Wood has a low thermal conductivity, so houses made of material require the least time and money for insulation. However, each log house has sections through which cold air enters the house, and warm air leaves from there. The largest percentage of losses awaits premises that do not provide thermal insulation of the foundation.

In an insignificant, at first glance, component of the building, the heat loss rate can reach up to 25%. This is due to the foundation materials - a concrete slab or a monolith has a high coefficient of thermal conductivity, so the heated air does not linger in the house. To reduce losses, you need to insulate the foundation in one of the known ways - from the outside or from the inside.

Heat loss through the building foundation

Advantages of internal thermal insulation

• protect the foundation from freezing;
• prevent frosty air from getting inside;
• extend the service life of concrete;
• become an additional barrier to the interaction of groundwater with the building;
• resist temperature fluctuations for many years.

Alas, there are cases when the outer cladding of the concrete slabs of the base of the house is impossible. The reason may be, for example, a deep foundation underground. Then the tenants have no choice but to insulate it from the inside. Especially this method suitable for houses with a basement.

The ideal option is external and internal insulation at the same time. But sometimes it happens that only the second way is possible. Among the factors contributing to the decision in favor of warming the foundation from the inside, include:

• it became necessary to transform the unheated underground into a heated one;
• the need to create a basement;
• lack of foundation in principle;
• moistened or donkey wall insulation;
• the lower crowns of the house are obviously damp.

The internal lining of the foundation of the building provides the following advantages:

• normalization of the microclimate in the rooms and basement (temperature increase);
• protection of the lower rims of the house (or bath) from the effects of groundwater;
• floor insulation in rooms;
• preventing the accumulation of condensate inside the basement.

Unfortunately, the insulation of the foundation from the inside is not without a couple of minor drawbacks:

• whatever one may say, outside the concrete base will freeze, which will lead to the appearance of microcracks;
• with temperature changes, deformation of the foundation is inevitable.

In the absence of the ability to insulate the outer side of the concrete base, the considered type of insulation becomes the only possible and correct one. ways correct operation many, and each of them is good in its own way. However, there is a general rule for everyone - concrete should be protected from moisture as much as possible.

To do this, you will have to make the base resistant to getting wet, giving preference to one of the popular waterproofing agents (for example, roofing material). Having understood this point, the residents of the house move on to the question of how to insulate the foundation.

Features of popular heaters

Before making a decision in favor of a particular material, it is worth analyzing the available options according to the following criteria:

• resistance to biological (rodents, insects, birds) and climatic (temperature changes) factors;
• low coefficient of thermal conductivity (from 0.03 to 0.5-1.0);
• fire safety (the material should not be prone to easy ignition).

These are the minimum requirements. About a dozen materials meet them to an acceptable degree, however, when insulating the foundation from the inside of the house, only three are most often used. They are discussed in more detail below.

Styrofoam

Universal insulation supplied in plates or sheets (depending on thickness). Durable, non-toxic, unattractive to rodents, has a minimum moisture absorption rate, that is, the liquid will not fall on the foundation at all. The latter property is found when the joints of the plates are reliably foamed with a mounting exchange or sealant. Expanded polystyrene is resistant to small rodents, for decades it is able to resist mold.

The slabs are fastened with bituminous mastic over the entire area of ​​​​the foundation (in the presence of a basement - also from the floor to the ceiling). The seams are filled with foam, to increase the reliability, frame sheathing is used. Insulation with extruded polystyrene foam (styrofoam) has only one drawback - the material significantly reduces the volume of the room. However, this is not so important for the foundation.

The use of polyurethane foam allows you to avoid the occurrence of "cold bridges", and also does not require sealant treatment - the insulation is applied in the form of foam, which effectively fills all the irregularities of the concrete base. The method is rightfully considered one of the best and fastest, but only a qualified team should perform it - firstly, special equipment (very expensive) will be required, and secondly, the material is very toxic (workwear is needed).

Expanded clay

simple and fast way, albeit inferior to the two previously described in terms of efficiency. To insulate the base, formwork is made 30-50 cm high, which is covered with expanded clay. The material does not retain heat so well, but the proper quality is achieved by the thickness of the poured layer. It is environmentally friendly, fire-resistant, and in addition to mineral wool (enclosed from the bottom of expanded clay), it ideally keeps heat.

There is another common way to insulate the foundation from the inside, which is morally obsolete in our time - falling asleep with earth, sand, ASG (sand and gravel mixture). In this case, the concrete base is filled to the level of the warm floor. The method is cost-effective, but very time-consuming, so now it is unattractive.

If it is impossible to insulate the foundation from the outside with your own hands, you can easily compensate for this. internal work. By adhering to the above recommendations and leaning in favor of the listed materials, even a novice builder will be able to achieve a positive effect in such an important matter.

The foundation of any building accounts for a significant percentage of heat loss. It can be reduced by external insulation around the perimeter of the building. But such work is not always realistic. It remains to insulate the foundation from the inside.

The essence of internal thermal insulation

Construction measures for thermal insulation of the foundation of the house from the inside are reduced to lining the walls of the basement with special materials. Subsequently, they prevent the leakage of heat and do not allow cold to penetrate inside. Also, these works reduce the likelihood of condensation, which can cause considerable damage to the structure.

Not all insulation materials are attached directly to the walls. Some, such as polyurethane foam, are sprayed onto the surface, quickly forming a protective layer. However, in most cases we are talking about the installation of special plates.

Step-by-step instructions using foam as an example

When thermally protecting the foundation with your own hands, it is better to choose foam. It surpasses other heaters in terms of price - quality and is easy to process. When buying it is difficult to make a mistake. To isolate the foundation from the inside, polystyrene plates with a thickness of 50 to 100 mm are sufficient. Better than polystyrene, only its many types, including extruded polystyrene foam. The main disadvantage of this material is brittleness.

Preparatory work

From the inside begins with the preparation of the foundation. First you need to clean the surface of the walls.

Insulation installation

The second stage involves gluing the plates. There are many different adhesives on the market, choosing the right one is easy.

Installation of foam boards starts from the floor. During installation, it is necessary to ensure that the surface is smooth, and the joints are not too wide. Then the voids are filled with sealants.

It is easy to do this work with your own hands. Difficulties can arise when working with uneven wall surfaces. In this case, either the walls or the foam layer must be leveled.

When the plates adhere to the wall, for greater reliability, the foam can be additionally attached with plastic dowels.

Reinforcing layer

After fixing the insulation, they proceed to the creation of a reinforcing layer. To do this, the plates are treated with an adhesive, into which a special mesh is embedded. A second layer of glue is applied on top.

Moisture protection - waterproofing

In order for houses to really benefit, basements must be protected from moisture. There should be no condensation, no dampness, no groundwater seepage. Otherwise, the efficiency of the work done will be equal to zero.

The presence of moisture in the basement often indicates errors in the project or unscrupulous construction. There are other reasons associated, for example, with problems in pipelines. In any case, moisture problems must be eliminated. Basements should not be damp.

Another important nuance- ventilation. Basements should be well ventilated.

What materials to use?

The choice of method and material of insulation depends on the following factors:

• required indoor temperature after thermal insulation;
• soil type;
• house construction;
• basement dimensions;
• ground water level;
• the presence of external thermal insulation.

It is possible to insulate the foundation from the inside with the help of plates, special structures, foam mixtures, expanded clay.

An example of house insulation with expanded clay.

Plates

Plates, regardless of the material of manufacture, are mounted as in the case of foam. They allow you to create an even coating under the cladding. With this method of insulation, it is better to insulate the foundation from the outside. If this is not possible, then it is necessary to make a penetrating waterproofing of the foundation. Then the concrete will not freeze, but retain vapor permeability. Since the plates do not allow moisture to pass through, equipment for supply and exhaust ventilation is mandatory.

Special designs are frames filled with heat insulators.

Mixes

Mixtures (for example, polyurethane foam) are sprayed onto the walls with a thin layer, swelling, they form a monolithic surface without seams.

The polyurethane foam layer has high hydro- and thermal insulation properties. This effective method suitable for any basement. The disadvantage of the method is its high cost and the need to call a specialist.

One of the cheapest ways is backfilling with expanded clay. It drains water and creates an air cushion under the floor, which protects the floor of the first floor from heat loss. This method is suitable for buildings without a basement. Usually it is used for warming private wooden houses, garden houses.

There are many options for insulation, the task is one - to protect the underground space from heat leakage and create a comfortable atmosphere there.

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 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. Helps to maintain the balance of concrete moisture, heat inside the room, reduces the cost of public utilities 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 work is 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:

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

Resume construction works possible after 3 weeks, when the insulating material is completely dry.

Internal heat insulation methods

Exist different ways how 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:

1. Prepare lumber for building a frame and treat the wood with an antiseptic.
2. Assemble formwork from boards that follows the contours of the basement.
3. Make slopes.
4. Cover the surface of the soil with polyethylene to prevent the penetration of water into expanded clay pebbles.
5. Compact the bulk material to the top level of the formwork.
6. 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:

1. Prepare the walls: grinding, removing bumps, gaps, flaws.
2. Waterproof the foundation.
3. Using a brush, apply a special dry glue around the perimeter of each sheet.
4. Fix the plates to the base in a checkerboard pattern. Styrofoam sheets have grooves that must be joined during laying.
5. Grease the seams between the plates with sealant.
6. 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 finishing and the installation of 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:

1. Fix the material with liquid nails on any surface with the reflective side inside the room.
2. From above, the wall is covered with foam.
3. Cut with a hacksaw.
4. A heat insulator tape with a reflective layer is lined with a floor covering and covered with expanded clay.
5. 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.

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 worth this moment disassemble in every detail.

• 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.
• Of the shortcomings - wooden house, yes at room temperature soon it slowly but surely depolymerizes 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:

1. First, we properly clean and align the walls manually.
2. We calculate the thickness of the insulation.
3. Now we spray the materials that are applied in this way, and glue the insulation board with a bitumen-based mixture.
4. We further decorate the walls at our discretion.
5. 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:

1. 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.
2. 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.
3. After the previous 2 points, the overall humidity in the basement will increase, effective ventilation will be needed, another burden on the work budget.
4. The basement space will be significantly reduced due to so many layers on the plinth plus ventilation equipment.
5. 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.

Foreword. Thermal insulation should be subjected to all structures of residential and industrial premises. The insulation layer will not only save heat during the cold season, but also protect the building elements from freezing, increasing the service life of the structures. Consider how to properly insulate the foundation of a wooden house, and what materials should be used. At the end of the material, see the video instructions for warming the foundation.

How to insulate the foundation of a wooden house from the outside or from the inside depends mainly on the design of the base. External and internal insulation have their advantages and disadvantages. For example, do-it-yourself insulation of the foundation of a wooden house from the inside will cost less, but this will not save concrete from freezing. External insulation will extend the life of the structure and protect the concrete from temperature extremes.

Do I need to insulate the foundation of a wooden house

We will answer right away that, of course, it is worth it, because no one likes it when the floor is cold, and it blows cold down the legs. If the foundation is not properly insulated in a wooden house for the winter, then the cost of heating the premises will increase many times over, not to mention the cold field on the ground floor. At the same time, even warming the window sills for the winter will not help to keep the heat in the house properly.

It is important to know that waterproofing and insulation of house structures - important point during construction. In addition, it is important to know how to insulate the foundation of an already built private house. Solving this issue, you need to first choose moisture-resistant thermal insulation. It is best to choose penoplex material characteristics - high density, moisture resistance and long service life.

How to insulate the foundation of a wooden house

The density of modern thermal insulation is from 50 to 98%. To calculate the thickness of the insulation layer, the thermal conductivity of the material is taken, determined by the thermal conductivity coefficient λ - this is the amount of heat passing through 1 m3 of material in 1 hour with a temperature difference of 10 degrees from different sides. It is also important to take into account the frost resistance and vapor permeability of thermal insulation.

Water conducts heat well, so if the insulation absorbs moisture, the thermal conductivity of the material will increase. For this reason, water-absorbing materials must be protected from moisture. Glass wool and mineral wool is a popular material, but it requires high-quality waterproofing during insulation. Extruded polystyrene foam is stronger than foam, durable and has low water absorption.

Insulation of the foundation of a wooden house outside

Insulation of the lower crowns of the log house in the house

In the absence of a basement in the house, there is nothing left but to fill the foundation from the inside, insulate the floor on the first floor and make a dam. Log cabins in the old days were insulated by dumping the lower crowns of a wooden house. The huts were placed on poles at the corners of the log house, and at a distance of half a meter from the walls of the house they built formwork, which our ancestors covered with earth mixed with sawdust or straw.

If a wooden house stands on a columnar or pile foundation, it is recommended to immediately backfill inside the foundation to the floor level with heat-insulating material (soil or expanded clay). Do not forget that all wooden structures must be treated with an antiseptic or mastic. Consider further the insulation of the foundation of a wooden house with foam plastic and foam plastic.

Insulation of the foundation in the house with foam

Photo. Insulation of the foundation and blind areas of the house

If the house has already been built, then to insulate the foundation, it is necessary to dig a trench around the perimeter of the walls, and then apply liquid waterproofing to the concrete. If the strip foundation is being insulated, then the thermal insulation layer should be at ground level, it is also possible to make an insulated blind area around the house.

Insulation of the foundation of a wooden house from the inside

Internal thermal insulation of structures is much cheaper, however, while the foundation will not be protected from freezing during the cold season. Freezing of the structure can lead to freezing of the soil and deformation of the concrete. Internal thermal insulation can be made using foam, expanded polystyrene, expanded clay or mineral wool. The thermal insulation layer can be sheathed with PVC panels, chipboard or OSB sheets.

Insulation of the foundation in the house with expanded clay

Backfilling of the foundation from the inside can be carried out both in a house under construction and in an already built house. To insulate the foundation of a wooden house for the winter, you can do it with a shallow foundation. To do this, fill the earth with an even layer in the basement, and expanded clay can be poured in a small layer. Or pour only a small formwork up to half a meter wide around the perimeter of the foundation.

Insulation of the foundation in the house with mineral wool

If the walls in the basement are concrete, then you should first waterproof the surface and lay the vapor barrier material. Then they make a frame on the vertical structures of the foundation and basement for laying URSA mineral wool. The slabs of basalt insulation are closely laid into the frame, and then the entire structure and mineral wool are covered with a vapor barrier with the smooth side inward.