Floor insulation in a wooden house: we do floor insulation in the house with our own hands. Proper floor insulation in a wooden house How to insulate floors in a wooden house from the outside

20.06.2020

The floor is considered the coldest part of the house, especially when it comes to a country wooden structure. There is nothing surprising in this, the usual laws of physics: warm air rushes up, and cold air creeps along the bottom, besides, drafts blow through the legs from the cracks between the cracked floorboards.

A solid foundation, four strong walls and a reliable roof - this is only part of a comfortable suburban housing. In order to reduce heat loss as much as possible, floor insulation should be carried out in wooden house.

The functions of this action are very clear: saving from 20% to 30% of heat, a significant reduction in humidity, preventing mold, reducing the cost of organizing a furnace, gas or electric heating. A solid, warm floor will make your life in a wooden house in the bosom of nature as pleasant as possible. You will feel comfortable both in the gloomy off-season and in the 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 heaters, which are poured in a layer over the floor rough flooring, which serves as an auxiliary base.

These materials have sufficient hygroscopicity, they protect the wood from decay, the appearance of fungus and microorganisms, and also provide air movement. However, this method of thermal insulation has a significant drawback: loose non-metallic heaters lose their hygroscopicity over time.

Introductory video guide

Country house made of logs or timber - environmentally friendly clean dwelling, therefore, environmental requirements are also imposed on materials for its insulation. This will help preserve the unique natural aura! Previously, for floor insulation, they were widely used sawdust, granulated sawdust insulation, sawdust concrete, wood concrete, as well as foam. But today there are more convenient and efficient materials which are also environmentally friendly.

Currently, manufacturers produce a wide range of heat insulators. They offer to insulate the floors in a wooden house with mineral wool made on the basis of basalt, stone chips or slags, ecowool made from cellulose, fiberglass, polystyrene foam, polystyrene foam, penofol, isolon and other modern materials. Usually they are also used for thermal insulation of walls, attic and roofing. Each insulation has its own characteristics, therefore, when choosing a material, you need to consider its pros and cons.

At the same time, there are General requirements to all heat insulating materials. They should be light (not weighing down the structure of a wooden structure), durable, safe, easy to install and, of course, have low thermal conductivity.

Insulation is selected taking into account the parameters of the building, while avoiding heat leakage is possible 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, incombustibility, 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 comply with environmental requirements has a yellowish tint, and mineral wool has a brownish tint.

Expanded polystyrene and foam – modern materials, which are sprayed onto the surface of the auxiliary floor and fill the space between the lags. They are distinguished by such qualities as profitability, low thermal conductivity, minimum water absorption, shape and volume stability, environmental friendliness, biostability, efficiency and durability.

Due to their low cost and ease of use, expanded polystyrene and foam plastic are used in wooden houses for floor insulation and other structures. High-quality polystyrene foam must be absolutely dry, without the presence of volatile compounds, which, when the temperature rises, can be released 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- flooring of the subfloor along the logs. 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 insulator material can be used.

Such a floor is made of wooden shields or unhewn boards approximately 25x150 mm in size. You can also use boards that are left over from the foundation formwork for these purposes, provided they are in good condition. In any case, the tree is recommended to be pre-treated with an antiseptic composition.

Lay down first wooden logs, not reaching the walls for about 2-3 cm. They are either installed by the method of a T-shaped cut into a log house, or laid on a foundation, brick posts or a wooden lining at a distance of 0.6-1.0 m from each other. A cranial bar with a section of no more than 50x50 mm is attached to the lags with the help of screws, then shields or draft boards are nailed to it from below, making sure that there are no large gaps between them.

Stage 2- installation of insulation. Sheet, slab or roll heat-insulating material (foam, glass, eco-, mineral wool, etc.) is tightly laid on a wooden base between the lags, and the remaining gaps are filled mounting foam. Sometimes such a heater 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 without fail is carried out when warming the wet rooms of 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 a heater. At the same time, it can be dispensed with in the case of the use of sprayed heaters.

Waterproofing is divided into impregnating, painting and pasting. Pasting materials include polyethylene films, PVC membranes, glassine, roofing felt, isoplast, etc. Film waterproofers perfectly protect the fibrous insulation from the penetration of condensate and soaking with moisture.

Sheets of vapor barrier film are laid on top of the thermal insulation layer with an overlap of about 15 cm, and the edges are folded over by about 10 cm and attached to the logs. Joints and gaps formed are glued with metallized adhesive tape. Sometimes two layers of moisture-resistant film are laid: waterproofing - on the subfloor, vapor barrier - on the insulation.

Stage 4- Laying the finishing floor and its finishing. 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 device, specially processed boards 9.8-14.5 cm wide and 3.0-4.4 cm thick are used, having longitudinal grooves on the underside to ensure natural ventilation.

Video guide to floor insulation in a wooden house

It is not recommended to use non-edged boards for laying the finished floor, because before laying they will need to be prepared: chop off the wane with an ax, plan front side. This is a rather laborious process that takes time and effort. Sometimes wood fiber boards (MDF) and a soundproof coating are placed on top of the boards.

To enlarge, click on the picture

as finishing finishing materials finishing insulated floor in a wooden house using paint and varnish or slabs, linoleum, carpet. They are laid according to generally accepted rules governing the installation of these materials, and then skirting boards, or profiled rails, are mounted along the joints with the walls. In straight sections they are connected at an angle of 90 degrees, and in the corners - at an angle of 45 degrees.

Profiled rails are pressed tightly against the floor and walls and fastened with 75 mm nails, keeping a distance of 60-70 cm between them. Also, the nails must be driven into the junctions of the skirting boards.

Everyone wants to live in a warm, comfortable and cozy home. But not all people initial stage building houses are thinking about thermal insulation. If it was decided to build a house from natural wood, then it will delight you with its high thermal insulation qualities, the natural smell of wood, and durability. Insulation of the floor from below in this is simply necessary.

There are many options for insulating floors. TO basic materials relate:

dry screed;
glass wool;

Let's look at them in more detail and talk about each option separately, as well as their advantages and disadvantages.

Attention: holding capital works in wooden buildings, when insulating walls and floors, it is only necessary after complete shrinkage of the building. As a rule, the shrinkage of a new house takes about a year. And if the house was built from, then shrinkage can be delayed for 5-7 years.

When choosing a material for insulation, it is necessary to take into account such characteristics as:

thermal conductivity;
moisture resistance;
thickness and weight;
environmental friendliness and safety;
fire resistance;
price.

The choice of material also depends on where and on what surface you place it: from below or above, from the basement side, to insulate the attic floor or inside the rooms.

It is best to consult qualified builders before making your final choice.

Warming with mineral wool

Most often, people resort to warming with mineral wool. This is explained:

high heat and sound insulation qualities;
long service life;
affordable cost;
resistance to high humidity and fire;
environmental friendliness.

Also, the advantages of mineral wool include its resistance to various types of damage both mechanical and chemical. Mineral wool has a wide range of applications. But if you plan to use it to insulate the basement, where there is high humidity, then this is not the best option. For such premises, it is better to choose synthetic materials that are more resistant to moisture, such as polystyrene foam, polystyrene and others.

Foam insulation

As for the foam, this material also has a number of advantages and positive qualities. The special structure of the material provides low level thermal conductivity and vapor permeability.

Also foam is refractory, differs in reliability and resistance to mechanical and chemical damages. It has a high level of operation, simple and convenient to operate.

note

The foam is not breathable.

Insulation with sawdust

Sawdust is considered the traditional method of floor insulation in wooden buildings. They differ affordable and low cost and ease of use. But keep in mind that this material does not deteriorate after a few months of operation, it must be carefully prepared.

Important: Freshly sawn sawdust is not suitable for thermal insulation of floors.

They must be stored in a dry and well-ventilated area for at least 6 months before use. To prevent mice and other pests from getting into the sawdust, add slaked lime to them.

Sawdust is mixed with lime in a ratio of 1: 4 and poured into the space between the finishing and subfloor. To achieve the maximum effect, it is necessary to make a layer of at least 20 cm.

TO benefits the use of sawdust can be attributed to them:

naturalness and safety; low cost;
high thermal insulation qualities.

How to insulate with expanded clay

As for thermal insulation, this method is also widely used in our country. This material is: natural and safe, light, strong and durable. It perfectly absorbs moisture. To make the embankment more dense, it is necessary to apply 2 fractions of expanded clay: sand and gravel.

Styrofoam

Insulation with polystyrene foam is one of the most modern methods. This material is similar to foam, but it is more durable. Styrofoam does not pass not only moisture, but also steam. It is an excellent waterproofing agent. It is used not only for the insulation of wooden houses, but also for roads and concrete foundations.

Dry screed

Warming with a dry screed is applied only after the shrinkage process of the wood. The advantages of dry screed include:

excellent thermal insulation performance;
fire resistance;
ease of installation;
small thickness of the material;
excellent soundproof qualities.

Dry screed does not tolerate high humidity and under its influence is deformed. This does not affect the thermal insulation qualities of the material in any way, but it can lead to damage to the finish coating.

glass wool

As for glass wool insulation, the positive characteristics of this material include: incombustibility, ease of use and environmental safety.

But be aware glass wool shrinks, due to which the integrity of the heat-insulating layer may be violated.

Proper insulation along the lags

Any insulation in a private house with your own hands should be carried out in accordance with building codes and rules. All thermal insulation works are complex and are aimed at preventing the ingress of cold air into the room.

Floor insulation is carried out only after all basements and basements are insulated. Lag insulation is one of the most common methods.

Before starting the workflow, you must:

Remove old flooring.
For clean, dry and flat surface logs are laid, which are pre-treated with an antiseptic.
The insulation of your choice is placed between the lags.
The top is waterproofed.
Next, a board, plywood, fiberboard or chipboard is laid on the logs.

Arrangement of a double floor

This method is suitable for buildings with high ceilings:

Remove the old skirting boards, inspect the wooden support elements for damage and fill the gaps with construction foam.
Fix the wooden logs in increments of 60-90 cm.
Check the horizontal lag. If they deviated from the horizontal, use a planer to get rid of excess wood.
From above, the surface of the base must be covered with moisture-proof material.
Next, the insulation of your choice is laid between the lags.
Thermal insulation is covered with a waterproofing film.
Carry out the installation of flooring elements.
Lay the cover and attach the skirting boards.

Features of thermal insulation of the first floor

Because natural wood prone to deformation, cracks may form in the floor over time. Therefore, the following work needs to be done:

Remove old floor covering.
Inspect the log for rotting or deformation and replace rotten beams if necessary.
Fill or lay insulated.
Lay a vapor barrier.
Carry out the installation of the final floor covering.

A cake made of additional vapor and heat-insulating layers will provide good and reliable protection against condensate and drafts.

Features of thermal insulation of the second floor

To insulate interfloor floors in a wooden house, roll materials should be used.. They are lighter in weight and do not carry loads on structures. To create a heat-insulating cake on the second floor, you will need to do the following:

Put the heater on the base.
Fix the heat insulator to the wooden base.
Seal the seams with masking tape.
Apply top coat.

concrete floor insulation

To insulate a concrete floor, it is necessary to create multilayer construction. This process is carried out in several stages:

the first stage is carried out before pouring the rough screed;
the second stage is carried out during the arrangement of the concrete structure;
the third stage - before laying the finish flooring.

As practice shows, this technology prevents heat loss.

Attic floor insulation

To insulate the attic, you can use any heat insulators. Before laying the heat-insulating layer in the attic, it is necessary to make a frame from a bar. Next, we proceed to the arrangement of the vapor barrier and put the insulation.

As an attic floor insulation, mineral wool or glass wool is perfect.

How to calculate the thickness of the insulation

note, the choice of thermal insulation layer plays an important role. The thickness of the materials is calculated individually for each individual building and depends on climatic conditions, features of the building and the type of insulation you have chosen.

Summing up, it can be noted that it is possible to insulate the floors in a wooden house on your own. The main thing is to choose the right Consumables, familiarize yourself with the basic technologies and the laying scheme and prepare the tools.

Useful videos

In the video below, see the option of floor insulation along the logs in a wooden house:

This video highlights a common floor insulation mistake - condensate, wet insulation:

Video - floor insulation with penoplex along the logs:

How to insulate floors with polystyrene foam, what tools are needed, all the technology - see the video below:

If you follow all the norms and rules of the insulation device, then you can cope with the tasks in a fairly short time.

There are several floor systems for a wooden house, both typical and quite specific. Today we will analyze the most popular of them in terms of the most profitable way of warming. Let's talk about materials, cake and carrier system.

Classic floor plan

Initially, the floors in wooden houses were bulk, which did not have a very good effect on the life of the residents and the efficiency of cleaning. Therefore, they began to deepen the floor inside the house and prepare a dense incompressible bedding. Logs or sleepers were laid on top of it with a half-wood cut and a staggered dressing pattern, and a plank shield of the main covering was already laid on top, which was then leveled, along the way filling up the cracks.

Such a floor, with all the simplicity of its device, has one drawback: it is cold and, in terms of heat saving, is slightly better than open ground. Therefore, more and more often a system of transverse lathing or undermining under beams began to be arranged for free air circulation. The floor did not adjoin the walls and the stove closely, due to which room air circulated under it, equalizing the temperature difference between the wood and the soil to an average value of 15-20 ºС.

Unfortunately, this approach works only with the abundance and availability of fuel. Modern fireplace and radiator heating systems, designed to save energy, do not provide proper heating. In addition, the floor level in the house was below ground level, which caused trouble during the floods, and the need for free circulation near the walls did not allow the junction to be closed with a plinth.

Yet such primitive systems provided the basis for two typical wood flooring techniques that find their way into most building projects. Their main difference is the use of highly efficient insulation techniques, which would be impossible without a well-thought-out carrier system that allows you to correctly place and fix the heat-insulating material without losing the height of the premises.

Floor with subfloor on piles

It is possible to slow down the transfer of heat from the wooden flooring to the ground by increasing the air gap and covering the ground with even a small layer of material that does not transfer heat well.

The floor in this case is arranged in the same way as floating on a continuous backfill, but at the same time, a rigid support is installed under each intersection of the lag. V modern construction the implementation of such a system is undertaken by piles: screw or manufactured using TISE technology.

At the same time, the ground in the building is significantly underestimated, which is quite normal for an old, well-established log house without a foundation with logs in girth. In a more modern MZLF, exposing one face of the foundation is unacceptable - twisting and lateral loads arise, for which working reinforcement is almost never provided. Therefore, the floor log system is installed in two levels: the first with bars in the spacer inside the tape, and the second with boards on the edge, over the tape and the log.

If it is not planned to warm up the subfloor by circulating room air, the top row of logs is covered with synthetic burlap, supported by planks stuffed on the bottom row. Insulation, including loose insulation, can be placed in the cells of the floor lag. If necessary, to increase its thickness, a counter-lattice is stuffed.

To reduce the volume of removed soil and support the foundation, a dump meter wide and 40-50 cm high is left under it, but not closer than 20 cm to the back surface of the boards. As a heat-cutting fill, both expanded clay or perlite mixed with lime, as well as more natural materials, can be used. For example, reeds, straw or moss, dried and sprinkled with dry sand, then laid on a layer of waterproofing.

Floor frame system

When constructing a wooden house on a pile-grillage foundation, the option with an underground disappears by itself. This requires a system that is able to reliably lock the heat inside and allow the use of underfloor heating even under the influence of natural convection.

The problem is solved by installing a crown of logs on the foundation, knocked down like a frame for a floating floor: with a hem and a run. These logs play the role of a second grillage, but they have a smaller cell - about 100-120 cm versus 4-5 meters for concrete beams under load-bearing walls. When laying logs on top of the grillage, they are separated by several layers of waterproofing and a windproof membrane with good vapor permeability is stretched.

The next task is to knock the wind protection with slats to the bottom surface of the log. Although you can get to the lags through the ventilation gap under the grillage, working in cramped conditions and in poor lighting is another challenge. Do not fasten the planks with self-tapping screws, they will wind the wind protection around themselves. Instead, take a 10 mm shingle and small ruff nails.

The floor insulation has the same thickness as the logs of the wooden grillage. Mineral filler with a low density is usually used here; in the classic version, these are several layers of rolled wool. To support heavier materials, the cell can be upholstered from the inside with a polymer mesh or wired around press washers.

1 - strips of filing wind protection; 2 - logs; 3 - wind protection; 4 - mineral insulation; 5 - vapor barrier; 6 - sandwich panel

With a thickness of beams from 120 mm, after laying the insulation, they can be covered with a vapor barrier, and then the floor can be laid with sandwich panels with a mineral or polymer core. In the floor system, logs from boards on the edge can also be provided if the thickness of the insulation is not enough according to the results of the heat calculation.

Floor in bathrooms

The biggest problem in a wooden house is the need to cast a preparatory screed. And if for floor heating the accumulating screed is cast after the installation of a compensation layer over the subfloor with total waterproofing, then how to underestimate the floor in the bathroom by the required 50 mm?

It is impossible to do without intervention in the floor system. In frame houses, the bathroom is arranged in a separate grillage cell, but it is cast deaf, possibly with transverse ribs. The depth of the cell should be sufficient for laying the required amount of synthetic insulation, wiring the drain system and, at least partially, rough plumbing.

Then the classic scheme of a frame floor with a screed operates: logs and flooring or SIP, waterproofing, pouring a cement-sand mixture or expanded clay concrete with lightweight reinforcement. A separate plus of such a system is the ability to easily arrange a common drain for the floor.

1 - cranial bar; 2 - boardwalk; 3 - lag; 4 - vapor barrier; 5 - insulation; 6 - OSB flooring; 7 - waterproofing; 8 - reinforced screed

In houses on a strip foundation, the same principle. If the walls of the bathroom are capital, at least a tape is poured under them, separating the insulated screed in the bathroom from the main floor system. If we are talking about prefabricated partitions, they are built on the flooring of the subfloor, the end is closed with a board and again an insulated screed is poured over the ground.

The difference in the use of heaters

Since mineral and polymer foam heaters are now being promoted by manufacturers equally diligently, the specifics of working with them are modestly silent. The key criteria for choosing a material for insulation are resistance to heat transfer, resistance to wetting, fire hazard and the likelihood of pests settling under the floor.

Expanded polystyrene and polyurethane foam provide benefits in terms of durability and insulation efficiency. They can harmlessly take over the dew point, even when sealed in a cake. The only negative is the price: insulation will cost about a third more, and the more affordable PSB is toxic when heated and requires protection from rodents.

Mineral insulation is very sensitive to moisture saturation. If they are operated at the border of two temperatures, then from the side of the room they must be insulated with a vapor barrier and limit the circulation of street air through the wool.

Currently, eco-friendly low-rise construction of houses from wood materials is becoming increasingly popular. Traditional log cabins made of rounded logs, cottages made of timber and even houses built from lightweight materials, their owners try to sheathe them with a board or clapboard. The same considerations, in order to create a microclimate closer to nature in a dwelling, are also guided by the choice of material for floors, giving preference to wood as a lighter, but sufficiently durable material.

Due to its natural origin, wood has a rather low thermal conductivity, but in the conditions of the Russian climate it still needs additional thermal insulation.

Options

There is a fairly large selection of fillers for insulation of interfloor ceilings, floors and ceilings. It can be difficult for an inexperienced builder to understand the properties of one or another insulation, objectively assess their advantages and disadvantages, and make the right choice.

The thing is that different heat-insulating materials are more applicable for some operating conditions and less suitable for others. Insulation of such specific premises as attic, underground, veranda requires a special approach, so it is worth studying all the properties of materials in order to produce the insulation device as efficiently as possible.

The following factors influence the choice of heat-insulating material:

Humidity. Constant indoor dampness (basements with open ground or insufficient foundation waterproofing, bathrooms, winter gardens or home greenhouses) or the likelihood of increasing humidity in it (balconies, rooms for drying clothes, bathrooms or steam rooms);
Purpose of the premises. Some types of materials contain certain resins or adhesives in their composition, which, 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 appeal to rodents, while others are repulsive to them.
Lower and upper temperature limits. Some thermal insulators are not resistant to severe frosts, while others lose their properties or are completely deformed and become unusable with significant heating.

It should be borne in mind that the heat-insulating material should “work in both directions” - not only protect the home from low temperatures in winter, but also maintain a comfortable environment for humans and pets in the summer heat.

Last but not least, the general condition of the house also affects the choice of insulation and the method of performing thermal insulation:

the age of the building - in an old house one method is required, in a newly built one - another;
foundation construction method - on bored or screw piles, on reinforced concrete blocks or on light foundations of small depth;
the number of storeys of the building and the site of work - whether the floor is insulated for the 1st or 2nd floor.

Bottom

In most cases wooden houses they build 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 erecting low-rise buildings on shallow piles. But even there, in most cases, they try to comply with 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, it will be necessary to remove the floor board to the log or other supporting structure.

Thus, it is possible to insulate from below with a sufficiently high subfloor for the first floor or insulation of the floor of the second floor, which, accordingly, is the ceiling for the first floor.

The performance of 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 the minimum comfort and the necessary level of security.

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 on a flexible cord of sufficient length should be used.

For the same reason, in the underground space, there is extremely meager 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 is heavier than other gases that make up atmospheric air, and therefore tends to the bottom.

And since the underground is the lowest point, carbon dioxide accumulates here, disrupts the full breathing of the worker, causes increased fatigue, drowsiness and, in especially severe cases, fainting. So it is very important to ensure sufficient supply ventilation from inside the house or from the street.

Of course, for the duration of the work in the basement, it is necessary to remove all things stored there, products and other objects that interfere with the free movement of the repairman.

If in the subfield open ground, if possible, it should be leveled and compacted. In the best case, if the budget allows, pour concrete at least 10 cm high 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 basement and the wooden floor structures.

In the absence of natural passive ventilation of the subfloor, it will not be superfluous to make outer 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, it is required to check the condition of the supporting elements - beams, logs, support posts.

Having identified areas of mold damage, carefully clean the surface with a spatula, sandpaper(popularly called "skin"), and then soak twice with antiseptic solutions. Then all available wooden elements abundantly impregnate 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 bituminous mastic to protect against moisture. If the works are carried out on days of high atmospheric humidity, it may be necessary to additionally dry them using heating equipment.

In some cases, a conventional household fan heater will suffice, but with large spaces subfloors may require a building heat gun. In no case do not use a gas or petrol / diesel heat gun, it is permissible to use only electric, and that should not be left unattended for safety reasons.

For insulation from below, it is rather inconvenient to perform work with rolled heat-insulating materials, such as mineral wool or isolon. And even more so, bulk materials are not suitable for these purposes - sawdust, expanded clay and the like. Therefore, preference should be given to insulation in sheets - foam, foam, and so on.

First of all, it is necessary to fix the vapor barrier material, in most cases it is a polyethylene film. For underfloor conditions, it is preferable to choose a film with a thickness of 350 microns or more, if possible even denser.

It must be fixed, observing a full fit. construction stapler along the logs (beams), taking into account all irregularities, bends and height differences, in places of sagging, additionally fasten along the floor boards. Fragments of the film must be laid with an overlap of at least 10 cm on one another, fasten the edges with a wide adhesive tape. Overlap on walls and vertical structures - at least 25 cm.

After that, you need to proceed with the installation of heat-insulating material in the intervals between the lags. If possible, fragments of the heat insulator should be cut so that there are no extra gaps between them and the lags, and the insulation itself does not fall out. If necessary, if the fragment does not hold the edges of the logs, it can be temporarily fixed with self-tapping screws, and the gap between its edges and the logs can be filled with mounting foam.

It should be remembered that the metal self-tapping screw has a very high thermal conductivity, therefore, after the building foam has hardened, they must all be removed.

Also, after the flooring of the heat-insulating material over the entire surface of the ceiling, all inevitably arising gaps must be filled with mounting foam, and after it has hardened, cut off the protruding excess.

After that, to ensure a more reliable retention of the heat-insulating material, it is necessary to fix it from below with a light filing. The most economical option is fiberboard sheets, but low grade plywood, edged boards and a number of other materials are also suitable. Do not use GKL (gypsum plasterboard) due to its high hygroscopicity and fragility.

After completing the filing, you should fix another layer of vapor and waterproofing. You can also use plastic wrap. In this case, it is permissible to use isolon, foilizol and other composite materials.

Above

In this case, there are two options for insulation, radically 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 taken out of the room where they are being repaired. The insulation is mounted between the existing joists, then the floor boards are installed back.

In the first case, the level of the floor rises - depending on the technology used, by a height of 10 to 25, and in some cases even 30 cm. This method is more cost-effective 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 to complete the work.

In the second case, the floor height remains at the same level, but the builder will need more work and time.

Whichever option is chosen, before starting all work, all furniture must be removed from the room, the floor must be freed from carpet or other covering, and the baseboard must be removed.

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. On the old boards, you need to apply soil, antiseptic impregnations and dry, if necessary, use additional heat sources for this.

As with the inspection of the underground space, areas affected by the fungus, but retaining their strength, must be cleaned to healthy wood and soaked abundantly with antiseptics.

Experienced builders recommend using for these purposes a composition that is practical and completely safe for humans and pets, but so unloved by rodents and woodworm insects - a cool solution of ordinary table salt. For its preparation in hot water salt is added until it stops stirring.

The parts of the board previously cleaned from mold damage from the outside are thickly spilled with hot saline. The gaps found between the boards or cracks in them must be filled with construction foam, leveled on top with an oil or acrylic-based putty. After drying, lay a waterproofing material - a plastic film or penofol, glue the joints with a wide adhesive tape.

After that, the lags are laid. You should choose a timber from coniferous wood, the minimum section of which is 50 * 50mm. However, if the floor of the lower floor is insulated and at the same time enhanced thermal insulation is required, then, accordingly, a beam of a larger section is required.

Dried timber is preferred without visible deformations (without bends along any of the axes), chips and other damage. It is important to consider that between the insulation and the top board there should be a gap of 1 - 2 cm for natural air microcirculation and humidity compensation, so the height of the material for the log must be calculated with a margin.

As a frame, in addition to timber, it is permissible to use edged board thickness from 50 mm of the corresponding 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 section of 50 * 120 mm is selected for installation on an edge, then the length of the shelf 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 larvae or even adults of wood-boring insects can be preserved in wane (bark residues) on wood, and, unfortunately, it is not always possible to eliminate them with the help of bioprotective impregnations.

Start laying from the highest area selected with building level. The lag laying scheme is quite simple. The step must be kept constant - from 50 to 60 cm. Horizontalness should be observed as far as possible, if necessary, placing rigid inserts resistant to moisture and fungus from below. 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 lags. When insulating from above, the choice is no longer limited to sheet insulation. In this case, it is possible to lay not boards on the floor, but plywood of sufficient thickness, then the floor will last even a little longer.

Do-it-yourself algorithm

Insulation from above with the dismantling of the 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 tongue-and-groove boards or tongue-and-groove fastening, an orientation error will violate their mutual fastening. The indication of the upper side will be the surface on which the marking is applied.

Dismantling must be done with the utmost care, without damaging the material. If the boards are screwed 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.

Some difficulty in finding attachment points with self-tapping screws can create old paint if the floor has been painted. A simple way will help with this - using a magnet, possibly from an old speaker (column). Although today a more powerful neodymium magnet is relatively inexpensive. With its help, there is a self-tapping screw head, the paint is peeled off with a spatula and the self-tapping screw is unscrewed.

Dismantling is performed a little differently if the boards are nailed. In no case should you try to remove the nails with pliers or a nail puller, this will only damage the board. Nail heads are also easily located with a magnet, these places are marked with a marker.

The builders of the “old school” use an ax to dismantle the boards: they carefully wedge it between the lag and the board, without damaging either one or the other, and lift the edge of the board with a slight wiggle.

You can use a pry bar or a flat-tipped nail puller. There is no need to try to lift the entire board at once, wedging with an ax in only one place, the wood can split from this.

It is necessary to raise the board at each attachment point to a small height, then go along the board again, repeating this operation. When the edge is already noticeably raised, place an additional support under the tool and raise the entire board. Wherein it is important to ensure that the tongue or tongue of the board is not damaged.

Old nails must be knocked out with a hammer from the side of the point, and when the head of the nail rises above the board, remove it with tongs or pliers. Having removed the boards, the builder opens the logs and, if their condition is satisfactory, lays a plastic film using construction stapler, fastens the joints with adhesive tape and mounts the heat-insulating material.

In both cases, with open logs, they should be impregnated with fire and bioprotective substances and dried thoroughly before laying the insulation.

If bulk material is used - whether it be 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, fill in all irregularities and cracks. In the case of using rolled materials, you should try to cut in accordance with the geometry of the space between the lags, avoid tearing and crushing, and do not leave voids.

It should be remembered that many rolled heat-insulating materials lose their properties when wet and turn from a heat insulator into heat conductors. When working with sheet material you need to try to cut as accurately as possible, avoid bending sheets, fill gaps and voids with mounting foam.

At the end of the laying of the heat insulator, regardless of how hygroscopic the material is, it is necessary to lay a polyethylene or other moisture-proof film again, and only after that mount the boards.

Thermal insulation materials

The modern market offers a fairly wide selection of materials for thermal insulation, and the inexperienced home master it can be difficult to choose the most suitable wood floor insulation.

In addition to the 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. Sufficiently 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.
Styrofoam. Unlike the older brother - penoplex, it is softer, less resistant to moisture, and can crumble when cutting. At the same time, it has a much lower density and, as a result, a somewhat greater heat-insulating ability. Unlike penoplex and EPPS, it does not contain styrenes in its composition, that is, it is somewhat safer when used in living rooms.

EPPS- extruded polystyrene foam. In fact, this is the same penoplex, but with slight differences in production technology. In terms of characteristics, it is neither inferior nor superior to it.
Sawdust. This bulk material is very cheap, in some cases even free, as it is actually a waste product. 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 the invasion of rodents and insects cannot be avoided. Sawdust must be mixed with cement or clay, while adding fire retardant, antiseptic and antifungal solutions. Sawdust is intolerant of dampness and, without proper processing and moisture insulation, is easily susceptible to rotting and mold damage. Over time, they become caked, losing their insulating qualities.
Expanded clay. Lightweight 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 needs high-quality waterproofing.

Penofol. It is a foamed polyethylene with aluminum foil applied on one side (less often on both sides). It has high moisture resistance, in terms of heat-insulating characteristics it is noticeably inferior to polystyrene foam. Very sensitive to even slight heat. It is not damaged by a fungus, it is not subject to rotting. When using, one feature should be taken into account - the foil side should be facing a warm room.
Izospan. quality material for steam and waterproofing. Used as a moisture barrier, it allows wooden structures"breathe", that is, does not interfere with air exchange with the environment. combustible Resistant to fungal attack.
Izolon. Foamed polyethylene without foil. Due to the peculiarities of production, it is not produced with a thickness of more than 7 mm, therefore, it does not have a heat insulator practical application. At the same time, it is a high-quality waterproofing material with some soundproofing properties. Sensitive to high temperatures, resistant to fungus, not damaged by rodents or insects.

Ecowool. Cellulose-based extrusion material. It is rarely used in private housing construction, as it requires specialized equipment and trained personnel for application. Unfortunately, it is not uncommon for a contractor to violate the formulation of the original composition in order to reduce the cost, as a result of which this material of high thermal insulation characteristics eventually begins to evaporate toxic substances in environment.
polyurethane foam, like cellulose ecowool, requires specialized equipment for application. Not included in the composition harmful substances. During hardening, it forms closed pores, which excludes any evaporation of substances into the environment. On the part of the contractor is not subject to violation of the recipe. Frost- and heat-resistant, not subject to rotting, mold, 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 with mineral chips, it 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, it is imperative to read the instructions for use attached to it. This document details the characteristics: thermal conductivity, allowable temperature range, humidity, and so on.

Typical mistakes

In some cases, builders, relying on the moisture resistance of the material declared by the manufacturer, neglect additional waterproofing. Rapid temperature fluctuations in high humidity environments can cause condensation to form, as can water flowing directly from the room through cracks in the floor. When freezing, water causes cracking or rupture of pores in the material, which drastically reduces the heat-insulating qualities.

When insulating the floor of the first floor with foam, the material is sometimes left open. The fact is that mice often gnaw on foam plastic, taking away its crumbs and “insulating” their holes with it. This approach helps to preserve the vapor barrier layer and, if necessary, update the heat insulator sheets without any problems.

It happens that the builder saves on adhesive tape and leaves an overlap polyethylene film loose. The moisture contained in the air penetrates through the edges of the film into the mineral wool and it becomes damp. So It is important to monitor compliance with the technology of work by employees.

Examples of successful designs

Consider the following:

The classic "pie" when insulated from above with the use of a screed under the finished floor.

Installation of the log "in a row", backfilling with expanded clay on top of the film, covered with plywood.

High-quality filling of gaps between lags and sheets with building foam.
Laying slabs in the space between the beams on top of the isospan layer.

The use of wide boards mounted on the edge.
Double-sided mineral wool waterproofing.

The better the building's heat saving performance, the lower the financial losses for maintaining the house in winter period time. But there is one point - if correct use insulation gives a significant positive effect, then the wrong one is very negative. How to choose the right insulation for the floor in a wooden house? Which is better? We will tell you more in today's article.

A wooden house was previously considered a very warm structure that did not require any additional insulation work. True, not all modern developers know that the floors in old houses were made from logs cut in half, and the thickness of such coatings reached 20–25 cm. The walls of the log house were assembled from round timber Ø 55–60 cm. and for floors, boards with a thickness of no more than 2.5 cm are used. Such thin lumber cannot in any way comply with the requirements of current regulations.

According to the existing standards for heat conservation of residential buildings (SNiP II-3-79), in order to achieve energy saving R = 3.33 ° C m2 / W, the thickness of the timber in the Moscow region should be 50 cm. In order not to install such thick walls, modern insulation materials must be used . 12 cm of expanded polystyrene has the same heat saving effect as a tree 53 cm thick or Brick wall 210 cm thick.

The construction industry offers consumers a wide range of thermal insulation materials, differing in structure, manufacturing technology and thermal conductivity parameters.

Table. Varieties of floor heaters

Type of insulation	Brief description of physical and operational characteristics
	In terms of cost, they belong to the middle category, quite technological and effective heaters. Rolls make it possible to cut materials exactly to the size of niches, due to this feature, it significantly reduces the number of unproductive losses. To insulate floors in a wooden house, rolled mineral wool insulation is most often used. There are also rolls of cork bark, but such materials are recommended to be used during the arrangement of underfloor heating only as additional lining insulation, since their thickness does not exceed a few millimeters. For basic insulation, this is very little. Often, rolled heaters have a foil coating. This reliable protection against the penetration of moisture, in addition, it is possible to slightly reduce heat losses due to infrared radiation.
	On special equipment, light and porous insulation materials are pressed into slabs with standard sizes. Plates, unlike rolled materials, can retain their geometry, which simplifies and speeds up the installation process. The dimensions of the slabs are taken into account at the design stage of the house, taking into account their dimensions, the distance between the floor lags is selected. Most often, mineral wool and glass wool are pressed, but ecowool slabs can be found. The price is slightly higher than rolled ones, the thermal conductivity parameters are almost the same. Separately, pressed polymer foam-based insulation is located. Modern technologies allow you to make them safe for health and do not support open combustion. Such operational properties make it possible to use these materials for floor insulation in wooden houses.
	The main difference is that the materials harden or polymerize after being applied to the surface. The insulation layer has no gaps, the technology makes it possible to isolate the most hard-to-reach places complex configuration. In liquid form, polymer thermal insulation and ecowool are applied. The disadvantage is the complexity of the technology of polymer insulation. According to the actual characteristics, these materials occupy the last places and are not recommended for use by professional builders.
	Traditional and cheapest heaters, most often - expanded clay and slag. The main advantage is that they are absolutely non-flammable. In terms of thermal conductivity, they occupy the last place among all existing heaters.