Insulation of the foundation of a wooden house from the inside. Do-it-yourself insulation of the foundation from the inside. Reasons for performing internal insulation

As the saying goes: "The master is the master." That is why everyone decides for himself how to build, when, from what. But if you can deal with such questions on your own, then in order to answer, for example, the questions: “Do I need to insulate the walls and foundation, and if you need to insulate the foundation from the outside, is it worth doing the same from the inside?” - the opinion of a specialist is required, because only a trained look of a pro can determine the degree of "need" in a particular case. And let's find out how best to insulate the foundation - from the outside or from the inside?

For the most part, builders agree that it is best to insulate the foundation from the outside. In order not to be unfounded, they give quite strong arguments in favor of this method.

Regardless of the type of insulation used and the type of foundation, external thermal insulation helps protect the foundation from freezing, preventing the penetration of low temperatures into the building.
External insulation has a positive effect on the quality of concrete, and on the design of the foundation, after all, maintaining their strength for many years.
Also, the outer insulation is an additional barrier to groundwater, helping waterproofing to protect the foundation from moisture.
In addition to the lower part of the foundation, the outer insulation resists temperature fluctuations that occur in the upper, basement part of the house when the seasons change.

But there are cases when it is impossible to insulate the foundation from the outside, then, of course, there is no dilemma for the owner and there is only one thing left - to insulate from the inside. In fact, there are not so many advantages, but to be honest, there are only three:

Insulation of the foundation from the inside has a positive effect on the microclimate of the basement and the whole house as a whole.
Internal thermal insulation protects the foundation from groundwater.
Internal insulation does not allow condensate to accumulate in the basement.

In principle, there are positive points, but there are also negative ones:

Yet outside the foundation freezes through.
Due to temperature changes and heaving of the soil, deformations of the foundation occur and cracks appear along its entire perimeter.

What good is it that the foundation, so carefully built by you, in a few years will begin to crumble and collapse?

How and how to insulate the foundation from the inside

So, you still decided to insulate the foundation from the inside, apparently you had good reasons for this. For thermal insulation of the inner surface of the foundation from the side of the basement or subfloor, it is best to use polyurethane foam, since it is much more convenient to work with it in a limited space, and it will take much less time for such work.

The process of thermal insulation itself is very simple - you need to spray polyurethane foam over the entire inner surface of the foundation, while partially catching the basement walls. For greater confidence in your actions, you can insulate the floor and ceiling in the same way. Then you will definitely protect the basement from cold and moisture. That's just then you should carry out work on the decoration of walls, ceiling and floor.

Styrofoam and extruded polystyrene foam can also be used.

Insulation of the foundation with foam plastic from the inside of the house

Materials and methods of insulation of the foundation from the outside

In this case, foam, polystyrene foam and polyurethane foam can be used as heat-insulating materials. The latter is applied in the same way as when insulating the foundation from the inside, only before spraying polyurethane foam, it will be necessary to carry out some preparatory work to expose the lower part of the base of the house.

Insulation of the foundation outside the house with polyurethane foam

Operative method - insulation with polystyrene foam

For insulation with polystyrene foam or polystyrene foam, it will be necessary to free the entire foundation from the ground. To do this, a trench is dug around the perimeter of the house to the depth of the foundation, about 40-50 centimeters wide. Then the surface is carefully cleaned from the remnants of the earth and leveled (if necessary, of course). Waterproofing is applied to clean, dry walls, and then sheets of insulation are attached to a special adhesive or bituminous mastic. The joints between them are filled with mounting foam (this technique will protect the foundation from moisture penetration).

Insulation of the foundation with polystyrene foam outside the building

Important: the top sheets of insulation should rise about 40 cm above the ground level - this will protect both the foundation and walls from a possible rise in groundwater.

After all the work on gluing sheets of expanded polystyrene or polystyrene is completed, you can start backfilling the trench. A layer of sand (10 - 12 cm) is poured onto its bottom, then you can put sheets of insulation (or you can not put it), after that - a layer of gravel (60 - 70 cm), and then you can fill it with concrete, you can fill it with the same sand, and you can roll up asphalt. If you are a creative person and love everything original and unusual, then you can decorate everything with stone or tiles.

The technology for performing thermal insulation using insulation boards can be viewed on the video:

Ensuring thermal insulation with expanded clay

Another way to insulate the foundation from the outside is to use expanded clay. True, this method is already partially disappearing into oblivion, since it is quite costly and inefficient, although our parents used it when building houses.

The process of expanded clay insulation is in many ways similar to foam insulation. We dig a trench with a width of at least 1 meter to the entire depth of the foundation. A waterproofing material is laid at the bottom of the trench, and expanded clay granules are poured on top. The layer should be thick enough, because expanded clay has very weak thermal insulation properties. Roofing material is laid on top of expanded clay and sand or earth is poured.

If you decide to save on workers and carry out the insulation of the foundation with your own hands, then you can use for these purposes not only modern materials, but also those that were used by our ancestors. True, there will be little sense from straw, peat, leaves or needles, because if these affordable, natural “insulators” really helped in the fight against cold and frost, would a person begin to look for a replacement for them?

Insulation of the foundation, no matter what they tell you, is necessary in any case, because the weather conditions in Russia are so unpredictable that even the weather forecasters themselves are not able to answer the question of what awaits us tomorrow. Even if you live in Sochi or the Krasnodar Territory, where the temperature usually stays stable around zero, do not take risks, but take care of your home, otherwise it will be too late later.

Before many people who are just starting to build their house, and at the same time want to fully delve into all the nuances of construction in order to fully control it, the question will certainly arise as to which way to insulate the foundation is better. As you know, there are only two ways, this is the insulation of the base of the house from the outside, or the work on thermal insulation from the inside. For each of them, the same materials can be used.

According to experts who have built more than a dozen houses, the method of carrying out thermal insulation work outside much more efficient than such an option as warming the foundation inside the house. Consider the main advantages of external insulation:

The heat-insulating material located outside the foundation does not allow it to freeze;
The dew point is shifting towards the street;
The insulation protects the foundation of the house from the adverse effects of the environment and, accordingly, prevents premature destruction;
Some types of insulation can further strengthen the foundation;
There are thermal insulation device technologies that allow you to protect even the soil from freezing within a radius of half a meter around the foundation, for example, a warm device.

Even if you think logically, people cover their faces with a scarf when walking in cold and windy weather. It acts as a heater and does not allow cold air to burn the face.

There are no downsides to external insulation.

Of course, in cases where it is not possible to insulate the foundation from the outside, there are no options left but to do it from the inside.

Features do-it-yourself insulation of the basement of the foundation

After the foundation is ready, you can proceed to. There are several options for how to do this.

The first is to mount sheet thermal protection on the surface of the foundation and at the same time not carry out work on the insulation of the earth directly touching it.
The second option is to use loose insulation, thus creating a barrier to the penetration of cold from the ground, and insulate the base with sheet insulation.
The third option is the installation of sheet material on the base and the arrangement of a warm blind area from it or loose insulation.
There is another way to isolate a shallow foundation by organizing the so-called "Swedish plate". The essence of the method lies in the fact that the base is completely installed on a pillow of insulation and, at the same time, is sheathed on the outside. This is a great option for areas with a harsh climate.

Let's consider in more detail the order of work.

The algorithm for conducting all types of insulation from the outside is approximately the same. First you need to free the base from the ground at a distance corresponding to the width of the insulation. For sheet materials, such as polystyrene, or insulation of the foundation with foam, it is enough from the outside dig a trench around the entire foundation with a width of not more than 20 cm.

For loose heaters, on top of which there will be a blind area, the width of the trench is selected in accordance with the width of the future blind area.
At the next stage foundation needs to be cleared, and after that, if, together with the insulation, it was planned to isolate it from moisture, it is necessary.

Once the waterproofing has been completed, start installation if the thermal insulation will be made of sheet material, backfill, or if it was planned to use loose insulation. Bulk material is poured 7-10 cm below ground level, this is necessary for organizing a blind area.

After the bulk thermal insulation has been raised to the required level, it is necessary to insulate the basement of the foundation from the outside with sheet insulation. Only after that it is possible to fill in the blind area, otherwise, if the blind area is poured close to the concrete, it will play the role of a conductor for the cold and all thermal insulation work will be in vain.

You can fix the thermal insulation on the foundation using special dowels for insulating materials, which are easy to find in any hardware store. As an adhesive and insulating composition for joints, you can use ordinary polyurethane foam.

The basement of the house can also be insulated with bulk material. To do this, you will need to make a block of flat slate or brickwork, inside which fill the insulation.

Internal thermal insulation

If you equip the insulation from the inside, the temperature regime of the room will change. It will affect the microclimate of the basement, dampness will disappear. When organized together with thermal insulation and, protection against penetration of groundwater into the basement will increase, this is a very important point, since it is impossible to insure yourself against this in any other way.

Along with the positive aspects, when the foundation is insulated inside, the opportunity to insure against some negative aspects will be lost:

Freezing of concrete and soil around it;
Moisture ingress and destruction of the base;
Dew point shifts to the inside.

Having considered the pros and cons of these types of insulation, there remains only one correct conclusion: to achieve the best results, it is necessary to insulate both outside and inside.

The process of carrying out the internal insulation of the foundation in a house without a basement using sheet insulation does not differ from how to carry out the exterior finishing of the foundation with insulating materials. Let us consider in more detail how insulation is carried out from the inside of the walls and floor in the basement.

The most important thing is to remember that you need to start with wall insulation, and only after the thermal insulation of the walls has been completed, it is necessary to proceed with the insulation of the floor of the room. The insulating material is attached to the basement walls in the same way as installing insulation from the outside, i.e. on mounting foam and dowels. Insulation joints must be foamed.

The insulation is laid on the floor only after it has been carried out. The places where the insulation laid on the floor adjoins the insulation on the wall, for greater efficiency, must be filled with mounting foam. After that, you can start arranging the floor screed.

To insulate the foundation from the inside in a house without a basement, you can also use loose insulation, for example, expanded clay. To organize thermal insulation, it will be necessary to install a blind area parallel to the entire inner perimeter at a distance necessary to create an optimal layer of insulation. After that, you can fill up the insulation there.

By spraying

In a separate point, it is possible to single out the insulation of the foundation from the outside with the help of the reason that it is carried out according to one algorithm both from the outside and from the inside of the base of the house.

Of course, it is much more effective to apply insulation spraying from the outside, but the effect of internal application is also significant. It is worth noting such positive points regarding this heater, such as:

Its lightness - does not create a load on the base;
Incombustibility - is fireproof;
High adhesion - it perfectly adheres to almost any material;
Low thermal conductivity - effectively protects against the penetration of cold;
Almost zero hygroscopicity - does not pass moisture.

Installation of this type of insulation is carried out by specialized companies.

conclusions

Summing up everything said in the article, it is worth paying attention to the insulation of the foundation of the house from the outside. This is the most effective way to protect the house from the penetration of cold and at the same time reduce the rate of destruction of the foundation.

For the organization of external insulation, there are many methods and techniques that can be combined and try to choose the most effective one for you. External insulation material can be: both loose and sheet, you can combine them.

When insulating the basement of the foundation from the outside, it is more convenient to use sheet materials, but if you wish, you can organize a beautiful mound of brickwork or practical - of slate.

The internal isolation of the foundation is less effective, but still has the right to exist, since the main result from it is available.

To achieve the maximum effect from the insulation work carried out, it is necessary to apply both types of foundation insulation together.

Useful video

How to insulate the foundation base from the outside with your own hands, see the video below:

In contact with

It is worth saying that it is very important to insulate the foundation inside. This will allow you to keep warm in the house, if for some reason the foundation was not insulated from the outside. Of course, there is no ideal option for such work, but there are quite acceptable ones. However, be prepared for possible problems that will make themselves felt soon, because work on the insulation of the foundation is carried out from the inside, when there is simply no other way out. We will understand the details and work on insulation, and possible subsequent problems.

Warming from the inside. Details

We decided to insulate the foundation inside the house, then the tips in this article may be useful. The option of an insulated basement is acceptable only for a deep foundation, the walls of which form a basement. With other foundation options, such as pile or tape, insulation work is simply meaningless, and, as a rule, is not carried out.

So, our main task is to choose the right option. And below, just, it is worthwhile to disassemble the moment in all the details.

We carefully study the characteristics, especially pay attention to the coefficient of thermal conductivity, as well as the operating conditions, and select a heater that is suitable for the parameters in your case.
Styrofoam is the best suited for internal insulation of the basement, it retains heat quite well, is inexpensive and any master can handle it with his own hands.
Among the shortcomings - in a wooden house, and at room temperature it will soon slowly but surely depolymerize to the state of styrene.

It should be noted the high flammability of foam. Here, as an option, it will be the purchase of heat-insulating foam.

So in order not to bother with possible problems, you should buy a modified version of the foam plastic from the first time and live in peace.

In second place in terms of popularity and practicality is expanded clay, it is less often used to insulate the basement. It can also be used in a strip foundation, but more as a calmer for the owners, because. its real benefit is extremely small in such cases.

How to make insulation

So, if the material is selected and purchased, now consider the stages of work on insulation:

First, we properly clean and align the walls manually.
We calculate the thickness of the insulation.
Now we spray the materials that are applied in this way, and glue the insulation board with a bitumen-based mixture.
We further decorate the walls at our discretion.
As you can see, it is not particularly laborious, and the meaning of these works is rather controversial.

What problems might arise?

Now you know how to insulate the foundation of the house inside. However, some difficulties may arise in this work. There are at least five of them:

Because your foundation remains unprotected from winter temperatures, and even the Isospan B vapor barrier will be powerless here, be prepared for the entire basement to freeze.
The budget for insulation work will increase due to the need for an additional vapor barrier that will protect the foundation at the junction of panels and concrete at the dew point.
After the previous 2 points, the overall humidity in the basement will increase, effective ventilation will be needed, another burden on the work budget.
The basement space will be significantly reduced due to so many layers on the plinth plus ventilation equipment.
When calculating the cost of internal insulation, they will unpleasantly surprise you with their size, which will not happen with external insulation.

Finally

So weigh everything again, calculate whether it makes sense to do internal insulation work even with Izospan AM, experts usually give a negative answer to this question.
And think all the same about external insulation at your leisure.

Insulation of the foundation from the inside is used in cases where the insulation of the foundation from the outside is not effective enough or is impossible for any reason. It should be borne in mind that internal thermal insulation allows you to increase the temperature inside the basement or basement floor, insulate the floors in the house, but does not protect the foundation itself from damage caused by freezing.

Insulation of the foundation from the inside

There are several ways to insulate the foundation from the inside, and they are often combined with the interior decoration of the basement. In any case, before starting the installation of thermal insulation, one should take care of effective and high-quality waterproofing of the foundation, and it is better to give preference to those methods of waterproofing that make it possible to make the entire thickness of concrete resistant to wetting, for example, penetrating foundation waterproofing. A dry foundation is less prone to freezing, and therefore damage.

Basement exterior and interior insulation

In general, the methods of insulating the foundation from the inside are similar to the external insulation of the foundation. The most commonly used methods are:

Backfilling of the basement with expanded clay. Allows you to reduce the cooling of the floor of the first floor. Insufficiently effective method, suitable for country houses of temporary residence;
Insulation of the basement walls with plates - polystyrene foam, polystyrene or foam plastic, with their subsequent finishing. A very popular method of thermal insulation, most often used in combination with external thermal insulation of the foundation for buildings with basements used.
Insulation of the foundation from the inside with polyurethane foam. A very effective way of additional or independent thermal insulation of the foundation, which allows you to create a seamless coating with excellent adhesion, but this work requires the involvement of professionals with a special installation.

The choice of method of warming the foundation from the inside

When choosing a method, you need to focus on several factors:

The design of the building, the dimensions of the basement or semi-basement;
The presence of external insulation and temperature conditions from the outside of the foundation;
Soil type and location of groundwater;
The required temperature regime in the basement after insulation, the presence of heating and ventilation;
The need for further decorative finishing.

A cheap method of internal thermal insulation of the foundation is filling the space under the floor with expanded clay. This material removes water and creates an air cushion that protects the floors of the first floor from cooling. You can fill up both the entire space under the floor and the formwork installed on the inside at some distance from the foundation walls.

If the basement is used to accommodate domestic premises, and its walls need not only insulation, but also finishing, it is advisable to use polystyrene or foam boards, which allow you to create an even coating ready for cladding. The most high-quality and durable in this case will be the insulation of the foundation both from the outside and from the inside - by eliminating the temperature difference, you can avoid the formation of condensate on the inner walls of the basement. If insulation from the outside is not possible, it is necessary to perform a penetrating waterproofing of the foundation: concrete treated in this way is not subject to freezing, but retains vapor permeability, reducing moisture under the insulation slabs. It is also necessary to arrange supply and exhaust ventilation, since these materials do not allow moisture to pass through.

If funds allow, you can choose thermal insulation with polyurethane foam - this method is effective and suitable for any basement.

The technology of backfilling the foundation with expanded clay

This technology is usually used in wooden houses, summer cottages and garden houses. Materials for filling thermal insulation are inexpensive, and its implementation does not require any special skills.

Backfilling the foundation with expanded clay

Backfill thermal insulation technology:

Formwork is prepared from boards or plywood panels, installing them at a distance of at least 0.3 meters from the inner walls of the foundation around the entire perimeter. The height of the formwork is up to the floor level of the first floor.
The boards used for formwork are carefully treated with an antiseptic for wood that is used in contact with the ground. Strengthen the formwork with slopes. A plastic film is laid at the bottom of the formwork - it serves as a waterproofing protection against the absorption of moisture from the soil by expanded clay.
The backfill is made with dry expanded clay - pebbles of volcanic origin. The expanded clay layer should be equal to the height of the formwork. In some cases, with a low height of the basement, it is possible to cover the entire space under the floor of the first floor with expanded clay, while waterproofing is laid on the entire backfill area.
You can additionally insulate the floors by laying a layer of vapor barrier membrane and mineral wool mats between the joists.

The technology of insulation of the foundation with polystyrene plates

Polystyrene is the second name for the familiar foam, modified to give it special properties. Polystyrene plates of various brands are presented on the market, they differ in density, resistance to mechanical damage, and thickness. To insulate the foundation from the inside, polystyrene plates 50-100 mm thick are sufficient.

Insulation of the foundation with polystyrene plates

The technology of thermal insulation of the foundation from the inside with polystyrene:

Polyurethane foam insulation of the foundation and basement

A modern, highly effective method applied by the method of spraying foaming liquid under pressure. The result is a layer of foam with a closed structure, resistant to getting wet, without seams and joints. The application of polyurethane foam does not require any special preparation of the walls and can be completed in the shortest possible time. The only serious drawback of this method is its high price and the need to call specialists, which, however, pays off during the operation of the building due to the excellent heat and waterproofing properties of the polyurethane foam coating. You can apply any finishing materials on it and use it for internal and external insulation not only of the foundation, but also of any other house structures.

basement polyurethane foam insulation

To insulate the foundation from the inside for the house using insulation for siding is not the most reasonable idea, but it is quite feasible. The fact is that the insulation of the foundation from the inside for the house has many problems, which, after the work of such insulation, will certainly come out.

However, in cases where there is simply no other choice, this method can be implemented, including with your own hands.

Thermal insulation boards under the foundation

The first step is to figure out how to insulate the foundation for a wooden house, or any other, inside, and then smoothly move on to why this idea is obviously losing and why there will be more problems than pluses in the output.

1 The process of warming the foundation from the inside

First of all, it should be remembered that the insulation of the foundation of a wooden house inside is acceptable only for a recessed type of foundation, when its underground part is, in fact, the basement of the house.

In other cases, for example, for a tape type foundation, insulation with neither expanded clay, nor foam plastic, or anything else is done by hand due to the lack of sense in this action.

If this procedure is needed not for a strip, but for a deep foundation and insulation of the basement from the outside, then before performing it, you should choose a material for insulation.

An important parameter and property of thermal insulation materials, which should be looked at, is the coefficient of thermal conductivity. In addition, you should also look at the characteristics of the heat-insulating material in order to find out under what operating conditions it can be used.

The most preferred option for insulating the foundation for a wooden building from the inside is foam insulation. Do-it-yourself insulation with foam plastic in this case is good because it has sufficiently high thermal insulation qualities. This material is also applicable for a strip foundation, although this plus is not relevant to this situation.

This material for warming the foundation and blind area also has disadvantages: foam insulation of the foundation of a wooden house is bad because at normal room temperature this material smoothly depolymerizes over time, which will lead to the formation of styrene.

Insulation of the building from the inside

Moreover, foam insulation is also dangerous with the possibility of a fire, since this material is combustible. However, this problem can be eliminated by simply purchasing a heat-insulating foam that is relevant to current insulating demands.

Therefore, in this case, it is better to spend money on warming the foundation for a wooden house with the help of polystyrene foam, rather than then get a huge number of problems.

The second best option for insulation is expanded clay insulation. It is worth noting that expanded clay insulation is used much less frequently for a deep foundation than foam insulation.

External insulation of the foundation of a wooden house with expanded clay is more suitable for a strip foundation, however, in cases where there is no other way out, this material is also suitable for a recessed type of foundation. However, this material is also contraindicated for the strip foundation, and is used only as an improvisation at the fear and risk of the building owners.

As soon as the choice of insulation for the foundation inside the building is made, it is necessary to carry out installation. Installation is carried out strictly according to the following step-by-step instructions:

The first step is to prepare the inner surface of the foundation. Preparation consists in cleaning and subsequent leveling of the base of the foundation with your own hands;
The thickness of the selected thermal insulation is calculated;
Next, it is necessary to fasten heat-insulating materials (and if polyurethane foam heat insulators are used, then spraying is carried out) using adhesive mixtures based on a bitumen component;
Next, you just need to arrange the interior decoration of the basement of the building.

Insulation work in the foundation

Summing up, we can say with confidence that the process of warming the foundation from the inside of the building is very easy and simple, although unreasonable.
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2 Reasons not to insulate the foundation from the inside

There are five good reasons why such construction work is not advisable. They are presented like this:

Freezing of the entire reinforced concrete structure of the building, even with vapor barrier Izospan V. In such a situation, the foundation is not protected in any way from unstable temperature surges, which adversely affects its operational life;
Due to the fact that the so-called “dew point” will shift to the “insulation-foundation” boundary, in the future it will be necessary to add an additional vapor barrier layer, which will hit the overall budget for insulation work;
The implementation of the previous paragraph will lead to the fact that the microclimate in the basement will be disturbed, the humidity of the air will increase quite strongly. Consequently, it will additionally be necessary to install effective ventilation, which will once again negatively affect the overall budget;
Due to such a huge amount of additional equipment, the space inside the basement will be much smaller than the original one;
In general, at the exit, the owner of the building will have huge financial costs for the construction work itself and the purchase of various materials, which the method of external thermal insulation is deprived of.

Internal insulation of the building foundation

Deciding whether or not to insulate the foundation of a building from the inside with Isospan AM is necessary only for its owner, however, all experts in the field of insulation clearly do not recommend this procedure.

Thus, it is much easier and more economical to make external thermal insulation.
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2.1 Reasons for insulating the building from the inside (video)

Mold, condensate, fungus, temperature changes reduce the level of thermal regulation of the base of the building, create discomfort for the residents of the house. Warming the foundation from the inside with your own hands will help to normalize and maintain a constant temperature regime in accordance with the climatic features of the area.

Reasons for the destruction of the base

Concrete is under constant influence of soil and water. The liquid penetrates the foundation of the house, damaging it from the inside. Aluminum fittings are constantly in contact with water, soil, alkalis, which leads to corrosion. To increase the resistance to chemical factors, thermal insulation of an internal or external type will help.
Insulation measures begin when the builders have access to the interior. Work is carried out on an unfinished basement floor with an open foundation. Thermal insulation will be relevant in the basement or high underground. In other cases, the base opens.

Problems solved by internal thermal insulation

protect the soil from deformation under the pressure of frost heaving forces;
help to regulate the temperature;
minimizes the impact of cold climates on the building material;
keep the internal heat in the room;
reduces the moisture content.

It is possible to make thermal insulation of the base at any stage of construction work and in the finished structure.

Types of insulation

Several methods will help to increase the heat transfer coefficient and the performance of the foundation:

internal insulation. In some cases, this is the only way to keep the amount of energy released. For a positive result, equip ventilation.
external. It helps to maintain the moisture balance of concrete, heat inside the building, and reduces utility bills during the heating season.
combined. Creates favorable conditions for the support buried in the ground and the part that protrudes above the soil.

Concrete has a high degree of resistance and is a poor thermal insulator. An insulated base will help create a barrier between the circulation of cold and warm streams.

Subtleties of outdoor work

The laying of the heat-insulating layer is carried out using several technologies. External works are preparatory for further warming of the solid foundation of the house from the inside with your own hands. Construction experts recommend using the following materials:

Installation of wooden formwork. It is placed at a distance of 30 cm from the wall. Soil or expanded clay is poured into the resulting space. The ledge is sheathed with a board.
Expanded polystyrene and expanded polystyrene in the form of plates ensure the seamlessness, tightness of the layer and the preservation of thermal performance.

The simplest way to preserve the structure of the foundation is waterproofing. If the site is located in an area with a high level of groundwater, drainage must be organized.

Waterproofing the base - the relevance of the application

Thermal insulation of the room from the outside is able to increase the temperature regime, reduce the amount of condensate, and protect concrete walls from freezing. Finishing the house from the inside requires thermal insulation of the foundation.

How waterproofing works

The components of the solution penetrate into the pores of the foundation, where they create a barrier to water penetration. Internal insulation of a monolithic foundation with a waterproofing liquid solves the problem of condensation.
The technological process of waterproofing consists of several stages:

Clean the concrete surface with a wire brush and dampen with water.
Prepare waterproofing mixture. The output should be a homogeneous mass.
Paint the structure on all sides. With an interval of 5-6 hours, repeat the action again.

You can resume construction work after 3 weeks, when the insulating material is completely dry.

Internal heat insulation methods

There are different ways to insulate the foundation from the inside. When choosing a particular scheme, you should focus on several factors:

type of construction and type of foundation;
room parameters;
the presence or absence of a plinth and ventilation in it;
climatic conditions;
the nature of the soil;
the presence of external insulation and its variety.

Expanded clay, a heat insulator with a reflective layer, polyurethane foam and polystyrene are used to insulate the base.

Indications for internal insulation measures

Construction requirements for internal work on the insulation of a concrete foundation do not allow the use of a single isolate. Measures are necessary if the building was erected without a fundamental foundation or there was a need to equip the basement.
Thermal insulation inside is carried out when a cold cellar is reconstructed into a heated one or the plinths are constantly damp. From the inside, laying insulation is cheaper if you choose the right material and work, adhering to a certain algorithm.

Popular types of insulation

The internal thermal insulation of the base is made of several materials. Among the assortment of the modern construction market, you can choose the following types:

expanded clay. Granular clay is an eco-friendly insulation that reduces the effect of cold on the floor. The material is chemically inert, does not crack in the cold, does not burn, does not rot.
plates from polystyrene, polyfoam and polyfoam. They are made of foamed synthetic raw materials, they are lightweight and easy to install. For internal insulation, sheets with a thickness of 2-5 cm are used, and for external insulation - from 5 cm.
polyurethane foam - foamed plastic - has good thermal conductivity, noise-absorbing qualities. On the foundation of the building creates a seamless coating with good adhesion.

Using any of the materials presented above, it is necessary to waterproof the surface, pay attention to the resistance and fire resistance of the insulator.

Foundation insulation methods

Base thermal insulation options are directly related to the type of material. Before laying them, it is worth considering the design of the house: the presence of a basement, the number of floors, the intensity of basement operation.

Backfill method

Inexpensive expanded clay is needed to insulate the foundation of a wooden house or summer cottage. The work will be effective if you act step by step:

Prepare lumber for building a frame and treat the wood with an antiseptic.
Assemble formwork from boards that follows the contours of the basement.
Make slopes.
Cover the surface of the soil with polyethylene to prevent the penetration of water into expanded clay pebbles.
Compact the bulk material to the top level of the formwork.
Close the space between the lags of the subfloor with mineral wool.

The backfill method will help to insulate the strip foundation at minimal financial cost and without special building skills.

Laying expanded polystyrene in the form of plates

Styrofoam boards are strong, light and inexpensive. Material with a thickness of 50 - 100 mm is used to fill voids in load-bearing structures. The insulation process goes like this:

Prepare the walls: grinding, removing bumps, gaps, flaws.
Waterproof the foundation.
Using a brush, apply a special dry glue around the perimeter of each sheet.
Fix the plates to the base in a checkerboard pattern. Styrofoam sheets have grooves that must be joined during laying.
Grease the seams between the plates with sealant.
Fix the stacked sheets with dowels. For each unit of material, you will need from 4 to 6 dowels with a head with a diameter of 60 mm.

Laying the finish and installing a reinforcing grid will increase the strength of the structure.

Heat insulator with reflective layer

It is applied together with blocks from polyfoam. It helps to reduce the loss of thermal energy and reduce the level of condensate, therefore it is used to insulate the foundation of a wooden house. Sequence of work:

Fix the material with liquid nails on any surface with the reflective side inside the room.
From above, the wall is covered with foam.
Cut with a hacksaw.
A heat insulator tape with a reflective layer is lined with a floor covering and covered with expanded clay.
Installing plasterboard floor boards.

The method of internal insulation takes up square meters, therefore it is mainly used for rooms with a large area.

Polyurethane foam in cylinders

The universal remedy is applied without pre-treatment of the surface and is relevant for warming the strip foundation. It is a foaming liquid with a dense structure, which is not afraid of frost, precipitation, high temperatures. After applying polyurethane foam for 2-3 days, the substance is in liquid form, filling every hole and slot. Easy-to-use product allows you to complete the work as soon as possible.
Compared to the previous options, this one is the most expensive. The high cost of the material is justified by its high performance properties.
The process of insulating the leaking foundation of a house from the inside, carried out with your own hands, seems complicated. But, if you follow the step-by-step instructions, there should not be any difficulties in the process. When choosing a material, you should pay attention to its coefficient of thermal conductivity, the higher it is, the more effective the thermal protection. To enhance the effect, you need to combine indoor and outdoor work. So you can protect your home from temperature extremes, high humidity, increasing the service life.

Foundation insulation can be done :

before pouring the base;
in the finished building, at the end of the work.

Types of insulation

Exists several types of foundation insulation:

external;
internal;
combined.

The advantage, of course, for combined insulation. Only it guarantees the complete isolation of the basement of the house from freezing in the winter months, when, under the influence of frozen moisture, the soil swells, which can push the foundation blocks to the surface.

It is more convenient to make external insulation, given the freedom of access to the basement of the house. But in some cases, the only possible way to insulate the lower part of the building is internal insulation.

Reasons for performing internal insulation

Using only internal insulation- deviation from the rules of building heat engineering, but there must be good reasons for this:

the house was built without insulation of the foundation at all;
there was a need for a basement;
it took the transformation of the cold underground into a heated one;
there was moisture in the wall insulation;
obviously dampness of the lower rims of the house.

Insulating the house from the inside in the basement is easier and cheaper. You can only be guided by the choice of insulation and existing technologies.

Methods of internal insulation

How to insulate the foundation from the inside of the house? Building Technology Recommends 3 ways to insulate the basement from the inside. But any of them requires waterproofing with a diffusion film or roofing material of all floor surfaces and basement walls, up to the level of the finished floor. Vapor permeability is allowed only from the side of the house. It is important to provide for both the biostability of the insulator and its fire resistance.

1st way: basement insulation is carried out using sheets or slabs of a heat insulator. A universal insulation for these works is extruded polystyrene foam. It is durable, non-toxic, has the lowest rate of water absorption. With a guaranteed service life (20-50 years) it is able to resist mold and rodents.

Insulation plates are laid from the floor to the ceiling of the basement and fastened with bituminous mastic. The seams are filled with mounting foam. For reliable installation of insulation, you will need a frame sheathing. It is worth foreseeing that thermal insulation of this type will significantly reduce the volume of the room.

2nd way: polyurethane foam is used to create a heat-insulating layer. It is sprayed with special equipment on concrete and metal structures. Foamed polyurethane foam reliably fills all cracks, irregularities and voids, nullifying the occurrence of "cold bridges". This method has the highest speed of insulation work, but should only be carried out by specialists with protective equipment, as it is very toxic in production.

3rd way: the simplest and cheapest (at the price of rough materials) - insulation of the foundation from the inside with expanded clay, expanded clay filling. To insulate the walls of a concrete basement, formwork is made of boards 30-50 cm from the basement and covered with expanded clay. It does not have very high heat retention rates, but in addition to mineral wool laid under it, it can well maintain a constant basement temperature, which is very valuable for storing crops. In addition, expanded clay is environmentally friendly, fire resistant.

There is another way to insulate the basement internally, which came from the distant past - earth insulation when the walls are covered from the inside with earth to the level of the insulated floor. But its laboriousness and the mass of soil necessary for these purposes (the volume of KamAZ) make its cheapness unattractive.

Know that the thermal insulation index is inversely proportional to the density of the insulation.
To preserve the effect of internal insulation, exceptional ventilation of the basement is required.
"Cold bridges" are the corners of the walls and the joints of the internal partitions.
If there are windows in the basement, then they are insulated according to the type of windows in the living room.
Carrying out the internal insulation of the basement, it is necessary to insulate the internal partitions.
A layer of sand should be poured under the waterproofing film, followed by compaction.
For the PPS frame, drywall is used.
Expanded clay in a concrete solution loses its thermal insulation qualities.

Exists several types of foundation insulation:

internal;
combined.

Reasons for performing internal insulation

Using only internal insulation- deviation from the rules of building heat engineering, but there must be good reasons for this:

the house was built without insulation of the foundation at all;
there was a need for a basement;
it took the transformation of the cold underground into a heated one;
there was moisture in the wall insulation;
obviously dampness of the lower rims of the house.

Insulating the house from the inside in the basement is easier and cheaper. You can only be guided by the choice of insulation and existing technologies.

Methods of internal insulation

Know that the thermal insulation index is inversely proportional to the density of the insulation.
To preserve the effect of internal insulation, exceptional ventilation of the basement is required.
"Cold bridges" are the corners of the walls and the joints of the internal partitions.
If there are windows in the basement, then they are insulated according to the type of windows in the living room.
Carrying out the internal insulation of the basement, it is necessary to insulate the internal partitions.
A layer of sand should be poured under the waterproofing film, followed by compaction.
For the PPS frame, drywall is used.
Expanded clay in a concrete solution loses its thermal insulation qualities.