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The better to insulate the foundation of the house from the outside. Ways to insulate the foundation from the outside

Most owners of private houses do not consider it necessary to insulate the foundation, believing that this is a waste of money. Thoughts about the need to insulate the basement from the outside come when problems with dampness and mold on the walls become visible, and the basement begins to crack. Do-it-yourself waterproofing will help to avoid these troubles, we will tell you how to do it in the article.

Basement insulation is as important an event as house wall insulation. Through the foundation, the room loses about 20% of heat. Many people think that it is enough to insulate only the basement, but this is a gross mistake. Since the destructive force of water and low temperatures continues to act on the base. Moisture, getting into the pores of the foundation, freezes when exposed to low temperatures and, expanding, destroys the structure. Microcracks appear, which become cold bridges, and when they grow, they can lead to the destruction of the building as a whole.


Insulation of the foundation prevents its destruction

External insulation eliminates the effect of low temperatures and groundwater. The dew point shifts to the insulation layer, and the foundation concrete does not change its properties. Warming is especially important in regions with a harsh climate and heaving soil. Such soil, freezing by 15%, is able to move 35 cm, which entails deformation of the base. On such soils, the depth of the foundation should be below the freezing point, and the insulation is done not only vertically, but also horizontally.

The benefits of insulation

With an uninsulated foundation, cold air from outside enters the living space through the flooring. Therefore, when building a house, the floors are raised above the ground level. Without insulation from the outside, constant dampness in the basement and cold floors in the house are guaranteed, which reduces the level of comfort. So, what facts speak in favor of insulation:

  • the heat loss of the building is significantly reduced, which means that the financial part of the budget for heating will also be reduced;
  • the effect of soil heaving forces is leveled;

Benefits of basement insulation
  • prevents the formation of condensation and mold;
  • prolongs the service life of the foundation structure;
  • protects waterproofing from mechanical damage;
  • it is easier to block the bridges of cold.

Advice. The corners of the structure require special attention. In these places, the thickness of the heat-insulating material is doubled.

Warming methods

When choosing a material for insulation, attention is paid not only to the cost, but also to its main characteristics, namely: hygroscopicity and resistance to deformation. There are several ways to insulate:

  1. Plate heaters: extruded polystyrene foam 200 kPa, foam glass, polyurethane foam and synthetic rubber in the form of foam.
  2. Backfilling with bulk materials: expanded clay, boiler slag.

Most often, polyurethane foam or extruded polystyrene foam is used for insulation.

Advice. On the plates, which are located below ground level, glue is applied pointwise. This is necessary so that the condensate formed between the waterproofing and the insulation flows freely into the equipped drainage.

Expanded clay insulation

Before the advent of new generation insulating materials, expanded clay was often used. Its main advantage is its low price, but the level of thermal conductivity of the material suggests its use in large quantities. So dignity becomes a disadvantage. It is rational to put it into action as additional insulation.


Expanded clay insulation

Warming is carried out as follows:

  • the foundation is dug up to the sole, to a trench width of 1 m;
  • clean the surface of dust;
  • in the absence of waterproofing, bituminous mastic is applied;
  • equip drainage if the groundwater level is high;
  • a film is placed at the bottom of the trench from the wall to the drainage;
  • the trench is filled with expanded clay and a blind area is made.

Sheet insulation technology

When erecting a new building, insulation work begins after the installation of the floor slab. If the house has already been erected, then the foundation is dug around the perimeter to the base to a meter wide. The walls are dried, all dirt is removed. With a close level of groundwater, drainage is arranged. After complete drying, a latex-based primer is applied to the foundation walls. It fills small voids and provides a strong adhesion of the waterproofing to the basement surface. Rolled waterproofing is laid, strongly pressing with a roller. Joints are covered with sealant for reliability. Wait until the waterproofing dries, and then proceed to laying the insulation.


Scheme: insulation with sheet material

Advice. Do not use plates torn from the surface or move them after the adhesive has hardened.

The advantage of extruded polystyrene

Styrofoam slabs are considered the best option for private construction. Since they have a long service life and high compressive strength. Practically do not absorb and do not pass moisture. For a long time it retains thermal insulation characteristics precisely because of its low hygroscopicity.


Thermal insulation of the base with extruded polystyrene foam

These plates are produced with special grooves. Moisture is drained through them. In tandem with geotextiles, polystyrene, in addition to insulation, performs the role of waterproofing and wall drainage.

Advice. Ordinary polystyrene, although it has an attractive price, is completely unsuitable for insulating the foundation. It absorbs moisture and breaks down quickly.

Insulation with liquid polyurethane foam

Polyurethane foam is applied in foamed form to the cleaned surface of the foundation. It combines the properties of waterproofing and thermal insulation. 50 mm of polyurethane foam is equal to 1.2 m of polystyrene foam. The material hardens very quickly, forming a cellular structure. Foam hermetically envelops the foundation, leaving no gaps and without forming seams, unlike tile insulation. The advantages of polyurethane foam insulation include:

  • lack of seams in the coating;
  • high adhesion of the material;
  • no need for waterproofing;
  • low vapor permeability;
  • service life of more than 40 years;

Insulation with liquid polyurethane foam
  • low thermal conductivity;
  • environmentally friendly and biologically neutral.

There are only three cons. This is a high cost and the need to purchase special equipment for laying. Polyurethane foam is destroyed under the influence of solar ultraviolet radiation.

Water drainage from the basement

Together with insulation, it would be good to provide for drainage so as not to dig out the foundation twice. Drainage pipes are laid below the level of the base of the foundation or below the level of the basement, if any. A gravel cushion is poured with a slope of 5 degrees. A drainage pipe is placed on top of it, wrapped in geotextile, and gravel again on top. Geotextiles will prevent clogging of drainage holes. Ground water will flow through the pipes into the drainage well.


Foundation drainage system

With knowledge of the advantages and disadvantages of insulation, you can choose the material that suits you best. Competently carry out construction work, and you will ensure comfort and warmth in the house for a long time, as well as a long service life of the building.

Insulation of the foundation with polystyrene foam: video













Solving the issues of thermal protection of the building in a complex, among all the options, contractors and owners most often choose the popular method of insulating the foundation of the house from the outside with polystyrene foam. There are other technologies, but unlike wall insulation, not all “usual” heat-insulating materials are used here - the features of operating conditions and a wider range of tasks impose certain restrictions. Since the foundation has not only an underground part, sometimes it is necessary to use a combination of several technologies. How and with what to close the foundation from the outside in order to reduce heat loss, we will consider in this article.

A warm house is the care of the owners Source vikonda.zp.ua

Why insulate the foundation

Thermal losses of the building through the foundation are small - from 5% to 15%. Its position and features of the "physics" of heat transfer affect.

About 15% of losses remain on the foundation and floor, but how much this is in absolute terms depends only on the owner of the house. Source ps-b.ru

There are only three ways to transfer thermal energy: radiation, convection (for gas and liquid media) and heat conduction.

Radiation is clearly not "about the foundation", but about the devices of the heating system. They have a higher temperature than the air and surrounding objects and serve as sources, not "sinks". But the walls of a heated room in the cold season radiate energy into the street in the infrared spectrum. To see this background, just look at them in the thermal imager. It is especially bright in non-insulated areas and "cold bridges".

It's so easy to see how heat escapes through uninsulated walls. Source rte-france.com

Natural convection is characterized by an upward flow of warm air and a downward flow of cold air. Of course, the temperature of the foundation cannot affect this process. Here it is important to insulate the roof and ceiling so that they do not quickly "cool" the warm air.

Of the above three ways of transferring thermal energy, it is “due to” the thermal conductivity of structural materials that a cold foundation affects heat loss and the cost of heating a house. And the thermal conductivity of reinforced concrete, from which the foundation is usually made, is quite high, so its low temperature is transferred to the walls and load-bearing partitions.

The air in the room cools due to the building envelope, which gives off heat to the environment. For the underground part of the foundation - this is soil, for the basement and walls - air. Insulation of the foundation reduces these losses.

Video description

Details about the heat loss of the building and the goals of insulation of the foundation are described in the video material.

But there is also another function of the thermal insulation of the foundation of the house - an increase in the service life of the base. Building materials have such a criterion as frost resistance. Its numerical expression means how many freezing cycles (in the condition of saturation with water) must pass before signs of destruction appear. Therefore, for regions with cold and long winters, insulation and waterproofing of the foundation is a prerequisite for ensuring the strength and durability of the structure.

Technologies and materials

There are only two types of foundation that are subject to insulation: slab and tape. For columnar and pile foundations, we can only talk about the thermal insulation of the floor of the first floor and the fence (basement) - a kind of screen that protects the underground. And directly piles and pillars are not insulated.

Plate

The technology of warming the foundation of the slab is no different from the thermal insulation of concrete floors on the ground:

    solid foundation of compacted soil;

    geomembrane as protection against capillary rise of groundwater;

    crushed stone-sand cushion to improve the bearing capacity of the soil and the correct distribution of the load;

    roll waterproofing;

    sheet insulation (polystyrene foam or EPS);

XPS is the best material for insulating the foundation of the slab. Source rmnt.ru

On our website you can find contacts of construction companies that offer foundation design and repair services. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

The Swedes have slightly improved the technology and already at the stage of pouring the foundations they mount a "warm floor" in the slab. We often do it the old fashioned way - in a screed or under the finishing floor covering. The Scandinavians are “boring” people and already know in advance where they will have not only partitions, but also how the furniture will stand (one of the conditions for the correct operation of the “warm floor”). Our people have a different character - they are not only furniture, but also the inner walls are often moved from place to place.

Strip foundation

Warming of this type of base has a wider choice of materials and technologies:

    fixed formwork;

    fastening sheets of foam or extruded polystyrene foam;

    spraying liquid polyurethane foam;

    expanded clay backfill.

Among the insulation for the foundation, only one popular heat-insulating material is missing - mineral wool. When saturated with water, any kind of it loses its thermal insulation properties. And although it not only easily absorbs, but also easily releases moisture, it is impossible to create conditions for its weathering for the foundation.

Places of insulation of the foundation Source anticafe-sandbox.ru

Strip foundation insulation technologies

Each type of insulation has its own characteristics that dictate how it is used.

This is the only method of insulation that is possible only at the stage of construction of a monolithic strip foundation. In fact, this technology can be called "two in one", when the formwork of heat-insulating materials remains as part of the structure after construction is completed. Moreover, fixed formwork solves two problems - how to insulate the foundation of the house from the outside and from the inside.

Structurally, there are two types: block and panel. When pouring the strip foundation, shields are used. The blocks have walls and transverse wide lintels, which reduces the strength of the reinforced concrete base.

Ready-made kits have a set of polymer jumpers that can be used to adjust the width of the foundation Source visualizepicture.com

Such formwork is made from different materials, but most often they insulate the foundation of the house from the outside with polystyrene foam (regular or extruded).

In addition to the "clean" technology, there is a combined one, when the plates are not "connected" to each other, but are attached to a removable formwork.

The combination of removable and non-removable formwork is an increased strength for large volumes of concreting Source pobudova.in.ua

After they backfill the sinuses near the underground part of the foundation, they prepare a “trough” for the blind area from the compacted soil. And then according to the standard scheme: crushed stone, sand, waterproofing film, insulation (expanded polystyrene or XPS boards), formwork, reinforcement and concrete pouring. Instead of concrete, you can use paving slabs or gravel, but the insulation of the blind area, as part of the general work, is a must.

Insulation of the blind area will reduce the effect of heaving of the soil on the foundation Source decorexpro.com

Unlike the previous method, an already existing foundation is insulated. Therefore, there is only external insulation. Work is carried out both during construction and during the reconstruction or repair of a house.

Warming during the construction of a house is much easier than during reconstruction

The most difficult work has to be carried out during the repair. Before insulating the foundation of the house from the outside, it is necessary to dig out and clean the tape from the soil up to the heel. Then the steps go in the following sequence:

  • Waterproofing is performed - first, a bituminous primer is applied, then strips of rolled materials are glued (soldered) from the bottom up with overlapping seams.
Note. It is better not to use bituminous mastics in tandem with sheet insulation - they are “fluid” and do not provide reliable fastening of the plates to the adhesive solution.

    A cement-based adhesive is prepared, with its help the plates are fixed to the foundation. In the above-ground part, additional fixation with dowels is not necessary - only on the base. Direct fastening of plates using mechanical fasteners without an adhesive solution is unacceptable - the adhesive also serves as a “gasket” between polystyrene foam and bitumen, which is an aggressive medium for the polymer.

    After backfilling and making the blind area, the basement is finished: a layer of adhesive solution is applied, reinforced with fiberglass mesh and plastered or tiled.

Video description

With the features of the technology of insulation with polystyrene foam can be found in the video:

Insulation with sprayed polyurethane foam

Among all polymeric heaters, sprayed polyurethane foam is the most expensive type. Its advantage is that the thermal insulation layer has no seams, and the foamed polyurethane has very good adhesion to all types of building materials.

The application of PPU on a surface cleaned of dirt is very fast. There are two types of materials: two-component and one-component.

In the first case, professional equipment is needed, the work of which consists in supplying both components under pressure to the working head, where they are mixed and foamed.

One-component PPU is produced in liter aerosol cans, and even an unprepared beginner can handle them correctly. But this technology is good for a small front of work, or when you need to apply a small layer up to 2 cm thick.

PPU spraying is similar to painting with an airbrush, so it is better to close the cladding of the house. Source ppuspb.ru

If the soils are dry, the level of the top water is low and competent drainage work has been carried out, then the waterproofing of the foundation and the plinth can be omitted - there are no seams, and the water absorption of the cured polyurethane foam is small (no more than 2%). When finishing the basement with plaster, reinforcement is not necessary - there are no joints, like foam plates, and, therefore, there are no prerequisites for cracks to occur.

In addition to the price, PPU has another small drawback, which is a consequence of its dignity - good adhesion. When carrying out basement insulation work, it is necessary to protect walls that already have a finish (or do not require it) - this is easier than peeling off hardened foam.

Recently, this bulk material has rarely been used to insulate the foundation. Two factors limit its use: rather high water absorption and thermal conductivity compared to polymeric heaters.

The thickness of bulk thermal insulation can reach 60 cm Source obustroeno.com

The first indicator lies in the range of 8-20% of the volume. Moreover, such water absorption is typical for "fresh" expanded clay - over time it becomes even higher. For comparison, in ordinary foam it is no more than 4%. Therefore, it is necessary to waterproof both the foundation and the entire layer of insulation.

It is impossible to ensure complete “tightness” of expanded clay, and it will take a long time to dry underground, wrapped in a film - its use is not recommended in conditions of high seasonal groundwater rise.

Thermal conductivity also does not meet modern requirements for the thermal protection of buildings - 0.07–0.18 (W / m * ° C) versus 0.02–0.04 for PPU, 0.03–0.04 for PPS / EPS. Therefore, the recommended thickness of bulk thermal insulation for our mid-latitudes lies in the range of 40–60 cm.

The wiring diagram looks like this:

    dig a trench of the estimated width (or clear the sinus of the pit) to the heel of the foundation;

    a waterproofing film is laid over the entire area of ​​the trench - foundation-bottom-wall;

    fall asleep and level expanded clay;

    cover with a film on top;

    pour a layer of sand;

    make a blind area.

Typical scheme for warming the foundation with expanded clay Source sevparitet.ru

The advantage of expanded clay is environmental friendliness and low price. Although, taking into account waterproofing and a large amount of materials, the cost of work in the end will not be so low. In addition, the base will have to be insulated using one of the above methods.

Conclusion

The choice of a specific material and how to insulate the foundation of a house from the outside depends on many conditions - construction or repair, dry or wet soils, the depth of freezing and heaving, the volume and budget of work, the design and depth of the foundation. Therefore, such a task should be solved by professionals.

It is no less important to insulate the foundation of the house from the outside than the walls and roof, because the non-insulated base of the building passes ≈ 20% of thermal energy to the street. And these are extra expenses for heating and energy carriers. Non-insulated walls are more susceptible to the destructive power of rains, winds, frosts and the sun - moisture, turning into ice, breaks concrete, and microcracks cause the appearance of "cold bridges", accelerating the transfer of heat from the house to the outside. Ultraviolet and wind only help the destruction of concrete or brick.

The benefits of insulation

Microcracks will not always remain small, they will increase over time, thereby increasing the risk of failure. Total insulation of the foundation from the outside is the displacement of the dew point from the wall material into the insulator, which helps to maintain the technical and physical characteristics of concrete. For example, when the ground freezes by 15%, the rupture of water molecules can cause the soil to shift by 30-35 cm, which can deform it. In hard rock, these risks are reduced, but do not disappear, so the depth of the foundation of the house is calculated based on the freezing point of the soil in the region. The material is fixed vertically and horizontally, and it is desirable to do this in 2-3 layers.

Insulation of the house outside is carried out not only for heated rooms. Even in the absence of a basement, the insulation of a shallow strip foundation, together with the plinth, reduces heat losses by 15-25%.

For those who like to save money: with proper insulation of the foundation and basement, the floor of the lower floor can not be insulated.


A cold foundation creates conditions for easy penetration of air from the street into the house. Therefore, the floor level is immediately brought to 20-30 cm above the ground. If it is not insulated, the rooms in the basement and the walls of the basement will be constantly damp and cold. The benefits of insulation are manifested in the following:

  1. The overall heat losses are reduced, energy costs during the heating season are reduced.
  2. The heaving soil under the house does not deform the foundation when thawing or freezing.
  3. Prevents condensation and fungal diseases from appearing on the walls of the basement.
  4. The service life of concrete structures is increased.
  5. An additional advantage is the protection of the waterproofing layer from damage.
  6. The displacement of "cold bridges" closer to the outer surface.

The issue of insulation is solved in the same way: before pouring it around the perimeter of the trench, a fixed formwork is equipped, and it is advisable to use expanded polystyrene for it, which will be an additional warming layer. Then the foundation after pouring will be in a "bag" of expanded polystyrene and will be insulated from the outside and from the inside.

How to properly insulate

  • Beginning - digging a trench along pre-marked lines, indicated by a cord tied to pegs around the perimeter of the foundation. With a large amount of work, it is easier to rent an excavator, and it is better to trim the walls of the trench with a shovel.
  • A sand-gravel cushion ≈20 cm thick is laid on the bottom and rammed with moisture.
  • A vertical fixed formwork made of expanded polystyrene boards is attached to the outer and inner walls of the trench. Slab gaps are filled with construction mounting foam - this will help to avoid wetting the foundation with groundwater.
  • A reinforcing frame is created. For the base, reinforcing bars of 10-16 mm are used, which are knitted together with soft steel wire or fastened with special plastic clamps. Reinforcement neutralizes the action of compression and bending forces from the ground and the weight of the building.

  • Concrete mortar, prepared by hand or purchased from the manufacturer, is poured into the trench. Ordering several tons is easier and faster than preparing it in a concrete mixer. It is desirable that the foundation be filled in one go. It seizes and hardens to the declared strength for about 28 days, during which the surface is watered several times so that the concrete outside and inside hardens evenly.
  • Waterproofing is being arranged - this can be done by mounting on the walls of roofing material or polyethylene.
  • When insulating the outer foundation with your own hands, it is important not to forget about the thermal insulation of the inner walls of the base. The insulation also captures the basement, so there is no need to create an additional one - it is enough to carry out decorative finishing work on the outer walls.

This method is good for warming a shallow foundation without a basement and basement. If the house has a basement, then the process looks different: first, a foundation pit is dug with an excavator, the foundation is made of reinforced concrete blocks. If it is poured with concrete, then a wooden removable formwork is built. It is mounted at a distance of 30-40 cm from the walls of the pit, so that after pouring and hardening of the solution, it can be disassembled. The space between the concrete and the excavation is covered with soil - this is called backfilling. Expanded polystyrene will not work here - the weight of the solution will crush it.

When arranging wooden formwork, it is possible not only to insulate the outer walls, but also to lay (or apply) a layer of waterproofing. You can mount it immediately if a block foundation was built, and only after four weeks when pouring concrete. When using liquid waterproofing (bitumen, tar, mastic), the room must have a positive temperature. Rolled materials are fixed with dowels or on the same mastic.

The question of how to insulate the foundation from the outside is solved by using extruded polystyrene foam (foam foam). It has high specifications. Moreover, the depth of insulation does not depend on the thickness of the foam layer, since the plates can be built up on top of each other (in a checkerboard pattern). The thickness of the thermal insulation layer should increase, approaching the soil surface. For central Russia, up to 1-1.5 m from the ground, foam boards up to 8 cm thick are laid, then 3 cm can be used. On the north side, plates of 10 cm are attached to a depth of 1-1.5 m, below - 5 cm.

Advantages of penoplex:

  1. High rates of heat and sound insulation, strength and moisture resistance.
  2. Neutral material, thanks to which rodents, fungal organisms and insects do not damage it.

Styrofoam is fixed in several ways:

  1. heating method. To do this, with the help of a building hair dryer, the waterproofing agent is heated until it begins to melt and, until it has cooled down, a foam polystyrene plate is pressed against the wall.
  2. If the walls are uneven, then the plates are fixed to the mastic or building cement-polymer adhesive. The mastic is applied pointwise with a brush; after gluing, the fastening can not be duplicated with dowels-umbrellas.

    In both the first and second versions, the joints are filled with mounting foam.

The last step is backfilling the trench. The soil is mixed with sand in proportions of 1: 1, the gap between the foundation and the foundation pit is covered with this mixture, every 20-30 cm the sand is watered and rammed. A blind area is made on top.
backfilling

Insulation of the foundation of a wooden house

The basement is a monolithic continuation of the base, located above the ground surface, so it also needs to be insulated and protected from moisture. According to the rules, the draft level of the floor on the first floor should be on the same level as the top of the basement. Therefore, the insulation of the latter will not allow the walls to freeze, while at the same time making the floors of the first floor and the basement ceiling warm. Small additional costs are offset by savings on heating.

A house made of logs or timber may have a wooden plinth, and foam plastic is not suitable for its insulation, since polystyrene foam does not allow air to pass through. This is important for long-term operation, because such a house suffers from condensation in the basement.

Such a base is recommended to be insulated with polyurethane foam. This is a new synthetic insulation, it is applied by spraying, and the PPU expands and fills all the pores, cracks and joints between the materials. Its good adhesion helps the foam adhere to any surface.

Algorithm for warming a wooden basement:

  1. First, a wooden crate is constructed - after applying PPU, it is sheathed with a decorative finishing material, for example, siding or clapboard. Between the laths, the crate is filled with polyurethane foam using a sprayer, which, expanding during hardening, forms a continuous durable layer up to 7 cm thick. And this is enough - the thermal conductivity of the material is 0.019-0.035 W / (m · TO).
  2. The hardened excess foam is cut off with a knife or a carpentry cutter, after which the surface is covered with decorative building materials.

This method is much easier, but only suitable for wooden bases. The general principles of insulating a house from any building materials are clear and simple so that it can be done independently without using the paid services of specialists.

In this article I will tell you about how to insulate the foundation of various types. This will allow you to independently make your home more economical and comfortable.

Do I need to insulate the foundation

Often, beginners ask on the forums what is the best thing to do, insulate - the foundation or the floor? In fact, the question is incorrect, since both operations are aimed at solving different problems.

So floor insulation prevents the penetration of cold into the room through the ceiling.

The thermal insulation of the foundation performs the following functions:

  • protects the base from moisture, as well as multiple freeze / thaw cycles, and other negative factors. Thus, the insulated foundation is more durable;
  • prevents cooling of the ceiling and walls as a result of contact with the frozen foundation, respectively, reduces the overall heat loss of the house;
  • protects the basement from low temperatures, if any. This allows you to store vegetables and other products in it.

Therefore, if you decide to insulate the house, it is highly desirable to insulate the foundation as well.

External insulation of the strip foundation

First of all, consider how to insulate the strip foundation, which is the most common.

There are two ways to insulate such a base:

  • thermal insulation outside it is this method that allows you to protect the base from freezing and other negative factors;
  • insulation from the inside - as a rule, it is performed in cases where there is a basement or basement under the house. This procedure allows you to make the room warmer and, accordingly, reduce heating costs.

Often, internal insulation is performed together with the external one. Next, consider both options for thermal insulation.

So, the insulation of the strip foundation from the outside can be divided into five stages:

Preparation of materials

First of all, you need to decide on the choice of thermal insulation material. Usually, expanded polystyrene or extruded polystyrene foam is used for these purposes.

  • this material has a much higher strength than polystyrene - 0.2-0.5 MPa versus 0.07 MPa for polystyrene;
  • not afraid of moisture;
  • durability is much higher than that of polystyrene;
  • has low thermal conductivity - 0.027-0.034 W / mK versus 0.037-0.043 W / mK for foam.

The density of extruded polystyrene foam for external thermal insulation must be at least 33 kg / m 3 so that it has sufficient strength. On sale you can find a special insulation for the foundation, for example, Penoplex Foundation.

The only drawback of expanded polystyrene is the high price, which averages 4500 rubles per 1m2.

In addition to thermal insulation, you will need the following materials:

  • liquid waterproofing, for example, bituminous mastic;
  • geotextiles for arranging drainage;

  • drainage;
  • glue-foam for penoplex;
  • rolled waterproofing, for example, roofing material;
  • materials for pouring the screed (needed to equip the blind area).

Excavation work

External insulation of the foundation of a private house begins with excavation, unless, of course, you are engaged in this procedure at the construction stage.

Earthworks are carried out as follows:

  1. First of all, you need to dig out the strip foundation. To do this, dig a trench to the entire depth of the foundation, about one and a half meters wide. After that the foundation should be left for a while so that it dries well;

  1. Next, you need to perform drainage. It is especially necessary if groundwater is located close to you or if rainfall is abundant in your area.
    To arrange drainage around the perimeter of the house, you need to dig trenches at a distance of half a meter from the foundation. The depth of the trench should be such that the drainage pipe is located at the level of the base of the foundation.;

  1. fill the bottom of the trench with sand and gravel. The thickness of the layers should be about ten centimeters;
  2. then the bottom of the trench should be covered with geotextile with a twist to the edges;
  3. after that, drainage pipes are laid in the ditch. In this case, it is necessary to withstand a slope of at least 2 cm per meter. The drainage system should be connected to a storm sewer or diverted to a storm well;
  4. then fill the trench with crushed stone and wrap the pipes with the edges of the geotextile.

It is necessary to start excavation work in dry, warm work. Therefore, it is best to deal with the insulation of the foundation in late spring or summer.

The earthworks have been completed so far.

Foundation preparation

Now it is necessary to prepare the surface of the foundation for further insulation.

The work is performed in the following sequence:

  1. the dried foundation must be cleaned of soil residues and other dirt. In this case, it is necessary to remove the chipping sections of concrete. To clean the surface, you can use a metal brush;
  2. protruding areas that will interfere with the installation of insulation must be removed. Try to keep the surface as even as possible, as the durability of the foundation depends on it;

  1. to improve the adhesion of the mastic, the foundation must be treated with a bituminous primer using a roller or brush;
  2. after the surface has dried, the foundation is waterproofed. To do this, apply bituminous mastic on its surface with a roller or brush. I recommend using a ready-to-use mastic that does not need the addition of a solvent or heating.

All recesses, cracks, etc. must be filled with mastic in order to form a continuous coating with a thickness of about 2-4 mm.

Now you need to wait for the mastic to dry, and you can start warming the foundation of the house.

Insulation installation

The installation instructions for the penoplex look like this:

  1. apply glue to the back of the insulation. Glue should be located around the perimeter of the plate, as well as in the center;
  2. then the plate must be applied to the surface of the foundation and lightly pressed down. Start pasting the foundation from the corner.

Try to place the tiles as close to each other as possible. Some types of extruded polystyrene foam have chamfers, due to which they are connected into a lock;

  1. as a rule, it is impossible to ideally paste over the foundation with insulation boards. Therefore, you need to inspect the walls and fill the existing gaps with adhesive foam.

This completes the heating process. I do not recommend additionally fixing the insulation to the foundation with dowels, since it will already be securely fixed with soil. In addition, when installing dowels, you will have to make holes in the foundation that will violate its integrity.

The arrangement of the blind area

Now you need to make an insulated blind area by doing the following:

  1. the pit along the perimeter of the house must be covered with earth so that a trench remains about 30 cm deep from the ground level;
  2. then fill the trench with sand about ten centimeters thick and carefully tamp;

  1. on top of the trench, roofing material should be laid close to the walls of the house. Joints of roofing material, which should overlap each other, glue with bituminous mastic;

  1. then foam is laid on the waterproofing;
  2. a screed is poured over the foam plastic according to the standard scheme.

This completes the insulation of the foundation from the outside.

Thermal insulation of the strip foundation from the inside

Warming the foundation with your own hands from the inside can also be divided into several stages:

It is possible to insulate the basement only after its thorough waterproofing, since the room must be dry.

Preparation of materials

To insulate the foundation from the inside, you will need the following materials:

  • slab insulation - you can use any, including polystyrene or even mineral wool;
  • glue for insulation;
  • dowels-umbrellas;
  • primer;
  • reinforcing fiberglass mesh.

Wall preparation

Before insulating the foundation of the house from the inside, it is necessary to prepare it:

  1. first of all, the walls must be cleaned of dirt and dust, as well as old peeling finishes, if any. To do this, they can be brushed and then wiped with a damp cloth;
  2. then the surface of the foundation must be coated with a primer. If the base is concrete, use an adhesive primer. In other cases, you can use a universal primer.

The primer is applied with a brush or roller in a thin layer. After the first layer has dried, the procedure is repeated.

Before insulating the foundation, you need to perform thermal insulation of the floor. This operation is performed in the same way as the thermal insulation of the blind area - waterproofing and insulation are laid, after which the screed is poured.

Insulation installation

After the walls have dried, we begin the installation of insulation:

  1. if a dry mixture is used as glue, it must be diluted in water to a mushy consistency;

  1. the adhesive is then applied to the back of the board with a notched trowel. If the surface of the walls is uneven, you can apply glue in lumps;

  1. then the plate is glued to the wall. At the same time, adjust its position using the level. According to this principle, the entire first row of insulation is pasted over;
  2. the second and all subsequent rows should be staggered so that the seams of the plates do not match. During the installation process, use the level and the rule to make the surface of the walls smooth;

  1. after the glue hardens, you need to drill holes and install the dowels. Each plate must be additionally fixed with five dowels. Slightly recess the caps of the fasteners so that they do not interfere with further finishing.

This completes the installation of the heater.

Reinforcement

Reinforcement of the insulation is carried out as follows:

  1. fiberglass mesh sheets must be cut into strips of the desired length;
  2. then glue the prepared mesh to the insulation. To do this, apply the adhesive to the wall surface with a notched trowel. Then attach to the area treated with glue, and draw a wide spatula over it so that the mesh is immersed in the adhesive solution.

In this way, paste over the entire surface of the walls with a grid. At the same time, it is important to arrange it so that each subsequent strip overlaps the previous one by 10 cm;

  1. Apply a second coat of adhesive with a wide trowel after the first has dried. The layer thickness should be several millimeters.

This completes the work. Now you can prime the walls and putty them for finishing.

Thermal insulation of the pile type foundation

Now consider how to properly insulate the foundation of a private pile-type house. This work can be divided into 4 stages:

Preparation of materials

To insulate the pile foundation, it is necessary to prepare the following materials:

  • insulation - the best option is extruded polystyrene foam;
  • materials for the frame - bars and boards, you can also make a frame from metal profiles;
  • antiseptic impregnation;

  • slab isolon;
  • expanded clay
  • material for covering the foundation, for example, basement siding.

Frame installation and insulation

When insulating a pile foundation, a big problem is heaving of the soil. If you place the skin close to the ground, then as a result of heaving it will be broken.

As a rule, this problem can be solved by the gap between the skin and the blind area. But it leads to a significant decrease in the effectiveness of thermal insulation. Therefore, I recommend performing insulation according to the technology I invented.

Work begins with the arrangement of the skin, which is performed as follows:

  1. around the perimeter of the house you need to dig a trench, which will be located above the skin. The depth of the trench should be 20 cm;
  2. then the trench must be filled with expanded clay. Due to this, when the soil is heaving, the skin will not break. On top, you can lay a layer of sheet isolon (foamed polyethylene) with a thickness of at least 50 cm, which will serve not only as a heater, but also as a damper;

  1. Now you can assemble the frame. To do this, bars or boards need to be fixed on piles around the perimeter of the house. To fix them, strips with holes for bolts are welded to the piles, you can also use clamps, and do without welding;
  2. to increase the strength of the frame, horizontal rails should be connected with vertical posts;
  3. all wooden parts of the structure must be treated with an antiseptic. If the foundation of a wooden house is being insulated, also treat the wooden grillage and the lower crown of the structure with a protective compound;

  1. after that, the penoplex should be fixed on the frame. To do this, you can use ordinary nails and rivers, to which the panels will subsequently be attached;
  2. fill the gaps between the foam boards with foam;
  3. near the lower edge of the structure along the perimeter of the house, you need to install a starting profile for attaching panels. Make sure the punk is vertical;

  1. install corner profiles at all corners using self-tapping screws. Make sure the corners are vertical.

The arrangement of the blind area

The blind area is performed as follows:

  1. dig a trench around the perimeter of the house about 40 centimeters deep and 1-1.5 meters wide;
  2. cover the bottom of the trench with a layer of sand and gravel 10 cm thick. Each layer must be carefully compacted;
  3. then cover the surface of the trench with waterproofing;

  1. along the outer edge of the future blind area, make drainage according to the scheme described above;
  2. then extruded polystyrene foam is laid on top of the insulation, and a screed is poured on top according to the standard scheme.

Try to make the screed as close to the foundation as possible, so that after sheathing it, a gap of about 5-7 mm is obtained between the blind area and the foundation.

The blind area should have a slight slope from the house so that water does not accumulate at the base.

Frame sheathing

The foundation is done like this:

  1. the panels are brought into the starting bar with the lower part, with which they are connected into a hook. The extreme panels from the corner are inserted into the corner profiles. From above, the panels are attached to the crate with self-tapping screws, as shown in the diagram above.
    Thus, the entire frame is sheathed;

  1. an ebb is mounted above the casing, which allows water to be diverted to the blind area. The ebb must be of such a width that it covers the gap between the base and the blind area;
  2. at the end of the work, the gap between the blind area and the foundation sheathing should be filled with isolon. On top, you can apply building sealant. Thanks to this, water will not seep under the foundation.

This completes the process of warming the foundation.

Conclusion

From this article, you learned in detail how to insulate the foundation. I also recommend watching the video in this article. If you have any questions for me on this topic, leave them in the comments, and I will try to answer as soon as possible.

More recently, in the 80s of the last century, utility bills accounted for only 3-4% of the total family income. Today, the share of a communal apartment on average already reaches 10-15% of family income, and payment for heating - 30% of this amount. Not surprisingly, most Russian citizens prefer to keep a close eye on spending, and especially on heat leaks in homes. It has been established that the basement and foundation account for about 20% of heat loss, so the insulation of the basement of the house is just as important and necessary as it is. Properly performed insulation will not only save expensive heat, but also avoid moisture condensation on the walls of the basement, the formation and development of mold, and also protect the structure from freezing.

No. 1. Basement insulation: outside or inside?

The basement is called one of the most vulnerable parts of the house, because it bears not only a large load in the form of the weight of all walls and ceilings, but also often high humidity. A socle is called a continuation that rises above ground level and goes into. Simply put, it is a connecting and building wall, starting from the floor level of the first floor. It protects the house from the penetration of moisture and cold, and also plays a decorative role, since a house without a base looks somehow squat.

Theoretically, it is possible to insulate the basement of the foundation both from the inside and outside, but the efficiency will be very different. If carried out internal insulation, then to a certain extent it will be possible to achieve insulation of the room from low temperatures, but condensate will accumulate between the wall and the insulation, from which the basement will suffer. In addition, the latter will not be protected from the harmful effects of cold. The result will not be long in coming - the appearance of microcracks from freezing, their expansion, constant wetting, and later deformation and crumbling, and a decrease in strength characteristics.

External insulation allows you to protect both the room and the basement material from the cold, and the dew point shifts towards the insulation, which is much more resistant to moisture and low temperatures than the basement. As a result, we get an extension of the service life of the structure. Thermal insulation work is best done at the stage of building a house, but even after its construction, it is possible to perform effective insulation, although it will be a little more difficult to do so.

No. 2. Is it necessary to insulate the basement of the house?

The peculiarity of the domestic mentality is such that you want to save on everything. Hence the popular question: Is it always necessary to insulate the basement of a private house? Thermal insulation may not really be needed in such cases:

  • if the house is intended only for summer residence;
  • if the house does not have a basement, and the basement is small (0.5 m) and arranged in order to avoid flooding;
  • if the house is located in an area where there is no harsh winter.

In all these cases, you can do without. If the climate in the region is harsh, the house is used for permanent residence, and it is supposed to store food in the basement, equip it, a boiler room or other utility rooms, then you cannot do without insulation.

No. 3. Basement insulation materials

In the recent past, a mixture of clay and straw was used to insulate the basement of the foundation. Over the past few decades, many new, more advanced and convenient ways to perform thermal insulation have appeared. A series of requirements:


In addition, the insulation must be durable, vapor-permeable, resistant to and rodents.

Today, the following materials are used for insulation:

  • heat-insulating boards (foam plastic, extruded polystyrene foam, mineral wool);
  • polyurethane foam, which is applied by spraying;
  • expanded clay - the most popular option for bulk thermal insulation;
  • warm plaster;
  • thermal panels;
  • priming.

No. 4. Basement insulation with extruded polystyrene foam

Extruded polystyrene foam - the most popular material for warming the basement of the foundation. Often it is also called penoplex by the name of the company that produces the material under the trademark of the same name. The insulation resembles the one we all know, but it is more rigid and durable, it withstands soil pressure well, does not wrinkle or sag.

Advantages:


Moreover, penoplex has soundproofing properties, and thanks to the impregnation with flame retardants, it receives resistance to fire. TO shortcomings include a large number of joints - minus all tile materials. Even the largest sheets of polystyrene foam do not allow you to create a monolithic insulation structure, and the joints will have to be carefully covered or foamed. It is better to take sheets with a lock, thanks to which they fit more tightly, reducing the risk of cold bridges. In regions with a harsh climate, it may be necessary to install foam in two layers, and the plates of the second layer should close the seams between the plates of the first.

In addition, the material, although not as fragile as polystyrene, can withstand decent loads, but crumbles when cut. Installation is simple, but requires accuracy and care, takes a lot of time. It is better to practice this summer, in warm, dry weather.

A more affordable analogue of the material is polystyrene foam, which is not obtained by extrusion. It holds heat well, but has a lot of disadvantages. Firstly, it is fragility, therefore, to protect the material from soil pressure, a half-thick wall is built. Secondly, it is damaged by rodents. Moreover, the material is able to absorb moisture, so you can’t do without high-quality roll or bitumen-polymer, and the need to carry out all these works negates all the benefits of buying polystyrene foam, so the material is less and less used to insulate walls and plinth.

No. 5. Foamed polyurethane foam for basement insulation

No. 6. Mineral wool for basement insulation

No. 7. Expanded clay insulation

No. 9. Insulation with warm plaster

The best options for insulation, of course, are extruded polystyrene foam and foamed polyurethane foam, but, as you can see, under certain circumstances, other heat-insulating materials have the right to use.