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 its strength characteristics and rot. Therefore, to make the room warm and comfortable, a number of thermal insulation works need to be carried out. In today's review by the HouseChief editors, we'll tell you how to properly insulate a floor in wooden house, which method and materials are better 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.
Extruded polystyrene foam
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. Insulating the floor of the first floor with this material requires the participation of experienced specialists and the availability of 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 than polyurethane foam, it also requires specialists 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, very important parameter is to determine the thickness of the insulation layer. It must be determined individually for each home and depends on design features building, climatic conditions of the region and type of insulating material. Calculation formula optimal thickness insulation layer is given in SNiP 02/23/2003 “ Thermal protection 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 necessary, lay thermal insulation material 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 on the installation of floor insulation, which must be observed regardless of the selected material. 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 ground 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 creates condensation upon contact with a warm surface, they begin 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 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.
Installation of a waterproofing layer Vapor barrier for floors in a wooden house
Working in the house 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, it is required mandatory presence vapor barrier layer. 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 making a choice, insulation for wooden house, it must be taken into account that each of thermal insulation 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 cross boards used for subsequent construction 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.
Installation of logs for insulation and floor installation How to properly insulate the floor in a wooden house with sawdust
The use of sawdust as a thermal insulation material is environmentally friendly and inexpensive way 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;
- Broken glass must be added to the prepared heat-insulating mixture. 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 the 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. After about a week, during the warm season, the 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.
Floor insulation with penoplex slabs 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 conducting 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 installing the floor beams, you can begin directly laying the 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
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 steps:
- If the building already has a subfloor made of, then waterproofing should be done with roofing felt or plastic film. Next are installed wooden joists with a pitch 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. Ecowool floor insulation
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 other thermal insulation materials. But there are still some differences. To insulate with expanded clay you should:
- on the subfloor even layer a sand “pillow” is poured in, 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.
Expanded clay is a lightweight and inexpensive insulation material 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 blown out polyurethane foam. It is also unacceptable to compress the insulation, such as mineral wool.
Mistake No. 3: underestimating the condition of 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
Thermal insulation of a wooden floor in a house is necessary because the main heat losses a private house carries precisely through the floor and roof. Despite the fact that wood has excellent insulating qualities, it alone is not enough to maintain comfortable temperature. Without thermal insulation in the floor, the structure will not be able to retain heat. Insulating a wooden floor in a private house is somewhat similar to similar work in the apartment. Before insulating a wooden floor, you need to select materials and installation method. The choice depends on various factors: whether the house stands on posts directly on the ground or on a foundation, whether there is a basement, how many floors there are in the house.
Materials
The choice of materials for floor insulation in a house or apartment is very rich. New insulation materials appear regularly, and insulating qualities are improved. The choice depends on the preferences of the owner, his capabilities, as well as the functionality of the room itself. Below we will look at the most popular and proven floor insulation in a wooden house, based on consumer reviews.
Mineral wool
Mineral wool is one of the most popular materials for thermal insulation. Vata happens:
- stone;
- slag;
- glass.
The main advantage of mineral wool, in addition to its excellent thermal insulation properties, is its non-flammability. In addition, Vata has high level soundproofing.
The disadvantages of such insulation are low strength and good moisture absorption. Cotton wool absorbs liquid and significantly loses its insulating properties. Therefore, when using it, great attention should be paid to vapor barrier at the bottom and top of the insulation. In addition, working with mineral wool requires compliance with safety precautions, since it itself and its dust can cause damage to health.
This also includes isovol, an insulation material made from mineral fibers. It has the same insulating properties as mineral wool, but withstands moisture much better.
Expanded polystyrene
Expanded polystyrene is also known as polystyrene foam. It occupies a leading position as a material for insulation, both in private houses and apartments. The explanation for this is a bouquet of thermal insulation qualities, affordable prices, strength and durability. Such properties are achieved thanks to the cellular structure.
The weak point of polystyrene foam is contact with water. Due to its structure, it absorbs water and deforms when temperature changes. There is extruded polystyrene foam, which has the advantages of regular polystyrene foam, but tolerates moisture better. In any case, insulating a wooden floor with foam plastic requires high-quality vapor and waterproofing.
Penofol
Penofol is one of the most modern insulation materials. This roll material, which consists of a layer of insulation, such as polyethylene foam, and a layer of thin aluminum foil. Present on the market different kinds penofol, from a variety of materials and different numbers of layers. Penofol has excellent insulating properties, has a small specific gravity and is resistant to mechanical damage. Plus, it eliminates the need for vapor and waterproofing, since foil plays this role. Penofol is often used to insulate floors in dachas and private houses; in apartments it is used to install underfloor heating systems.
Ecowool
Ecowool has high thermal insulation characteristics, does not burn, retains its properties after contact with moisture and, in addition, complements the environmental friendliness of the wooden floor in the country, as it consists of natural materials. The only drawback is its price. It can be laid on top of the old coating, outside and inside the building. It can be used as bulk material or applied by spraying with a special installation, where ecowool is mixed with water under pressure and carbon dioxide, forming a sticky mixture.
Bulk materials
Insulation of a wooden floor with expanded clay, wood concrete, shavings, sawdust - methods that have been known for a long time and have positive reviews. The peculiarity of such insulation materials is their light specific weight. They can be used both for the first floor and for the second. Among the disadvantages, one can note the labor intensity of the work.
Floor insulation methods
Floor insulation methods vary in the complexity of installation and the degree of insulation, and are selected based on means, preferences, and what is located underneath the house. Houses with a foundation made of a full foundation and brick columns on the ground will have different heat losses. The number of floors, area of the house and climate zone also play an important role in the choice.
Thermal insulation of the second floor in a private house is required if one of the floors is not heated or, as often happens, the first floor is built from more warm material than the second one. Then the temperature difference between below and above will be very large and insulation is necessary. If the design allows you to maintain the same climate throughout the house, then there is no need for floor insulation.
Double floor device
Insulation of floors in this case It's right to start from the bottom up. Therefore, first of all, logs and subfloor are installed, then work is carried out to insulate it. The first layer is a vapor barrier. Simple polyethylene can be used as a vapor barrier material. Insulation is laid on top of the vapor barrier, the denser the better. Then another layer of vapor barrier and the insulation of the subfloor is completed. This method is suitable for houses with any foundation, regardless of the presence of a basement. This kind of work can also be done in an apartment, especially on the first floor, if the ceiling height allows. Further in the video, see recommendations on how to properly arrange a double floor in an apartment
Thermal insulation over a high subfloor
The method is similar to the previous one, with the difference that the work is carried out not indoors, but outside. This method is possible if there is a basement or any space at the bottom of the house that allows access to load-bearing beams. Correct order the work looks like this:
- Laying a layer of waterproofing;
- Installation of insulation;
- A second layer of vapor barrier to protect the insulation from moisture;
- Additional layer of waterproofing;
- Sheathing with sheets of plywood, fiberboard or OSB.
Any materials except bulk materials can be used as insulation. The advantage of this method is that the floors in the room will not rise. The disadvantage is the inconvenience of installation from the outside and from bottom to top. It is also worth taking care that rodents do not make homes for themselves in the floor layers.
An example of this method of insulation from the outside can be seen in the video
This method is perfect for ground floor apartments suffering from cold floors.
Foam insulation
This method is most suitable for the second floor. First, all the cracks in the rough coating are eliminated, then logs are installed in increments of approximately 0.7 m. A layer of vapor barrier is laid on top and secured with staples. It is correct that the vapor barrier layers overlap and are secured with tape. Then all free space is covered with foam. It is recommended to seal the joints with polyurethane foam. Next, everything is covered with a layer of waterproofing, and, finally, with floorboards. Also, if the ceiling height allows, you can insulate in this way directly on top of the old floor, without dismantling.
When insulating floors in this way, not only polystyrene foam can be used, but also any other insulation materials. An example of such technology in the video
Spray insulation
A quick and affordable method of thermal insulation. Its advantage is its unpretentiousness to the application surface. Expanded polystyrene foam is applied to the subfloor, instead of, on, or under the old insulation, using special device. It penetrates into the smallest holes and has the highest insulating properties. Perfect for insulating wooden floors in a private house and apartment.
Warm floor
Universal insulation method. Suitable for flooring in country houses and apartments, installed on top of almost any surface. Its essence lies in the fact that thermal communications are laid under the finishing layer. It can be electric, water, or infrared heated floor. By the names you can understand how the heating occurs. The advantage of this floor is its unpretentiousness and versatility. Any finished floor can be laid on top of it, from linoleum to tiles.
Drastic measures for insulation
If none of the methods worked, or did not give the desired result, the most decisive method remains - insulating the base. It's difficult and long process, but, judging by the reviews, it has a clear positive effect. All work will be done outside. To begin with, along the ground around the house, close to the foundation, you need to dig a ditch about 50 cm wide and about 0.5 m deep. A screed of expanded clay concrete is made at the bottom. Then, outside, around the perimeter of the house, the insulation is attached using glue. The joints of thermal insulation sheets are sealed with polyurethane foam. Then we install formwork around the perimeter, on top of the insulation, and fill the entire space with expanded clay concrete. Thus, the house becomes insulated from the ground, and the floors from the cold. Obviously, this method is only suitable for private houses and cottages.
Alternative methods
There are several more interesting ways how to insulate a wooden floor. For example, using insulated linoleum as a finishing coating. This linoleum differs from regular linoleum in the presence of a felt or jute backing. But it’s better not to count on him as independent insulation. Insulated linoleum is an addition to an already insulated floor. The advantage of linoleum is its availability, durability and ease of installation. It can be laid directly on top of the old coating. In addition, linoleum is waterproofing.
Many people prefer to live in a wooden house. But here a completely justified question arises: how can you reliably insulate floors? In this article we will try to get a detailed answer about what materials and technologies are used for these purposes.
Nowadays, quite a large number of effective modern thermal insulation materials are presented on the shelves of construction markets. There are both natural and synthetically produced insulation materials. However, not all of them are suitable for insulating floors in a wooden house.
Types of heat insulators used
To insulate wooden floors, experts recommend choosing one of the following thermal insulation materials.
Mineral wool
This insulation is available in several types:
- Soft rolls.
- Rigid pressed slabs.
Both types are easy to install and easy to cut, which is important when installing it yourself. It is better to use slabs for single-layer insulation, but fluffy rolls can be laid in several layers; they are compacted quite well. Mineral heat insulator has the following performance properties:
These properties make mineral wool one of the leaders for use in a wooden house.
Expanded polystyrene
This man-made insulator is great for insulating foundations or wood floors that have a basement underneath. Expanded polystyrene can also be used in underfloor heating systems. This insulation has the following properties:
- Excellent thermal and sound insulation performance.
- Durability.
- Moisture resistance.
- Chemical resistance, not susceptible to the formation of fungi and mold.
- Mechanical strength, including compression.
- Easy processing and installation.
Advice! Despite its high cost, extruded polystyrene foam is very popular for thermal insulation in a wooden house. With its help you can insulate not only the floor, but also other surfaces.
Alternative insulation materials
In some cases, the use of mineral wool or expanded polystyrene is not justified. In such cases, it is better to replace them with the following heat insulators:
These materials are not basic, but they can easily replace more expensive insulation materials if necessary.
Used insulation technologies
To insulate floors in a private wooden house, you can use several methods. Let's consider available options more details.
Double floor system
This method of insulation is the most common. It is quite easy to implement, effective and reliable. This technology is as follows:
Advice! Instead of boards, you can use cheaper plywood flooring. But you will have to lay a finishing floor covering on it: linoleum, laminate or carpet, which allows you to additionally insulate the wooden floor.
Floating floor technology
The previous method has one significant drawback: it is best used at the construction stage. If the moment is missed and the house is used without insulation of the floors, then the cold will be noticeably drawn from below. Of course, you can carefully remove the boards and insulate between the joists, but this method requires a significant amount of time.
It is for insulation in a residential wooden house that floating floor technology is used, which consists of the following:
Advice! This method, due to its multi-layer nature, allows you to achieve tangible results in saving heat in the house.
Underfloor heating system
To insulate a wooden house, a heated floor system is often used. This type of heating is quite economical and has high efficiency heating This method requires a special approach to the use of thermal insulation so that heat does not escape into the basement.
The technology for installing heated floors in a wooden house is as follows:
- Due to the fact that such a system is mounted from below, it is necessary to dismantle the flooring boards.
- After the floors are dismantled, a layer of waterproofing is laid between the joists. The joists can also be covered with plastic film.
- Insulation is laid over the waterproofing. Experts recommend using special products - perforated penoplex, which has special grooves for laying electrical cables or water circuit pipes.
- Having finished installing the heating elements and performing a test run (to make sure the system is working), you can install the floor covering. These could be previously removed boards, new laminate or parquet.
Advice! If desired, you can make a concrete heated floor in a wooden house. To do this, it is necessary to lay a reinforcing mesh on the heating elements and pour cement screed. This method is most often used for styling ceramic tiles, for example, in the bathroom or kitchen.
The considered methods of insulation in a wooden house will help you decide not only on the thermal insulation materials and technologies used, but also on the upcoming scope of work. It is worth noting that almost all the work can be done with your own hands, without the involvement of specialists.
Needless to say, how important it is to insulate a wooden floor in a private house to achieve proper comfort for the people living in it. When heat is lost through the floor covering, residents constantly feel cold feet, which affects their overall well-being. It is equally important to save energy resources, up to 20% of which can be spent on heating the ground under the building. Therefore, this article is devoted to the questions correct production works on insulation of wooden floors and selection suitable materials for this purpose.
Wood floor insulation technology
We decided to start with this question because this technology is performed the same way, regardless of what type of insulation you decide to choose. The simplicity is explained by the presence of logs, thanks to which an empty space is formed between the base and the floor covering. It remains to figure out how to properly fill it with thermal insulation material and thereby insulate the floors in a village or country house.
First, a little about the design wooden floor on the ground floor in order to better understand the physics of the insulation process. Logs are load-bearing wooden beams big cross section, resting on various types of foundations:
- strip foundation;
- frame of a pile-screw foundation;
- brick pillars;
- solid concrete slab.
In the first three cases, the beams are above the ground, so to create a rough filing, cranial bars are nailed to their sides on the sides. Boards impregnated with an antiseptic are placed and fastened on them, and they serve as the basis for laying the insulation. The floor insulation scheme on the first floor of a private house is shown in the figure:
- In order for do-it-yourself floor insulation in a wooden house to comply with generally accepted technology, it is correct to proceed in the following sequence:
- The bottom lining of the joists (subfloor) is covered with thick polyethylene film for waterproofing. The canvases are laid with an overlap of at least 10 cm.
- Insulation is placed tightly and without gaps between the joists.
- A vapor barrier film is again laid on top.
- A clean floor covering with a ventilation gap is installed. When the thickness of the insulation is equal to the height of the beam, it will not be possible to create a gap and you will need to additionally install special strips - counter-battens.
For reference. Sometimes in old houses you can see how the floors are insulated from below. This method can be used when there is sufficient clearance between the first floor and the ground. Then in an old house you can not remove the floor covering, but insulate it from below and immediately attach boards directly to the beams, which is very inconvenient.
The bottom layer of waterproofing is needed to prevent water from getting inside and wind from blowing in. The upper vapor barrier will not allow moisture released inside the premises to penetrate into the thickness of the insulation, and ventilation will allow the surface of the film to be ventilated and dried. In principle, the same technology is used to insulate floors on joists lying on concrete base. Only the waterproofing film is laid directly on top of the concrete surface, overlapping the joists.
Which insulation is better to choose for a wooden floor?
It must be said that the choice of thermal insulation materials is modern market so wide that it is sometimes very difficult for a simple homeowner to understand which insulation for a wooden floor is better. Let's give a general list of the most popular insulation materials and analyze the properties of each of them separately:
- sawdust;
- expanded clay;
- basalt wool;
- polystyrene foam and extruded polystyrene foam (penoplex);
- foamed polyethylene (isolon, penofol);
Before we begin to consider all the insulation materials used for floors on joists, it is worth touching on the topic of the thickness of the thermal insulation layer. In order not to go into complex calculations, the following method for determining it is proposed: for the middle zone with a temperate climate, the thickness of the foam layer (density 25 kg/m3) should be at least 100 mm. Accordingly, in the north this figure increases to 150-200 mm, and in the south it decreases to 80 mm.
Note. Polystyrene foam is one of the most common materials, so the calculations were made based on it. Other insulation materials will differ in thickness, but it still cannot be greater than the height of the beam and this must be taken into account.
Insulation with sawdust and expanded clay
These materials are still used to this day for insulating wooden floors on joists because they are the cheapest. Another thing is that their thermal insulation properties leave much to be desired compared to modern insulation materials very low. Therefore, they should be used when the requirements for insulation are low at home or at a dacha, where people visit periodically.
For reference. For example, the thermal conductivity of penoplex with a density of 33 kg/m3 is 0.031 W/m °C, while the best indicator of expanded clay with a density of 200 kg/m3 is 0.1 W/m °C. That is, 3 times worse.
Given the high thermal conductivity, when insulating with expanded clay or sawdust, there is no point in determining the thickness of the layer; each opening between the joists is filled to the top. In this case, the sawdust should be dry and, if possible, compacted. To prevent mice from eating them, an old one is offered folk way– Sprinkle milk of lime on top.
Although sawdust decays over time, they can easily be replaced with new ones, and this is a plus. It will take more time to dismantle and reassemble the floor covering. At the same time, expanded clay is a very durable insulation material and will happily serve for as many years as the house itself lasts. By the way, expanded clay insulation is used as a combination with other materials. In this case, it is poured into the cavity between the subfloor and the ground, as shown in the diagram:
Use of mineral wool
The main advantage of mineral wool in slabs or rolls over other insulation materials is resistance to high temperatures and non-flammability, which is very important for wooden structures. In addition, rodents do not like it very much. On the other hand, the material is able to absorb moisture and at the same time sharply increase thermal conductivity. Therefore, when insulating basalt wool it must be carefully protected from water vapor using different membranes (films).
Important. You cannot use different types of glass wool inside the house. This applies to ISOVER products intended for roof insulation.
Now let’s talk about how to correctly determine the thickness of the insulation layer for the floor. Since the thermal conductivity of mineral wool is only slightly higher than that of polystyrene foam, it can be taken with a thickness of 100-120 mm for the middle zone. If you take rolled material of a lower density, then it should be laid in 2 layers.
Polymer insulation
With polystyrene foam the situation is completely opposite: it is flammable, does not absorb moisture and is loved by rodents. The last drawback can create a lot of problems in the southern regions, since mice love to make nests out of foam plastic. Therefore, it would be better to insulate the floors of a wooden house with polystyrene foam or penoplex high density. Rodents avoid these polymers, and their thermal conductivity is even better.
In addition, foam insulation will last longer, since foam plastic simply crumbles after 15-20 years. Another thing is that these materials will cost significantly more. There is one point regarding the process of laying polymer sheets itself. They must be clearly cut to size between the beams so that the insulation is inserted there tightly, no gaps are allowed. This can result in a lot of useless waste material.
As for products made of foamed polyethylene such as isolon or penofol, they are too thin and will not provide the necessary degree of insulation for wooden floors. The same penofol can be used to lay the subfloor before laying mineral wool, that is, to use the materials together. Both isolon and penofol are vapor-tight products, which means they can be used as an additional barrier against moisture penetration.
Polyurethane foam has virtually no disadvantages. It is durable, does not absorb moisture, is not damaged by rodents, and can withstand fire for some time. The thermal conductivity of insulation is almost the lowest among polymers. One problem - to apply it you need compressor equipment, which will cost you a pretty penny, you won’t be able to insulate the floor with your own hands.
Conclusion
As you can see, mastering the technology of insulating a wooden floor on joists is much easier than choosing insulation for this purpose. Which of the following is better - you need to be guided by local conditions and the size of your budget. In practice, homeowners most often introduce inexpensive options - cotton wool and polystyrene foam. If you have financial capabilities, then The best way- application of polyurethane foam.
In any private home, the main sources of heat loss are the roof and floor. Timely insulation of the floor in a wooden house will significantly reduce heat loss, improve the microclimate and reduce housing costs. Depending on the material load-bearing structure, type of foundation, glazing area and architectural features are applied various methods carrying out thermal insulation measures. This publication will tell you how to insulate a floor in a wooden house with your own hands, and what materials to use to carry out proper thermal insulation measures.
Thermal insulation schemes for the floor of a wooden house
A wooden house is considered sufficient lightweight design, which can be built on almost all types of foundations. Based various options base, the house may have a ground floor or basement, a small underground. In the case of erecting a supporting box on a monolithic foundation slab, the design of the building does not imply the presence of space under the floor at all. 
Depending on the design At home, a specific scheme for thermal insulation measures is selected:
- Insulation of the floor in a wooden house from below (from the basement side) is carried out in the presence of a technical room, basement or cellar.
- Thermal insulation from the premises is carried out if the house has a low underground or stands on a monolithic slab.
Thermal insulation of a wooden floor from the basement side
The technology for insulating the floor of a wooden house from the basement side is as follows:
All that's left is to close the space finishing coat(waterproof plywood, OSB sheets, boards, etc.) and the warm floor in the wooden house is ready.
Method of insulating a wooden floor from the room side
The difficulty of carrying out such activities lies in the mandatory dismantling of the finished flooring to gain access to the underground and support beams (joists).
If the finished floor is made of tongue and groove floorboards and is in good condition, then when dismantling it is recommended to number each one to simplify the process of reinstalling the material.
So, how to make a warm floor in a wooden house from the side of the home? The process of installing thermal insulation is relatively simple and is very similar to insulation from the cellar side, but only in reverse order:
The length of each subfloor fragment should be less step installation of logs by 10-20 mm.
Everything else is simple. Layers are laid on the subfloor: waterproofing, heat insulation, vapor barrier membrane, counter batten (to create a ventilation gap), finishing floor covering. 
As can be seen from the instructions, insulating the floor of a wooden house outside is a fairly simple, but labor-intensive process. Next, we will consider another common scheme of thermal insulation measures, in which there is no need to dismantle the finished floor covering.
“Double floor”: stages of work
This technology is suitable for wooden structures built on a monolithic concrete foundation.
It should be understood that installing a new heated floor on the wooden floor of a building will take up from 12 to 20 cm of home space, so this technology is used in rooms with “high ceilings”.
- Remove the baseboards and inspect the covering. If necessary, replace fragments of the old flooring and fill the cracks with foam.
- Install new logs across the laying of the old support beam in increments of 600-700 mm. Adjust their location so that the upper edges of the joists are strictly in the same horizontal plane.
- Cover the structure with a layer of vapor barrier membrane with an “overlap” of 100-150 mm on the walls.
- Place insulation between the new support beams. For such work, mineral wool heat insulators are most often used. Budget option Expanded clay will be used.
- Place a layer of waterproofing material on the insulation.
- Place a counter batten 15-20 mm thick along the new joists.
Install a new flooring, which can be plywood, OSB sheets, tongue-and-groove floorboard and install the baseboards.
Warm floor system
One of the options for carrying out insulation measures is to create a “warm floor” system in a private house. There are several ways to implement this project.
Laying the heating element under the screed. This method involves performing the following work:
- leveling the base;
- laying a layer of heat insulation (foamed foil polyethylene, polyethylene foam);
- heating element laying (cable, mats);
- reinforcement;
- finishing screed based on ready-made mixtures or sand-cement mortar.
It should be understood that each base can withstand a mass of about 300 kg/m2. That is why the technology of creating a “warm floor” system in a wooden house without screed is very popular among our compatriots. This design does not overload the floor and practically does not “steal” the useful space of the living room.
Please note that electrical systems must fully comply with all requirements fire safety and not be heated above 27°C and have a power of no more than 10 W/m of cable length.
The "warm floor" system is installed on wooden base into the space between the joists. How to make a “warm floor” on a wooden floor with your own hands?
- Inspect the old base and repair if necessary.
- Install logs on the wooden floor in 60 cm increments.
- Place between the joists metal mesh and thermal insulation. The thickness of the layer is ¾ of the height of the log. Perfect option– foamed foil polyethylene with the metallized layer facing up.
- Lay out and fix on the grid a heating element, install a temperature sensor (in the corrugated pipe).
- Lay the flooring.
It is important to remember that the heating cable is electrical systems The “warm floor” should not be located closer than 3 cm from any wooden structures, including the finishing coating.
Insulation for wooden floors
Today, domestic construction market offers huge selection thermal insulation materials, among which the greatest demand is:
Another representative of “new technologies” is foamed polyethylene (penofol), which has the same advantages as izolon. There are types of penofol with a self-adhesive side, which facilitates installation of the material during repair and construction work.
Video review of thermal insulation materials
