How to properly insulate the foundation of the house from the outside. How to insulate the foundation of the house from the outside How to insulate the concrete foundation of the house

Master of Architecture, graduated from the Samara State University of Architecture and Civil Engineering. 11 years of experience in design and construction.

Thermal insulation of the foundation structure allows you to simultaneously solve two important problems: to reduce the heat loss of heated premises through the basement, soil or subfloor, and also to save the material of building structures from destruction during the winter freezing of the soil.

When arguing whether it is necessary to insulate the foundation of a house from the outside, it should be understood that both concrete and other materials from which foundations are built are only conditionally considered waterproof. A small top layer of concrete is able to absorb moisture, which will freeze at a negative temperature, expand and lead to a violation of the integrity of the foundation.

Comparison of thermal conductivity of building materials.

As a result of repeated freezing of the soil and insufficiently reinforced hydraulic insulation, the building structure can be severely damaged or even destroyed.

Heat loss through the floors and the basement of the building can reach 15% of the total volume. This is especially noticeable in slab foundations and in the construction of houses without basements. Therefore, the insulation of the foundation of the house from the outside will allow in the future to save significant funds on energy resources, the cost of which is constantly growing.

Before warming.
After warming.

General requirements for insulation

The foundations of buildings are regularly exposed to moisture, temperature changes with possible freezing, they are subjected to constant soil pressure, both in the transverse and longitudinal directions. How to insulate the foundation of the house from the outside? First of all, the selected insulation must have:

• low thermal conductivity;
• resistance to temperature extremes in the range from -40°C to + 20°C;
• resistant to moisture, be impervious to it;
• good strength with structure retention under pressure on the surface;
• unattractive to mice and insects.

The combustibility of the material for external insulation of the foundation, located below ground level, does not matter, since the probability of exposure to a flame is extremely low. There are also no special conditions for vapor permeability, although water resistance already implies the presence of this parameter.

Types of heaters used

Among the heat-insulating materials that meet the above requirements and have an affordable cost, we can name:

• sprayed polyurethane foam;
• sheet expanded polystyrene;

Each of listed species thermal insulation has its own characteristics associated with the installation technology, the effectiveness of the insulation layer and the amount of costs for the purchase of material.

Polyurethane foam (PPU)

Of all the listed heaters, sprayed polyurethane foam is the most expensive and requires the use of special equipment for its application to the surface of the material. However, it is also the most effective insulation of all existing polymeric materials.

Its main feature is that the polyurethane foam coating does not have connecting seams, representing a single continuous layer. This material for warming the foundation of the house from the outside:

• has excellent adhesion and excellent adhesion even on contaminated surfaces;
• has one of the lowest thermal conductivity coefficients;
• after complete hardening becomes waterproof;
• characterized by good hardness combined with high ductility;
• absolutely unattractive to rodents and insects.

The water resistance of polyurethane foam allows you to abandon the installation of a waterproofing layer. This significantly reduces the time required to insulate the foundation of the house from the outside, reduces the overall cost.

Ordinary polystyrene boards

This material is made by heating the feedstock poured into the mold with hot steam. Under the influence of temperature, expanded polystyrene granules expand, forming a porous mass that occupies the entire volume of the mold. This technology is used to make most soft foams.

PPS is supplied to the market in the form of flat slabs with a key notch at all ends. This form allows for partial overlapping of the seams at the junction of adjacent plates and avoiding the formation of cold bridges.

The material is cheaper than polyurethane foam, but the presence of connecting joints cannot guarantee the protection of the surface from moisture. Therefore, before installing the heat-insulating layer, a mandatory waterproofing device is required.

Extruded polystyrene foam

This material differs from the previous version in the manufacturing technology and quality of the plates. Slab molding provides for the supply of ready-made molten polymer mixture through a special extrusion machine. In this case, the foaming of the composition occurs due to filling it with neutral or carbon dioxide. Ordinary air is not used for this, because. this will affect the fire hazard.

Extruded polystyrene foam is somewhat more expensive than usual, but, thanks to this molding method, it does not have a single open pore on a smooth and even surface. This means a longer service life and improved thermal insulation properties.

Expanded clay

The main advantage of expanded clay granules is the lowest cost among all heaters used for foundations. For other technical indicators, expanded clay, frankly, loses to foamed polymers. Application of new modern technologies for the insulation of building structures made this material poorly in demand, its use is now rare.

The ability of expanded clay to partially absorb water over time increases its thermal conductivity by 25-30%. Therefore, ensuring the effectiveness of the bulk heat-insulating layer requires a large thickness, and, therefore, a significant consumption of material. This, in turn, leads to an increase in costs and, as a result, the complete leveling of the previously mentioned main advantage of expanded clay.

Features of the use of thermal insulation for foundations

Insulation is performed only for two types of foundation foundations - tape and slab. Speaking about the thermal insulation of pile and column structures, they mean the installation of insulation on the lower surface of the slab, which is the floor of the first floor, and the insulation of the foundation base from the outside.

There is simply no point in insulating support pillars and piles. In these places, there is practically no temperature difference between the surface of the building structure and the environment.

Application of polyurethane foam

For the professional performance of thermal insulation work, a two-component composition of polyurethane foam and special equipment for mixing and spraying the finished mixture are used.

Before starting work, the surface must be cleaned of old plaster layers and large contaminants. It should not have grease stains and loose layers of building materials. Thorough cleaning and priming is not required if the surface is dense and sound.

Styrofoam boards

Speaking about the installation of polystyrene foam boards, first of all, you need to study:

• the need for a waterproofing layer;
• method of fixing the plates on the vertical surface of the foundation;
• protection of the polymer from negative environmental influences.

Bitumen-impregnated roll materials are used as hydraulic insulation. They paste over the surface with hot bitumen.

Use primers or other liquid materials is not recommended, since they will not be able to ensure the normal fixing of the heat-insulating material on the surface.

Initially, PPS boards are fixed to the surface with a special adhesive. When installing adjacent elements, it is necessary to provide interlocks to seal the joints. The final fixing of the plates is carried out using special plastic nails with large round caps (fungi).

Plates made of ordinary PPS, which is thermally manufactured, are subject to protection from negative influences. This is due to the presence of open pores on the surface of the material. The treatment can be done with a cement or stable adhesive mortar, which is applied after the installation of the boards.

Expanded clay backfill

The foundation wall must be covered with a waterproofing layer of rolled materials. To insulate the strip foundation with expanded clay, a trench 40-60 cm wide is dug along the perimeter of the building to the depth of soil freezing.

A sand cushion 5-7 cm thick is poured onto its bottom. After that, the trench is completely covered with expanded clay granules to the level of the blind area, well tamped. The blind area is poured directly onto the expanded clay layer.

For slab foundations, a layer of expanded clay can be used as a support pad instead of sand. The granules are covered with an even layer 70-100 mm thick, the slabs of the main heat insulator are laid on them, on which concrete is then poured.

Instructions for warming the foundation outside with your own hands

The technology of installing thermal insulation on the foundation depends on the type of foundation structure and the season of work.

To insulate the underground part of the strip foundation, it is necessary to provide free access to the surface of the building structure. For a building under construction, this is easier to do. The insulation is installed immediately after the formwork has been removed and before backfilling is performed.

For already operated buildings around the perimeter of the house, it is necessary to dig a trench at least 500 mm wide and deep, to the freezing point of the soil.

The slab base is insulated with heat-insulating plates only during the installation of the structure.

Strip foundation

The most common option for insulating the vertical walls of the foundation tape from the outside is the use of extruded polystyrene foam boards.

Order of execution installation work in this case the following:

• dig a trench along the perimeter of the building with a width of at least 0.5 meters and a depth to the bottom of the base or the freezing point of the soil;

• thoroughly clean the surface of the wall from soil residues and other contaminants, allow time to dry well;
• apply a layer of bituminous soil in 2 times, which can be bought ready-made or made from a primer;
• using hot bitumen, stick two layers of rolled waterproofing, roofing felt or other similar material on the foundation wall;

• start the installation of polystyrene foam boards from laying the bottom row, providing primary fixation with a special mounting adhesive;

• perform the final fastening with wide-headed plastic mounting nails, using at least 5 pcs. on one plate.

When laying the slabs, it is necessary to observe the locking connection of adjacent insulation elements. The vertical seams of the second row should not coincide with the seams of the first.

After the installation of polystyrene foam plates is completed, it is necessary to backfill the trench with a layer-by-layer rammer. The blind area can be performed only after a year, when the final shrinkage of the soil occurs.

slab foundation

Insulation of the foundation slab is carried out at the initial stages of building a house and is included in the general scope of work on the foundation foundation.

Therefore, the instruction includes part construction works this stage:

• remove the topsoil layer to the design depth;
• level and compact the surface;
• spread a layer of geotextile, which is designed to prevent the capillary rise of groundwater and the germination of weeds;
• pour a layer of crushed stone-sand or expanded clay cushion 100 mm thick, compact it well;

• lay a layer of polyethylene film overlapping adjacent strips by 100-150 mm;

• lay on the surface polystyrene boards with the provision interlock connections and offset seams along the horizontal rows;

• for reliable fixation of adjacent elements of the heat-insulating layer, connect them together using metal or plastic brackets;
• cover the plates with plastic wrap and fix it on the surface.

After that, you can proceed with the installation of the formwork and the collection of the reinforcing frame for pouring concrete.

Insulation of the basement of the foundation from the outside should be considered as a stage of general work on the thermal insulation of the building. Each enclosing surface has its own characteristics in terms of the nature of operation, the physics of heat transfer and the influencing factors. This affects the choice of materials and methods of insulation. What works well on a roof or attic is completely unsuitable for the foundation and its visible part - the basement.

The general scheme of complex insulation of the base of the house Source stroy-dom-pravilno.ru

Why is it necessary to insulate the basement

In its “pure form”, the basement is insulated if the house is on a pile or screw foundation. At the tape or slab foundation It is customary to carry out thermal insulation of the entire base of the house. The effect of warming only its visible (above-ground) part under conditions middle lane Russia is purely decorative.

If you look at the map of the depth of soil freezing, you can see that from the western border to the Urals it lies in the range from 1 m to 1.8 m. And in the Moscow region, the soil freezes up to 1 m 40 cm.

It looks like a map with isolines of freezing depth Source centermira.ru

It turns out that any shallow foundation for several months a year (up to six months, depending on the "severity" of the season) is entirely exposed to negative temperatures. Even the full-length foundation is mostly located in this zone. And this is bad for several reasons:

Thermal conductivity monolithic reinforced concrete is quite high, and the mass and area of ​​contact with cold air and earth is large. It turns out that the entire foundation is a large heat exchanger that is in direct contact with the ceiling and load-bearing walls. And if the walls are made of brick, and the floor is a reinforced concrete slab, then the heat loss is quite significant - up to 20%.

In the underground of the house pass engineering Communication - plumbing and sewerage. When they "rise" from the ground, they have to cross the freezing zone. Not to mention those cases when horizontal laying of communications on the first floor is carried out in the subfield. Cold plinth and foundation do not create Better conditions for this part of the water supply and sewerage.

It is even possible to lay pipes along the plinth Source giropark.ru

And with reliable waterproofing in the micropores of concrete, and even more brick, there is always some moisture. When freezing, it expands, microcracks appear, which increase in size during the next thawing / freezing cycles. The number of such cycles that the material transfers without destruction determines the frost resistance index. No matter how great it is, there comes a point when this fortitude ends.

And the insulation of the foundation basement from the outside reduces heat loss, creates more “comfortable” conditions for the basement and engineering networks passing in the subfield, moves the dew point from the wall to the insulation (thereby extending the life of the foundation). It is only important to choose the right way to insulate the basement of the house from the outside.

The pile foundation is not such a powerful heat exchanger, but its insulation will increase the overall level of protection of the house, and especially the first floor, from exposure to cold air.

Video description

Why it is generally necessary to insulate the foundation, as well as other necessary measures, is described in the following video:

The choice of insulation for the basement

The choice of materials for the thermal insulation of the base is not as great as for the walls. Due to its proximity to the ground, its operating conditions are more extreme than near the walls.

When calculating wind loads, it is taken into account that they are significantly lower near the ground. This means that the conditions for weathering excess moisture from materials are worse. Source docplayer.ru

Almost always there is a higher level of intrinsic moisture content of materials. Rain and snow melt have an effect. There is also a capillary rise of water through micropores in concrete, in brick or in the plaster layer of the finish - it is not in vain that they carry out horizontal waterproofing of the basement before building walls. And the conditions for weathering excess moisture near the base are worse than near the walls - the wind speed and pressure are lower near the ground. Therefore, the use of mineral wool for insulation of the basement is also eliminated according to the technology " wet facade”, and by ventilated technology.

Insulation for the basement of the foundation choose from three types of foam:

expanded polystyrene;

extruded polystyrene foam (EPS);

sprayed polyurethane foam (PPU).

Note! Usually, “in everyday life”, polystyrene means expanded polystyrene, but this is a whole class of cellular plastics from different polymers and varying degrees of rigidity.

In practice, extruded polystyrene foam is most often chosen. Conventional expanded polystyrene and hardened polyurethane foam have lower resistance to mechanical stress, higher water absorption coefficient and higher thermal conductivity.

The thermal conductivity and operational humidity of XPS is better than that of conventional foam Source severnaya-palmira.ru

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

basement insulation technology

There are several ways to insulate the basement of a house, depending on its design and finishing method.

Insulation of the basement strip foundation

If we draw parallels with the insulation of the facade, then the basement of the strip foundation is insulated and finished in two ways - using the technology of a "wet" or hinged facade. But of course, the course of work has differences, ranging from the preparation stage to the decorative finish.

Preparatory stage

As mentioned above, the basement is the visible part of the foundation, and it must be insulated in combination with the underground part. This is best done during the construction phase before backfilling. If insulation is carried out separately or during reconstruction, then the foundation must be dug up to the sole and a full range of waterproofing and insulation should be carried out.

Important! Unlike the facade, basement waterproofing is included in the mandatory list of works before insulation.

The width of the trench must be sufficient so that a person can freely work in it.

Carrying out thermal insulation work for the basement already standing house harder than during construction Source w-proofing.ru

Work procedure this stage is the following:

surface carefully cleared from the earth. Give it time to dry.

Clean up concrete spills("folds" from the irregularities of the formwork) or remove the remnants of the masonry mortar, if the base is made of bricks. Cleaned from dust.

Deep chips and gouges sealed with repair mortar. To do this, use special mixtures, which include modifiers that accelerate the hardening of the solution.

The walls are primed bituminous primer and wait for it to dry completely.

Cover the foundation to its full height roll waterproofing. The work goes from the bottom (from the sole) up, with the overlap of the strips along the horizon, and when building up along the length - vertically. Fixing to the wall occurs with the help of a gas burner, which heats the bitumen for inner surface waterproofing strips. For reliability, the joints are additionally treated with bituminous mastic. And if the house stands on wet soils with a high level of top water, then pasting is carried out in two layers.

Waterproofing must pass in a continuous layer from the sole of the base and to the entire height of the base. Source pol-pro.com

Insulation with expanded polystyrene and EPS

The fundamental difference between how to insulate the basement of a house from the outside with polystyrene foam or XPS and how to insulate the underground part of the foundation lies in the method of attaching the plates.

The slabs are fixed to the surface of the underground part of the foundation exclusively with the help of an adhesive solution. The use of mechanical fasteners will damage the waterproofing, which is basically unacceptable.

Alternatively, fixing the slab to the wall on the molten bitumen of the upper layer can be used. roll waterproofing. But the method itself is quite risky and requires verified accuracy in handling the burner, and in order for the fastening to be reliable, the surface itself must be as even as possible.

Attention! Use cold bituminous mastics to isolate joints or fasten insulation boards, it is necessary to be extremely careful. Some types of ready-made compositions contain components that are aggressive towards polystyrene.

It is easier to fix the plates with a conventional adhesive solution, a layer of which allows you to compensate for small irregularities in the base. And this is the only way of fastening when the insulation is carried out in two layers.

Two-layer insulation is necessary for the basement floor Source giropark.ru

The fastening of the insulation to the above-ground part of the foundation takes place in a combination of glue plus mechanical fasteners (plastic dowel-umbrellas). If the backfill presses the insulation in the underground part, then on the surface the adhesion forces of the adhesive will not be enough for reliable fixation. In addition, there is no water pressure on the surface, which means that there are no conditions for its penetration through the fasteners into the materials from which the base is built.

After the expanded polystyrene plates are fixed over the entire surface of the foundation, backfilling is carried out and a blind area is equipped (insulated if the soils are heaving).

Video description

Once again about the choice between foam and XPS. It is better to choose extruded polystyrene foam. And why - well explained the author of the following video:

Finishing work

There are two types of finishes for the insulated basement of the strip foundation:

Plaster or tile. A layer of adhesive (approximately 3 mm) is applied to the surface of the expanded polystyrene and a fiberglass mesh is pressed into it. Apply another layer of the same thickness of the solution and level the surface. After the base has dried, the base is plastered or tiled.

Source stroyfora.ru

hinged facade. Mounted from metal profile crate. To reduce heat loss, the brackets are blown mounting foam. Sheathe the frame with panels.

Source mypodval.ru

Insulation of the base of the pile foundation

In this case, we are talking about the construction of a small closed subfloor under the floor of the first floor.

There are two types of insulation - external and internal.

External insulation is resorted to when a small wall of ordinary brick is built along the outer perimeter of piles (reinforced concrete or screw). For it, they can even cast a small reinforced concrete foundation. And in this case, the insulation technology is the same as for the base of the strip foundation.

A brick fence on a concrete base does not differ from a wall on a shallow foundation Source etokirpichi.ru

Internal insulation is carried out when the base (or pick-up) is made in the form of sheathing piles on a wooden or metal frame.

Conclusion

Insulation of the basement from the outside is carried out as part of the complex work on the hydro- and thermal insulation of the foundation. To do this correctly, and not “by eye”, it is necessary to carry out calculations and develop a full-fledged project, taking into account the characteristics of the region, site and base design. And this is a task for specialists. However, as well as the performance of the work itself.

Insulating the basement of the foundation from the outside is a laborious and difficult job, but if you follow the recommendations and follow the exact procedure for laying the material, you will get a result that will keep the house warm for many years. Before starting thermal insulation work, it is necessary to study the structural features of the house. A competent approach will save on heating and protect the foundation from deformation.

Insulation of the basement of the foundation to avoid its destruction and deformation

The benefits of thermal insulation

Basement insulation in a private house from the outside protects it from negative impact underground groundwater and atmospheric precipitation, thereby improving the microclimate not only in residential premises, but also in the basement of the house.

Thermal insulation keeps the plinth from freezing and mechanical damage

Such a structure will last much longer without overhaul. On the walls of the insulated basement no condensation, it saves Construction Materials from premature failure.

Internal thermal insulation performs a similar function. As practice shows, external and internal insulation has the same result. The difference between them is only external.

Used for internal insulation finishing from decorative materials for more attraction. Whereas the inner lining is often left simply plastered.

How to properly insulate the foundation with polystyrene foam yourself, you will see from this video:

Material characteristics

The foundation, along with other structures of the house, needs to be insulated. It is important to choose the right insulator, taking into account the structure of not only the basement, but also the house. Basement insulation materials:

For independent work most often choose polystyrene foam.

Mounting the sheathing on the plinth

You can insulate the basement of the house from the outside with your own hands both during construction and during the operation of the house. Stages of installation of thermal insulation:

Production of concrete pavement

Every foundation needs a concrete pavement. It can be from 80 cm to 2 m, it all depends on the characteristics of the soil. If the trench was covered with a sand and gravel mixture, the blind area is made 1 m wide.

Concrete blind area is necessary to protect the foundation from moisture

To get started, you need to do formwork which prevents spreading concrete mortar. A mixture of gravel and sand is leveled with a rake. Further, pegs are hammered along the entire perimeter, a frame of boards is installed in front of them.

The blind area is performed with a slope so that water does not linger at the foundation and move away from the wall of the building. Then proceed to pour the blind area with concrete. If desired, tiles are laid on top of the concrete base. The foundation is trimmed decorative stone or tiles after the plaster has dried. You can limit yourself to simple painting.

It is not difficult to insulate the basement from the outside. This work will take no more than 3-4 days, but the result will please for many years. The house will be reliably protected from bad weather and rapid destruction.

Measures for warming a private house for our climatic latitudes are mandatory. Moreover, if with the insulation of walls and roofs everything is more or less clear and in the public domain you can find many manuals describing how to properly insulate interior spaces buildings, less attention is paid to the insulation of the foundations of private houses. This article is devoted to the features of the thermal insulation of the foundation and the results that are achieved with its help.

What goals are achieved by insulating the foundation

Like waterproofing, insulation serves as a tool to protect the foundation from negative influences. external environment. If the walls and roof of the building are provided with thermal insulation, then the foundation becomes the main source of heat leakage from the dwelling, especially if the house has a basement and it is used as a garage or for another purpose. As a rule, not the entire basement is insulated, but only the basement of the foundation in order to reduce the level of heat loss at the level of the first floor. This measure becomes mandatory if the house is built on a pile foundation.

1. As a result of thermal insulation of the foundation, the following tasks will be achieved:
2. overall reduction of heat losses;
3. reducing the cost of heating the building;
4. reduction of negative effects caused by heaving of the soil;
5. stabilization of the average temperature in the house;
6. prevent condensation on the walls;
7. additional protection of the waterproofing layer.

Two main types of insulation

It is possible to insulate the foundation of a private house, both at the stage of its pouring, and after the mixture has solidified. The second option is used to insulate an already built house, but it is not as effective as the first method, which is implemented only in the process of building a foundation. If possible, the outer side of the base is provided with thermal insulation, since in this case it provides additional mechanical protection.

One of the most effective ways foundation insulation involves the use fixed formwork. It is mounted from polystyrene foam and after the concrete mixture has hardened, it is not disassembled, but continues to serve as thermal insulation from the inside and outside of the foundation.

What materials can be used for insulation

To create an effective thermal insulation layer, it is necessary to choose a material that does not absorb moisture and withstands a serious mechanical load exerted by the surrounding soil. Given these conditions, the following methods are best suited for insulation:

• creation of an insulating layer of expanded clay, sand or earth;
• installation of an insulating structure made of foam plastic, polystyrene or similar functional properties materials;
• the use of mineral wool;
• insulation of the foundation of a private house with polyurethane foam.

These materials are suitable for buildings, as well as houses built from foam blocks. Their thermal insulation parameters and cost are different, so when choosing a material, you should analyze the advantages and disadvantages of the selected material in order to find the best option.

Creating thermal insulation using expanded clay and sand

In the past, this method of external insulation of the foundation was the most popular. Its advantage lies in the property of expanded clay, which protects the surface of the foundation from moisture and creates air layer, protecting the structure from damage during heaving of the soil during severe frosts. And it is also necessary to note the simplicity of this technique - everyone could organize the thermal insulation of the foundation of the house with their own hands without the use of special equipment.

The process of thermal insulation using expanded clay is carried out in several stages:

• A pit is dug along the outer perimeter of the foundation;
• The bottom of the pit is equipped drainage system, consisting of a layer of crushed stone, a perforated pipe and another layer of crushed stone. The created pipeline is diverted to the well;
• The surface of the foundation is cleaned and dried, after which waterproofing work is carried out;
• The pit is filled with expanded clay or sand.

The advantages of this method include the low cost of materials and ease of work.

Insulation with sheet material

Before insulating the foundation of an already erected building, it is dug around the outer perimeter, while the width of the trench should be about a meter. Before starting work, the base wall must be thoroughly cleaned of dirt and dried, after which a latex primer is applied to it. The primer fills all the voids and provides a strong setting with the waterproofing layer. Laying rolled waterproofing material is carried out with pressure. After sealing the joints and drying the waterproofing, you can start working with insulation:

• A special adhesive is applied, necessary to hold the plate (along the perimeter of the heat-insulating plate with a solid line and several strokes in the central part).
• Separate slabs are pressed against the foundation, each new sheet overlaps the previous one.
• If the foundation wall is high enough and one row of slabs is not enough, a checkerboard arrangement is preferable to avoid seams.
• In case of formation of cracks, they should be puttied with a sealant or filled with foam.
• Part of the insulation above the ground is covered with finishing glue, fixing a reinforcing mesh on the surface. Before continuing work, you must wait three days for the glue to dry.
• Formwork is being assembled for the basement. The slab is located on a sand and gravel cushion and is closed with a reinforcing mesh.
• After the blind area has dried, you can start finishing work.

Use of liquid polyurethane foam

Cured polyurethane foam provides, in addition to thermal insulation, additional protection against moisture. Due to the cellular structure, a 5-centimeter layer of this material is comparable in efficiency to a meter-thick polystyrene foam plate, which means that additional work from inside the basement are not required.

The technique for applying expanded polystyrene is quite simple: the external, pre-cleaned wall of the foundation is covered with the material in a liquid state. Examples of the work can be found on the numerous videos published on the Internet.

Advantages of polyurethane foam as a heat-insulating material:

• increased adhesion;
• complete absence of seams in the heat-insulating layer;
• savings on additional waterproofing;
• service life within 40 years;
• the material is environmentally friendly.

Unfortunately, there are also disadvantages:

• relatively high cost;
• special equipment is required to work with the material;
• it is necessary to protect polyurethane foam from exposure to ultraviolet radiation.

Warming with mineral wool

A rather rarely used method that requires the equipment of an additional protective frame that prevents the cotton wool from getting wet. How to properly insulate the base of the building with mineral wool:

• cleaning and drying of the foundation wall, elimination of surface defects;
• creating a frame from a metal profile or other material;
• fixing mats on a frame basis, the outside of the wool is covered with a protective vapor-permeable film;
• construction of an additional brick wall providing partial mechanical protection.

Warming of the columnar foundation

The methods described above are applicable to monolithic and strip foundations, however, they are not suitable for a columnar foundation. To ensure thermal insulation of the space between the soil and the grillage, it will be necessary to create a special pick-up. This element is functionally similar to the base, but since it is not loaded, the requirements for structural strength are significantly lower. Work sequence:

• In the intervals between the pillars of the base, a 50-centimeter trench is dug, a third of its volume is filled with a sand-gravel mixture;
• Placed on a pillow metal carcass over which concrete mortar is poured;
• Solid brickwork is installed on the hardened concrete, small ventilation holes are left.

Conclusion

This article described the main methods of how to properly insulate the foundation of a private house, listing the order of construction work. For a more detailed acquaintance with the technology of foundation insulation, we recommend that you familiarize yourself with the advice of specialists, watch several videos in which these techniques are applied in practice.

What is the best way to build a house?

Insulation of the foundation of the house

One of the key building elements that is often overlooked is foundation insulation. At the same time, the installation of foundation insulation is just as important as for walls. Particularly relevant data of the work for regions with a harsh climate and in cases of freezing of the ground level to a considerable depth. The penetration of cold air leads to the rapid destruction of the structure of building materials.

According to studies, the foundation accounts for 15-20% of the heat loss of the entire structure. It is from the basement and the quality of its performance that the heat inside the living quarters depends.

Why is it necessary to insulate the foundation

Insulation for the foundation is calculated at the design stage of the future building. Based on the initial data (temperature indicators and humidity of the region, load, groundwater), a specific material is selected and the required layer thickness is calculated.

The waterproofing of the foundation, as well as the thermal insulation of the foundation, play an important role in maintaining its integrity. If the ground level rises, then the deformation of the foundation is inevitable. Especially if the technology is violated during the work: the foundation slab must be insulated. And the foundation itself goes below the freezing depth of the soil. This avoids the destructive effect of frost heaving mounds that occur in winter. Determination of the seasonal level of soil subject to freezing lies with the designers.

Foundation insulation is not only the installation of additional insulation to protect against cold air. This process includes the calculation of the floor level.

Direct insulation of the foundation guarantees the preservation of heat in the lower part of the house, and hence throughout the building. During the operation of the building, the owner saves significant funds on heating.

The insulation of the foundation also serves to waterproof the structure.

At proper conduct work on the insulation of the base of the building, you get:

• Reducing heat loss.
• Reduced heating costs.
• Eliminate the negative effects of frost heaving.
• Stabilization of the temperature inside the house.
• Minimizes the formation of condensation.
• Promotes strength under mechanical stress.

What is the best way to insulate the foundation - from the outside or from the inside

The thickness of the insulation for the foundation is determined by many factors, including:

1. Building class and future use.
2. Atmospheric indicators of the region.
3. The type of soil underlying the base (including the level of soil freezing).
4. Insulation material.

Thermal insulation of the foundation inside and outside the house,

Thermal insulation for the foundation can be done both from the outside and from the inside. Most builders claim that external insulation gives the best results. Compared to external insulation, internal insulation does not provide protection against external freezing. There are also problems with ground movement due to the expansion of freezing moisture.

Application of additional bituminous waterproofing contributes to the preservation of the structure of the material, but does not save from frost heaving.

How and how to insulate the foundation from the outside

The insulation of the foundation determines the creation of a comfortable temperature regime in the premises. Also, the owner of the house will experience an impressive reduction in the cost of heating rooms - this is due to a decrease in heat loss. Depending on the level of soil freezing, the type of optimal insulation is also established.

The soil has a set of its own physical characteristics. It has been established that the freezing resistance of the foundation walls should be one less than the heat resistance of the outer walls of the house.

Insulation of the foundation from the outside

The thickness of the insulation is determined by the formula:

δ ut \u003d (R required -1.05-δ / λ) * λ ut
In the presented values
δ ut - the thickness of the thermal insulation of the foundation, m;
R required - normalized resistance to heat transfer of the wall;
δ - thickness bearing wall foundation in meters;
λ - coefficient of thermal conductivity of the material of the bearing part of the foundation;
λ ut - coefficient of thermal conductivity of the thermal insulation of the foundation.

Of course, not only the level of soil freezing affects the development of insulation for the foundation. Depending on the type of foundation construction, a project is drawn up for strengthening and insulation, as well as measures such as covering bituminous waterproofing and much more.

pile foundation

Pile foundation insulation

This type of foundation is gaining popularity, in view of the strength and reliability at the speed of construction and low cost. If the piles are installed below the freezing depth of the soil, then there is no need to insulate the pile. But it is important to insulate the foundation around the perimeter - for this, extruded polystyrene foam plates are used. So it is possible to maintain the integrity and position of the blind area. These plates should be laid below the blind area by 0.3-0.4 meters. The recommended size is 1.25 meters wide and 50 mm high.

Column Foundation

The insulation of the foundation, which is a system of columns, is most often carried out using extruded polystyrene foam. Sometimes expandable polyurethane foam is used.

Styrofoam is optimal for insulating a columnar foundation from the inside. But it has one clear advantage over other materials - low cost. Therefore, it is readily mounted outside. Although this is not recommended.

Warming of the columnar foundation

Expanded clay is also a cheap material. It is often poured into pre-installed formwork from the inside of the foundation.

TechnoNIKOL foundation insulation is a classic mineral wool. It is also installed from the inside. The main advantage of warming the foundation with technonicol is the absorption of moisture by the material.

Penoplex is distinguished by the best strength and durability. In all respects, he is among the leaders, but the cost of the material corresponds to the quality.

Strip foundation

For this type of foundation, insulation from the outside is much more important. To secure the walls of the basement, several layers of heat-insulating materials are used. For the preservation of the structure of materials, it is important that the waterproofing of the foundation guarantees the removal of moisture.

After preparing the trench, before pouring the foundation, the soil must be tamped. After that, a layer of a sand cushion of 10-15 cm is covered. The ramming is carried out again. Now a thin layer of “concrete” is poured, and in some cases insulating materials are applied to the sand cushion. After waterproofing, the basement is additionally insulated.

Materials and methods of insulation of the foundation

The choice of thermal insulation materials in the modern construction market is incredibly diverse. It is best to build on what is proposed in the project (if this is not the case, contact the architect for revision).

After determining all the necessary indicators, including the depth of soil freezing, decide on the type of insulation. They may differ in structure and form:

• Piece heaters.
• Flexible.
• Loose, etc.

There are also fibrous, cellular and granular types. Raw materials for manufacturing are divided into organic, inorganic and artificial.

One of the most popular materials for insulation is foam. It is cheap and has good performance in operation. There is foamed and extruded. Installation is also extremely simple and can be done on your own.

A popular type of foam is extruded polystyrene foam. It has a strong structure and is characterized by high hygroscopicity, and expanded polystyrene also retains heat well. Extruded polystyrene foam has its drawbacks:

• Low resistance to solvents.
• Ignition susceptibility.

When working with polystyrene foam, there are separate mandatory rules:

1. Solvents of organic origin must be used in fixing compositions. Mechanical destruction of the structure of the material reduces its protective properties.
2. If the soil is subject to frost heaving, then it should be additionally protected from mechanical damage. This is done using brickwork or a special polyethylene membrane.
3. It is mandatory to lay a waterproof coating to protect against rainwater.

Polyurethane foam allows you to create a heat-insulating layer that does not have seams during work. This creates reliable protection against the ingress of low temperature air. The coating is applied with a special pump in several layers.

The material has low thermal conductivity and excellent protection against noise and corrosion. It is fireproof, waterproof and durable.

Most modern projects insulation is provided, in which plates of extruded polystyrene foam are used, which are one of the types of foam. It has a number of advantages that make it a leader among heaters:

• The material is durable and has a long service life.
• He is absolutely harmless.
• Stable under compression and stretching.
• Extruded polystyrene boards are relatively inexpensive.

What insulation for the foundation to choose

Thermal insulation of the foundation cannot be universal. For each specific house and for each conditions can be selected best type material.

Foundation insulation requires attention from builders at all stages, starting with the choice of insulation.

The main criteria for choosing material for the foundation of the house:

1. Stability under changing pressure, under the influence of compressive and tensile forces that change throughout the year.
2. Resistance to the penetration of moisture into the structure of the material.

1. extruded polystyrene foam
2. spraying with polyurethane foam.

Insulation of the foundation with polyurethane foam

- This is a special material that is used for thermal insulation of the foundation. It successfully implemented high rates of insulation of heat, water and sound. It is applied to the surface in layers and using a special pump. This coating is about 0.5 cm and creates excellent insulation and protection of the foundation.

During practical application polyurethane foam has the following advantages:

1. The absence of butt joints, which are weak point insulation structures.
2. High adhesive properties.
3. Low thermal conductivity.
4. Reduced vapor permeability.
5. Reliability.
6. Material durability.

Of the minuses can be identified:

1. The need to use special equipment for installation.
2. Destruction under the influence of ultraviolet radiation.

The well-known extruded polystyrene foam wins only due to its low cost and simple installation. These plates perfectly isolate the foundation from the destructive effects of moisture. They absolutely do not let water through and maintain the integrity of the foundation. This allows us to talk about the long service life of the plates while maintaining the original characteristics.

Insulation of the foundation with polystyrene foam

Styrofoam, which is so willingly used to protect the foundation, has low performance. Yes, it's cheap and convenient. But after several seasons and cycles of freezing and thawing, it simply collapses and ceases to protect the foundation.

To complete buildings and vertical insulation of foundations, plates with different degrees of compression are used (an indicator of the strength of the product). So, when strengthening the foundation, plates with a strength of 250 kPa are suitable. For the floor, it is necessary to choose materials that have this indicator at the level of 500 kPa.

When choosing extruded polystyrene foam, the user must clearly understand its main advantages:

1. Duration of operation - from 40 years and more. At the same time, all material properties are preserved in their original form for the entire period of use.
2. High material performance in strength tests.
3. Stable level of thermal insulation properties throughout the entire period of operation.
4. Stability under the mechanical influence of rodents.