under the insulation will get wet and fungus will appear. Moisture condensation inside the “pie” is promoted by 2 factors: the penetration of water vapor and the formation of a dew point at the junction of dissimilar materials.

When the outer fence is sewn up from the inside, the point of moisture condensation is located near the junction of 2 different building materials

About the notorious dew point, which is used to frighten ordinary homeowners. To avoid condensation inside the structure, it is worth meeting 2 conditions: do not allow water vapor from the room to enter there and use an insulator of sufficient thickness. Then the dew point will be inside the insulation, where there is nothing to condense. The second way is to organize moisture removal using ventilation (read below).

Reference. Dew point is the phenomenon of condensation of water vapor from the air at a certain humidity and temperature. The lower the air temperature, the sooner the degree of extreme saturation with moisture is reached and condensation begins to form.

There are exceptions to the rules; not every room can be insulated from the outside. Examples:

• ceiling of the upper apartment of a multi-story building;
• attic;
• balcony, loggia;
• concrete garage floor above the basement, cellar;
• the need to save money, etc.

For obvious reasons, it will not be possible to insulate a garage basement from above

In these cases, internal thermal insulation of ceilings is arranged with strict adherence to technology. We will describe the work procedure in the form step by step instructions, but first you need to find out...

The best way to insulate ceilings

To insulate ceiling structures, 4 groups of materials are used:

1. Fibrous - mineral, stone (basalt) and glass wool.
2. Bulk – sawdust, clay, expanded clay, vermiculite.
3. Polymers made from expanded polystyrene and polyethylene.
4. Sprayed - ecowool, polyurethane foam, liquid foam - penoizol.

We will not focus on the last group of insulation materials - liquid mixtures are applied by spraying or filling cavities under pressure, which requires appropriate technological equipment. You cannot do such ceiling insulation in a private house with your own hands - you need to hire specialists from a specialized company and pay for the services.

Application of cellulose ecowool (left) and polyurethane foam (right)

Note. Sprayed materials are the most effective and at the same time expensive. Only insulation is applied manually polyurethane foam Polynor with a low thermal conductivity coefficient λ = 0.04 W/(m °C). The price of an aerosol can is 8 USD. That is, the coverage area is 1 m² with a thickness of 50 mm. Thermal resistance of the layer: R = 0.05 / 0.04 = 1.25 m² °C/W - information will be useful to us for comparison.

Let's take a closer look at each group of building materials, then choose suitable insulation materials for ceilings in various rooms.

Porous-fibrous materials

For thermal insulation of roofs and attics under a cold roof, 3 types of fiber products are used:

• mineral wool on a synthetic binder, thermal conductivity λ = 0.055-0.06 W/(m °C);
• basalt non-flammable insulation λ = 0.05-0.053 W/(m °C);
• mineral wool based on glass fiber (otherwise known as glass wool) λ = 0.044 W/(m °C).

Clarification. We present insulation parameters for real operating conditions, taken from regulatory construction documentation. To increase the characteristics of insulators, manufacturers indicate the λ coefficient for the material in a dry state. The lower the thermal conductivity, the better insulation resists cold.

Above we calculated the thermal resistance R of penoizol with a thickness of 5 cm (1.25 m² °C/W). Let’s compare the indicator with the characteristics of fibrous materials of similar thickness by performing a short calculation for each (we applied the methodology from SNiP):

• mineral wool - R = 0.05 / 0.055 = 0.9 m² °C/W;
• stone wool - R = 0.05 / 0.05 = 1 m² °C/W;
• glass wool - R = 0.05 / 0.044 = 1.14 m² °C/W.

Conclusion. In terms of thermal insulation properties, fiber insulation is inferior to liquid and foamed polymers. The best result is shown by glass wool, the worst – by ordinary mineral wool insulators. By the way, the values ​​of thermal resistance R are interpreted the other way around: the higher the indicator, the more efficiently insulation of a certain thickness works.

Externally basalt wool differs from mineral in color and corrugated fiber structure

Let us list the other, no less important properties of fiber insulation:

1. Cotton wool is produced in rolls, slabs and mats of various densities - from 35 to 200 kg/m³.
2. The open-pore structure promotes good vapor permeability of materials.
3. Mineral wool absorbs moisture, but with proper ventilation it dries quickly.
4. Basalt fiber is considered non-flammable because it can withstand temperatures of 600-700 °C. Ordinary mineral wool slabs also do not burn, but are destroyed by strong heat. Glass wool begins to melt at 250 degrees.
5. Insulation materials do not have high strength; they are attached with glue or using a frame.

Fiberglass wool contains tiny glass particles and is therefore not suitable for indoor use. The well-known manufacturer of roofing insulation, Izover, recommends covering the outside of attic floors with glass wool.

The structure of glass wool - the fibers form many air layers

In others mineral insulation a synthetic binder containing formaldehyde is used. Under certain conditions, these substances can be released and mixed with the air. For internal insulation, mineral wool must be well insulated from the living space using film, drywall, and so on.

Bulk insulation materials

All backfill materials have natural origin, and therefore environmentally friendly. The following insulation materials are used to insulate ceilings:

• expanded clay;
• small shavings, sawdust;
• clay;
• vermiculite gravel.

Reference. Vermiculite is much more expensive than expanded clay, so it is used quite rarely. Clay in its pure form is also not used - it is usually mixed with reeds or sawdust.

The main disadvantage of natural insulation materials is their low efficiency compared to mineral and polymer products. Example: the thermal conductivity of expanded clay gravel with a density of 200 kg/m³ is 0.11 W/(m °C). Thermal resistance R of a 50 mm layer will be only 0.05 / 0.11 = 0.45 m² °C/W. The indicators of high-density expanded clay, sawdust and clay are even lower.

Vermiculite (left) and expanded clay gravel (right)

Briefly about the properties of building materials:

1. All bulk insulation materials allow water vapor to pass through well.
2. The flammability of clay, expanded clay and vermiculite gravel is practically zero. Sawdust or reeds mixed with clay mortar also successfully resist fire.
3. Long service life (excluding wood chips).

The low price of natural insulation is a relative concept. To create a thermal insulation layer comparable to 5 cm thick mineral wool, you need to fill expanded clay to a height of 100 mm, that is, spend twice as much.

Characteristics of polymer thermal insulation

To begin with, we will give a list of materials used with an indication of the thermal conductivity characteristics in operating mode:

• polystyrene foam with a density of 15...35 kg/m³, λ = 0.045-0.041 W/(m °C);
• extruded polystyrene foam EPS, density - 20...40 kg/m³, λ = 0.039-0.037 W/(m °C);
• foamed polyethylene 30...50 kg/m³, λ = 0.044-0.042 W/(m °C).

Reference. Extruded polystyrene foam is often called Penoplex after the popular brand. Products made from polyethylene foam are known by the names “Penofol”, “Izolon” ​​and “Tepofol”.

Thin polyethylene foam insulation with foil reflective layer

For comparison with fibrous insulators, we determine the thermal resistance of polymers 50 mm thick:

• foam 25 kg/m³ - R = 0.05 / 0.043 = 1.16 m² °C/W;
• “Penoplex” - R = 0.05 / 0.038 = 1.32 m² °C/W;
• “Penofol” - R = 0.05 / 0.042 = 1.19 m² °C/W.

It is noticeable that the thermal insulation properties of polymer insulation exceed those of mineral and basalt wool. The leader is extruded polystyrene, whose results are comparable only to polyurethane foam applied by machine.

The rest of the properties look like this:

1. Thanks to the closed air pores, insulation materials practically do not allow moisture to pass through. The exception is foam plastics, which have a meager vapor permeability of 0.05 mg/(m h Pa). Mineral wool indicators are 0.4...0.6 mg/(m h Pa).
2. All polymers are flammable, no matter what sellers and manufacturers claim.
3. Polystyrene-based materials are highly durable and are produced in slabs.
4. Foamed polyethylene has a soft and flexible structure and is sold in rolls. To reflect the infrared heat flow, the surface of the insulation is covered with aluminum foil.

In terms of availability, foam plastic is the leader - its price is comparable to natural materials. The “extruder” is sold at the price of basalt non-combustible wool or even more expensive.

Useful fact. A polymer stretch ceiling, which forms an air gap under the ceiling, can be a good insulator. This cavity cannot be called airtight, but there are very few ways for warm air to penetrate.

A review and comparison of the characteristics of insulating materials showed that each group of insulators has strengths and weaknesses that limit their scope of application. For example, flammable polymers cannot be used to insulate the interfloor ceilings of wooden houses - fire regulations prohibit it. You should not ignore the requirement - with the help of insulation, the fire will easily spread to the next floor.

Reference. When installing wooden ceilings, regulations require treating the load-bearing beams with a fire-resistant compound and using non-combustible insulators. If you follow these instructions, then in the event of a fire the ceiling will last 30-60 minutes until it completely collapses. Here is the answer to the question, is it possible to insulate wooden ceiling polystyrene foam.

Building codes It is recommended to treat wooden structures with a fire retardant compound

Based on experience in construction and others regulatory requirements, we will give the following recommendations for choosing thermal insulation:

1. It is better to insulate wooden floors from the attic side with basalt wool, expanded clay, vermiculite or a mixture of clay and sawdust.
2. Ceilings in bathhouses (especially steam rooms) must be insulated with environmentally friendly materials. Here the choice is small - the same expanded clay, sawdust, vermiculite gravel, natural moss. No polymers or mineral wool; strong heating will cause the release of harmful substances.
3. The ceilings of attic rooms are lined from the inside with dense basalt fiber; glass wool is not applicable.
4. Concrete monolithic coverings usually insulated with polystyrene foam or expanded polystyrene. In a country house - from the roof, on the balcony of a high-rise building or in the basement of a garage - from the inside.
5. It is more correct to insulate flat reinforced concrete roofs with polymers from the outside, before installing a built-up bitumen roof. If this is not possible, Penoplex can be hemmed from below without any problems, but in compliance with the technology.
6. It is advisable to use foiled polyethylene foam as an additional insulating layer. How to properly insulate a ceiling with Izolon and Penofol, from a separate manual.

Practice shows that it is better not to combine wood and vapor-tight building materials. The polymer, tightly adjacent to the beam, blocks the access of air, the wood does not “breathe”. If steam begins to condense at the joint and has nowhere to escape, the tree will turn black and rot.

The author of the video is clearly exaggerating and exaggerating the problem, but the situation shown is, of course, unacceptable. There is only one way out - when using polymers, you need to ensure contact of wood with air, which is not easy to implement technically.

How to calculate the thickness of thermal insulation

We will show the determination of the thickness of the insulating layer using examples. Let's take the formula for calculating thermal resistance as a basis (in previous sections we have already used it to compare efficiency different materials):

• R – heat transfer resistance of the insulating “pie”, m² °C/W;
• δ – insulation thickness, m;
• λ – coefficient of thermal conductivity of the material, W/(m °C).

The essence of the calculation: using the standard thermal resistance specified for your region of residence, calculate the thickness of the insulation, knowing the characteristic λ. The R value is determined according to the scheme given in the regulatory documents; a map with indicators for the Russian Federation is shown in the photo.

Similar maps can be found in regulatory documents of other CIS countries

Example 1. It is necessary to calculate the insulation of a dacha with an attic located in the Moscow region. We find the characteristics R for Moscow, select the indicator 4.7 m² °C/W (for coatings), take the coefficient λ of basalt wool equal to 0.05 W/(m °C) and calculate the thickness: δ = 4.7 x 0.05 = 0.235 m ≈ 240 mm.

Example 2. We determine the thickness of the Penoplex insulating layer for the concrete floor, location - Cherepovets. The algorithm is like this:

1. We find on the Internet or reference literature the thermal conductivity of reinforced concrete λ = 2.04 W/(m °C) and find out the thermal stability of a standard 220 mm floor slab: R = 0.22 / 2.04 = 0.1 m² °C/W.
2. Using the schematic map, we find the standard value of R for Cherepovets, take the overlap indicator - 4.26 m² °C/W (the figure is highlighted in green).
3. We subtract the found plate resistance from the required heat transfer value: 4.26 - 0.1 = 4.16 m² °C/W.
4. We calculate the thickness of polystyrene foam insulation λ = 0.037 W/(m °C): δ = 4.16 x 0.037 = 0.154 m ≈ 160 mm.

Comment. The algorithm does not take into account the heat resistance of interior finishing and attic floors, so it gives the result with a small margin. If we take away the resistance of the flooring boards and plasterboard ceiling lining, the thickness of the EPS will decrease to 135 mm.

We insulate the ceiling with mineral wool

As mentioned above, mineral wool is used to insulate wooden floors and ceilings of attic rooms. To prevent the material from becoming saturated with moisture and losing heat resistance, 3 conditions must be met:

• protect the cotton wool from the entry of water vapor from inside the premises;
• ensure ventilation of the outer surface so that the resulting moisture is evaporated from the thickness of the insulation;
• the vapor permeability of the materials used in the “pie” should increase towards a colder room or street, as shown in the diagram.

Slab or rolled mineral wool is located in the space between ceiling beams, as shown in the insulation diagram. When laying thermal insulation with your own hands, follow the following procedure:

1. Roll out a vapor barrier film from the bottom of the beams, laying adjacent sheets with an overlap of 100 mm wide. Make an overlap on the walls 10-15 cm wide. Carefully tape the joints with tape.

   The right photo shows the option of moisture insulation with foamed polyethylene with a reflective layer of foil

2. Glue the film overlaps to the walls of the structures with silicone sealant. The goal is to cut off room moisture from entering the attic.
   
3. Work is being carried out from the cold roof side. Therefore, first make a rough padding of the ceiling, where the cotton wool will subsequently lie.
4. Lay mineral wool boards as shown in the photo. Roll material carefully trimmed and inserted between the joists; creasing the cotton wool is unacceptable.
   
5. Lay waterproofing sheets on top of the insulation - a diffusion membrane that allows moisture to pass in only one direction - outwards. Overlap 10 cm and glue the joints.
6. Arbitrarily lay attic floors from edged boards across the joists. It is not necessary to make a continuous flooring.

Important point. A ventilation duct must be provided between the surface of the wool and the waterproofing. Thanks to the air gap, moisture is removed from the insulation.

Sometimes builders lay the first moisture-proofing film on top of the rough ceiling boards, going around each beam. We do not recommend using this approach - a vapor barrier will block the access of air to the log wood, and from below it will remain open for saturation with steam. Then it is clear - the tree will begin to rot.

How to lay mineral wool on the ceiling if the thickness of one layer is not enough. In such cases, a second tier of heat-insulating slabs is made, shifted by 30-50 cm relative to the first row. If the height of the load-bearing beams is not enough to organize ventilation, a frame of sheathing beams is built up, then a 2nd layer of insulation and waterproofing is installed.

The device for additional sheathing is shown on the left when the height of the beams is not enough

The insulation scheme for the attic floor is very similar to the thermal insulation of a wooden floor:

1. A counter-lattice is provided on the roof, the diffusion membrane is rolled out from above along the rafters. If there is no external frame, waterproofing can be attached from the inside, bypassing each rafter leg and shooting the edges of the canvases with a stapler.
2. The insulation is placed between the rafters at random. If the width allows, we lay the slabs in 2 layers with bandaging, otherwise we install a horizontal counter-lattice.
3. We nail the vapor barrier to the rafters through slats, where the interior trim from gypsum plasterboard or lining is subsequently attached.

Reminder. When working with glass wool or basalt fiber, do not forget to wear a respirator and gloves, the material is very dusty and irritates the skin. How to isolate wood covering no errors, look at the video:

It is extremely undesirable to insulate concrete ceilings with cotton wool from the inside, especially in wet rooms - the kitchen and bathroom. The porous material will harden and lose its properties if not provided. Another thing is to attach mineral wool in space behind suspended ceiling, where water vapor almost does not penetrate.

Expanded polystyrene cladding technology

Polymers are usually used to insulate reinforced concrete floors and ceilings, on both sides. To insulate the structure from the inside, the surface needs to be prepared - seal the joints of the plates, level with mortar and carefully treat with a primer.

The second stage of internal thermal insulation is the installation of a subsystem of wooden bars or metal profiles. The frame plays the role of a platform for the installation of finishing - plasterboard, suspended ceiling and so on. Polystyrene boards are attached to concrete surface directly using the adhesive mixture and umbrella dowels.

Reference. When performing thermal insulation of balconies and loggias with extruded polystyrene, craftsmen often do without a subsystem - they glue or screw the slabs to the ceiling in a continuous layer. Reiki under interior lining attached to concrete floor through the insulation with special screws - dowels.

How to insulate a reinforced concrete ceiling in a private house from the inside:

1. After preparing the surface and assembling the frame (or not), prepare the adhesive mortar mixture according to the instructions on the container.
2. Apply glue to the foam board and press it to the surface, hold it for a while. Attach the next element end-to-end with the previous one, make the adjacent row with a shift relative to the first.
   
3. When the mixture hardens, additionally secure the polymer boards with dowels in the form of umbrellas. It is advisable to blow out the joints polyurethane foam.

   The right photo shows an option for installing EPS together with a suspended ceiling frame under gypsum plasterboard

4. Cover the ceiling with a vapor barrier, ensuring overlaps and taping joints. The film or “Penofol” is aimed at the subsystem with a stapler.
   
5. Place the edges of the film on the walls and glue them with construction sealant. Install the sheathing slats and move on to finishing.

Advice. You should not screw Penoplex to the ceiling without glue. Firstly, there will be gaps under the insulation, and secondly, the surface needs to be perfectly leveled. Otherwise, differences of 1-3 mm will appear at the joints of the plates.

External insulation of reinforced concrete slabs with polymer materials is used on flat roofs and used attics. The “pie” on the roof is formed like this:

The technology for installing polystyrene insulators from below to the ceiling is demonstrated in detail in the video:

Of course, you can insulate reinforced concrete from the inside with mineral wool, and the ceiling of a log house with expanded polystyrene. Then take additional measures: very carefully isolate the mineral wool from the room, and blow polyurethane foam between the polymer and the wood - it allows air to pass through and prevents rotting.

Finally, about backfilling the attic

The use of bulk materials is the simplest option for insulating the ceiling of a country house, although not the most effective. Thermal insulation is carried out on top of the ceiling in various ways:

If you have a concrete auger mixer at your disposal, you can prepare a more modern insulation for the ceiling - polystyrene concrete. Cement-sand mortar mixed with polystyrene balls and laid on the ceiling in a layer of 200-300 mm. There is no need to lay the flooring - the monolith has sufficient strength.

Note. There is a mistake in the video - there is no need to place the film under bulk materials. Water vapor (especially in a bathhouse) should escape freely through the expanded clay or sawdust concrete to the outside, and the wood should dry thoroughly.

An uninsulated attic floor is one of the most vulnerable building structures in relation to heat loss. Through it, 20 to 40% of the thermal energy needed by residents easily “evaporates” into the atmosphere.

The percentage of losses depends on the material used in the construction rafter frame, and on the type of roofing used in the roof arrangement.

Insulating the ceiling in a house with a cold roof will significantly reduce heat loss. We will talk about how thermal insulation work is carried out.

We will list in detail what materials will be required to implement the activities. Taking into account our recommendations, you can significantly improve the energy efficiency of your building.

The ceiling is insulated if there is a non-residential attic above it, which is not equipped with thermal insulation.

It is not used as a living space in winter, therefore, there is no need to lay a layer of insulation on the slopes. Often this is just a warehouse for equipment and a room for drying mushrooms/berries.

The non-residential attic itself plays the role of an air chamber, preventing the movement of heat waves both inside and outside the building. However, to dry the wooden elements of the frame structure, roofing, and metal fastening parts, a cold attic is usually equipped with effective ventilation.

Ventilate it naturally, i.e. regular ventilation without the use of any mechanisms. The system operates without coercion. Air moves due to the difference in temperature and pressure outside the attic and inside it.

The air flow enters the attic space through dormer windows in summer and the gaps framing them in winter, when a vacuum forms inside. It is removed spontaneously, replaced by a new portion coming from the street.

For building structures, constant air circulation is really necessary. But along with continuously moving air masses, heat is blown out of the attic. As a result, instead of saving it to save energy resources, additional costs result.

How to deal with them? Be sure to insulate! Insulation is carried out in two standard ways:

• Installation of thermal insulation along the ceiling from above. Those. from the attic side, on the reinforced concrete floor or between wooden joists, slabs of foamed polymers, mineral wool are placed, expanded clay is poured or folk remedies(sawdust, dry leaves, etc.).
• Installation slab insulation from inside the premises. Simply put, fastening polystyrene boards from the side of the premises to the lower plane ceiling.

In both cases, the insulation layer increases around the perimeter, i.e. along the line of junction of the ceiling and the adjacent wall. Reinforcement is required here due to increased heat loss. A vapor barrier membrane is placed between the wall, ceiling and insulating layer.

Why is it not waterproofing that is used in the formation of a heat-insulating pie over the ceiling? Yes, because it is necessary to protect it, first of all, from steam penetrating from living quarters, and not from atmospheric water flowing from above.

It is the fumes emitted during breathing by us, our pets and house plants, formed during the cooking process, during hygiene procedures that can harm the thermal insulation system. But the roof above must protect it from water.

By the way, when laying all types of insulation from the side of a cold attic, they are not covered with either vapor or waterproofing on top. This allows the materials to dry out spontaneously when the attic space is ventilated.

“Sweat” and “get wet” under an almost airtight insulating film Under no circumstances should insulation be used. Together with moisture, they lose their insulating properties. Wet thermal insulation preserves almost nothing, but it can rot, and mold will spread to wooden elements.

The vapor barrier under the insulation, laid from the attic side, is arranged in the form of a trough: with the edges of the panel extending onto the walls. So it will prevent the insulation from getting wet not only from steam moving upward from the side of the premises, but also from the walls that absorb atmospheric moisture.

It is permissible not to use a vapor barrier layer only when extruded polystyrene boards are used as thermal insulation. They have virtually no pores capable of absorbing and retaining moisture.

Moreover, this is allowed only above rooms with stable “dry” operating conditions. Above bathrooms, showers, and swimming pools, a vapor barrier layer is installed in combination with extruded polystyrene as usual. There is a possibility of moisture penetration between the joints of the slabs.

Insulation from the attic side

Almost all types are used to insulate the ceiling on the side of the cold attic. insulating materials. Bulk options, hard foam slabs, and soft cotton mats are in use.

Both industrial products and good old folk materials are used. The main advantages of the former include manufacturability. Their manufacturers have thought through and provided everything for the quick implementation of lightweight installation.

Folk remedies are much more difficult to install. It is not easy to collect them in the required volume, and even to deliver them to the place of work, which is most often done by hand in buckets. But they are much cheaper, better than industrial products, they coexist with wood and do not emit toxins harmful to us.

The installation of thermal insulation from the attic space requires periodic maintenance of the insulation system.

Bulk materials must be periodically loosened so that they dry better, the rest must be inspected and artificially dried, for example, with a hairdryer if necessary.

For inspection and maintenance, “paths” of two or three boards are constructed along the joists above the thermal insulation. If it is planned to pour the screed over heat-insulating boards and rigid mats, then the trajectory of the proposed path is laid out with a reinforcing mesh.

Use of mineral wool

The group of mineral wools includes glass wool, stone (i.e. basalt) wool and slag wool. Glass wool in last years It is used less and less because of its ability to “dust” abundantly with small glassy particles, inhaling which is strictly prohibited.

Working with glass wool is only allowed in a respirator and goggles. In addition, the smallest glass fibers are harmful to the skin.

Therefore, personal protective equipment should include overalls made of thick fabric with strong elastic bands on the legs and sleeves, and gloves are also a must.

Slag wool is not used for insulating ceilings in low-rise buildings due to its toxicity. What remains is basalt, also known as stone wool, produced from volcanic rocks. This is because it is not harmful to use and is easy to install.

The technology for installing thermal insulation with basalt wool is determined by the type of floor:

• On reinforced concrete floors. First, the base is repaired and leveled, then a vapor barrier is laid with the edges extending onto the walls. Then roll out and lay the mats in 2 layers so that the butt seams lower tier overlapped with the middle of the upper mat, i.e. at a run.
• On wooden floors. The mats are laid in the space between the joists. Previously, a vapor barrier material is placed in each “cell” formed by the joists, extending onto the joists and around the perimeter of the walls.

The wool is cut before installation. Cut it so that the piece is at least 2 cm wider and longer than the actual size of the cell.

Before installing in place, the cotton piece is slightly compressed so that after it straightens out in its proper place and covers the entire space. This prevents the formation of cold bridges.

Thermal insulation with polystyrene foam boards

Slab insulation is used mainly on reinforced concrete floors. It is difficult to choose the size for laying in the space between the joists. You have to cut, waste time, and often material when cutting incorrectly, and in general it’s difficult to do everything without gaps, and these are ways for heat loss.

When constructing an insulation complex for reinforced concrete floors, two types of slab thermal insulation are used:

• Styrofoam. It is also non-extruded polystyrene foam. The material requires the installation of a vapor barrier layer before installation due to the fact that its structure contains channels that can absorb water.
• Extruded polystyrene. Most often it is Penoplex. Due to the almost waterproof surface, it is not necessary to lay a vapor barrier before laying it over living spaces, bedrooms, living rooms, and children's rooms.

Before installing slab thermal insulation on the cold attic side, the foundations must be repaired and leveled. The vapor barrier film is laid in the form of a pallet with sides curved onto the walls.

Lay the slabs freely. Placed in two layers with seams in the lower and upper tier. If Penoplex with a mounting chamfer is used, the seams do not need to be sealed; if polystyrene is used, then the seams and stacks are filled with sealant or mounting foam.

Screeding on slabs is most often carried out partially, only in the area where service paths are installed. It is either filled with a cement-sand mixture with a reinforcing mesh layer not exceeding 4 cm, or constructed from gypsum fiber sheets.

If the solution is poured, then waterproofing is laid over the insulation. Purely so that concrete milk does not seep into the insulation and affect its insulating qualities.

Arrangement with expanded clay gravel

The most famous backfill thermal insulation material is expanded clay. It is used both directly for insulation and to lighten insulating compounds and mixtures. Expanded clay is produced in the form of gravel ranging in size from 4 to 10 mm.

Expanded clay is made from environmentally friendly, easily sintered clay. The material is affordable, non-flammable, moisture-resistant, lightweight, which greatly facilitates delivery and filling. They pour it either into the space between the joists, or directly onto the reinforced concrete floor.

Before filling the expanded clay, the base is covered with a vapor barrier film, the edges of which, according to tradition, extend onto the walls. These peculiar sides should be 10-15 cm above the level of the gravel layer poured onto the ceiling.

It is not necessary to arrange maintenance paths on expanded clay. You can walk straight on the backfill. Periodically it needs to be turned with a rake so that all the artificial pebbles of the insulating layer can dry.

In addition to expanded clay, a wide range of folk fill-in insulation products are still used, attracting mainly owners of eco-houses as adherents of safe and environment materials.

Bulk folk materials

Adherents of environmentally friendly construction methods have their own opinion, based on centuries of successful practice, regarding the options for thermal insulation of the ceiling.

They believe that it is correct and reasonable to insulate both the ceiling under a cold roof and the slopes using natural materials.

In terms of insulating qualities, natural options are certainly inferior to industrially produced insulation materials.

But thermal insulation of natural origin is distinguished by:

• Environmental priorities. They do not create the slightest threat to the environment, do not emit or distribute harmful chemical components. Natural thermal insulators do not need to be disposed of in a special way; they can simply be burned or placed in a compost heap.
• Practicality. Traditional insulation materials retained heat perfectly even in those days when the home was heated only by a stove. In addition, there was no such powerful heating equipment that current owners of private houses have.
• Economic advantages. Prepare natural thermal insulation You can do it for pennies or even for free. Replacement as technical characteristics are lost can be carried out much more often than factory products.
• Symbiosis with natural building materials. Natural heat insulators work well alongside wood, clay, and soil backfill. When stable temperature conditions they do not deteriorate from contact with stone.
• Safety for residents. In extremely rare cases, natural materials can cause an allergic reaction, the origin of which has undeniable chemical prerequisites.

Most natural heat insulators, according to the installation method, belong to the backfill varieties. They are freely distributed over the ceiling, periodically turned to dry and increase the thermal insulation properties. For maintenance, paths are made of a pair of boards laid on logs.

One of the popular options for natural insulation is ecowool, made from natural cellulose. Its advantages include ease of application, thoroughly thought out by the manufacturers, and pre-treatment with fire retardants and antiseptics.

The following are still used as natural thermal insulation:

• Wood shavings and sawdust. An abundance of them remains after the construction of a wooden house; supplies can be replenished at sawmills and woodworking workshops. Cover with a layer of 15 - 30 cm.
• Straw. You can prepare it at the nearest farm that grows cereal crops. Lay in a layer of 25 cm.
• Moss. Excellent, practically non-rotting thermal insulation, used both inside and outside the building. The qualities inherent in nature allow moss to be used for ten years or more. The insulation layer can be relatively small, up to 10 cm.
• Dry leaves, hay. You can stock up on such thermal insulation absolutely free, but you will have to change it almost every year due to the tendency to quickly become saturated with moisture. You can use not only foliage, but also pine needles. It is enough to insulate with a layer of up to 20 cm.
• Seaweed. This insulation option is not readily available in all regions of our country. True, residents of Primorye have them in abundance and can change them every year. The laying power is up to 20 cm. Significant advantages include the distribution of volatile iodine molecules that are useful for people.

If your area has a pond overgrown with reeds, this plant will also serve. Its stems are tied together with a rope or metal wire. Then the fagots are used to fill the space between the ceiling beams and joists.

The above types of natural thermal insulation have a number of significant disadvantages that are not typical for factory products. Therefore, to improve consumer qualities, natural insulation materials must be carefully prepared before installation.

Disadvantages that should be minimized before use include:

• Flammability and ability to support combustion perfectly. Treatment with fire retardants ideally combats this disadvantage. Instead, you can use clay or slag, a layer of which is covered with an insulating backfill on top.
• Reducing the heat-insulating thickness. Thermal insulating natural filling must be stirred frequently to avoid pressing; it must be dried to prevent wetting and the associated decrease in insulating properties.
• Incoherence. During the maintenance of the insulation and the device within the attic, drafts necessary for drying, some of the material can simply be carried outside. This means you need to constantly replenish the stock. This disadvantage can be overcome by baling.
• Tendency to rot. The ability to quickly and easily absorb moisture can lead to rot, especially if regular maintenance is neglected. Antiseptics used for wood treatment are suitable as a preventative measure.
• Attractive to rodents. Rats and mice live freely in dry and warm beds made of straw, moss, and hay; to repel them you will have to purchase specialized products from the SES.

There are two more popular types of folk thermal insulation: soil-vegetative layer and crumpled clay. They do not burn and do not attract mice.

They are not afraid of moisture and drafts that erode dry plants. But there is a serious drawback - considerable weight, due to which it is necessary to strengthen the overlap.

Soil is a layer of soil in contact with the daytime surface, enriched with waste products of representatives of flora and fauna, which is mixed with any of the above-mentioned folk heat insulators for ease. It is simply scattered over the ceiling, like expanded clay.

The clay is diluted in a container with water to the consistency of sour cream, chopped straw or shavings are added to it and poured onto the ceiling in a layer of 10 - 15 cm. After the poured composition has hardened, the cracks are sealed with softened clay.

Ceiling-side insulation technology

If for technical reasons insulation from the side of the cold attic is impossible, then thermal insulation systems are installed from the side of the room, i.e. put on the ceiling. This option is more difficult to implement, but sometimes it is the only possible one.

For thermal insulation of floors from the ceiling side, the following are used:

• Styrofoam. Panels of non-extruded polystyrene foam can easily be glued to a pre-leveled ceiling. Inject into the gaps between the elements silicone sealant or polyurethane foam, the excess of which should be removed immediately.
• Extruded polystyrene foam. They also stick it on. Most often, Penoplex is used with a mounting edge, which eliminates the possibility of cold bridges. The thickness of the insulation can be accurately calculated according to the climatic data of the area and a material with the appropriate characteristics can be selected.
• Cork. The simplest option is a cork sheet used as a flooring for heated floors. Panels glued to the ceiling will also work, but the cost of the insulation system will ultimately be much more expensive.

Gluing while holding the material in a canopy is, of course, much more difficult and complex than pouring it from above. In addition, these options are not applicable without external finishing. They just need to be decorated.

System camouflage ceiling insulation is carried out by installing frame structures: suspended and slatted ceilings. To install them, a fixing profile is installed around the perimeter of the room, located below the glued insulation by at least 1-2 cm.

If you plan to install ceiling lights and exhaust ventilation ducts, then the distance between the plane of the decorative ceiling and the thermal insulation system increases even more. As a result, you may end up with an excessively low, as if “pressing” ceiling, which negatively affects the interior design and the well-being of the home owners.

Options actively used in practice also include single- and multi-level plasterboard structures. The rigid GVL option is a priority due to the fact that if the heat-insulating board gets wet and peels off, it will freely hold the separated part.

In the field of installing an insulation system from the inside of a room, heat-insulating plasters stand apart. Materials for their implementation have been developed relatively recently. The pioneers in their use were progressive industries: the military space complex, civil aircraft construction.

The heat-insulating plaster material applied to the ceiling contains tiny ceramic balls, which contain air inside. This is the most effective insulator.

Valuable advantage heat-insulating plasters lies in the ability to apply a thin layer of 1 mm, the effectiveness of which will be equal to that of foam board 5 cm thick. The downside is the considerable cost and complexity of application, which requires special equipment.

Video #1. Correcting errors in the installation of ceiling insulation made by the former owner of the house:

Demonstration of the process of insulating an attic floor with mineral wool:

Use of ecowool in thermal insulation of ceilings:

Properly executed thermal insulation of the ceiling will ensure ideal heat retention, while creating conditions for the unhindered removal of household fumes and condensate outside the roof structure.

However, not only technologically accurately performed work is important, but also the correct selection of the insulation scheme and material for its implementation. We hope that our article will provide you with effective assistance in this matter.

From the author: Hello, dear reader. If you are reading this, I assume that you have a private house, and you have decided to insulate the ceiling on the cold attic side with your own hands. If so, then further information is what you need to properly insulate the ceiling of your home.

What you need to know before starting work

Where to start?.. The topic is quite extensive, and work related to insulation requires, if not professional, then at least basic knowledge about the materials available on the market, their properties and methods of their use.

If you do the work without having this knowledge, you can, at best, waste time, effort and money, so to speak, in the wind, which is why it gets cold, and at worst, you can provoke a fire due to neglect of technical rules fire safety and improper installation of insulation material. Yes, insulation is needed to keep warm, but a fire is clearly too much in every sense.

Now we will look at the most popular materials, and also find out how to create a cold attic using common types of insulation. We'll find out what the advantages and possibly disadvantages of each are.

Insulation using foam plastic

Polystyrene foam is one of the most popular materials for insulation. It is lightweight and easy to cut even with a regular cardboard cutter. In a word, working with polystyrene foam is convenient, fast, pleasant and, in principle, not difficult. The main thing is to take the correct measurements and not cut off too much from a whole sheet. But even if you overdo it, there is nothing fundamentally terrible about it: this place can be easily filled with polyurethane foam. Let's present the advantages of polystyrene foam in the form of a short list:

• it is easy to cut;
• easy to transport to the top;
• it is not afraid of moisture and is not sensitive to temperature;
• it is not suitable for consumption by insects and rodents;
• if the foam is laid correctly - on a dry base treated with an antiseptic, the likelihood of fungal formations (mold) appearing is minimized;
• the material has a relatively low cost.

The list can be continued, but I think this is quite enough. Basic positive sides We have listed the materials.

But foam plastic can also be different. Yes, there are different manufacturing companies, but that’s not about that now. The fact is that the sheets are produced in different parameters. In this case, we are interested in thickness.

For insulation of residential premises, sheets with a thickness of 5–7 cm are usually used, and their density, as a rule, is 15 kg/m³. Of course, the higher the density, the higher the material’s thermal insulation ability. You can, of course, choose 25 kg/m³, you can lay the sheets in two layers - this is not forbidden.

But, nevertheless, there is a recommendation: if you are going to install an attic floor made of hard material (for example, fiberboard/OSB boards), then it is enough to choose polystyrene foam with a density of 15 kg/m³. If installation of a hard surface is not planned, for better thermal insulation It is worth choosing sheets with a density of 25 kg/m³.

In general, if there is such a possibility, then a hard floor should be installed in any case. This will allow you to store various things in the attic or even turn it into additional living space, if, of course, it is properly equipped.

But if there is no hard surface above the sheets, then walking on them often, much less moving objects, is not advisable. Simply, they are not designed for this, no matter what density indicator they have.

Insulation from a wooden or brick attic is not fundamentally different: in both cases, the process consists of simply laying polystyrene foam on the floor of the attic. More specifically, the following work needs to be done:

• check the entire wooden structure for rot. If you find a rotten area, it must be cut out and replaced with a new piece of wood, pre-treated with an antiseptic. In general, it would be a good idea to treat all elements of the wooden structure with an antiseptic. Even if these measures were taken during the construction of the house, prevention will never be superfluous. Moreover, in matters related to construction;
• clear the attic floor of debris (including small ones) - the base must be clean;
• do necessary measurements, make calculations;
• cut foam sheets according to calculations;

• lay polystyrene on the surface. Be prepared for the fact that this material will cost more than the foam itself, but it is quite justified. In essence, there are alternative options, and in some cases they can do without it at all;
• lay the prepared ones;
• fill the gaps between the sheets with polyurethane foam. The distance between the sheets and the supporting structures also needs to be foamed.

Here's a simple way to insulate your home from the attic with polystyrene foam. Now let's move on to another, no less popular and effective insulation- mineral wool.

Insulation with mineral wool

Insulation with mineral wool is another, no less popular method. Mineral wool is widely used for insulation of apartments, houses, balconies, loggias. Moreover, both ceilings and facades. The range of its applications is no less wide than that of polystyrene foam.

Just like polystyrene foam, mineral wool has its own advantages:

• relatively low cost;
• it is unsuitable for rodents and insects;
• it is quite easy to work with;
• the material is considered to be highly flammable.

But, among other things, mineral wool also has its own characteristic disadvantages, associated, for the most part, with its structure, with the nature of the material itself:

• when wet, it loses its valuable qualities. Of course, if a few drops of water get on it, nothing bad will happen, but if your roof leaks with enviable regularity, dampness will accumulate in the wool - then it will not only cease to perform its functions, the main of which is heat preservation, but also with Over time it will become a place of residence for fungal formations. But growing such “mushrooms” in the attic is unlikely to be part of your plans;
• cotton wool cannot be pressed for the same reasons. No, this won’t cause mold to grow in it, but its effectiveness will decrease by about 30–40%, depending on how hard you try;
• People with diseases of the respiratory system (for example, asthma) should not look at mineral wool at all. But if you happen to work with it, then you need to use personal protective equipment - of course, not a gas mask, but at least a gauze bandage.

I would not say that the disadvantages of mineral wool are significant so as not to consider it as a possible option. I repeat, mineral wool is an affordable, reliable and widespread insulation material. The main thing is to take precautions and not violate the operating rules.

As for the thickness, then, again, the thicker the layer, the warmer the room will be. Taking into account natural conditions, in attics, as a rule, a layer of mineral wool from 15 cm to 30 cm or more is laid.

Another important point: if you use several types of insulation (yes, this is also possible), then the bottom layer should be the least vapor-permeable. In other words, it is possible to lay mineral wool on polystyrene foam, but it is impossible to lay polystyrene foam on mineral wool. If there is a need for sound insulation, it is recommended to use mineral wool with a density of 40 kg/m³.

Here we come to the essence of this section. Let's get started:

• Be sure (!) to check the boards for rot. Outwardly, they may look intact, but if you hear a dull sound when you hit it with a hammer, it is most likely rotten inside. It should be replaced with a new fragment treated with an antiseptic. In general, the preparation is the same as when using polystyrene foam;
• checking the roof. If it leaks even a little, the mineral wool will not forgive you for it. Therefore, be sure to fix the leak;
• checking communications. Although mineral wool is a highly flammable material, it is still worth being safe;
• clean the surface of debris;
• we build a wooden frame;
• We lay vapor barrier material. Just in case, I will say that vapor barrier cannot be laid on both sides. If you suddenly want to spread it on top, resist this destructive desire. The condensate will have nowhere to evaporate, and then the mineral wool will begin to slowly but surely melt;

• we roll out the rolls between the beams (or lay the tiles);
• install a wooden base;
• We enjoy the work done.

You can do without installing a hard floor. This is not necessary, but, again, you will not be able to walk on the surface or place anything on it (remember that the cotton wool cannot be pressed).

We have already looked at two popular methods of insulating a house with a cold attic. Now let's look at other options. I’ll say right away that they are more labor-intensive, but at the same time, more economical from a financial point of view. One of these methods is the use of expanded clay.

Insulation using expanded clay

Expanded clay is a material that is obtained by firing low-melting grades of clay. The resulting gravel has the shape of oval pellets, and the color is somewhere between brown and orange. The bulk density of expanded clay also varies - from 350 to 600 kg/m³ or more. Now this is not so important for us.

Let's consider characteristic virtues and disadvantages of expanded clay. So, the advantages:

• low price (as a rule, it costs several times less than mineral wool or polystyrene foam);
• fire resistance - expanded clay does not burn at all;
• high ability for sound insulation - if this is, of course, relevant;
• Expanded clay is an environmentally friendly material: it does not emit any fumes into the air.

It would seem ideal. Yes indeed it is great option for insulation of a private house. There is only one specific detail: it is a porous material - and by absorbing moisture, its weight increases, and its thermal insulation qualities decrease. If the roof of your house is leaking (even just a little), the first thing you should do before starting work is to repair the roof. Moisture, as we have already found out, is harmful not only for expanded clay, but also for mineral wool and other alternatives.

Keep in mind that expanded clay is quite heavy - it is not foam or cotton wool. Therefore, before pouring it out, make sure that the attic floor/ceiling of the room below is secure. If the boards are hemmed from below to the beams, there is a possibility that the former will not withstand the pressure and will come off the beams. Then the expanded clay will be right in the room.

Floors in private houses are usually made of wood: beams are laid, and then they are lined with boards from below. If the house does not have a heated attic, the ceiling in the building must be insulated. And when installing equipment in the attic of a living space, it won’t hurt to lay something over the ceiling. After all, most, among other things, can also serve as excellent sound insulators.

Material selection

So, let's see how to insulate a house. And first, let's figure out what type of insulator is best to choose in a given case. Typically, floors in country buildings are insulated:

• mineral wool;
• expanded polystyrene;
• sawdust;
• expanded clay.

Advantages and disadvantages of mineral wool

This heat insulator is currently the most popular and is used most often in private homes. Its main advantages include:

• Low cost.
• Easy to install.
• High heat-retaining qualities.
• Insulating the ceiling in a house with this material can also improve the soundproofing properties of the floors.
• Durability.
• Non-flammability.

The disadvantages of this material include:

• The ability to accumulate moisture and lose some of its thermal insulation qualities.
• Not too high a degree of environmental cleanliness.

Expanded polystyrene

This material is also an excellent answer to the question of how to insulate a wooden ceiling in a house. It is a lightweight, environmentally friendly board. Although they are made using a slightly different technology, their appearance is very similar to the well-known polystyrene foam. They differ from the latter in that they practically do not crumble and retain heat much better. Expanded polystyrene lasts much longer than polystyrene foam. Unlike mineral wool, this material is not at all afraid of moisture. Its main advantage over basalt insulator is its smaller thickness with the same heat-retaining qualities.

Its disadvantages include only its rather high cost and flammability. In addition, it is strictly not recommended to use this material if there are rodents in the house. Mice simply love to make passages and holes in foamy materials.

Expanded clay

This material is also very often used to insulate a wooden ceiling in a private house. Expanded clay is a special porous granule made from clay. The material is very inexpensive and retains heat well. Its main advantage is that it can last much longer than any other insulation. Not afraid of expanded clay and water. In addition, it is very durable and fire resistant.

Sawdust

The main advantages of this bulk material are absolute environmental friendliness and low weight. Insulating the ceiling with sawdust is very inexpensive. At sawmills they sell this material for literally pennies, and sometimes even give it away for free. The disadvantages of sawdust include, first of all, a very high risk of fire. In addition, they may dry out or begin to rot. Like polystyrene foam, they can harbor mice or rats.

Insulation of a wooden ceiling in a private house with mineral wool

When insulating the ceiling from the attic side, this material is laid as follows:

• In a building under construction, the actual ceiling itself is placed on the beams from below. edged boards. If the house is old and there are already floors in the attic, a cellular frame should be installed on them.
• A vapor barrier is laid between the beams. You can use either polyethylene or foil material. The latter option is more expensive, but performs its function much better. In addition, foil can reflect heat back into the room. Therefore, such materials, in addition to everything else, are also capable of additionally retaining heat. A vapor barrier is installed on existing attic floors in old houses before installing the frame under the slabs.
• At the next stage, the mineral wool itself is installed. They put her to shame. That is, the step between the beams should be slightly less than the width of the slabs. This allows for the most effective insulation. You need to start laying the wool from the corner farthest from the door. To make it comfortable to walk on the floor, it is worth lining the attic with strips of plywood.
• A waterproofing layer is laid on top of the mineral wool if the attic is not intended to be insulated in the future. If the roof is waterproofed with film, this step can be skipped.
• Next, the finishing floor of the attic is filled.

In exactly the same way, insulation of a wooden ceiling in a brick or poured concrete one is carried out. If there is a chimney in the attic, the slabs are placed on it to a height of 40-50 cm and secured.

Installation from inside

Next, let's see how to insulate a wooden ceiling in a house with mineral wool from the living room side. Most often, the material in this case is installed simultaneously with the pre-assembled metal carcass under drywall. The distance between its constituent profiles is usually 40 cm. Mineral wool slabs have a width of 50-120 cm. Therefore, installation is carried out using the “accordion” method. The cotton wool is simply slipped under the frame elements. In this case, the plates are installed close to each other. Carrying out this work, you should try not to wrinkle the material. Otherwise, the cotton wool will lose some of its performance characteristics.

Do-it-yourself ceiling insulation from the inside continues with the installation of a vapor barrier film. Next, the gypsum boards themselves are installed on the frame. In the event that suspended ceilings are not installed, the work is performed using a slightly different technology:

• The ceiling is first covered with a vapor barrier film. If there is no attic above, it is better to use a waterproofing membrane.
• Next, a wooden sheathing is placed on it. For its manufacture, bars with a cross section of 30*30 - 40*40 mm are used. In this case, the step between the frame elements is made so that the slabs lie sideways.
• At the next stage, mineral wool is inserted between the bars. If the sheathing was installed correctly, the slabs will hold up well just like that. However, in order to completely eliminate the risk of falling out, it is worth additionally securing them with special mushroom dowels.
• Next, it is stretched onto the frame. You need to nail it with slats at least three centimeters thick. This will provide an additional ventilation layer.
• At the next stage, the ceiling is usually sheathed with plywood and covered with ceiling tiles.

Installation of polystyrene foam

Now let's figure out how to insulate the ceiling in a wooden house using another modern material. Typically, expanded polystyrene is laid in the attic in the same way as mineral wool - between beams or in the sheathing. However, it is entirely possible to install it directly on the attic floors, if any, that is, without installing a frame. In this case, the base must be thoroughly cleaned of dirt and leveled. Then the work is done like this:

• Check to see if the floor boards have rotted or come loose.
• Lay a layer of vapor barrier. Fastening is done using staplers.
• From the corner farthest from the door, begin laying out the expanded polystyrene slabs. At the same time, make sure that the joints do not meet in a cross. That is, they perform staggered laying.
• The joints between the plates are sealed with polyurethane foam and additionally taped with construction tape.
• Since the slabs are a rather fragile material, they either put a board on top of them, or pour a 3-4 cm cement screed. In the first case, before laying polystyrene foam on the floors, you will need to fill several logs.

Using polystyrene foam from the inside

Insulation of a wooden ceiling in a private house in this case is carried out as follows:

• The ceiling is thoroughly cleaned of dirt, old plaster(if available), etc.
• After this it should be primed.
• Next, polystyrene foam boards are glued to the ceiling using foam glue. In this case, the material should also be additionally secured with “fungi”.
• A reinforcing mesh is glued on top of the slabs.
• Next, the ceiling is plastered.

Of course, you can install polystyrene foam in the same way as mineral wool, that is, in the sheathing. In this case, the ceiling is sheathed with plywood, clapboard or edged boards at the final stage.

We insulate the ceiling in a wooden house with expanded clay

In this case, the space between the floor beams is pre-covered with roofing felt. You can also use very thick plastic film. must cover the beams themselves as well. The seams on the roofing felt are glued bitumen mastic, on film - with tape. Along the perimeter of the attic, the waterproofing material must be raised to the height of the future backfill layer.

Next, the ceiling itself is insulated with expanded clay. Sometimes the roofing material is pre-coated with a clay solution. The thickness of the expanded clay layer is usually 12-16 cm. It is advisable to use a material that has different fractions of granules. In this case, the insulating layer will be denser and more even. Sometimes crushed foam is added to expanded clay to enhance the thermal insulation effect.

The heat insulator is covered on top waterproofing film. Next is arranged concrete screed 4-5 cm thick. 20 days after pouring, you can begin finishing the floor.

Insulation with sawdust

For such material, cement is usually used as a binder. In order to prevent the appearance of rodents, you can also add a little lime to the sawdust. Rotting is prevented by using borax.

As with expanded clay insulation, the attic floors in this case are first covered with roofing felt or plastic film. You can also use sheet glassine.

The sawdust itself has the following requirements:

• They must be aged for at least a year.
• The material must be dry.
• It is not allowed to insulate the ceiling with sawdust, rotten or infested insects.
• It is best to use sawdust of the middle fraction.

After the attic floors have been prepared and waterproofed, they begin to actually prepare the insulating solution itself. To do this, for ten buckets of sawdust, take one bucket of cement and half a bucket of lime. In addition, dilute a glass of borax in a bucket of water and spray this solution from a watering can over the mixture. The amount of water depends on the moisture level of the sawdust. Usually you have to add 5-10 liters.

The chimney must be laid before installing this type of insulation. The wiring in the attic in this case is pulled in special metal pipes. It is not necessary to screed over sawdust insulation. The frozen mixture itself will be quite strong.

So, you now know how to insulate a wooden ceiling in a house. If the work will be done from the inside, use thinner polystyrene foam. When insulating from the attic side, it is better to use mineral wool. You can save money by using expanded clay or sawdust.

A very significant part of the heat generated in the house is lost through cold ceiling and the attic, if the ceiling does not have reliable insulation. Therefore, high-quality thermal insulation of this structure is extremely necessary. Warm air always strives upward. And if a cold obstacle is encountered on its way, it will rapidly cool down. And this means, firstly, that the heating system will partially work on unnecessary heating of the uninsulated floor, that is, waste expensive energy resources. And secondly, meeting a cold barrier leads to condensation of water vapor, which is always contained in the atmosphere of the premises. Well, who would like that the ceiling is constantly wet? And this has a very negative effect on the durability of the finish and the ceiling itself.

In a word, the ceiling, or rather, the overlap between living rooms and a cold attic must be insulated without fail. Moreover, if earlier it was problematic to find a suitable material, today the market offers a very wide range of different insulation materials for “different tastes and budgets.”

To begin with, the table lists some of the main characteristics of the insulation materials listed above:

Name of insulation	Thermal conductivity, W/m×K	Flammability group	Environmental friendliness of the material
Glass wool	0.038÷0.046	NG - G3	contain phenol-formaldehyde resins
Basalt wool	0.035÷0.042
Slag wool	0.046÷0.050
Cork boards	0.03÷0.05	NG	natural
Ecowool	0.038÷0.045	G3-G4	natural
Linen mats	0.037÷0.04	G4	natural
Thermal insulating peat blocks	0.052÷0.064	G3-G4	natural
Foam glass	0.045÷0.07	NG	natural
	0.032÷0.035	G1-G3	capable of releasing toxic substances, especially during thermal decomposition
Spray polyurethane foam	0.028÷0.030	G2	the original components may pose a danger before they are mixed, foamed and polymerized
Expanded clay	0.16	NG	natural
Slag	0.29 – boiler room; 0.15 - granular	NG	may contain substances hazardous to human health
Sawdust	0.06÷0.08	G4	natural

Mineral wool

Mineral wool can be made from different materials - these are basalt rocks, glass raw materials and slag. Materials have different characteristics, and therefore products made from them differ in some parameters.

Mineral wool of any type is produced in mats and slabs of different densities, and the spread is very large: from 25 to 200 kg/m³. Low-density products are used mainly for thermal insulation of horizontal surfaces. Denser options are produced in slabs and are suitable for insulating facades, roofs, floors, etc. To thermally insulate the ceiling (that is, the attic floor), there is absolutely no need to pursue increased density.

Basalt (stone) wool

This type of material has the best performance characteristics of all mineral wools. True, it costs more.

You may be interested in information about what kind of insulation

Stone wool is made from the melt of rocks of the gabbro-basalt group. Microscopic fibers are drawn from the molten mass, from which mats and slabs are then formed.

Thanks to the special processing of high-quality products, they have a low moisture absorption coefficient, sometimes reaching almost complete hydrophobicity. This indicates that the insulation does not lose its thermal insulation properties throughout the entire period of operation.

High-quality basalt wool can withstand high temperatures. Many products are completely non-flammable, that is, they belong to the NG group. The advantage is the increased flexibility and elasticity of the fibers. It is easier to work with such material, and there is practically no tendency for shrinkage in high-quality basalt wool.

The disadvantages of this material include the content of phenolic resins, which serve as a binder for the fibers. If you decide to purchase such insulation, then you should pay attention to products labeled “ECO”. Such materials, of course, have a higher cost, but the manufacturer guarantees their environmental friendliness, since the binder for the fibers in them is acrylic resins that are not dangerous to humans.

Glass wool

Glass wool is made from broken glass, sand, soda, limestone and borax - all of them are safe for human health and the environment. These components also melt and turn into fibers. However, the binders for them are the same phenol-formaldehyde resins, which is one of the “disadvantages” of this material. Moreover, evaporation of these substances can occur throughout the entire operation of the insulation.

Glass fibers are much more fragile compared to basalt fibers. They can cause superficial damage to the skin, enter the respiratory tract, and pose a danger to mucous membranes, especially if they get into the eyes. Therefore, when installing glass wool insulation, you should always use protective equipment for exposed areas of the body (overall clothing), eyes (glasses) and respiratory organs (respirator).

The positive characteristics of this material, manufactured without violating technology, include the following qualities:

• Quite high fire resistance.
• Low thermal conductivity.
• Frost resistance.
• Inert to chemical reagents.
• Affordable price - glass wool will always be cheaper than its basalt counterpart with the same performance characteristics.

In terms of thermal insulation qualities, glass wool sometimes even surpasses its basalt “counterpart”. But due to the insufficient elasticity and strength of the fibers, it is still subject to shrinkage, which reduces the heat-insulating properties of the material. It also has worse hygroscopicity indicators, that is, it is much easier to wet the insulating layer.

Slag

Slag is produced from blast furnace slag. The material consists of fibers (again, drawn from the melt), slag dust and solid particles, although the presence of the latter indicates low quality insulation.

Since waste from metallurgical production is used, it is absolutely possible that the slag wool may contain substances hazardous to humans. In addition, such a “chemical bouquet” can lead to rapid development of corrosion on metal elements structures in contact with insulating material.

Today, this insulation is practically not used in individual construction. There are too many risks that do not justify the affordable price. And there are plenty of other significant shortcomings:

• High hygroscopicity - slag wool absorbs moisture well.
• Over time, the material shrinks greatly, and its thermal insulation qualities decrease.
• The presence in the material not only of formaldehyde binders, but also of other substances hazardous to human health.
• The material is brittle, the fibers are sharp, that is, it is slag-like and very uncomfortable to work with.

So, basalt wool seems to be the optimal choice. However, high-quality products made from glass wool (in many of them its disadvantages are minimized) are also quite suitable for insulating floors. It is better not to even consider slag as a possible option.

With all the advantages of mineral wool, it also has a serious “minus”

Although very often manufacturers claim that mineral wool does not attract rodents, it is impossible to agree with this. Mice feel great in both basalt and glass wool, as well as slag insulation. They make nests in slabs and gnaw passages, and this happens especially often if the insulation is closed. This means that you will have to take some protective measures, for example, surround the thermal insulation layer around the perimeter with a fine metal mesh in order to, in principle, exclude the possibility of mice entering it.

Cork boards

Slabs made of natural cork (agglomerate) can be called a unique material. They are made from cork oak bark, and natural wood adhesives serve as a binder for the crushed chips. They are activated when raw materials are processed under certain conditions of temperature and pressure (pressing). Therefore, cork boards can be safely classified as environmentally friendly insulation materials.

Due to the characteristics of natural raw materials, the heat insulator has excellent performance characteristics, namely:

The disadvantage of this material, perhaps, is only one factor - its cost, which significantly exceeds the price of any type of mineral wool.

Ecowool

Ecowool is made from cellulose fibers, as well as waste from cardboard and paper production. This material is sold in packages - in bulk or in the form of molded slabs of a specified size.

The loose version of the material is used in dry form to fill cavities left for insulation, or in moistened form, using the spraying method. The most convenient and cheapest installation is slab material, since the insulation process does not require additional equipment.

The advantages of insulation materials based on ecowool include the following qualities:

• Enough high level soundproofing.
• Low thermal conductivity.
• High vapor permeability, which means that moisture will not be retained in the insulation layers if the installation rules are followed.
• The material creates a monolithic seamless coating, which eliminates the occurrence of “cold bridges”.
• Quite affordable price.

Ecowool also has its disadvantages:

• High level of hygroscopicity.
• Over time, the thermal insulation qualities of the material decrease due to its shrinkage. Therefore, it may be periodically necessary to add ecowool to the initial layer.
• It is difficult to apply ecowool using the “wet” method, since this purpose requires special equipment and skills to work with it.
• Ecowool receives treatment against the excessive flammability inherent in cellulose. But it still cannot be called a completely non-flammable material.

Extruded polystyrene foam

Expanded polystyrene is a modern board material that can have different thicknesses and densities. This insulation is used both for internal and external external insulation residential and non-residential buildings.

The insulation consists of 98% air, therefore it has very high thermal insulation capabilities.

The advantages of this material include the following qualities:

• Low thermal conductivity, one of the lowest among all insulation materials..
• Ease of processing and installation, along with high strength and stability of shape throughout the entire service life.
• Long service life without loss of thermal insulation properties.
• Almost complete absence of moisture absorption.
• Included quality material Fire retardant additives are introduced that prevent the fire of polystyrene foam in extreme situations.
• Chemical stability, resistance to biological damage.

The disadvantages of extruded polystyrene foam are:

• With prolonged exposure to an open flame, the slabs still ignite and melt, and the molten mass can spread, spreading the fire. But what’s even worse is that when burning, extremely toxic smoke is released, deadly to human life.
• Extruded polystyrene foam is not vapor-permeable, that is, it is not a “breathable” material. This should be taken into account when planning the “insulation pie”.

Let us clarify one point: the article deliberately does not discuss the “close relative” of extruded polystyrene foam, namely ordinary white polystyrene foam. Simply because it has much more serious shortcomings, and using polystyrene foam for internal insulation of a house or apartment is a very risky business. Extruded polystyrene foam is still much safer.

Spray polyurethane foam

This insulation is produced directly during its application using special equipment by mixing two initial components. When stirred, these components react, resulting in the formation of a foam-like substance. It is sprayed onto the surface in a relatively thin layer and begins to expand, filling all the surrounding free space, forming a monolithic coating.

After expansion, the solidification phase begins, and a durable thermal insulating coating is obtained, which is a homogeneous porous mass with isolated gas-filled cells.

Polyurethane foam is one of the most effective, reliable and durable insulation materials. This is evidenced by a number of its advantages:

• Very low thermal conductivity. And the solidity of the applied layer eliminates the occurrence of “cold bridges”.
• Quite high strength of the frozen layer with a low specific density.
• Completely resistant to moisture - the material is impenetrable to either water or water vapor.
• High adhesive properties with almost any building materials.
• High noise insulation qualities.
• The material does not settle and does not lose its thermal insulation qualities over time.
• High speed of thermal insulation work on structures of any complexity.

Disadvantages of sprayed polyurethane foam:

• The material is not “breathable”, but in some cases this can be regarded as a positive quality.
• Low resistance to ultraviolet radiation - insulation requires absolute protection from sunlight.
• Flammability of the material during prolonged exposure to open fire. True, its rapid self-extinguishing is observed if the source of flame is removed. In addition, the material does not flow when exposed to fire, and charring of the upper layers prevents the further spread of the fire.
• Very high cost of material, taking into account the invitation of a master with equipment. Disposable kits for self-application have appeared on sale, but their price still seems frighteningly high.

Expanded clay

One of the options for ceiling insulation is the use of expanded clay of various fractions. This is a natural material made from clay through special heat treatment.

Expanded clay has a number of positive qualities:

• Ecological cleanliness. The material does not contain or emit toxic substances.
• Quite low thermal conductivity. Expanded clay does not lose its thermal insulation properties throughout the entire period of operation.
• Good noise insulation abilities.
• Low moisture absorption.
• High vapor permeability.
• Expanded clay is a non-combustible material.
• High frost resistance.
• Inert to temperature changes.
• The biological stability of the material, that is, pathogenic microflora does not form on it, rodents bypass it.
• Ease of use.

But, despite its many advantages, expanded clay also has its disadvantages:

• In terms of thermal insulation, it is almost three times inferior to modern insulation materials such as mineral wool or expanded polystyrene. That is, for a complete high-quality insulation a lot of overlap will be required thick layer expanded clay, which is not always possible.
• Since a lot of expanded clay will be required, this can lead to a significant increase in the cost of the floor insulation project. Moreover, taking into account the transportation of large volumes of material and lifting them to a height.
• The material is loose and quite dusty, especially if a variety with a small fraction of expanded clay is used. This affects the structure of the “insulating pie”.

Sawdust

Sawdust is one of the oldest insulation materials for thermal insulation of private houses. The thermal conductivity of sawdust is perhaps slightly higher than that of modern materials, however, the combination of all characteristics often looks more advantageous than the use of synthetic insulation.

So, sawdust has both positive and negative qualities. The first include the following characteristics:

• Affordable cost of material. Sometimes it even comes for free.
• Low thermal conductivity, although for sufficient thermal insulation you will have to lay a thicker layer of material.
• Excellent vapor permeability. Sawdust is a “breathable” heat insulator that does not retain moisture. They have unique properties to absorb excess moisture, and when air humidity decreases, release it into the environment.
• Long service life. Properly prepared sawdust will serve as a heat insulator for 50 years or more.
• Environmentally friendly material.

The disadvantages of sawdust insulation include its following characteristics:

• Flammability. However, if a wooden house is insulated with them, it itself has the same characteristics. When burned, sawdust does not produce toxic smoke.
• The need for special treatment to prevent biological degradation or damage to the material. That is, sawdust will last a long time without losing its original thermal insulation qualities only if it is properly prepared.

Ceiling insulation using sawdust is done in three ways:

Filling the floor cavities with sawdust treated with boric acid, lime, antiseptics and fire retardants;

Filling with a solution of gypsum sawdust, cement, clay or PVA glue;

Formation of insulation boards from sawdust and clay.

In any case, it will take a lot of time for high-quality insulation with sawdust. Such labor intensity often scares off the owners of private houses, and they prefer ready-made materials that are easier to install.

Installation of different types of insulation for thermal insulation of the ceiling

As mentioned above, there are slab, roll, backfill and spray insulation. Some of them use very similar technology. Therefore, this process will be considered in this way.

Use of slab and roll insulation

If you choose slab or roll insulation, then when carrying out the work you usually follow the diagram presented below. However, the use of mineral wool and extruded polystyrene foam has its own nuances, since the materials differ in their density and rigidity.

The layout of materials for insulating the ceiling from the attic side is as follows:

1. Floor beams.
2. Windproof membrane.
3. Insulation material.
4. Vapor barrier membrane.

The insulation process step by step is as follows:

• If slabs or rolls of mineral wool, linen slabs or other vapor-permeable material are used, then the first step is to cover the floor surface vapor barrier membrane.

The material goes around the floor beams and is laid loosely between them, then attached to the wood using a stapler and staples. A vapor barrier will protect the insulation from evaporation from the premises of the house - there the water vapor pressure is always higher, especially in the cold season. When laying the membrane, you must follow the markings on the film. The manufacturer indicates which side it should be laid down.

The membrane is laid in strips with an overlap of 100 mm between each other. The joint line is sealed with moisture-resistant tape.

• If you use foam plastic for insulation (although, to be honest, it is better not to use it at all) or extruded polystyrene foam, before installing it you will have to level the surface between the floor beams - usually a rough ceiling liner is filled. If mineral wool takes the shape of the base due to its elasticity, then rigid foam boards will simply break when pressure is applied to them. That is why the base must be level. In fact, there is no need to install a vapor barrier at all under extruded polystyrene foam, since it is vapor-tight and non-hygroscopic, that is, it does not absorb vapors and moisture.
• The next step is to lay slab or roll insulation on the vapor barrier film between the floor beams.

Installation of slab or roll insulation is a simple process. Usually, such a step between the beams (lags) is already provided in advance so that the slabs or rolls are laid out sideways.

If foam or other rigid slabs are laid, they should be cut exactly to the width of the step between the beams or slightly less. If after installing this insulation there are gaps between the beams and slabs (and this, one way or another, cannot be avoided), they must be filled with foam.

• After laying the insulation, the entire surface of the attic floor is covered with a windproof membrane, which is secured with staples to the beams.
• Further, if you plan to install a floor in the attic, a compressed or plywood flooring is laid on top of the wind protection. In this case, it is advisable to leave a ventilation gap so that it is easier for moisture from the insulation to evaporate into the atmosphere.

• When using insulation with a foil layer, the resistance to heat loss will be increased. In this case, the insulation is laid with the foil side down.
• If the floor beams are recessed into the backfill, then logs are fixed perpendicular to them with a “clear” pitch of approximately 550 mm. After this, a vapor barrier is fixed to the surface, and then the insulation is laid.

It is not necessary to lay thermal insulation from the attic side, although it is probably easier this way. Sometimes the installation of the “insulating pie” is carried out from the side of the room. But the location of the membranes remains the same. That is, after laying the insulation, it must be covered with a vapor barrier from below, and only then the ceiling is hemmed. This will be discussed in detail below.

Laying backfill thermal insulation

In order to insulate the ceiling from the attic side with backfill material, it is necessary to prepare the base.

You can prepare the grounds in two ways:

Lay a material that will preserve backfill insulation V required area, not allowing you to get into the cracks between the boards of the rough ceiling cladding;

Seal the gaps between the boards, as well as between the boards and floor beams, with a solution of clay and lime.

The second option requires more time to work, but the amount allocated for covering material will be saved.

Roofing felt, glassine, or the same vapor barrier membrane can be used as a covering covering for loose insulation. The canvases are overlapped by 100÷150 mm and taped with wide moisture-resistant tape. If roofing material is used, then its joints are glued with bitumen mastic.

If a backfill material such as sawdust is chosen, then the base for it should be prepared by coating it with a clay-lime mixture. For ecowool, it would be better to use a vapor barrier membrane.

When filling the floor with ecowool, it must be compacted well, otherwise it will shrink over time.

When the ceiling is completely covered with insulation, the entire surface is covered with a diffuse membrane, so that moisture from above (for example, when the roof leaks) does not enter the thermal insulation layer, but can freely evaporate from it. Again, it is recommended to leave a ventilation gap.

Well, then the attic floor is laid.

Sometimes, in cases where the attic does not become a usable space, and there is no doubt about the reliability of the roofing, they do without a top membrane at all, and even without plank flooring.

Video: insulating the ceiling of a private house with expanded clay

Insulating the ceiling from inside the house - step by step

It is clear that it is more convenient to insulate the floor from the attic side. But it also happens that the roof slopes are located at a very slight angle, and there is no possibility of free work in the attic.

As an example, the process of such insulation will be shown step by step - from the side of the room. However, some processes may still require penetration under the roof. How the master solved this problem in this case will also be presented in the instructions for laying insulation.

To begin with, you should determine a list of everything you need to carry out the work:

• Insulation material. In this case, it is Isover Profi mineral wool in a roll, but you can also purchase a slab version.
• Windproof membrane "Isover".
• Vapor barrier membrane "Isover".
• Beam with a section of 50×50 mm.
• Boards 120×15 mm for lathing under the ceiling cladding.
• Antiseptic impregnation for wood processing.
• Nylon or polypropylene twine.
• Material for external cladding - plasterboard, lining, Qwick Deck boards, etc.
• Self-tapping screws of different lengths.
• Screwdriver.
• Electric jigsaw.
• Scaffolding or a reliable, stable ladder (horses).
• Stapler and staples.
• Building level.
• Stationery knife.
• A respirator to protect the respiratory tract, gloves and clothing that completely covers the surface of the skin.

Illustration	Brief description of the operations performed
	So, in a room with an area of ​​9 m² it is necessary to arrange and insulate the ceiling. As you can see in the photo, so far only floor beams made from 200x50 mm boards are attached to the Mauerlat.
	To complete the work, you will need a beam with a cross-sectional size of 50×50 mm. The timber must be smooth and clean. Therefore, if black stains of mold are found on its surface, it is recommended to clean them, for example, using an electric plane.
	Then the wooden parts are treated with an antiseptic solution - fire retardant. It is best to use solutions that have a peculiar tint - then the treated areas will be immediately visible. It is convenient to coat the timber with an antiseptic by placing the parts in a row. Having applied the composition to one side of the wood, the bars are turned on the other side - and so on until all the material has been processed.
	The next step along the perimeter of the ceiling, under the floor beams, is to attach the prepared beam to the end of the mauerlat.
	Next, for the convenience of laying the windproof film, temporary retaining boards are laid on top of the floor beams. They are not fixed as they will move. A windproof membrane is laid on top of the boards. In this case, the hydro-wind barrier “Isover HB Light” was chosen.
	The membrane is first fixed on the outer beams, as well as on the end boards (mauerlat) installed on the concrete frame of the walls. Fixation is carried out using a stapler and staples. Adjacent membrane sheets are overlapped by 150 mm.
	Next, the work is carried out from the attic side, since it is necessary to fasten the wind protection to the upper ends of the floor beams. For safety of movement along the beams, the master laid the membrane on top perpendicular to the beams support boards 150÷170 mm wide and 25 mm thick.
	The next step is to supplement the previously fixed bars framing the ceiling with sheathing crossbars. They seem to line up in frames. These lintels will provide good support for mineral wool blocks when they are laid between the beams, and will subsequently serve as lathing for the ceiling cladding. The pitch is chosen so that the insulation strips fit tightly between the crossbars. That is, since a roll with a width of 600 mm is used, then there should be approximately 550 mm of clearance between the beams.
	The master chose Izover Profi mineral wool, sold in rolls, as insulation. Material thickness - 100 mm. It is more convenient to purchase thermal insulation material in a roll because it can be cut into slabs of the required width. This way, less waste can be generated.
	The first step in working with insulation is to cut strips from it to seal the gaps between the Mauerlat and the windproof membrane along the entire perimeter of the ceiling. The width of the strips should be 40÷50 mm.
	Next, the mineral wool is cut from the roll into slabs required length and, if necessary, width. Calculations carried out in advance showed that an insulation layer of 200 mm would be required. This was foreseen - the height of the floor beams is exactly 200 mm, that is, two layers of insulation 100 mm thick will be required.
	Prepared fragments of mineral wool are laid between the floor beams. Each layer is carefully distributed in space and carefully pressed against the windproof membrane.
	Then a second layer of insulation is laid below. In this case, the place where the mineral wool blocks of the upper layer were joined is covered with a whole slab in the lower one.
	To speed up the work, you can immediately form a 200 mm mat from two pieces of insulation 100 mm thick and lay it under the timber crossbars attached to the floor beams.
	However, do not forget that when laying insulation in this way, it is necessary that the joints of the slabs of the upper and lower layers be separated from each other by approximately 250÷300 mm. This arrangement will completely remove the issue of possible “cold bridges” in the insulation layer.
	If there are a lot of scraps left, then you can assemble the inner (top) layer from them, and make the bottom one from solid pieces.
	To prevent the insulation from sagging down between the jumper bars, it should be reinforced with plastic twine, securing it to the ends of the floor beams using a stapler and staples.
	For this purpose, ordinary inexpensive string is used, for example, nylon or polypropylene twine. You will need quite a lot of it, since the very bottom layer of insulation still needs to be tied up. It is not recommended to spare the twine. Let everything be safe.
	The last, outer layer of thermal insulation material is mounted along the padded bars Its thickness should correspond to the thickness of the timber, that is, 50 mm. To do this, cut slabs 100 mm thick must be divided into two thicknesses. Here, when laying each slab, it must immediately be fixed with twine, aligning it to the bars.
	Next, the thermal insulation structure should be covered from below with a layer of reliable vapor barrier material so that moisture from inside the house does not penetrate into the insulation. This material should not be confused with a windproof membrane! What is important here is that the couple be provided with a reliable barrier. If moisture accumulates inside the mineral wool, it will lose its thermal insulation qualities. Yes, and waterlogging wooden parts the design does not benefit them.
	The master uses the vapor barrier membrane “Isover VS 80”. It will be more convenient to work if you choose a material equipped with an adhesive strip, which makes it easier to fasten two adjacent canvases. The adhesive strip is covered with a protective film, which is removed before bonding the sheets.
	After the second canvas is secured overlapping with the first by a width usually indicated on the canvas itself by a line, the protective film is removed from the edge of the first canvas. After this, it is enough to run your hand along the joint of the canvases so that they are securely connected to each other.
	If the connection does not seem strong enough, it can be glued with tape. For this purpose, it is best to use reinforced plumbing tape, which is moisture resistant and has good adhesive properties with almost any surface. In any case, it holds up perfectly on any membranes.
	The membrane is cut to the size of the ceiling and secured on three sides. Then, holding the canvas with a piece metal profile or at a building level, the membrane is pulled up and finally fixed on the beam using staples.
	To make it easier to work at heights, it is recommended to use reliable scaffolding or sawhorses. If you work from them, both hands of the master remain free, and it is also possible to cover a fairly large work area. With an ordinary stepladder you can get into a lot of trouble.
	When securing the last side of the vapor barrier material, it is better not to stretch it, but to assemble it into an “accordion”, in order to compensate for the linear expansion of the material when temperatures change. To keep the accordion in the required position, it should be secured with tape.
	The joint between the wall and the vapor barrier should be sealed with sealant. To do this, the edge of the canvas is raised up, sealant is applied to the wall, then the edge of the material is lowered and pressed against the wall.
	The main task of using sealant is to prevent moisture from penetrating into the insulation during the operation of the premises. The remaining folded down edge of the vapor barrier membrane can then be mated to the wall vapor barrier if required.
	Next, on top of the vapor barrier, sheathing boards are attached to the bars, perpendicular to them, for subsequent cladding of the ceiling. In this case, the step between them is 600 mm, but if desired, they can be installed more often, depending on the chosen decorative material. Self-tapping screws, of course, will make holes in the vapor barrier, but boards securely pressed in these places to the bars will not allow steam to penetrate into the insulation. If the vapor barrier film is accidentally pierced during work, the hole should be immediately sealed with plumbing tape.
	The result of the work done was an insulation sealed with membranes on both sides, enclosed between the floor beams and supported by sheathing boards. Boards stuffed underneath are not only a frame for finishing the ceiling. They also set the necessary ventilation gap between the vapor barrier membrane and the finishing layer. If this is not provided for, condensation may begin to accumulate on the ceiling surface.
	The ceiling can be covered with plasterboard or clapboard. But in this case, the master chose moisture-resistant “Quick Deck” sheets. To fasten the sheets, it is necessary to choose self-tapping screws of such a length that they do not pierce through the sheathing boards and do not break through the vapor barrier. To make it easier to fix the sheathing on the sheathing, it is recommended to pre-install self-tapping screws along the edges of the slab.
	Before attaching the casing, you must remember to run the electrical cable for the ceiling lighting fixture. It must be insulated in a special corrugated tube. Next, the sheets are fixed to the sheathing boards using self-tapping screws, the heads of which should be recessed into the material of the boards to a small depth (about 1 mm). This can be easily solved by correctly adjusting the tightening torque of the screwdriver (ratchet).
	It is necessary to leave a small gap between the wall and the sheathing slabs to allow for thermal expansion of the material when the temperature and humidity in the room changes. If necessary, additional marking, cutting and adjustment of sheets is carried out.
	“Quick Deck” panels are equipped with a tongue-and-groove lock, so when they are installed, the connection is tight and even. In this case, the lock itself already provides a temperature gap. First, the slabs are grabbed in several places and then secured with additional screws.

Thanks to precise markings and well-fitted parts, the ceiling turned out smooth and neat. Further? the surface is puttied and painted or glued decorative material. But this is already finishing work, but we, in fact, have already completely figured out the insulation of the ceiling.

As you can see from the description presented, it is quite possible to insulate the ceiling yourself, without involving professional builders. True, working extremely carefully, strictly observing the sequence of installation of the layers of the overall “pie” /

And one more important question remains unclear to us - how thick should a sufficient insulation layer be? Let's consider it in the appendix to the article.

APPENDIX: What thickness of ceiling insulation will be required?

To determine this parameter, you will have to make a small thermal calculation. You shouldn’t be afraid of this right away - with our calculator it won’t be difficult to perform the necessary calculations.

The calculation itself is based on the fact that the total thermal resistance ceiling structure under a cold attic (or without it at all, for example, with a flat roof) should be no less than the normalized value established by SNiP. And this total resistance consists of the indicators of each of the layers of the structure. Thus, knowing the materials of manufacture and thermal conductivity indicators, having a clear plan for further cladding of the ceiling and attic floor, it is easy to calculate which layer and which insulation will provide the required value of thermal resistance.

And you can find out the normalized value of heat transfer resistance for your region using the proposed diagram map. A small nuance: for walls, ceilings and coverings it is different - that’s why the values ​​​​are highlighted in the diagram different colors. In this case, we are interested in “for floors” - these indicators are highlighted in blue.

We will not overload the reader with formulas, but rather immediately offer an online calculator. Directly below it will be a number of explanations that may be necessary for a quick and accurate calculation.