Insulation of an existing wooden floor. Instructions for insulating a wooden floor in a wooden house. What materials can be used for insulation
The floor is considered the coldest part of the house, especially if we are talking about a suburban wooden structure. There is nothing surprising in this, the usual laws of physics: warm air rushes upward, and the cold one spreads along the bottom, and drafts blow down the legs from the cracks between the cracked floorboards.
A solid foundation, four strong walls and reliable roof– this is only part of comfortable suburban housing. In order to minimize heat loss, it is necessary to insulate the floor in a wooden house.
The functions of this action are very clear: retaining 20% to 30% of heat, significantly reducing humidity, preventing mold, reducing the cost of organizing stove, gas or electric heating. A good, warm floor will make your life in a wooden house surrounded by nature as pleasant as possible. You will feel comfortable both in the gloomy off-season and in winter frosts.
What is the best way to insulate the floor in a wooden house?
Floor insulation in wooden houses is carried out using different materials having the same characteristics. As the simplest and inexpensive insulation materials, which are poured in a layer on top of the floor roughing, which serves as an auxiliary base.
These materials are sufficiently hygroscopic, they protect the wood from rotting, the appearance of fungus and microorganisms, and also ensure air movement. However, this method of thermal insulation has a significant drawback: bulk non-metallic insulation materials lose their hygroscopicity over time.
Introductory video guide
A country house made of logs or timber is an environmentally friendly home, so the materials for its insulation are also subject to environmentally friendly requirements. This will help preserve the unique natural aura! Previously, they were widely used for floor insulation. sawdust, granulated sawdust insulation, sawdust concrete, wood concrete, and foam plastic. But today there are more convenient and efficient materials, which are also environmentally friendly.
Currently, manufacturers produce a wide range of thermal insulators. They suggest insulating floors in a wooden house mineral wool made from basalt, stone chips or slag, ecowool made from cellulose, fiberglass, penoplex, expanded polystyrene, penofol, isolon and others modern materials. Usually they are used for thermal insulation of walls, attic and roofing slabs. Each insulation has its own characteristics, therefore, when choosing a material, you need to take into account its pros and cons.
At the same time, there are general requirements for all thermal insulator materials. They should be light (not weigh down the structure of the wooden structure), durable, safe, easy to install and, naturally, have low thermal conductivity.
The insulation is selected taking into account the parameters of the building, and it is possible to avoid heat leakage only with proper organization of thermal insulation.
Fiberglass and mineral wool– these are materials whose distinctive characteristics are density, low thermal conductivity, good noise absorption, durability, availability, environmental friendliness, non-flammability, chemical resistance, water resistance and high level thermal insulation, so they are most often used for floor insulation in a wooden house.
Sometimes unscrupulous manufacturers use harmful phenol-formaldehyde resins to connect the fibers in these materials. Glass wool that does not meet environmental requirements has a yellowish tint, and mineral wool has a brownish tint.
Expanded polystyrene and penoplex– modern materials that are sprayed onto the surface of the auxiliary floor and fill the space between the joists. They are distinguished by such qualities as efficiency, low thermal conductivity, minimal level of water absorption, stability of shape and volume, environmental friendliness, biostability, efficiency and durability.
Due to their low cost and ease of use, expanded polystyrene and penoplex are used in wooden houses for insulating floors and other structures. High-quality polystyrene foam must be absolutely dry, without the presence of volatile compounds, which can be released when the temperature rises and cause harm to health.
Acrylic and latex binders used in the production of these materials are safe for the human body. This is confirmed by quality certificates.
The main manufacturers of materials for thermal insulation of buildings today are the following companies: Izovol, Izorok, Izorus, Knauf, Rockwool, Ursa and others.
Stage 1– laying the subfloor along the joists. This simple and versatile design is most often used in renovations and new construction. Its main advantage is that the insulation is not affected by mechanical loads, so any heat-insulating material can be used.
This floor is made of wooden panels or rough boards measuring approximately 25x150 mm. You can also use boards left over from the foundation formwork for these purposes, provided they are good condition. In any case, it is recommended to pre-treat the wood with an antiseptic composition.
First they lay wooden joists, not reaching the walls by about 2-3 cm. They are either installed using a T-shaped cut into a log house, or laid on a foundation, brick pillars or wooden spacer at a distance of 0.6-1.0 m from each other. A cranial beam with a cross-section of no more than 50x50 mm is attached to the logs using screws, then shields or rough boards are nailed to it from below, making sure that there are no large gaps between them.
Stage 2– laying insulation. Sheet, slab or roll thermal insulation material (foam plastic, glass, eco-, mineral wool, etc.) is placed tightly on wooden base between the lags, and the remaining gaps are filled polyurethane foam. Sometimes such insulation is laid under the subfloor.
Sprayed insulation is fixed using special equipment. These materials have good adhesion, follow the contours of the surface and do not form joints.
Stage 3– laying vapor barrier (waterproofing) material. Waterproofing of the subfloor is mandatory when insulating wet rooms in a wooden house, as well as in the case of using hygroscopic heat insulators. In particular, it is necessary when using fiberglass, ecowool or mineral wool as insulation. At the same time, you can do without it if you use sprayed insulation.
Waterproofing is divided into impregnation, painting and pasting. Pasting materials include polyethylene films, PVC membrane, glassine, roofing felt, isoplast, etc. Film waterproofing materials perfectly protect fiber insulation from condensation and moisture penetration.
Sheets of vapor barrier film are laid over the thermal insulation layer with an overlap of approximately 15 cm, and the edges are folded by approximately 10 cm and attached to the joists. The joints and resulting gaps are taped with metallized tape. Sometimes two layers of moisture-resistant film are laid: a waterproofing layer on the subfloor, a vapor barrier on the insulation.
Stage 4– laying the finished floor and finishing it. The finished floor is laid on top of the vapor barrier layer at a distance of 3-4 cm from the auxiliary base (subfloor). For its construction, specially treated boards with a width of 9.8-14.5 cm and a thickness of 3.0-4.4 cm are used, which have longitudinal grooves on the bottom side to ensure natural ventilation.
Video guide for floor insulation in a wooden house
It is not recommended to use unedged boards for laying the finished floor, because before laying they will need to be prepared: cut off the wane with an ax, plan the front side. It's pretty labor-intensive process, which takes energy and time. Sometimes fibreboard (fibreboard) and a soundproofing coating are placed on top of the boards.
To enlarge, click on the picture
Paint and varnish, or slabs, linoleum, and carpet are used as finishing materials for a finished insulated floor in a wooden house. They are laid according to generally accepted rules governing the installation of these materials, and then skirting boards or profiled slats are installed along the joints with the walls. On straight sections they are connected at an angle of 90 degrees, and in corners - at an angle of 45 degrees.
The profiled slats are pressed tightly against the floor and walls and fastened with 75 mm nails, keeping a distance of 60-70 cm between them. Also, nails must be driven into the joints of the baseboards.
The coldest place in a living space is the floor, especially in a wooden house. And this is natural, because a simple physical law works: warm air rises to the ceiling, and cold air descends and spreads along the floor.
Plus, there are drafts that appear from the cracks between the floorboards. The key to a warm and comfortable country house is a strong foundation, reliable walls and roof, as well as a high-quality insulated floor. In this article we will look at how to properly insulate a floor in a wooden house.
Why insulate the floor
When the floor in the house is well insulated, then it has:
- 20-30% more heat is retained;
- the humidity level is significantly reduced;
- mold does not form.
In addition, the costs of installing any type of heating are reduced many times. During the cold season, a wooden house with insulated floors will be warm and cozy.
Thermal insulation materials for floor insulation
Thermal insulation of the floor is carried out using various materials that have similar properties.
Sand and expanded clay are simple and cheap types of insulation. They are poured onto the subfloor in a layer required thickness. These materials have good hygroscopicity, protect wooden floor elements from rotting, fungus and various microorganisms, provide air circulation. But it has one significant drawback: after some time, non-metallic insulation materials lose their hygroscopicity.
Since a house built from wood (timber, logs) is an environmentally friendly home, the thermal insulation materials must meet these requirements. This way you can preserve the unique natural atmosphere.
Previously, sawdust, sawdust pellets, sawdust concrete, and wood concrete were used as insulation. Now how to insulate the floor in a wooden house? Today they sell more convenient and effective, environmentally safe, insulation materials. Manufacturers produce a large number of different heat-insulating materials.
You can insulate the floor in a wooden house using the following insulation materials:
- mineral wool, which may be based on basalt, slag or stone chips;
- ecowool made from cellulose;
- glass wool;
- penoplex;
- expanded polystyrene;
- penofol;
- isolon and other materials.
Usually the same materials are used to insulate walls, attics and roofs. Each type of heat insulator has its own characteristics, so when choosing a material you should take into account its advantages and disadvantages.
At the same time, general requirements are imposed on all insulation materials, such as:
- lightness, that is, design wooden building should not be heavy;
- strength;
- safety;
- ease of installation;
- low thermal conductivity.
The decision of which insulation to choose for the floor in a wooden house is influenced by the construction parameters. Only when proper organization thermal insulation can avoid heat loss.
Most well-known manufacturers thermal insulation materials are from the companies Izovol, Izorok, Knauf, Rockwool, Ursa.
Fiberglass and mineral wool
These materials are distinguished by the following qualities:
- density;
- low thermal conductivity;
- good noise absorption;
- long service life;
- accessibility;
- environmental friendliness;
- non-flammability;
- not susceptible to chemical influences;
- moisture resistance;
- high degree of thermal insulation.
Due to these qualities, thermal insulation of the floor in a wooden house is most often carried out with these materials.
Some unscrupulous manufacturers add harmful phenolic and formaldehyde resins to their products. Glass wool, which does not meet environmental requirements, has a yellowish tint, and mineral wool takes on a light brown color.
Expanded polystyrene and penoplex
These modern materials are used to insulate the subfloor in a wooden house. These thermal insulation materials are located between the joists.
Expanded polystyrene and penoplex have the following qualities:
- efficiency;
- low degree of thermal conductivity;
- minimal degree of moisture absorption;
- constancy of shape and volume;
- environmental friendliness;
- not exposed to microorganisms;
- efficiency;
- durability.
Calculation of the thickness of the insulating layer
It is important to determine what the thickness of the floor insulation in a wooden house should be. Calculated for a specific house. This takes into account the design features of the building, weather conditions typical of the region, as well as the type of insulation chosen.
In the section " Thermal protection buildings" building codes and regulations provides a formula for calculating the average thickness of the thermal insulation layer.
All values are specified in the appendix to the building codes and regulations. The thermal conductivity coefficient of the insulation can also be found in the instructions attached to the insulation material.
If you need to lay a small thickness of insulation, you can use materials produced in rolls or mats, as well as extruded polystyrene foam. Thermal insulation material in mats has higher strength and elasticity.
Floor design for insulation
When insulating the floor in a wooden house, a double structure is created.
It classically consists of the following layers:
- rough flooring;
- insulation;
- vapor barrier;
- finishing floor
This floor structure can withstand heavy loads and does not allow heat to escape.
Floor insulation technology
This process is quite simple, so it is quite possible to insulate the floor in a wooden house with your own hands.
It is important to take into account such essential aspects as:
- type of room;
- average temperature and humidity in it;
- minimum thickness of the insulation layer.
You should also purchase high-quality insulation. Next, we’ll look at how to properly insulate a wooden floor.
The technology includes several stages:
Laying the subfloor along the joists. It is a simple structure that is used in the repair and construction of a house. In this case, the insulation is not subjected to any loads, so any thermal insulation material can be purchased for insulation.
The subfloor is made of wooden panels or untreated boards measuring 25x150 mm. For flooring, you can also take formwork boards from the foundation, only if they are not damaged. Wood must be impregnated with an antiseptic before use.
Laying insulation. The selected thermal insulation material must be laid tightly on wooden base between the lags. All existing cracks must be filled with foam. In some cases, the subfloor is insulated.
Laying the waterproofing layer. If the floor is insulated in a room with high humidity, and also if the thermal insulation materials used are hygroscopic, then waterproofing must be performed. It is necessary when glass wool, ecowool, and mineral wool are used for insulation. But if the floor is insulated using the spraying method, then you can do without a waterproofing layer.
There are impregnating, painting and pasting types of waterproofing. Pasting materials are polyethylene films, roofing felt, polymer membranes, glassine, isopaste and others. Film waterproofing insulators do an excellent job of protecting fiber insulation from condensation and moisture.
Strips of vapor barrier film are spread on top of the thermal insulation material. They should overlap each other by 15 cm, and the edges of the film should overlap the logs by 10 cm, to which they are then fixed. Metallized tape is glued to the joints and existing gaps. In some cases, two layers of moisture-resistant film are laid: a waterproofing layer is laid on the rough flooring, a vapor barrier layer is laid on the thermal insulation.
Organization of the finished floor and finishing. A finishing floor is laid on top of the vapor barrier layer. It is made from boards processed in a special way, the width of which is 9.8 - 14.5 cm, and the thickness is 3 - 4.4 cm. They have longitudinal grooves at the bottom, which are necessary for organizing ventilation.
You should not use untreated boards to install the finished floor, because they will need to be prepared before laying, and this is a rather complicated process that takes a lot of effort and time. Fiberboard and a soundproofing layer can be laid on top of the boards.
The finished insulated floor can be painted or varnished. You can also complete the finishing using slabs, linoleum or carpet. Their installation is carried out in accordance with generally established rules that govern the installation of these floor coverings. Then skirting boards or profiled slats are installed. If their joining occurs on a straight line, then they should be connected at a right angle, and if in the corners, then the connection angle should be 45°.
Profiled slats are laid close to the floor and walls and secured with nails 75 mm long in increments of 60 - 70 cm. The joints of the skirting boards should also be nailed.
The most common problem is cold floors. This is due to the fact that air currents coming from the ground penetrate into the room through the cracks between the boards. In addition, if the humidity and temperature conditions are violated, the material begins to lose strength characteristics and rot. Therefore, to make the room warm and comfortable, you need to carry out a series of thermal insulation works. In today's review by the HouseChief editors, we will tell you how to properly insulate the floor in a wooden house, which method and materials are best to choose.
Read in the article
Why insulate the floor in a wooden house from below?
The second most popular thermal insulation material is expanded clay. It consists of granules of foamed and fired clay. Expanded clay is strong, light and durable, but due to its porosity it absorbs moisture well, which is its significant drawback. Therefore, using this thermal insulation material, it is necessary to arrange a good one. Among the advantages of expanded clay, it is worth noting good sound insulation characteristics, resistance to low temperatures and environmental safety.
One of the most budget materials is polystyrene foam. This insulation is comfortable and durable. It tolerates moisture well. The material is very easy to install. All you have to do is cut out a tile that suits your size, insert it and... The weak point of polystyrene foam is that rodents like to make their nests in it.
One more traditional material For insulating the floor in a wooden house with your own hands, mineral wool is considered. It is difficult to call it a completely budget option, but in the line of this material on the market there are several inexpensive models. For example, glass and some soft mineral wool mats are quite affordable for the average consumer. However, this insulation can last no more than 10 years, since it quickly cakes and loses its qualities when wet. It is very popular with rodents.
Insulation of wooden floors with modern materials
Among modern thermal insulation materials, extruded polystyrene foam (EPP) has gained the most popularity. Thanks to its closed cell structure, it is not afraid of moisture and steam. EPP is also not tolerated by rodents. The material is so durable that it can even be placed in.
The next most popular is ecowool, which consists of 80% cellulose and 20% antiseptics and fire retardants. The material is not expensive in production, and the high cost is due to its novelty.
Quite expensive and effective insulation is polyurethane foam. To insulate the floor of the first floor with this material, participation is required experienced specialists and availability professional equipment. Despite the fact that the foam is close in its characteristics to EPP, it will not withstand the device.
Penoizol. Although this material is cheaper polyurethane foam, however, specialists are also required to work with it. Many people consider it inappropriate to overpay for this type of insulation, since it is the same polystyrene foam, only in liquid form. The advantages include speed of installation and tightness of the coating.
We suggest watching a video on how to choose insulation:
How to calculate the thickness of insulation
When carrying out thermal insulation work, a very important parameter is determining the thickness of the insulation layer. It must be determined individually for each house and depends on the design features of the building, the climatic conditions of the region and the type of insulating material. Calculation formula optimal thickness insulation layer is given in SNiP 02/23/2003 “Thermal protection of buildings”.
The calculation formula is as follows:
R·λ = thickness of the thermal insulation layer,
Where R – thermal resistance of the structure, determined for a specific region (registered in special tables in the appendix to SNiP);
λ – thermal conductivity coefficient (indicated in the instructions for the material and SNiP).
If it is necessary to lay thermal insulation material in a thin layer, it is recommended to use extruded polystyrene foam or insulation in mats and rolls. The latter option is more preferable due to its high strength and elasticity.
Technology of floor insulation in a wooden house from below
Each thermal insulation material has its own installation methods. However, there are general requirements for installing floor insulation that must be observed regardless of the material chosen. So, if correct, the thermal insulation cake should consist of the following layers:
- insulation;
- vapor barrier;
- structural elements of the floor;
- finishing floor covering.
Professionals say that this arrangement of layers makes it possible to create inside the house optimal temperature and maintain a normal level of humidity in the premises.
For your information! When installing thermal insulation of the basement floor, it is recommended to use beams with a cross section of 50-100 mm.
Laying waterproofing
When carrying out work on insulating subfloors in a wooden house, it is necessary to perform waterproofing. Due to the fact that cold air upon contact with a warm surface, it creates condensation and begins to be exposed to moisture. From its constant presence in the room, the active development of fungus and mold begins, which leads to rotting and destruction of wooden structures. This happens especially often in cases where, during the construction of the house, the wood was not treated with special protective equipment.
Carrying out insulation without a layer will lead to a negative effect of moisture on the thermal conductivity qualities of the material. As a result, humidity increases and the temperature in the house decreases. Therefore, a waterproofing layer is so necessary. It is arranged on the side exposed to cold air currents.
Vapor barrier for floors in a wooden house
Working in the house household appliances, equipment and the human body generate a large amount of heat. It penetrates through the cracks and, upon contact with cold air, turns into condensation, settling inside the wooden structure. As a result of such exposure, the wood swells and rots from the inside. Even treatment with special protective agents cannot prevent this. Therefore, when insulating the floor in a wooden house, a vapor barrier layer is required. The simplest and available material for this purpose - polyethylene film, which is perfect for hydro- and vapor barrier. However, it is best to use moisture-windproof membranes that ensure normal air circulation and retain moisture inside.
How and with what to insulate the floor in a wooden house from below: installation technology
When choosing insulation for a wooden house, you need to take into account that each of the heat-insulating materials has its own installation features. Below we will consider fastening methods depending on the selected material.
Insulation of floors in a wooden house using joists
The best way to insulate the floor is to lay it on joists. These are transverse boards used for subsequent installation of flooring. The main stages of laying thermal insulation:
- Logs are installed. The distance between them should be no more than 1000-1200 mm.
- The base for laying thermal insulation or subfloor is being prepared. To do this, using self-tapping screws, sheets of thick or thick sheets are installed.
- Laying is done between the joists waterproofing membrane and the selected insulation. The thickness of the thermal insulation layer is determined according to special tables or manufacturer’s recommendations. In any case, it should not be higher than the logs themselves.
- A layer of vapor barrier is laid.
- Now you can start laying the flooring (old or new).
This algorithm of actions will allow you to insulate the floor in a wooden house with almost any type of insulation.
How to properly insulate the floor in a wooden house with sawdust
Using sawdust as a thermal insulation material is an environmentally friendly and inexpensive way to insulate floors in a wooden house. When choosing them as insulation, you should adhere to some recommendations:
- The thermal insulation mixture consists of 50% sawdust, 10% clay or 40% water. A thicker solution will be stronger, but the thermal conductivity will be reduced;
- cooked thermal insulation mixture you need to add broken glass. This should repel rodents;
- The prepared mixture must be filled into the space between the joists and compacted thoroughly. This will make it possible to obtain an even and effective thermal insulation layer.
In addition to the above-described composition of sawdust thermal insulation, there are two more options, namely:
- Bulk. Take 80% dry sawdust and mix with 20% slaked lime powder and pour the mixture between the joists. Thermal insulation layer for middle zone Russia should be at least 150-200 mm, and for northern regions– 300-400 mm.
- Slab or sawdust concrete. To make thermal insulation boards, you need to take sawdust, slaked lime and cement in a ratio of 8/1/1, respectively. All this must be moistened generously and mixed thoroughly. The resulting wet mixture must be placed in molds, compacted and allowed to dry. About a week later, in warm time years, sawdust slabs will be ready. You can fill the space between the joists and the wet mixture, but in this case, installing the final floor covering is only permissible after 2-3 weeks, until the mixture is completely dry.
Insulating the floor in a wooden house with penoplex
Most often, they prefer to insulate floors in wooden houses with penoplex because affordable price and high strength material. Installation proceeds as follows:
- cut into the right size, accurately and tightly fitting the edges of the slabs between themselves and the joists to prevent the penetration of cold air;
- lay a layer of waterproofing;
- Installation of slabs on the subfloor is carried out using mounting adhesive;
- All joints are additionally glued for stronger adhesion.
Due to the fact that penoplex is lightweight, it is excellent for thermal insulation of floors in frame houses. With such material, the load on the houses will be minimal, which will avoid shrinkage of the structure in the future.
Features of floor insulation with mineral wool
Before carrying out thermal insulation work, it is necessary to check the condition of the surface of the subfloors. If it is in excellent condition, then you can move on to the next stage. Otherwise, you need to either restore the old coating or dismantle it and create a new one. Next, a layer of waterproofing is laid and guide beams are installed.
The logs are mounted with an optimal pitch of 500 mm. It should not exceed a distance of 900 mm. After installation floor timber you can start direct installation insulation. The mineral wool should lie close to each other and the joists, but not wrinkle.
Next, you need to lay a layer of vapor barrier membrane and, after that, begin installing the base under the finished floor. The material used for such a base is plywood, etc. Only after this can the final finishing coat be laid.
Features of floor insulation in a wooden house with ecowool
The insulation of floors with ecowool is practically no different from the process of thermal insulation with mineral wool. In this case, 2 methods are used: dry and blowing or spraying. Each of these options has its own advantages and disadvantages. We will consider the first option, since it is suitable for independent work.
Dry installation method
This method is most suitable for self-installation and consists of the following stages:
- If the building already has a subfloor made of, then waterproofing should be done with roofing felt or plastic film. Next, wooden logs are installed in increments of 600 mm.
- If there is no concrete floor and the logs are mounted on posts, then they should be lined underneath with plywood or.
- The joists and base are moistened with a spray bottle. The loosened contents of the briquette with insulation are poured into the resulting box. The mixture is poured slightly above the thickness of the lag.
- The ecowool mass is compacted. If the thickness of the thermal insulation layer is significant, the insulation is laid in several layers. However, you should not compact them too much. This can reduce the effectiveness of the insulation.
- The surface of the insulation must be moistened, since in this case the structure of the material changes and, due to this, a denser outer layer is created.
How to insulate a wooden floor with expanded clay
Insulation of floors with expanded clay is carried out using almost the same technology as with the rest thermal insulation materials. But there are still some differences. To insulate with expanded clay you should:
- a sand “cushion” is poured onto the subfloor in an even layer, which needs to be compacted;
- for waterproofing, a layer of liquid mastic is applied to the “cushion”;
- expanded clay is filled in and leveled;
- a vapor barrier is laid and the finished floor is laid.
Features of insulating the floor of a wooden house from above
As already mentioned, floor insulation, both from below and from above, is the installation of several types of materials, which as a result form a multi-layer “pie”. The technology for both cases is identical, with the difference that thermal insulation of the floor from below is more labor-intensive.
Typical mistakes when insulating the floor of a wooden house
Inexperienced specialists and those who try to insulate floors on their own often make a number of mistakes. We list the most common of them. After familiarizing yourself with them, you can avoid similar mistakes when insulating floors on your own.
Mistake #1: improper storage and unpacking
You cannot store unpacked material for a long time, since humidity will affect the quality of the insulation. It must be unpacked about a day before installation. This is best done in the house or under. After laying the insulation, you need to cover it with a vapor barrier and a finished floor as quickly as possible.
Mistake No. 2: gaps or compression of insulation
When laying insulation, it is necessary to observe the dimensions so that there are no gaps that will become. If there are still gaps between the material and the joists, then they need to be filled with foam. It is also unacceptable to compress the insulation, like mineral wool.
Mistake #3: Undervalued condition interfloor ceilings
Often, joists and floor slabs are exposed to moisture, fungi or mold, or are simply very worn out. If you do not assess the condition of the floors and joists, then the work on thermal insulation is carried out in vain, therefore, if the structures are in poor condition, they need to be replaced.
Mistake #4: lack of special treatment of wooden structures
In the absence of special protective treatment, the wood that ends up under the insulation will begin to quickly rot and be exposed to fungus and mold.
Mistake #5: The insulation is too thin
Mistake #6: Skipping waterproofing
When occurring groundwater at a depth of less than 2 m, insulation of the floors of the first floor must begin with the installation of a waterproofing layer.
Error No. 7: violation of the sequence of laying layers of thermal insulation
If you want your home to be warm, be sure to follow the technology for installing thermal insulation. Don't skip any layers and use only quality materials.
Watch the video about typical mistakes performed during the installation of thermal insulation of floors in wooden houses.
Currently, environmentally friendly low-rise construction of houses from wood materials is becoming increasingly popular. Traditional log houses made of rounded logs, cottages made of timber and even houses built from lightweight materials, their owners try to sheathe them with boards or clapboards. To create a microclimate in the home that is closer to nature, the same considerations are used when choosing materials for floors, giving preference to wood as a lighter, but quite durable material.
Due to its natural origin, wood has a fairly low thermal conductivity, but in the Russian climate it still requires additional thermal insulation.
Options
There is enough large selection fillers for insulation of interfloor ceilings, floors and ceilings. It can be difficult for an inexperienced builder to understand the properties of this or that insulation, objectively evaluate their advantages and disadvantages, and make the right choice.
The thing is that different heat-insulating materials are more suitable for some operating conditions and less suitable for others. Insulation of such specific rooms as an attic, underground, or veranda requires a special approach, so it is worth studying all the properties of the materials in order to produce insulation as efficiently as possible.
The choice of thermal insulation material is influenced by the following factors:
- Humidity. Constant dampness in the room (basements with open ground or insufficient waterproofing of the foundation, bathrooms, winter gardens or home greenhouses) or the likelihood of increased humidity in it (balconies, rooms for drying clothes, bathrooms or steam rooms);
- Purpose of the premises. Some types of materials contain certain resins or glues that, for safety reasons, are not suitable for bedrooms or children's rooms.
- Possibility of damage by rodents or insects, resistance to fungal attack. Some of the materials are liked by rodents, while others are repellent to them.
- Lower and upper temperature limits. Some heat insulators are not resistant to severe frosts, while others lose their properties or are completely deformed and become unusable when subjected to significant heating.
It should be borne in mind that the heat-insulating material must “work both ways” - not only protect the home from low temperatures in winter, but also maintain comfortable environment presence of humans and domestic animals in the summer heat.
Last but not least, the choice of insulation and the method of performing thermal insulation are also influenced by the general condition of the house:
- age of the building - an old house requires one method, a recently built one requires another;
- foundation construction method - on bored or screw piles, on reinforced concrete blocks or on light foundations of shallow depth;
- the number of storeys of the building and the area where the work will be performed - whether the floor insulation is being carried out for the 1st or 2nd floor.
From below
In most cases wooden houses They are built with a high base, that is, the height of the subfloor allows for insulation from below. The only exception may be the southern regions, where private houses are being built on stable soils using the technology of constructing low-rise buildings on shallow piles. But even there, in most cases, they try to adhere to the traditional construction of houses with a high base.
Otherwise, if the subfloor is not high enough, to insulate the floor of the first floor you will need to remove the floor board to the joists or other supporting structure.
Thus, it is possible to insulate from below with a sufficiently high subfloor for the first floor or insulate the floor of the second floor, which, accordingly, is the ceiling for the first floor.
Carrying out thermal insulation work in the underground is not much more complicated than the same work when insulating the floor of the second floor, but it has a number of features. Before starting work, you need to prepare the place and provide yourself with both minimum comfort and the necessary level of safety.
Most likely, there are no windows in the basement, so first of all you need to take care of sufficient lighting. If there are no stationary lamps, Waterproof portable light sources with a flexible cord of sufficient length should be used.
For the same reason, the underground space is extremely scarce natural ventilation, and sometimes it is completely absent. Unfortunately, many builders do not take this factor into account, which has an extremely negative impact on labor productivity. Exhaled carbon dioxide heavier than other gases that make up the atmospheric air, and therefore tends to the bottom.
And since the underground is the lowest point, carbon dioxide accumulates here, disrupts the worker’s full breathing, causes increased fatigue, drowsiness and, in especially severe cases, fainting. That's why it is very important to ensure sufficient supply ventilation from inside the house or from the street.
Of course, while work is being carried out in the basement, it is necessary to remove all things, food and other objects stored there that interfere with the unhindered movement of the repairman.
If there is open ground in the underground, if possible it should be leveled and compacted. In the best case, if the budget allows, pour concrete to a minimum height of 10 cm with reinforcement, thereby significantly reducing the humidity in the underground space. This will significantly extend the service life of both the load-bearing elements of the plinth and the wooden floor structures.
In the absence of natural passive ventilation of the subfloor, it would not be a bad idea to external walls small (about 10*10 cm) ventilation vents. This will improve the microclimate in the cellar, additionally prevent an increase in humidity and, as a result, avoid damage mold fungus wooden structures.
Having completed the preparatory work, first of all you need to check the condition of the load-bearing elements - beams, joists, support posts.
Having identified areas of mold damage, thoroughly clean the surface with a spatula and sandpaper (popularly called “sandpaper”), and then soak it twice with antiseptic solutions. Then all available wooden elements are generously impregnated with fire and bio- protective compounds, dry thoroughly.
If the foundation and plinth are built using concrete or brick (block), these areas must be treated with bitumen mastic to protect them from moisture. If work is carried out on days of high atmospheric humidity, there may be a need to additionally dry it using heating equipment.
In some cases, a conventional household fan heater will be sufficient, but for large underground spaces, a construction heat gun may be required. No way Do not use a gas or gasoline/diesel heat gun, it is permissible to use only an electric one, and it should not be left unattended for safety reasons.
For insulation from below, it is quite inconvenient to carry out work with rolled heat-insulating materials, such as mineral wool or isolon. Moreover, bulk materials such as sawdust, expanded clay and the like are not suitable for these purposes. Therefore, preference should be given to insulation in sheets - penoplex, polystyrene foam, and so on.
First of all, you should fix the vapor barrier material, in most cases it is polyethylene film. For underground conditions, it is preferable to choose a film with a thickness of 350 microns, if possible even denser.
It must be secured, ensuring complete adherence with a construction stapler along the joists (beams), taking into account all irregularities, bends and height differences; in places where it sags, additionally secure it along the floor boards. The film fragments must be laid with an overlap of at least 10 cm over one another, and the edges must be secured with wide adhesive tape. Overlap on the walls and vertical structures– at least 25 cm.
After this, you need to begin installing heat-insulating material in the gaps between the joists. If possible, the fragments of the insulation should be cut so that there are no unnecessary gaps between them and the joists, and the insulation itself does not fall out. If necessary, if the fragment does not hold onto the joists with its edges, it can be temporarily secured with self-tapping screws, and the gap between its edges and the joists can be filled with polyurethane foam.
It should be remembered that metal self-tapping screws have a very high thermal conductivity, so after the construction foam has hardened, they all need to be removed.
Also, after laying the heat-insulating material over the entire surface of the ceiling, all gaps that inevitably arise must be filled with polyurethane foam, and after it has hardened, the protruding excess must be cut off.
After this, to ensure more reliable retention of the heat-insulating material, you need to secure it from below with a light hem. Most economical option- fiberboard sheets, but low-grade plywood, edged boards and a number of other materials are also suitable. You should not use gypsum plasterboard ( plasterboard sheet) due to its high hygroscopicity and fragility.
After completing the filing, you should attach another layer of vapor and waterproofing. You can also use plastic film. In this case, it is permissible to use isolon, folgoizol and other composite materials.
Above
In this case, there are two options for insulation, fundamentally different from one another:
- Without dismantling the floor covering. Logs are laid on the old floor, insulation is placed between them and a new floor covering is placed on top.
- With dismantling. In this case, the boards are marked, dismantled and removed from the room where they are being repaired. The insulation is installed between the existing joists, then the floor boards are installed back.
In the first case, the floor level is raised - depending on the technology used, by a height of 10 to 25, and in some cases by 30 cm. This method is economically more expensive and reduces the usable volume of the room. But if the budget allows and the ceilings are high enough, this option can significantly reduce the time it takes to complete the work.
In the second case, the floor height remains at the same level, but more labor and time will be required from the builder.
Whatever option is chosen, before starting all work, you need to remove all the furniture from the room, clear the floor of carpet or other covering, and remove the baseboard.
First you need to check the condition of the floor boards. Elements damaged by rotting or affected by mold must be replaced, unstable elements must be fixed. Old boards need to be coated with primer and antiseptic impregnation and dried; if necessary, use additional heat sources for this.
Same as during inspection underground space areas affected by fungus, but retaining their strength, must be cleaned down to healthy wood and generously soaked in antiseptics.
Experienced builders recommend for these purposes using a composition that is practical and completely safe for humans and pets, but so unloved by rodents and wood-boring insects - cool solution of ordinary table salt. To prepare it in hot water Add salt until it stops stirring.
The areas of the board that have been previously cleared of mold from the outside are thickly spilled with hot saline solution. Any gaps found between the boards or cracks in them must be filled with construction foam, leveled on top with oil-based putty or acrylic base. After drying, lay a waterproofing material - plastic film or penofol, and glue the joints with wide tape.
After this, the logs are laid. You should choose a timber made from coniferous wood, the minimum cross-section of which is 50*50mm. However, if the floor of the lower floor is insulated and enhanced thermal insulation is required, then, accordingly, a beam of a larger cross-section is required.
Preferably dried timber without visible deformations (without bending along any axes), chips or other damage. It is important to take into account that there should be a gap of 1 - 2 cm between the insulation and the top board for natural microcirculation of air and humidity compensation, therefore the height of the material for the logs must be calculated with a margin.
As a frame, in addition to timber, it is permissible to use edged board from 50 mm thick of the appropriate width, installed on the edge (the wider side will be located vertically) - in this case, a more rigid fastening of the boards to the floor is required. You may need metal corners with a shelf length of at least half the width of the board: for example, if a board with a cross-section of 50*120 mm is selected for installation on an edge, then the shelf length of the metal corner must be at least 60 mm. The installation step of the corners is no more than 1 meter.
It is strongly not recommended to use unedged materials, since wane (remnants of bark) on the wood may contain larvae or even adult wood-boring insects, and, unfortunately, it is not always possible to eliminate them using bioprotective impregnations.
Installation should begin with the most high area, selected using building level. The lag laying scheme is quite simple. The step must be kept constant - from 50 to 60 cm. It should be kept as horizontal as possible, if necessary, placing hard inserts resistant to moisture and fungus underneath. The logs are attached to the floor with self-tapping screws in increments of 100-120 cm.
Heat-insulating material is placed in the space between the joists. When insulating from above, the choice is no longer limited to sheet insulation. In this case, it is possible to lay plywood of sufficient thickness on the floor rather than boards, then the floor will last even a little longer.
DIY work algorithm
Insulation from above with the dismantling of floor boards implies that the floor boards have been checked, their condition is satisfactory and they do not need to be replaced.
Before dismantling, the boards must be marked, indicating their order and orientation, since in the case of using tongue-and-groove boards or with a tongue-and-groove fastening, an error in orientation will disrupt their mutual fastening. The top side will be indicated by the surface on which the marking is applied.
Dismantling must be done with the utmost care, without damaging the material. If the boards are fastened with self-tapping screws, they all need to be unscrewed and only then lifted one at a time, starting from the edge of the room.
Finding fastening points with self-tapping screws can create some difficulty old paint if the floor has been painted. A simple method will help with this - using a magnet, perhaps from an old speaker (speaker). Although today a more powerful neodymium magnet is relatively inexpensive. Use it to find the head of the screw, use a spatula to remove the paint, and unscrew the screw.
Dismantling is performed a little differently if the boards are nailed. Under no circumstances should you try to remove nails with pliers or a nail puller; this will only lead to damage to the board. Nail heads can also be easily found with a magnet; these places are marked with a marker.
Builders of the “old school” use an ax to dismantle boards: they carefully wedge it between the joist and the board, without damaging either one, and lift the edge of the board with a slight rocking.
You can use a pry bar or a flat-tipped nail gun. There is no need to try to lift the entire board at once, wedging it with an ax in only one place, as this may cause the wood to split.
You should lift the board at each attachment point to a small height, then walk along the board again, repeating this operation. When the edge is already noticeably raised, place additional support under the tool and lift the entire board. At the same time It is important to ensure that the tongue or tongue of the board is not damaged.
Old nails need to be knocked out with a hammer from the point side, and when the nail head rises above the board, remove it using tongs or pliers. Having removed the boards, the builder opens the joists and, if their condition is satisfactory, lays plastic film using a construction stapler, fastens the joints with tape and installs heat-insulating material.
In both cases, with open joists, they should be impregnated with fire and bioprotective substances and thoroughly dried before laying the insulation.
If bulk material is used - be it sawdust, wood concrete granules, expanded clay or any other, it is necessary to carefully level the layer of insulating material, avoiding too loose laying or, conversely, excessive compaction, and fill all irregularities and cracks. When using rolled materials, you must try to cut in accordance with the geometry of the space between the joists, avoid tears and creasing, and do not leave voids.
It should be remembered that many rolled heat-insulating materials, when wet, lose their properties and turn from a heat insulator into a heat conductor. When working with sheet material you need to try to cut as accurately as possible, avoid bending the sheets, fill gaps and voids with polyurethane foam.
Upon completion of laying the heat insulator, no matter how hygroscopic the material is, you should re-lay polyethylene or other moisture-proofing film, and after that install the boards.
Materials for thermal insulation
The modern market offers enough wide choice materials for thermal insulation, and it can be difficult for an inexperienced home craftsman to choose the most suitable insulation for a wooden floor.
In addition to price, each type of material has its own advantages, and some have obvious disadvantages:
- Penoplex. Sheet insulation, produced in a fairly wide range of thicknesses. Quite durable and at the same time easily processed material with high heat-insulating characteristics, resistant to moisture and mechanical stress. For ease of installation, it is available in a tongue-and-groove version. Afraid of high temperatures and organic solvents. Unattractive to rodents and insects.
- Foam plastic. Unlike its older brother - penoplex, it is softer, less resistant to moisture, and can crumble when cut. At the same time, it has a much lower density and, as a result, a slightly greater thermal insulation ability. Unlike penoplex and EPS, it does not contain styrene, that is, it is somewhat safer when used in living rooms.
- EPPS– extruded polystyrene foam. Essentially, this is the same penoplex, but with slight differences in production technology. In terms of characteristics, it is in no way inferior to or superior to it.
- Sawdust. This bulk material is very cheap, in some cases even free, since it is actually a production waste. One of the most environmentally friendly and safe materials for humans and pets. It should be remembered that sawdust cannot be laid in its pure form, otherwise an invasion of rodents and insects cannot be avoided. Sawdust must be mixed with cement or clay, and fire retardant, antiseptic and antifungal solutions must be added. Sawdust is intolerant to dampness and, without proper treatment and moisture insulation, is easily susceptible to rotting and mold. Over time they cake, losing their insulating qualities.
- Expanded clay. Light porous bulk material made of baked clay, which is why it is absolutely harmless. Resistant to high temperatures. Expanded clay does not have closed pores, which is why it is hygroscopic and requires high-quality waterproofing.
- Penofol. It is foamed polyethylene with applied on one side (less often on both sides) aluminum foil. It has high moisture resistance and is noticeably inferior to foam plastic in terms of thermal insulation characteristics. Very sensitive to even slight heat. Not damaged by fungus, not susceptible to rotting. When using, one feature should be taken into account - the foil side should be facing the warm room.
- Izospan. High-quality material for vapor and waterproofing. Used as protection against moisture, it allows wooden structures to “breathe”, that is, it does not interfere with air exchange with the environment. Flammable Resistant to fungal attack.
- Izolon. Foamed polyethylene without foil. Due to the nature of production, it is not produced in thicknesses greater than 7 mm, therefore it does not serve as a heat insulator. practical application. At the same time, this is a high-quality waterproofing material with some sound insulating properties. Sensitive to high temperatures, resistant to fungus, not damaged by rodents or insects.
- Ecowool. Extrusion material based on cellulose. Rarely used in private housing construction, since application requires specialized equipment and trained personnel. Unfortunately, it is not uncommon for a contractor to, in order to reduce costs, violate the recipe of the original composition, as a result of which this material with high thermal insulation characteristics begins to evaporate toxic substances over time. environment.
- Polyurethane foam, like cellulose ecowool, requires specialized equipment for application. No harmful substances are used in the composition. When cured, it forms closed pores, which eliminates any evaporation of substances into the environment. It is not subject to recipe violations on the part of the contractor. Frost- and heat-resistant, not susceptible to rotting, mold, or fungal attack. It has high noise and heat insulating characteristics.
- Mineral wool. One of the most undemanding and easy to use heat-insulating materials. It is afraid of moisture, but after drying it restores its properties. Thanks to the filling mineral chips eliminates damage by rodents or insects, and the absence of organic fillers prevents rotting or mold damage. Easily wrinkled material, therefore requires careful handling
When choosing an insulating material, be sure to read the instructions for use attached to it. This document describes in detail the characteristics: thermal conductivity, permissible temperature range, humidity, and so on.
Typical errors
In some cases, builders, relying on the moisture resistance of the material declared by the manufacturer, neglect additional waterproofing. When sudden temperature changes occur in a high-humidity environment, condensation can form, as does water flowing directly from a room through cracks in the floor. When water freezes, it causes cracking or rupture of pores in the material, which sharply reduces the thermal insulation qualities.
When insulating the floor of the first floor with polystyrene foam, the material is sometimes left exposed. The fact is that mice often gnaw on polystyrene foam, taking its crumbs and “insulating” their holes with it. This approach helps to preserve the vapor barrier layer and, if necessary, update the heat insulation sheets without any problems.
It happens that a builder saves on tape and leaves the overlap of plastic film unsecured. The moisture contained in the air penetrates through the edges of the film into the mineral wool and it becomes damp. That's why It is important to ensure that workers comply with the work technology.
Examples of successful designs
Consider the following:
- A classic “pie” when insulating from above using a screed under the finished floor.
- Installation of logs “staggered”, filling with expanded clay on top of the film, covering with plywood.
- High-quality filling of gaps between joists and sheets with construction foam.
- Laying slabs in the space between the beams on top of a layer of isospan.
- The use of wide boards mounted on edge.
- Double-sided waterproofing with mineral wool.
Kirill Sysoev
Calloused hands never get bored!
Content
One of the problems of living in a private house made of wood is a cold floor. The fact is that low-temperature air currents descend downwards, and coolness also emanates from the ground. Insulating the floor covering, which is done using a variety of materials, will help make your home cozy, warm and comfortable, and protect it from freezing.
How to insulate the floor in a wooden house from below
It is known that home is the fortress of every person, so it should always feel cozy and warm. One way to transform a living space is to insulate the floor in a wooden house from below. To get a positive result, you should carefully familiarize yourself with the range of insulation products, find out the features, and choose the most best option and complete the installation.
Installation of the thermal insulation layer has several specific nuances:
- It is necessary to have two-layer insulation of the floor in a wooden house from below. It is necessary to reduce the loss of heat escaping through the rough bottom. As a rule, the floor is made of ordinary boards that are adjusted to each other. The surface will suffer from strong impact humidity and low temperature from the ground, so building materials must be treated with special means in advance.
- Given the fact that wood absorbs liquid well, waterproofing will be required. Before you begin to insulate a wooden floor, it is recommended to lay one-sided fiber.
- Products for floor insulation in a wooden house from below should not change their characteristics when in contact with wood.
Which insulation is better for the floor in a wooden house
Very often, consumers think about what material is more profitable to use to insulate a cold floor in a wooden house from below. The choice of insulation depends on the following factors: room size, type of surface, type of wood, climate, price. It’s worth saying right away that it’s expensive. finishing material not always the best in quality and may simply not be suitable for a particular building. To make the right choice, it is recommended to find out what types of insulating materials there are flooring materials, study their characteristics and advantages.
Materials for thermal insulation
Assortment modern thermal insulation very wide. Products may differ in dimensions, characteristics, installation technologies, and so on. Insulation of floors in a wooden house is often carried out with the following building materials: mineral wool, expanded clay, penofol, polystyrene foam (expanded polystyrene), polyurethane foam, sawdust, penoplex. The choice of thermal insulation layer depends on the individual preferences of the owner of the building and the characteristics of the floor covering. How to insulate the floor in a wooden house during the construction or renovation of a living space?
Mineral wool
Cold wood flooring is often insulated with mineral wool. This type of sealant is available as elastic mats or durable panels. The material must be laid in a single layer. The main advantages of mineral wool:
- high sound and heat insulation;
- long period of practical use;
- fire resistance and high humidity;
- affordable price;
- environmental friendliness;
- This insulation is resistant to damage: mechanical and chemical influences.
Polyurethane foam
The ideal sealant for wooden floors, the pores of which are closed with air and gas for insulation, is polyurethane foam. This cellular material has a small mass, but retains heat well. This insulation is most resistant to the formation of fungus and mold, is not afraid of rotting, and is not susceptible to acids. Polyurethane foam is applied using a special technique and has good adhesion (adhesion to the surface). Thanks to the use of this type of thermal insulation, it is possible to insulate a floor of any shape without creating joints.
Foam plastic
Thermal insulation of floors using polystyrene foam (expanded polystyrene) is different a large number pros. The structure of the material ensures a low level of vapor permeability and thermal conductivity, fire resistance, reliability, and resistance to chemical and biological factors. Expanded polystyrene has a long service life and retains its characteristics for a long time. The main disadvantage is that the seal absorbs a certain amount of liquid, which may affect some properties.
Penoplex
Insulation of a wooden floor is also done with penoplex - a very light polymer homogeneous material that does not put any load on the base of the building. It is produced by extrusion - forcing molten raw materials through the molding cavity of an extruder (special equipment). Penoplex is very strong, resistant to low temperatures, durable, and has minimal moisture absorption and combustion.
Expanded clay
Thermal insulation of a wooden floor can be done using expanded clay - a loose, porous product that consists of small round balls. Insulation is produced by burning slate or clay in a special oven. Expanded clay for preserving the heat of wood floors is a durable and environmentally friendly material. He has high performance sound insulation, fire resistance, frost resistance. There is one significant drawback: after a certain period of time, expanded clay becomes compacted under the weight of its own weight and loses its thermal insulation qualities.
Penofol
Roll-type insulation for wooden floors, which is made from foamed polyethylene, which is covered with aluminum foil on top - this is penofol. This seal is not very thick (3-10 mm), but it conducts heat well and does not require additional vapor barrier. Due to its composition, penofol has several disadvantages: foil can be “eaten” by rust, and polyethylene loses strength over time.
Installation technology
Reliable and effective option Laying insulation for wooden flooring from below involves installation along joists - transverse boards (beams) on which the floor covering is located.
- First, logs are attached to the brick foundation, the distance between which should be 1-1.2 meters (as in the photo).
- Chipboard or thick plywood is mounted on the beams below using self-tapping screws. This is necessary for laying thermal insulation.
- The insulating material is laid on the surface between the joists. The thickness of this layer of thermal insulation can be varied, so you need to be guided by the dimensions of the transverse boards (joists).
- Waterproofing is laid on top of the seal (for example, plastic film). This type of material is not always used, because some types of insulation are themselves resistant to moisture.
- The final stage of installation is the installation of elements of the old or new wooden floor covering on the ground floor.
