How to properly insulate the foundation of a house outside. How to insulate the foundation of a house outside How to insulate the concrete foundation of a 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 simultaneously solving two important tasks: to reduce heat losses of heated premises through the basement, ground or subfloor, and also to preserve the material of building structures from destruction during winter freezing of the soil.

Arguing whether it is necessary to insulate the foundation of the house from the outside, it should be understood that both concrete and other materials from which the foundations are built are only conditionally considered waterproof. A small top layer of concrete is able to absorb moisture, which will freeze at negative temperatures, 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 basement of the building can reach 15% of the total. This is especially noticeable on slab bases and in the construction of houses without basements. Therefore, insulating 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 insulation.
After insulation.

General requirements for insulation

The foundations of buildings are regularly exposed to moisture, temperature extremes with possible freezing, constant soil pressure is exerted on them, both in the transverse and longitudinal directions. How to insulate the foundation of the house 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;
• resistance to moisture, be impervious to it;
• good strength while maintaining structure under pressure on the surface;
• unattractive to mice and insects.

The flammability 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 insulation used

Among the thermal insulation materials that meet the above requirements and have an affordable cost, you can name:

• sprayed polyurethane foam;
• sheet expanded polystyrene;

Each of the listed types thermal insulation has its own characteristics associated with the installation technology, the effectiveness of the insulation layer and the cost of purchasing the material.

Polyurethane foam (PPU)

Of all the insulation materials listed, sprayed polyurethane foam is the most expensive material that requires the use of special equipment for its application to the surface. 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, being a single continuous layer. This material for insulating the foundation of a house outside:

• has excellent adhesion and adheres well even to dirty surfaces;
• has one of the lowest thermal conductivity coefficients;
• after complete curing, it becomes waterproof;
• has 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, reducing the overall cost.

Conventional Styrofoam Boards

This material is made by heating the raw material 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 for the manufacture of most soft foams.

PPP is supplied to the market in the form of flat slabs with a locking recess at all ends. This shape allows for partial overlapping of the seams at the junction of adjacent slabs and avoids the formation of cold bridges.

The material is cheaper than polyurethane foam, but the presence of connecting joints cannot guarantee the surface protection from moisture. Therefore, before installing the thermal insulation 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. Forming of plates provides for the supply of ready-made molten polymer blend through a special extrusion machine. In this case, the foaming of the composition occurs by filling it with neutral or carbon dioxide gas. Normal 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 method of molding, 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. In terms of other technical indicators, expanded clay, frankly, loses to foamed polymers. The use of new modern technologies for the insulation of building structures has made this material poorly in demand, its use is now rare.

The ability of expanded clay to partial water absorption over time increases its thermal conductivity by 25-30%. Therefore, ensuring the effectiveness of the bulk thermal insulation 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, a complete leveling of the previously mentioned main advantage of expanded clay.

Features of the use of thermal insulation for foundations

Warming is performed only for two types of foundation foundations - strip and slab. Speaking of thermal insulation of pile and columnar 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 basement 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.

Polyurethane foam application

For 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 coarse dirt. It should not have grease stains and loose layers of building materials. Thorough cleaning and priming is not required if the surface is firm and firm.

Expanded polystyrene boards

Speaking about the installation of expanded polystyrene plates, first of all, you need to study:

• the need for a waterproofing layer;
• method of fixing slabs 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 are glued over the surface with hot bitumen.

Use primers or others liquid materials not recommended, as they will not be able to ensure the normal fixing of the thermal insulation material to the surface.

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

Plates made of ordinary PPS, which are thermally made, 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 mortar or a permanent adhesive, which is applied after the boards have been installed.

Backfilling expanded clay

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

A sandy pillow 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 cushion instead of sand. The granules are covered with an even layer 70-100 mm thick, the plates of the main heat insulator are laid on them, onto which concrete is then poured.

DIY instructions for insulating the foundation outside

The technology of installing thermal insulation on the foundation depends on the type of foundation structure and the time of year of the 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 removal of the formwork before backfilling.

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

Execution order installation works in this case the following:

• along the perimeter of the building, dig a trench with a width of at least 0.5 meters and a depth to the bottom of the base or the point of freezing 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, glue two layers of rolled waterproofing material, roofing felt or other similar material to the foundation wall;

• start the installation of expanded polystyrene boards from the bottom row, providing primary fixation with a special mounting glue;

• carry out the final fastening with plastic mounting nails with a wide head, using at least 5 pieces. on one plate.

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

After the completion of the installation of polystyrene foam plates, it is necessary to backfill the trench with layer-by-layer tamping. The device of 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 on initial stages construction of a house and is included in the general scope of work on the construction of the foundation.

Therefore, the instruction includes the 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 plastic wrap overlapping adjacent strips by 100-150 mm;

• lay on the surface expanded polystyrene plates with provision lock connections and displacement of the seams along the horizontal rows;

• to securely fix adjacent elements of the heat-insulating layer, connect them together using metal or plastic brackets;
• cover the slabs with plastic wrap and fix it to 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 base 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 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.

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

Why it is necessary to insulate the base

In "pure form" the basement is insulated if the house is on a pile or screw foundation... Have tape or slab foundation it is customary to insulate the entire base of the house. The effect of insulating only its visible (aboveground) part in the conditions of central 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-scale foundation is mostly located in this zone. This is bad for several reasons:

Thermal conductivity monolithic reinforced concrete is quite high, and the mass and area of \u200b\u200bcontact 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 bricks, and a reinforced concrete slab as a floor, then the heat losses are quite significant - up to 20%.

In the subfield, houses pass engineering Communication - water supply 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 of the first floor is carried out in the underground. The cold base and foundation do not better conditions for this part of plumbing and sewerage.

It is even possible to lay pipes on a plinth Source giropark.ru

And with reliable waterproofing in the micropores of concrete, and even more so 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 indicator. No matter how big it is, there comes a point where this resilience ends.

Insulation of the basement basement from the outside reduces heat loss, creates more "comfortable" conditions for the basement and engineering networks passing in the underground, 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 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 the effects of cold air.

Video description

Why do you need to insulate the foundation at all, as well as other necessary measures, is described in the following video:

The choice of insulation for the base

The choice of materials for thermal insulation of the basement is not as great as for the walls. Due to its proximity to the ground, its operating conditions are more extreme than those of 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. Influenced by rain and melting snow. There is also a capillary rise of water through micropores in concrete, in a brick or in a plaster finishing layer - it is not in vain that the horizontal waterproofing of the basement is carried out before the construction of the walls. And the conditions for weathering excess moisture at the basement are worse than at the walls - at the ground there is less wind speed and pressure. Therefore, the use of mineral wool for warming the basement is also eliminated according to the technology “ wet facade", And ventilated technology.

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

expanded polystyrene;

extruded polystyrene foam (EPS);

sprayed polyurethane foam (PPU).

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

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

Thermal conductivity and operating humidity of EPS are better than those of conventional foam Source severnaya-palmira.ru

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

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 trimmed in two ways - using the technology of "wet" or hinged facade. But naturally, the course of work differs, from the preparation stage to decorative finishing.

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 prior to backfilling. If the insulation is carried out separately or during reconstruction, then the foundation must be dug up to the sole and a full complex of waterproofing and insulation must be carried out.

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

The width of the trench should be sufficient for a person to work freely in it.

Thermal insulation work for the basement is already standing house harder than during construction Source w-proofing.ru

Work procedure this stage is as follows:

Surface carefully cleared of earth... Give it time to dry.

Clean up concrete build-ups ("Folds" from the unevenness of the formwork) or remove the remnants of the masonry mortar if the base is made of bricks. Dust cleaning.

Deep chips and potholes close up with repair mortar... For this, special mixtures are used, which include modifiers that accelerate the hardening of the solution.

Primed walls bituminous primer and wait until it is completely dry.

Paste the foundation to full height roll waterproofing... The work takes place from the bottom (from the sole) upwards, with the overlap of the stripes along the horizon, and when building up along the length - along the vertical. Fixation to the wall is carried out using a gas burner, which heats the bitumen on the inner surface of the waterproofing strip. For reliability, the joints are additionally treated with bitumen mastic. And if the house is on wet soils with a high level of perching water, then the pasting is carried out in two layers.

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

Thermal insulation with expanded polystyrene and EPS

The fundamental difference between how to insulate the basement of a house outside with expanded polystyrene or EPS and how to insulate the underground part of the foundation lies in the method of fixing 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, in principle, is unacceptable.

Alternatively, fixing the slab to the wall with molten bitumen of the top layer 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 flat as possible.

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

It is easier to fix the boards with a conventional adhesive solution, the layer of which allows you to compensate for small unevenness 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

Fastening of the insulation to the aboveground part of the foundation takes place in a combination of glue plus mechanical fasteners (plastic dowel-umbrellas). If in the underground part the insulation presses the backfill, then on the surface the adhesive forces of the glue will not be enough for reliable fixation. In addition, there is no pressure water pressure on the surface, which means 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, backfill 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 EPS. Better to choose extruded polystyrene foam. And why - the author of the following video well told:

Finishing work

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

Plaster or tile... A layer of glue (approximately 3 mm) is applied to the surface of the expanded polystyrene and the fiberglass mesh is pressed into it. Another layer of mortar of the same thickness is applied and the surface is leveled. After the base has dried, the base is plastered or tiled.

Source stroyfora.ru

Curtain facade... Mounted from metal profile crate. To reduce heat loss, the brackets are blown out polyurethane foam... The frame is sheathed with panels.

Source moypodval.ru

Insulation of the basement of the pile foundation

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

There are two methods of insulation - external and internal.

External insulation is used when a small wall of ordinary bricks is built along the outer perimeter of piles (reinforced concrete or screw). A small reinforced concrete foundation can even be cast for her. And in this case, the insulation technology is the same as for the base of the strip foundation.

Brick filling 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 filling) is made in the form of pile sheathing on a wooden or metal frame.

Conclusion

Insulation of the basement from the outside is carried out as part of 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 structure. And this is a task for specialists. However, as well as the execution of the work itself.

Insulating the basement base from the outside is a laborious and difficult job, but if you follow the recommendations and follow the exact order of 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 base to avoid its destruction and deformation

Thermal insulation benefits

Insulation of the basement in a private house from the outside protects it from negative impact 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 base from freezing and mechanical damage

Such a structure will last much longer without major repairs. On the walls of the insulated basement no condensation, it saves construction Materials from premature destruction.

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

For internal insulation used finishing of decorative materials for more attractiveness. Whereas the inner lining is often left simply plastered.

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

Material characteristics

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

For independent work, polystyrene foam is most often chosen.

Installation of cladding on a plinth

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

Making a concrete blind area

Any foundation is required to make a concrete blind area. 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

First you need to do formwork, which prevents the spreading of the concrete solution. The mixture of gravel and sand is leveled with a rake. Further, pegs are hammered along the entire perimeter, a frame made of boards is installed in front of them.

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

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

Insulation measures for 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 guides describing how to properly insulate indoor spaces buildings, then less attention is paid to the insulation of the foundations of private houses. This article is devoted to the features of foundation insulation 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 a basement is provided in the house and it is used as a garage or for other purposes. As a rule, not the entire basement is insulated, but only the basement part 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 the thermal insulation of the foundation, the following tasks will be achieved:
2. general reduction in heat loss;
3. reducing the cost of heating the building;
4. reduction of negative effects caused by soil heaving;
5. stabilization of the average temperature in the house;
6. preventing the formation of condensation on the walls;
7. additional protection of the waterproofing layer.

Two main methods of insulation

It is possible to insulate the foundation of a private house, both at the stage of its filling, 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 during the construction of the foundation. If possible, the outer side of the base is provided with thermal insulation, since it then provides additional mechanical protection.

One of the most effective ways to insulate the foundation involves the use permanent formwork... It is mounted from expanded polystyrene and, after the concrete mixture has set, 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 can withstand the serious mechanical stress exerted by the surrounding soil. Given these conditions, the following methods are best suited for insulation:

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

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

Creation of thermal insulation using expanded clay and sand

In the past, this method of external basement insulation 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 gap, which protects the structure from damage due to 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 using 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 systemconsisting of a layer of crushed stone, a perforated pipe and another layer of rubble. The created pipeline is diverted to the well;
• The surface of the foundation is cleaned and dried, after which waterproofing works are carried out;
• The pit is covered 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 in along the outer perimeter, while the width of the trench should be about a meter. The base wall must be thoroughly cleaned of dirt and dried before starting work, after which a latex primer is applied to it. The primer fills in all voids and ensures a strong adhesion to the waterproofing layer. Laying roll waterproofing material is carried out with pressure. After sealing the joints and drying the waterproofing, you can start working with the insulation:

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

Using liquid polyurethane foam

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

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

Advantages of polyurethane foam as an insulating material:

• increased adhesion;
• complete absence of seams in the heat-insulating layer;
• savings on additional waterproofing;
• operational 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 the polyurethane foam from exposure to ultraviolet radiation.

Thermal insulation by means of mineral wool

A rather rarely used method that requires the equipment of an additional protective frame to prevent cotton wool from getting wet. How to properly insulate the base of a 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, outside the cotton wool is covered with a protective vapor-permeable film;
• erection of an additional brick wall, providing partial mechanical protection.

Insulation of a columnar foundation

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

• 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;
• A metal frame is laid on the pillow, on top of which a concrete solution is poured;
• Solid brickwork is installed on the hardened concrete, small ventilation holes are left.

Conclusion

This article describes the basic methods of how to properly insulate the foundation of a private house, listing the procedure for carrying out construction work. For a more detailed acquaintance with the technology of basement insulation, we recommend that you read the advice of experts, watch several videos in which these methods are applied in practice.

What is the best way to build a house?

Insulation of the foundation of the house

One of the key elements of construction that is often overlooked is foundation insulation. At the same time, the installation of foundation insulation is just as important as for walls. Especially relevant work data 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 a rapid destruction of the structure of building materials.

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

Why it is 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 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 base plate must be insulated. And the foundation itself goes below the depth of soil freezing. This avoids the destructive effect of frost heaving mounds that arise in winter. The determination of the seasonal level of the soil subject to freezing lies with the designers.

Insulation of the foundation is not only the installation of additional insulation to protect against cold air. This process includes calculating the floor level.

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

Insulation of the foundation is also used for waterproofing the structure.

With the correct work on the insulation of the base of the building, you get:

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

How best to insulate the foundation - outside or 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 foundation (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 made 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 frost penetration. Problems also arise during 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 outside

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

The soil has a set of its own physical characteristics. It was found that the resistance to freezing of the foundation walls should be one less than the thermal resistance of the outer walls of the house.

Insulation of the foundation outside

The insulation thickness is determined by the formula:

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

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

Pile foundation

Insulation of the pile foundation

This type of foundation is gaining popularity due to its strength and reliability at a 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, plates of extruded polystyrene foam are used. So it is possible to maintain the integrity and position of the blind area. These plates should be laid 0.3-0.4 meters below the blind area. The recommended size is 1.25 meters wide and 50 mm high.

Column foundation

Thermal insulation of the foundation, which is a system of posts, is most often performed using extruded polystyrene foam. Foaming polyurethane foam is sometimes used.

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

Insulation of a columnar foundation

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

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

Penoplex has 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, outside insulation is much more important. To protect the walls of the basement, several layers of thermal insulation materials are used. For the preservation of the structure of the materials, it is important that the waterproofing of the foundation guarantees the removal of moisture.

After preparing the trench, the soil must be compacted before pouring the foundation. After that, a layer of sand cushion of 10-15 cm is poured. Compaction is carried out again. Now a thin layer of "footing" is poured, and in some cases insulation materials are applied to the sand bed. After waterproofing, the basement is additionally insulated.

Materials and methods of warming 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 shape:

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

Also, fibrous, cellular and granular types are distinguished. The raw materials for manufacturing are divided into organic, inorganic and artificial.

One of the most popular materials for insulation is polystyrene foam. It is cheap and has good operating characteristics. It happens 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 polystyrene foam keeps heat well. Extruded polystyrene foam has its drawbacks:

• Low resistance to solvents.
• Fire susceptibility.

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

1. Solvents of organic origin must be used in fasteners. 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 install a waterproof covering to protect against rainwater.

Polyurethane foam allows you to create a heat-insulating layer without seams during work. This creates reliable protection from the penetration of air with low temperatures. 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.
• It is completely harmless.
• Resistant to compression and tension.
• Extruded polystyrene foam boards are relatively inexpensive.

What insulation for the foundation to choose

Foundation insulation cannot be universal. For each specific home and for each condition, the best type of material can be selected.

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

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

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

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

Insulation of the foundation with polyurethane foam

Is a special material that is used for thermal insulation of the foundation. It has successfully implemented high performance in heat, water and sound insulation. It is applied to the surface in layers and using a special pump. This spraying is about 0.5 cm and provides excellent insulation and foundation protection.

During practical application polyurethane foam, its following advantages were determined:

1. Lack of butt seams that are weak point insulation designs.
2. High adhesive properties.
3. Low heat permeability.
4. Reduced vapor permeability.
5. Reliability.
6. The durability of the material.

The disadvantages are:

1. The need to use special equipment for installation.
2. Destruction by ultraviolet radiation.

The known extruded polystyrene foam only benefits from low cost and easy installation. These slabs perfectly insulate the foundation from the damaging effects of moisture. They absolutely do not let water through and preserve the integrity of the foundation. This allows us to talk about a long service life of the plates while maintaining the original characteristics.

Warming the foundation with expanded polystyrene

Foam, which is so readily used to protect the foundation, has low performance characteristics. Yes, it's cheap and convenient. But after several changes of seasons and passing through cycles of freezing and thawing, it simply collapses and ceases to protect the foundation.

For a complete set of buildings and vertical insulation of foundations, plates with various degrees of compression are used (an indicator of the strength of the product). So, when strengthening the foundation, slabs with a strength of 250 kPa are suitable. For the floor, you must 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. The duration of operation is from 40 years and more. At the same time, all the properties of the material are preserved in their original form for the entire period of use.
2. High performance of the material in strength tests.
3. Stable level of thermal insulation properties throughout the entire period of operation.
4. Resistant to mechanical stress from rodents.