How to insulate a wooden attic floor. Rules for insulation of interfloor ceilings. Insulating the attic with various materials
Attic spaces, the frame of which is presented in the form wooden trusses, are correctly called “cold”. These objects are not particularly durable compared to reinforced concrete structures, but they have their advantages.
Basically they come down to great possibilities of use thermal insulation materials. A classic attic floor on wooden beams is equipped with insulation using ordinary carpentry tools, unlike reinforced concrete, where special equipment is required.
Insulation attic floor In addition to insulation, it requires the installation of proper vapor barriers and exhaust hoods that prevent the formation of mold and mildew. And if you correctly follow the technology when installing insulating material, then air exchange will be guaranteed.
The design of the attic directly depends on the parameters of the building and the purposes intended for the use of this room. The under-roof space plays the role of a kind of air gap separating warm heated rooms from the cold roof.
In this case, the floor in the attic performs two tasks:
Isolating. In the attic of a house, the air temperature is almost no different from the outside temperature. In this case, the floors have an insulating function, thereby preventing the penetration of cold air into the living spaces.
Carrier. In most cases, the ceiling on wooden beams between the attic space and the upper floor of the house, like the walls, has a load-bearing function. In this regard, it must be reliable and durable, since people move along it, utensils are stored or any equipment is placed.
Therefore, in order to know the permissible load on the attic floors, it is necessary to make a calculation. Then, based on their results, draw up a project that will show how to properly insulate the attic floor of a building.
Selection of material for insulation
The technique for insulating an attic is simple, since the material is laid directly on the floor, in the gap between the rafters and wooden floor beams. If you plan to use the attic space as an attic, then you also need to insulate the roof.
To insulate the floor between the beams in the attic, several types of insulation are used:
- Mineral wool.
- Styrofoam.
- Expanded polystyrene.
- Sawdust.
- Expanded clay.
- Foam.
Let's take a closer look at each insulating product.
Mineral wool insulation
In order to save heat, the material must be placed between steam and waterproofing films. Vapor barrier protects against moist air masses that form in living spaces near the ceiling, especially at the junction with the walls. The second layer protects the wool from water entering from the roof through microcracks and holes in the roof.
The attic space of a house is insulated most often from the floor rather than from the ceiling of the lower floor. For this purpose, mineral wool is a reliable, inexpensive insulating material with high compression, allowing it to cover the surface of not only the floor, but also beams of various shapes. This insulation is sold in rolls or slabs of different thicknesses.
At the same time, it has the following advantages:
- Budget cost.
- Easy to install.
- Rodents do not grow in such insulation.
- High fire safety of the material.
- Ability to isolate any uneven surface.
At the same time, when working with mineral wool, it is necessary to take protective measures: wear thick clothing, work in goggles and protective gloves, and it is also advisable to use a respirator.
Styrofoam
Insulating an attic space with polystyrene foam is a good option for converting it into an attic, suitable for year-round residence. This material has low thermal conductivity, as it is produced in the form of foamed air granules pressed into slabs.
During installation, the foam must be cut so that the plates fit tightly between the attic floors. Any gaps and cracks become “bridges” for the penetration of cold, and thereby significantly worsen the quality of insulation.
In this case, it is necessary to maintain a distance between the foam board and the waterproofing film of at least 2-3 cm. It is recommended to use it as insulation with a thickness of 70 mm, and in regions with a harsh climate - 100 mm.
Attention! When installing a vapor barrier film, you need to pay attention to the fact that it faces the insulation with the required layer, according to the instructions. Otherwise, the opposite effect will be produced: all the steam will be directed towards the insulating material.
Extruded polystyrene foam
When insulating the ceiling of a living space over attic floors, this material is considered the best option for many builders. This insulation does not cause any difficulties during installation; it can be laid under any beam ceiling.
It also saves space, since you can get by with two to three times less thickness than using the same mineral wool. Extruded polystyrene foam comes in different types, as it is produced by different manufacturers. To insulate attic floors, the density of such material should be about 32-34 kg/m, and its thickness should be from 40 to 100 mm.
Manufacturers also produce shaped elements from expanded polystyrene, which are used to lay out complex fragments in the attic ceiling. It is convenient to install this insulation in two layers: the first layer is laid between the attic floors, and the second layer is applied end-to-end along the bottom row, covering the wooden beams as well.
The main disadvantage of such insulation is that it is flammable. To reduce the fire hazard, you can lay mineral wool with expanded polystyrene, or add antipyrine.
Expanded clay
Expanded clay for the attic of a house is traditional method thermal insulation of the technical floor. This material is poured between wooden floors with a layer thickness of at least 150 mm. This mass is a universal means that can insulate floor structures, and it can also be used as thermal insulation together with other bulk materials.
Attention! Expanded clay is a fairly light insulation material, but when a thick layer is applied, the load-bearing surface of the ceiling will bear a large load.
Thermal insulation is best carried out at the construction stage of the building, since it is easy to waterproof the ceilings of the rooms under the attic and provide for an exhaust hood.
To do this, cover the floor with vapor barrier film to protect the expanded clay layer from getting wet. It is not recommended to pour it directly onto the floorboards for another reason: during operation and operation of the room, a lot of dust is released, which penetrates into the living rooms.
Sawdust
Sawdust is a product of lumber processing in the woodworking industry. This is the cheapest insulation for attic floors, since you can buy sawdust at any sawmill for free. Thus, sawdust is still an option as a reliable heat insulator in attic spaces.
On a note! Sawdust is of organic origin, therefore, it is completely harmless to human health. Since ancient times in Rus', sawdust mixed with clay has been used as insulation in attics.
Sawdust has the following advantages:
- Low cost of thermal insulation. Probably, the popularity of such insulation lies precisely because of this factor: its cost is almost equal to the cost of transportation.
- Safety for human health. Wood shavings and sawdust do not cause skin irritation, allergies, or poisoning, which cannot be said with complete confidence about modern insulation materials.
- Low thermal conductivity coefficient. Unlike wood, chips have a porous structure, so they have low heat conductivity.
- Easy installation. To form a heat-insulating layer in the attic floors, no special skills are required. You just need to mix sawdust with clay or lime, and then pour it into the space between the attic floors.
The only significant drawback is the fire hazard of the material, despite the mixture with other non-flammable substances.
Foam
IN Lately For insulating attic floors, two types of insulating materials have become popular: blown-in wool and ecowool. The latter material consists of 80% cellulose fibers made from waste paper, and 20% from additives, which are fire-fighting and antiseptic components.
This material has low thermal conductivity, is very light, and looks like regular polyurethane foam. Both types of insulation are usually sprayed onto the boards between wooden beams, but sometimes ecowool is used in granules in a crumbly state. In this case, this mixture, as an option, is simply poured between the floor beams and compacted.
Vapor barrier
The vapor barrier film protects wooden beam ceilings from moisture formed in the air of residential premises. In addition, it protects floors from the appearance of mold and mildew in the insulating material.
Regardless of how the attic floor is made, the vapor barrier for the floor should form a continuous carpet that does not allow condensation to penetrate. Particular attention should be paid at the joints with walls, where there is a high probability of condensation penetration. To do this, the covering film is overlapped and its edges are glued together with tape.
Insulation technology
For correct application insulation, follow the step-by-step instructions:
Step #1. Carry out an inspection and, if defects are found, eliminate them. Treat boards and timber with antiseptics and fungicides.
Step #2. Post vapor barrier material, seal all gaps with mounting tape.
Step #3. Lay (pour) insulation into the openings of wooden floors on the floor.
Step #4. Pay special attention to the joints between slabs of insulating material. If necessary, apply additional insulation.
Step #5. Lay with an overlap waterproofing film, fasten the joints with mounting tape.
Step #6. Separately install insulation on the ventilation duct, chimney pipes in the form of basalt wool, perlite, and it is advisable to install a special corrugation on top.
Installation of wooden attic beams
The attic ceilings are designed to separate the living rooms from the under-roof space. They don't miss cold air, therefore the main task is their thermal insulation. Various equipment is also often installed in the attic.
In this regard, another important task is to create solid foundation, capable of withstanding this load. Thus, from quality arrangement wooden flooring depends on the safety of people, their comfortable accommodation, as well as the durability of the structure.
Attic flooring on wooden beams - standards, requirements
According to the requirements of SNiP 31-02, attic floors must withstand thermal, statistical, acoustic and fire conditions. In addition, they must be energy-saving, therefore, reliable thermal insulation must be installed on the floors.
When installing an attic floor on wooden beams, you must strictly adhere to all sanitary and hygienic requirements. When erecting a frame, it is necessary to construct the structure, and then insulate the attic floor. At the same time, the same temperature must be maintained between the lower part of the attic and the living room. The difference in indicators in degrees according to the standards is allowed no more than 4˚C.
For structural elements of the attic, dry, seasoned timber with a cross-section of 100×150 or 200×250 mm should be used, and the humidity in it should not exceed 20-30%. The distance between the load-bearing beams depends on the load, but usually it is taken at intervals of 3 to 6 meters. In addition to bearing the load, wooden floors require a maximum safety margin.
It must be borne in mind that the minimum load on such load-bearing beams is 100 kg/sq. m. And the period of trouble-free operation of wooden floors according to the standards is 60 years. It is due to the fact that the wood is susceptible to damage from fungus and insects, as well as a change in the strength of the beams under the influence of possible condensation.
For more information about the regulatory requirements for attic floors, watch the video:
The joints between the rafter beams and the wall, as well as the load-bearing ceiling beams, should be especially protected with insulating material. If all these conditions are met, the house will serve you faithfully for a long time.
Are you insulating your house for winter and don’t know how to insulate the attic floor using wooden load-bearing beams? Having gained experience in this matter, I will definitely convey technical points thermal insulation, and I will also describe step by step the procedure for carrying out the work.
Why insulate an attic?
We must not forget that a significant part of heat loss occurs through the roof. Therefore, when constructing buildings with cold attics, it is very important to pay attention to proper thermal insulation of the ceiling between the heated room and the attic.
Below I will try to explain in an accessible language how attic insulation affects the internal microclimate and total losses heat in the house:
- Purpose of the attic. Any unused attic under a sloped roof is essentially a buffer technical floor between the street and residential premises. Its purpose is to smooth out significant changes in air temperature inside the house and outside;
- Temperature conditions. At any time of the year, during the day the air temperature inside the attic will be several degrees higher than outside. Thus, in winter there will almost always be negative temperatures in the attic, and on sunny summer days there will be intense heat;
- Heat losses in winter. When the temperature of any substance increases, its density always decreases. Therefore, in heated rooms, heated air from household heating appliances always rises up to the ceiling. If the ceiling has insufficient thermal insulation, then during the cold season, all the heat from the room will go outside through the attic;
- Excess heat in summer. On hot summer days this process will occur in reverse. The air in the attic will become very hot from the hot roof in the sun, and then transfer its heat through the uninsulated ceiling into the apartment.
- Reverse air circulation. After touching an uninsulated ceiling, the heated air quickly cools down, and due to the increase in density, it sharply sinks down. Indoors, this leads to excessive reverse air circulation and the constant formation of drafts, which have an adverse effect on the health of residents;
- High humidity. Upon contact of heated humid air with a cold, uninsulated ceiling, small drops of condensation may form under the ceiling. This will lead to an increase in air humidity in the house, and will also contribute to the appearance and development of mold on the walls and ceiling;
- Economic factor. Confirmed heat loss through an uninsulated roof is at least 20-30%. This means that proper insulation of attic floors using wooden beams will save up to 30% of fuel during each heating season. Air conditioning in summer will also require lower costs;
- Damage from a “warm” attic. Among other things, penetration warm air to an uninhabited attic, from time to time, can lead to unpleasant consequences:
- As warm and cold air mixes, condensation will begin to form in the attic. Drops of water will settle on all surfaces, which will lead to rotting and destruction of the wooden supporting structures of the roof;
- From the warmth of the attic, the snow masses on the roof slopes will begin to gradually melt. Thawed water will freeze as it flows down. This can lead to the formation of large icicles along the edges of the roof, as well as freezing of rain gutters and downspouts.
All the factors described are typical not only for residential buildings. They should be taken into account when designing and constructing any outbuildings on the site where the heating system will be used (for example, a garage, bathhouse, barn, etc.).
Stage 1: Selecting insulation
When choosing materials for ceiling insulation, you should be guided by several criteria. In addition to low thermal conductivity, attic insulation must have the following qualities:
- Moisture resistance and mechanical strength. The material should not be deformed or destroyed under the influence of mechanical load, and should not change its properties in the event of direct contact with water;
- Heat resistance. The insulation must be absolutely non-flammable and should not be destroyed under the influence of high or low temperatures;
- Light weight. In order not to create additional load on the load-bearing structures of the building, the thermal insulation of the attic floor should be quite light, so you need to choose insulation with a low specific gravity;
- Vapor permeability. To ensure normal temperature and humidity conditions in residential premises, all finishing and building materials must freely allow air and water vapor to pass through;
- Environmental Safety. Insulation for residential buildings must be hypoallergenic and chemically neutral. It should not contain harmful volatile compounds or toxic substances;
- Lack of organic matter. I recommend using exclusively mineral or polymer based materials. They do not contain organic substances, therefore they are not susceptible to mold, and are not suitable for food for small rodents and pests.
Taking into account all these factors, several types of thermal insulation materials can be used to insulate attic floors:
- Mineral wool. Produced in the form of rolls or rigid mats, from intertwined frozen fibers of molten sedimentary rocks. Mineral basalt wool is characterized by all of the above qualities, so it can be considered the most suitable material. Below I will give some recommendations for its use:
- Basalt wool itself is very soft. To prevent it from being pressed or dented while walking, plank flooring should be laid on top of it in the attic;
- When choosing insulation, I advise you to give preference to rigid slabs that are covered on one side aluminum foil;
- They need to be mounted with aluminum foil inside the room. It simultaneously reflects heat and acts as a vapor barrier layer.
- Glass wool. It has a similar manufacturing technology, only molten glass is used as the raw material for its production. I do not recommend using this material for insulating residential buildings for the following reasons:
- Glass fibers are more fragile, so they can break under load;
- The price of glass wool is much lower, but after creasing or getting wet, it partially loses its heat-insulating properties;
- Small particles of glass penetrate deeply into a person's skin and cause severe irritation.
- Expanded clay. This bulk insulation It is produced in the form of small round pellets of light brown or red color. Expanded clay balls are formed as a result of sintering special varieties of red clay under high temperature conditions.
Expanded clay has the following characteristic qualities:
- The internal structure of the material has many closed pores, so it has low thermal conductivity;
- Each pellet is covered on the outside with a dense glassy layer of baked clay, so moisture practically does not penetrate inside it;
- Small crumbly expanded clay pellets freely fill the entire volume, so they are convenient to use for insulating hidden cavities and hard to reach places in building structures;
- Thanks to mineral based, this material does not burn at all, does not emit harmful substances, is not susceptible to mold, and is not suitable for rodent food.
- Styrofoam. This polymer thermal insulation material is made by hot molding from small round granules of polystyrene foam. It is usually produced in sheets measuring 1000x1000 mm, which can be from 10 to 150 mm thick. The following features are characteristic of polystyrene foam:
- Of all existing species insulation, it has the lowest thermal conductivity;
- The foam contains no organic substances, so it is absolutely not afraid of water, does not rot and does not contribute to the formation mold;
- By itself, polystyrene foam does not burn and does not support combustion, however, when exposed to high temperatures, it can emit toxic gases and acrid thick smoke;
- Due to the polymer base and closed porous structure, foam sheets do not allow air and water vapor to pass through. For this reason, it is not very good to use for insulation. living rooms and rooms with high air humidity.
- Extruded polystyrene foam Abbreviated as EPPS. It has the same composition as polystyrene foam, but is made by hot extrusion from a molten mass of polystyrene foam. Specifications These two materials are also very similar, but EPS still has some differences:
- Expanded polystyrene has a porous, uniform structure and a higher specific density;
- Due to this, it has higher thermal conductivity, but at the same time is more durable, and therefore is able to bear higher weight loads;
- For this reason, I recommend using it for insulating unheated attics that will be used for storing seasonal items or household equipment.
- Foil polyethylene foam. It is also called “Penofol” in another way. This roll material consists of thick polyethylene foam film, which is covered on one or both sides with a thin layer of aluminum foil. I recommend using it in combination with other types of insulation, because by itself it has specific properties:
- The porous structure of polyethylene foam provides a low heat transfer coefficient, so it functions as an additional insulation;
- Polyethylene film does not allow air, drops of moisture or water vapor to pass through at all, so Penofol can be used as waterproofing;
- Mirror aluminum foil reflects infrared heat waves well. In other words, it does not allow radiant heat to pass through itself, and returns it back to the room.
- Wood sawdust. This one is cheap and available material, is still often used to insulate ceilings in bathhouses, heated barns or small country houses. It is applied to wooden floor from the attic side, in the form of a homogeneous thick mixture of sawdust with a liquid clay solution. Despite the seeming primitiveness of this method, it has its advantages and disadvantages:
- Sawdust or small shavings can be bought inexpensively, or even taken for free, at almost any large sawmill;
- There can be no problems with clay either, so such insulation is easy to prepare with your own hands in the required quantity at any time;
- The mixture of sawdust and clay has a low specific gravity, and after hardening it becomes quite hard. Therefore, it does not exert a significant load on the load-bearing beams, and allows you to walk on it with your feet;
- Due to the mineral components, such a coating is permeable to air and steam, but due to sawdust, it may grow mold or be chewed on by mice.
All mineral-based thermal insulation materials, to one degree or another, are capable of allowing water vapor and air to pass through. To protect such insulation from the formation of condensation or moisture penetration from the outside, they must be installed using a vapor-permeable waterproof membrane.
Stage 2: Preparation of materials and tools
In addition to insulation, for the work you will need lumber, waterproofing, as well as the usual set of carpentry and carpentry tools:
- Two hammers: one medium, weighing 200-300 grams, and one heavy, weighing 800-1200 grams;
- Longitudinal and transverse hacksaw for wood. Instead of a cross saw, it is more convenient to use an electric cutting machine;
- A carpenter's plane, a large wooden mallet and a set of chisels;
- From electric tools you need to have an ordinary household drill, and it is advisable to have a cordless screwdriver with a set of replaceable attachments;
- To fasten rolled materials (waterproofing, vapor barrier), I recommend using a construction or furniture stapler with a set of metal staples;
- You will also need a straight metal ruler, a tape measure 3-5 meters long, a building level and a simple rope plumb line;
- To work near the ceiling, it is most convenient to use a folding stepladder. If it is not there, you can adapt a high strong table or homemade goats from scraps of boards;
- From lumber you will need wooden blocks with a cross section of 62x62 mm, and planed edged boards thickness 25-30 mm;
- As a waterproofing layer, you can use a film of foamed polyethylene and a vapor-permeable waterproof membrane;
- To seal the joints of the panels, you will need metallized aluminum tape, which is usually used in ventilation systems;
- Each homeowner chooses materials for finishing the ceiling at his own discretion. This could be lining board, drywall, laminated OSB or plywood, or other finishing materials;
If you plan to use mineral or glass wool for insulation, then I recommend purchasing a special protective suit that is designed to work with these materials. Otherwise, severe irritation may occur on exposed areas of the skin from small glass fibers.
Stage 3: Filing the rough ceiling
During construction attic floor or erecting a sloping roof, you can do without expensive and heavy concrete slabs ceilings Instead, the entire load from the roof is carried by wooden load-bearing beams made of logs or timber, with a cross-section of at least 120x120 mm. They are usually laid on top of two main exterior walls, perpendicular to the long side of the house.
Such beams serve as a supporting structure for the ceiling itself. top floor, and for the floor of the attic. The same beams will also be used for installing insulation between the residential building and the attic. This type of ceiling is called hemmed, because both the rough and the finished ceiling are hemmed from below to the load-bearing beams.
Before insulating the attic floor, you need to mount the rough ceiling:
| Illustration | Description of work |
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Installation draft ceiling. To file the rough ceiling, you should use dry edged boards 25 mm thick, or sheets of plywood 10 mm thick. |
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Hemming boards. They must be secured to the lower plane of the load-bearing beams and beams around the perimeter of the room. Hemming boards must be fastened without gaps or cracks, close to each other. For fastening, use galvanized self-tapping screws 5-6 mm. |
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Waterproofing. When the entire rough ceiling is hemmed to the load-bearing beams, panels of foiled polyethylene foam need to be secured to it from below. This can be done using a stapler. "Penofol" will perform the functions of heat and waterproofing. It should always be placed with a foil layer towards the warm room. |
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Sealing joints. To prevent moist air from the room from entering the insulation, the ends of the polyethylene film must be wrapped on the walls by 150-200 mm. The joints between the panels must be glued with metallized tape on an aluminum base. |
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Fastening the sheathing. From below, across the entire area of the rough ceiling, nail a counter batten made of wooden slats thickness 15-22 mm. It is needed in order to provide a ventilation air gap between Penofol and the finished ceiling. The distance between the slats should be about 400-600 mm. In the future, a finishing ceiling covering will be attached to them from below. |
Before starting work, everything wooden elements structures must be treated with antiseptic and fire-retardant impregnations. Antiseptics are needed to protect wood from rotting and mold development. Fire retardants give dry wood fire retardant properties.
Stage 4: Installation of thermal insulation
After filing the rough ceiling, the transverse load-bearing beams will be on the side of the attic. Insulation will be laid in between them.
Depending on the thermal insulation materials used, further installation technology may have some differences. Therefore, below I will briefly discuss the use of the most common types of insulation.
- Laying mineral wool. Mineral insulation materials, when wet, partially lose their properties. To prevent condensation from forming in the mineral wool, the entire thermal insulation layer of the cold attic floor must be permeable to air and water vapor:
| Illustration | Description of work |
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Vapor barrier. First, you need to lay a vapor-permeable waterproofing membrane on top of the rough ceiling. Its peculiarity is that it freely allows water vapor molecules to pass through, but does not allow bound liquid water molecules to pass through. The membrane panels must overlap each other by at least 150 mm; |
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Installation of insulation. Place sheets or rolls of mineral wool in the spaces between the wooden beams. If it is very soft, then it does not need to be squeezed or squeezed much. Lay another layer of vapor-permeable membrane on top of the mineral wool. To prevent it from moving over time, it must be stapled to the beams and walls, throughout the entire area and along the perimeter of the attic. |
- Installation of foam plastic. Polymer-based insulation does not have breathable properties, so it does not allow air and moisture to pass through. In this case, there is no point in using a waterproof membrane:
| Illustration | Description of work |
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Laying foam. Panels of foam or extruded polystyrene foam can be laid between cross beams, right on top of the rough ceiling boards. I advise laying them in two layers, so that the joints of the sheets are located in different places and do not intersect with each other. |
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Polyurethane foam. To prevent the insulation sheets from moving to the sides, they can be glued to the sub-ceiling using a special glue for polystyrene foam or polyurethane foam. Thus, it is necessary to fill the entire area of the attic floor with insulation. If there are gaps and cracks between the sheets of foam plastic, then they must also be blown out from a balloon with polyurethane foam. |
- Clay with wood shavings. Insulating the attic floor with a sawdust-clay mixture does not require any additional materials, and is also quite simple:
| Illustration | Description of work |
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Preparation of the solution. To make the sawdust-clay solution plastic, the clay must be soaked in water 2-3 days before starting work. To prepare the solution, you need to take 3-4 volume parts of sawdust, and 1-2 parts of dry red clay without large solid particles and foreign impurities. Mix the soaked clay with water until a liquid, flowing solution is obtained; Add sawdust to the resulting mixture and mix thoroughly until smooth. To protect against mold formation, a small amount of copper sulfate can be added to the prepared solution. |
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Laying sawdust-clay mixture. Lightly moisten the supporting beams and boards of the rough ceiling with liquid clay milk. After this, fill all the gaps between the beams with sawdust-clay mortar and leave for several days until completely dry. |
- Expanded clay backfill. I want to say right away that expanded clay does not have very good heat-insulating properties, therefore, in individual construction, such floor insulation is rarely used. At the same time, it is considered inexpensive, unpretentious and the easiest to install:
| Illustration | Description of work |
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Preparatory work. Expanded clay pellets do not absorb moisture, and therefore are not afraid of water ingress or condensation. Therefore, they can be used both with and without a waterproof membrane. To prevent condensation from seeping through the ceiling into the house, I still recommend laying a waterproofing membrane under the pellets; |
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Filling of pellets. Expanded clay pellets should be poured on top of the rough ceiling boards and evenly distributed in a thick layer over the entire area of the attic. No covering material is required on top of expanded clay. |
To prevent expanded clay pellets from bunching up and spreading throughout the attic, a retaining plastic geogrid is used. It needs to be stretched in the spaces between the load-bearing beams, and then expanded clay should be poured into its cells.
Stage 5: Arrangement of the floor in the attic
Many residents use cold attic in your private home, as a storage room for storing long items, seasonal items and all unnecessary rubbish. In order for a person to safely walk on the insulated floor, the attic must be equipped with a durable subfloor.
The choice of material for installing the floor in the attic will depend on the type of insulation used:
| Illustration | Features of application |
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Mineral wool and polystyrene foam. These materials themselves are very soft. To prevent them from being destroyed or wrinkled while walking, the upper flooring should be quite tough. In such cases, OSB or plywood sheets with a thickness of at least 18 mm should be laid on the load-bearing beams. You can also use unplaned edged boards with a thickness of 25 or 30 mm. |
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Extruded polystyrene. It has higher rigidity, so it can withstand significant loads. To prevent it from being pressed when walking, it is enough to put a light flooring of thin boards or plywood 5-9 mm thick on top of it. |
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Under the weight of a person, they will crawl in different directions. To prevent this from happening, you need to lay 10 mm thick plywood sheets or light wooden ladders made of boards on top of the beam floor. |
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Sawdust-clay insulation. After the solution hardens, it becomes hard like cement. A person can move freely on its surface, even without installing additional flooring. |
When installing rough flooring in the attic, you should always leave gaps 15-20 mm wide between boards or sheets of plywood. This is done so that moisture and condensation can freely evaporate from the insulation.
Conclusion
Using this operating algorithm, you can easily insulate the attic floor in your own home. More visual information on each method of insulation can be viewed in the attached video in this article, and I suggest leaving all your comments and questions in the comment form.
Master of Architecture, graduated from Samara State University of Architecture and Civil Engineering. 11 years of experience in design and construction.
To maintain normal temperature and humidity conditions in a private home, it is necessary to provide reliable protection against the penetration of cold air. It is necessary not only to thermally insulate the walls and ceilings of the basement, but also to insulate the attic floor with effective materials over wooden beams.
Types of attic floors
The following types of horizontal structures can be used in a private house:
- prefabricated reinforced concrete;
- monolithic reinforced concrete;
- on metal beams;
- on wooden beams.
For construction wooden house The most rational solution would be to cover it with wooden beams. The tree has higher thermal insulation characteristics than concrete, but still the thermal insulation is insufficient.
Insulation technology
How to insulate the attic floor so that there are no problems in the future? IN general case DIY thermal insulation technology is almost the same. But the methods of its installation depend on the specific situation.
Insulation of the attic floor is carried out in the presence of a cold attic. Thermal protection of the structure is carried out from above, since in this case the thermal insulation is most competent. But in some cases, another scheme is used - protection from warm air.
The answers to the question why insulation from the ceiling side of the upper floor is undesirable can be the following disadvantages of thermal protection from below:
- the insulation only protects the ceiling, and the ceiling remains cold;
- doing work from below with your own hands is quite labor-intensive;
- the point of condensation moves inside the floor pie, which can lead to rotting of the structure along the wooden beams.
It is also important to observe correct order all related materials.
When insulating, you need to remember one rule: the vapor barrier is always located on the warm air side, and the waterproofing on the cold air side.
Incorrect placement can lead to the following problems:
- insulation getting wet;
- condensation on the ceiling surface;
- rotting of the ceiling of a cold attic along wooden beams.
Whether vapor barrier and waterproofing is needed depends on the chosen insulation.
Choice of insulation
Methods for insulating the ceiling of the upper floor of a beam in a private house are very diverse. When doing the work yourself, the insulation is placed between the joists and provides reliable thermal insulation and noise protection.
- There are many options for insulating a structure, the most common of which are:
- insulation with mineral wool;
- laying expanded polystyrene (foam plastic or penoplex) on wooden beams;
- filling with expanded clay;
- insulation with sawdust;
filling the ceiling space with foam.
Each of these options has its own characteristics and advantages. Mineral wool insulation
Insulation with mineral wool between joists
- The material is available in two versions: plates and rolls. Insulating the attic floor with mineral wool has the following advantages:
- excellent heat-shielding characteristics;
- resistance to fire;
- low water absorption;
- resistance to chemical reagents and biological damage;
Styrofoam
long service life. Foam plastic has become one of the most common materials for thermal insulation. It has earned its place in the top three thanks to its very attractive price. The use of this insulation in individual house
- provides the following benefits:
- high degree of protection;
- resistance to rotting and mold and mildew;
- low degree of water absorption; ease of installation and no need for complex instruments
- and protective equipment;
Extruded polystyrene foam
the light weight of the material prevents excessive load on the structure and allows for insulation from below. More often this material is called more in a few words
- penoplex. Being the closest relative of foam plastic, penoplex is devoid of most of its disadvantages. In the process of improving performance characteristics, the cost has increased. The material is produced fireproof, it has sufficient strength for use as a base for flooring and is light in weight for use in ceiling construction. Do-it-yourself installation is quite simple. This issue is discussed in detail in the article. The text discusses options for using both penoplex and polystyrene foam for different types
floor structures. For people who decide to build their own wooden house , the naturalness of the materials is usually important.
Here penoplex, like foam plastic, loses to other types of insulation due to its artificial origin.
Expanded clay or sawdust Insulation of wooden floors If you decide to use it completely in the house natural materials , these two types of insulation will become. They do not have high heat-protective characteristics, like previous types, but provide reliable protection from the cold with a sufficient layer thickness.
Sawdust can be obtained almost free of charge; expanded clay is also an inexpensive material. Insulation of the attic floor can be carried out by non-professionals and does not require special skills.
The application is limited by the physical characteristics of these materials: they cannot be used for thermal protection from below.
Foam for thermal protection Polyurethane foam insulation is a fairly new material in construction. At self-construction
buildings, this method can provide high speed work and reliable protection from the cold. You can read about insulating a building, including attic floors, with foam in the article. This provides big choice
materials for insulation and significantly save on construction.
The insulation of a wooden floor is carried out between the joists, and therefore does not require high strength heat-insulating material: the main load from people, furniture and equipment will be borne by boards or timber.
A large percentage of heat loss occurs precisely through the ceiling of the upper floor, which is why it is so important to choose the right insulation and follow the installation technology. The roof protects various buildings and structures from precipitation and wind. The attic under the roof serves as a boundary between the warm air from the house and the cold environment
. To reduce the outflow of heat from the heated room to the outside, thermal insulation of the attic space is used.
Why insulate? For comfortable living conditions in winter period
, houses are heated, consuming a huge amount of coolant. Every year the cost of heating only increases. In order to save costs and reduce heat loss, energy-saving double-glazed windows are installed and walls, floors and ceilings are insulated with heat-insulating materials. More than a third of the heat from a home escapes through the roof
as warm air rises. Through an uninsulated ceiling, warm flows leave the living spaces and rush into the attic, where, in contact with the roof covering, they form condensation on the floor beams and rafter system. High humidity leads to material deterioration and fungal growth, reducing the durability of the roofing structure.
In this case, you can achieve multifunctionality of the insulation:
- protection from hot hot air in the attic in the summer allows the living space to remain cool;
- sound absorption function: noise from howling wind and precipitation is reduced;
- retaining warm air indoors heating season achieved by creating an insulating barrier.
The use of various types of insulation will reduce the level of heat loss by 20%, which will extend the life of the roof without repairing or replacing wooden elements.
Types of attic floors
Depending on the location, floors are divided into interfloor, attic, basement or basement. To create the ceiling and floor in buildings, load-bearing elements consisting of beams and slabs are constructed. Reinforced concrete slabs, steel and wooden beams are used as attic floors. During the construction of brick and panel high-rise buildings use reinforced concrete floors. Beam flooring is used in low-rise construction. Timber, logs and boards go to wooden beams large section, stacked on load-bearing walls.
Each type of floor, wooden or concrete, has its own advantages and disadvantages. Reinforced concrete floors are durable and fire-resistant, but are difficult to install and require increased wall strength during construction. Wooden floors place less load on load-bearing walls, are suitable for construction with any types of building materials, they are installed without the involvement of construction equipment. The disadvantage of wood is its fire hazard, therefore wooden structures need additional processing antipyretic impregnations.
Whatever material the attic floor is made of, it is necessary to carry out thermal insulation work, since the thermal conductivity of concrete and wood is high. The insulation scheme consists of a vapor barrier, the insulating material itself and waterproofing, forming a layered cake that helps perform a protective function for the roof and heated rooms.
Attic floors used to separate rooms at different levels must meet certain characteristics:
- Strength. Floors must withstand heavy loads.
- Fire resistance. The fire resistance limit is regulated by technical requirements. It is different for all materials: concrete lasts 1 hour, and untreated wood - 5 minutes.
Variety of materials
Before choosing an insulation material, you need to understand the variety of thermal insulators produced, taking into account their basic properties and characteristics. Based on the type of installation, thermal insulation products are divided into: roll, bulk and slab.
Rolled
Mineral wool is produced in the form of soft rolls. This fibrous material There are three varieties - stone wool, glass wool and slag wool. Rock alloys are used as raw materials in the production of stone wool. Glass wool is produced from sand, dolomite and glass waste. Metallurgical waste – slag – is used for slag wool. Attics are insulated with basalt wool and glass wool.
Mineral wool has the following advantages:
- do not burn when high temperatures melt;
- there are no rodents;
- available;
- easy to install;
- are light in weight.
A negative point when using cotton wool is its hygroscopicity and low environmental friendliness. Cotton wool absorbs water well, reducing its thermal insulation qualities. When laying glass wool, you must follow safety rules and use personal protective equipment. The environmental friendliness of the material is low, since the production of mineral wool uses phenol-formaldehydes, which are harmful to human health.
To prevent moisture from penetrating into the wool, you must strictly follow the installation technology with vapor barrier films and a waterproofing layer, leaving gaps for ventilation. At proper insulation mineral wool and compliance with all technical requirements, you can achieve an economical and high-quality thermal insulation layer.
Rolled polyethylene foam, or isolon, is used for complex thermal insulation and as a hydro-vapor insulator. It is a foamed polyethylene 0.3-2.5 cm thick with a one-sided foil layer. Izolon has heat-dissipating, fire-resistant and hydrophobic qualities.
Bulk
The following types of bulk insulation are used in the form of fractions of different sizes:
- sawdust;
- straw;
- slag;
- vermiculite;
- expanded clay;
- foam glass;
- ecowool;
- polyurethane foam.
Sawdust was used to insulate houses for a long time, until they were put into mass production. modern insulation materials. The main advantages of sawdust are high environmental friendliness, caused by the naturalness of the raw materials, light weight and availability of the material at a cheap price. The main disadvantage of sawdust is the flammability of the material. Also, when sawdust absorbs moisture, it can become moldy. The sawdust layer is easily damaged by mice.
Straw insulation is a traditional village method of keeping a house warm. This is a lightweight and affordable material. Due to high thermal conductivity, the layer of straw should be large - up to half a meter.
The negative sides are obvious:
- straw serves as a good habitat for rodents;
- lights up quickly and burns well;
- gets wet and rots;
- cakes, reducing the insulation layer.
Slag is a raw material obtained from metallurgical waste. Slag pumice and blast furnace slag have long been used as a cheap backfill insulator. This is a non-flammable, durable and cheap material.
As a result of the swelling of mica, vermiculite is formed - a natural, lightweight, durable insulation. The thermal conductivity coefficient is comparable to mineral wool. Its adsorbing qualities make it possible not to install waterproofing. Vermiculite is not affected by fire.
Expanded clay is lightweight clay granules. Natural mineral material is environmentally friendly, durable and non-combustible. Among the advantages of expanded clay insulation, it is worth noting the ease of installation - the granules are simply scattered throughout the attic in the required layer thickness. To achieve reliable thermal protection in different regions, expanded clay is laid with a thickness of 20-40 cm. A large layer of expanded clay is heavy, so the possibility of loading on wooden floors is taken into account.
Foam glass belongs to the low-thermal conductivity fill insulation materials. In production, waste from the glass industry is foamed to produce a high-quality insulator. Foam glass is moisture-resistant, durable, environmentally friendly and durable. The high cost of foam glass is a limitation for widespread use.
Ecowool is a modern cellulose insulation material.
Advantages of using ecowool:
- natural anti-allergenic composition;
- fire retardants provide fire resistance;
- does not lose thermal conductivity when wet.
Polyurethane foam belongs to the category of self-leveling insulation. Polyurethane foam is a liquid plastic that does not require a vapor barrier or waterproofing. He has the most low coefficient thermal conductivity, imparting high thermal insulation properties to the small thickness of the insulation. The coating is applied in a continuous layer without seams, covering all cracks. Water-repellent qualities do not allow fungi and bacteria to multiply in attic space. Strength during hardening does not give a chance to rodents. The composition contains substances that give polyurethane fire resistance.
Polyurethane has only one drawback - its high price. This is due to the use of professional compression equipment for spraying foam. You have to resort to the help of specialized companies.
In slabs
Plates and mats different sizes issue:
- Styrofoam;
- extruded polystyrene foam;
- mineral wool;
- reed;
- seaweed.
Foam boards consist of polystyrene granules.
Polystyrene foam has the following features:
- low thermal conductivity makes it an effective heat insulator;
- very light, easy to install;
- flammable, releases toxic substances when the temperature rises;
- waterproof;
- not resistant to mechanical stress;
- The popularity of polystyrene foam is due to its low cost.
Extruded polystyrene foam is the same foam produced by extrusion. This allows you to preserve all the advantages of polystyrene foam, acquiring an increased density that can withstand heavy loads. Expanded polystyrene boards have grooves, which facilitates installation without gaps and creates a continuous coating.
One option for producing mineral wool is slabs, often covered on one side with reflective aluminum foil. The foil acts as a vapor barrier and reflects heat out of the house. It is convenient to use a mini-slab for self-assembly.
Reed mats and algae ladders are produced in the form of compressed briquettes. Natural, natural, lightweight materials - reeds and algae - are used as raw materials. High environmental and vapor-permeable properties allow them to be used for wooden buildings. The problem of fire safety can be solved by treating raw materials with fire-resistant compounds.
How to choose?
When choosing thermal insulation materials, the type of floor and the characteristics of the insulation are taken into account. The characteristic qualities of the heat insulator become the decisive criterion.
A number of factors are taken into account:
- Thermal conductivity level. The best insulation has low thermal conductivity and a small layer thickness.
- Fire resistance and frost resistance. The material must not ignite.
- Ease of installation.
- Durability. The insulation must be durable, not collapsing under the influence of adverse conditions.
- Ecological cleanliness. How more natural composition material, the safer it is for human health.
- Price. In private construction, price often becomes the main criterion.
Taking into account all the features of the material, you can choose the appropriate insulation for your home. Often the most optimal choice– insulation with mineral wool. Following the installation instructions will allow you to perform high-quality thermal insulation work.
Calculation of insulation thickness
In accordance with the requirements of SNiP for building insulating materials, the thickness of the insulation depends on the type of thermal insulation, the duration of heating and the average temperature in winter in a particular region.
The thickness of the insulation is calculated based on the thermal conductivity coefficient of a particular material. This indicator is indicated on the packaging of the purchased insulation. Moreover, they select the upper limit of the norm for a humid environment.
Features of the work
The type of overlap determines the feature thermal insulation works. Methods for laying thermal insulation differ depending on the type of insulation.
On reinforced concrete slabs
Insulating an attic with a floor made of reinforced concrete slabs is easy to do, since the attic floor is flat. Mineral wool rolls, slab versions and any bulk varieties are suitable as insulation. The weight of the material can be ignored, since reinforced concrete slabs can withstand heavy loads.
To eliminate the largest heat losses in a residential building, it is impossible to do without insulation. The process of insulating the floor of the first floor using wooden beams located above the basement begins at the construction stage, but the work can be done after construction. Mandatory thermal insulation and sound insulation of horizontal structures of the upper floors is also required.
Benefits of wood
Floors are called horizontal structural elements buildings and structures, dividing them into floors or separating them from technical premises(attic or basement). Depending on what material the building is constructed from, the floors can be monolithic, prefabricated reinforced concrete or wooden.
For the construction of a private house, floors on wooden beams are most suitable, since their weight is less than that of structures made from other materials, and constructing them with your own hands is cheaper and easier.
Wooden interfloor ceilings can be installed in houses made of any material, with the exception of monolithic reinforced concrete. They are erected simultaneously with the construction of the walls, as the latter are built to the height of the next floor. In frame wooden buildings, floors can be completed simultaneously with the construction of the frame of the entire building, even before it is insulated and covered.
Correct floor design
Interfloor wooden floors are arranged on beams. They are usually used as timber. The size of the section depends on the size of the span that needs to be covered, as well as on the size of the expected load on the floor and the types of wood used. Most often, timber with a section width of 100 mm and a section height of 150-200 mm is used.
Next, the ceiling itself is formed by installing the floor boards of the upper floor and hemming the ceiling materials of the lower floor. You can often see that floor boards are laid directly on beams, but it is more correct to first install logs on the beams, and then make flooring from the boards over them. The second option is the most preferable, as it will allow for proper interfloor insulation along wooden beams.
The fact is that in the pie, which the filling of the interfloor ceiling is so similar to, there must be layers of vapor barrier.
They are made from a special membrane with a certain coefficient of vapor permeability, and upper layer membranes allow steam to pass in only one direction - from the insulation into the air. Therefore, an air gap is needed between the membrane and the plank floorboard, which will remove steam from under the boards. Otherwise, the latter will simply begin to rot.
In this case, the membrane is laid on the interfloor floor beams, and the air gap is formed due to the thickness of the logs laid perpendicular to the beams.
Steam is removed from under the boards through specially cut holes in the floor or slotted skirting boards used to edge the perimeter of the room.
Note! The bottom layer of the membrane should be made of a material with a very low vapor permeability coefficient.
This is necessary so that moisture from the lower rooms does not seep upward through the interfloor ceilings, and also does not linger in the layers of insulation. All air from the floor must be vented to the atmosphere only through ventilation ducts or windows for ventilation.
Insulation layers
So, if you imagine a cross-section of the interfloor insulation cake, it will consist of the following layers:
- floor covering boards for the upper floor;
- logs;
- floor vapor barrier;
- beams with a layer of heat and sound insulation laid between them;
- ceiling vapor barrier;
- ceiling cladding.
In multi-storey buildings, insulation of the interfloor floor is relevant only if this floor is made between the basement and the first floor, as well as in the case of the floor between the upper floor and an unheated attic.
If the ceiling separates two residential heated floors, then the role of insulating material for insulation is negligible. In this case, the soundproofing properties of the structure are much more important. Despite the fact that it is warm and soundproofing materials are included in the same group when classified according to purpose and technological characteristics, their properties may be different.
These differences must be taken into account when using this or that material in a specific interfloor covering.
Insulation materials
Various thermal insulation materials can be used as interfloor insulation for a wooden house:
- glass wool;
- basalt wool;
- slag;
- Styrofoam;
- penoplex;
- expanded clay;
- foamed polyurethane;
- shavings, sawdust.
The choice is based on the availability of the material, its cost, and characteristics. Thus, mineral wool and expanded clay are the most acceptable from the point of view fire safety. At the same time, penoplex does not absorb moisture, does not cake, and has high thermal insulation properties. Sometimes materials are combined to increase thermal protection.
Various types of cotton wool
Most often, various types of construction thermal insulating mineral wool are used to insulate interfloor ceilings. They are made by melting and drawing fibers from raw materials. Next, these fibers are special machines intertwined and formed into mats or rolls. IN in some cases such mats or rolls are stitched with synthetic threads to increase the strength of the products.
For glass wool, the raw materials are waste and waste from glass production; for mineral wool and basalt wool, igneous rock melts are used. Slag is produced by melting blast furnace slag.
Different types of cotton wool have different properties. They have different densities and different thermal conductivities. These characteristics depend not only on the type of feedstock, but also on the specified production parameters.
Foam plastic and penoplex
These are two similar materials in properties and production method. The starting materials for their production are plastics. of various compositions. During the production process, they foam and, when hardened, are formed into sheets of the correct geometric shape. The difference lies in the fact that during formation, penoplex is extruded through a special device - an extruder.
Both foam plastic and penoplex have in their volume closed pores filled with gas. Only in polystyrene foam is this ordinary air, but when foaming polystyrene foam, as a rule, it is used carbon dioxide. In terms of thermal conductivity, both materials are almost identical. But due to the fact that the pores in the penoplex mass are distributed more evenly and they themselves have almost the same size, its strength is much higher.
Very often, when forming sheets of penoplex, their ends are not made even, but in the form of two or more ledges. When insulating, two adjacent sheets, connecting to each other during installation, provide better insulation, since the joints are not blown through and retain heat well.
Expanded clay
Note! Expanded clay is environmentally friendly material. It is durable and will not rot or decompose.
Polyurethane
Foamed polyurethane is used, as a rule, for insulating basement and attic floors. It is simply applied using special equipment, and later it foams in air and takes on a three-dimensional shape. The advantage of using such material is that it fills all the leaks and cracks in the ceiling structure, allowing you to create a sealed water- and windproof thermal protection.
Sawdust
Wood shavings and sawdust have recently been used much less frequently, but more recently they have also been used to insulate interfloor ceilings, filling the cavity between the beams. To prevent such insulation from rotting inside the ceilings, it is treated with special compounds that kill putrefactive bacteria and woodworms. When laying, shavings or sawdust are mixed with lime.
Vapor barrier
To properly insulate interfloor ceilings, it is not enough to use only materials with thermal insulation properties. If you do not protect the insulation from the action of moisture located in the interior of the premises, various microorganisms will multiply in the material, which can subsequently lead to mold or mildew. To avoid this phenomenon, it is necessary to make the correct vapor barrier for the insulation.
Any of the many options produced by industry can be used as a vapor barrier. Ready-made protective membranes are very widely represented on the building materials market. When building and insulating a private house with your own hands, you can use available materials if you know their strength and vapor barrier properties and use them correctly.
As the main layer, the coefficient of vapor permeability of which should be minimal, you can use conventional plastic film or foil. This layer is laid below the insulation, preventing moisture vapor from the basement or lower floor from penetrating into it.
As the second layer, which will be on top of the insulation, you can use wax paper or glassine. These materials have greater vapor permeability than foil or polyethylene. They will facilitate the free release of vapors from the thickness of the insulation upwards.
Work technology
The most effective will be the insulation of the interfloor ceiling if it is carried out during the construction process. It is in this case that all the subtleties can be taken into account and all available materials can be used.
If the interfloor ceiling is not yet ready, but only consists of a set of wooden beams laid on load-bearing walls, it is necessary to install a vapor barrier layer on the lower surface, and then hem the ceiling of the lower floor. As a result, if you look at the ceiling from the upper floor, it will look like several long boxes formed by the beams and ceiling covering.
It is in these boxes that you need to put the insulation. After the material is laid in the space between the beams, it must be covered with a second layer of vapor barrier. Sheets or panels must be overlapped and glued together. Logs are installed immediately along the top layer of vapor barrier, on which the floor boards of the upper floor will subsequently be laid.
If you do insulation of the finished interfloor ceiling, as often happens during overhaul residential buildings, the insulation will have to be installed on the underside of the ceiling. To do this, from the side of the ceiling of the lower floor or basement, a frame is arranged on wooden blocks or metal profiles. Insulation is secured between the frame elements using special fasteners. Next, a lower layer of vapor barrier and a ceiling covering are mounted along the frame, close to the insulation.
Properly performed insulation will protect against frost and heat in the summer, and provide good sound insulation.
