Types of insulation for walls. Review of types and characteristics of insulation materials, their areas of application

Insulating the foundation of a house from the outside is no less important than the walls and roof, because the uninsulated base of a building allows ≈ 20% of thermal energy to pass through to the street. And this extra expenses for heating and energy. Uninsulated walls are more susceptible to the destructive power of rain, wind, frost and sun - moisture, turning into ice, breaks concrete, and microcracks cause the appearance of “cold bridges”, accelerating the transfer of heat from the house to the outside. Ultraviolet and wind only help the destruction of concrete or brick.

The benefits of insulation

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

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

For those who like to save: when proper insulation the foundation and plinth, the floor of the lower floor does not need to be insulated.

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

The overall heat loss is reduced, and energy costs during the heating season are reduced.
The heaving soil under the house does not deform the foundation when thawing or freezing.
Prevents condensation and fungal diseases from appearing on the basement walls.
The service life of concrete structures increases.
An additional advantage is the protection of the waterproofing layer from damage.
Shift of “cold bridges” closer to the outer surface.

The issue of insulation is resolved in the same way: before pouring it, the perimeter of the trench is not equipped with removable formwork, and it is advisable to use polystyrene foam for it, which will be an additional warming layer. Then, after pouring, the foundation will be in a “bag” of polystyrene foam and will be insulated from the outside and inside.

How to properly insulate

The beginning is digging a trench along pre-marked lines, marked with a cord tied to pegs around the perimeter of the foundation. At large volume It’s easier to rent an excavator, and it’s better to level the walls of the trench with a shovel.
A sand-crushed stone cushion with a thickness of ≈20 cm is placed on the bottom and compacted with moisture.
Vertical permanent formwork made of expanded polystyrene slabs is attached to the outer and inner walls of the trench. Inter-plate cracks are filled with construction material polyurethane foam– this will help avoid the foundation from being moistened by groundwater.
A reinforcing frame is created. For the base, reinforcing bars of 10-16 mm are used, which are tied together with soft steel wire or fastened with special plastic clamps. Reinforcement neutralizes the effects of compression and bending forces from the soil and the weight of the building.

It is poured into the trench concrete mortar, prepared by hand or purchased from the manufacturer. Ordering several tons is easier and faster than preparing it in a concrete mixer. It is advisable that the foundation be poured in one go. It takes about 28 days to set and harden to the stated strength, during which the surface is watered several times so that the concrete hardens evenly outside and inside.
Waterproofing is installed - this can be done by attaching roofing felt or polyethylene to the walls.
When insulating the external foundation with your own hands, it is important not to forget about the thermal insulation of the internal walls of the foundation. The insulation also extends to the base, so there is no need to create additional ones - just make decorative Finishing work external walls.

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

When settling in wooden formwork It is possible not only to insulate the outer walls, but also to lay (or apply) a layer of waterproofing. It can be installed immediately if a block foundation was built, and only after four weeks when pouring concrete. Using liquid waterproofing(bitumen, tar, mastic) the room must have a positive temperature. Rolled materials are secured with dowels or the same mastic.

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

Advantages of penoplex:

High levels of heat and sound insulation, strength and moisture resistance.
Neutral material, so it is not damaged by rodents, fungal organisms and insects.

Expanded polystyrene is attached in several ways:

Warm-up method. To do this using construction hair dryer heat the waterproofing material until it begins to melt and, until it cools down, press the expanded polystyrene slab against the wall.
If the walls are uneven, then the slabs are attached with mastic or construction cement-polymer adhesive. The mastic is applied pointwise with a brush; after gluing, the fastening does not need to be duplicated with umbrella dowels.
In both the first and second options, the joints are filled with polyurethane foam.

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

Insulation of the foundation of a wooden house

The base is a monolithic continuation of the base, located above the ground surface, so it also needs to be insulated and protected from moisture. According to the rules, the subfloor level on the first floor should be at the same level as the top of the plinth. Therefore, insulating the latter will prevent the walls from freezing, while simultaneously making the floors of the first floor and the ceiling of the basement warm. Small additional costs are offset by savings on heating.

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

It is recommended to insulate such a base using polyurethane foam. This is a new synthetic insulation, it is applied by spraying, and the polyurethane foam expands and fills all the pores, cracks and joints between materials. Its good adhesion helps the foam adhere to any surface.

Algorithm for insulating a wooden base:

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

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

For normal operation of the building, it is necessary to insulate the foundation of the house from the outside and lay polystyrene foam under the blind area. The thermal insulation circuit solves several problems - expanding the frost-free zone, eliminating swelling, cold bridges and heat loss. The need for measures to eliminate swelling conditions (freezing + moisture + clay soil) is separately indicated in the standards SP 22.13330 (foundations), departmental VST, territorial TSN (for example, MF-97 for the Moscow region).

In order for an individual developer to insulate the foundation without errors, it is necessary to take into account that the owner’s expenses always consist of the construction estimate and the operating budget. Accordingly, by changing any of these points, you can automatically affect the other:

by refusing to insulate the blind area or foundation, the owner saves on the purchase of expanded polystyrene, but heating and repair costs increase;
By investing in thermal insulation, the developer increases initial costs, but automatically reduces operating costs.

By investing money in their own home, a young family receives an advantage in retirement in the form of significantly lower payments utilities due to energy savings and lack of foundation repairs.

Heat distribution diagram near the foundation. It can be seen that the freezing boundary is moving away from the foundation.

Depending on the operating mode of the building, the developer’s budget and the type of soil, horizontal and vertical insulation contours solve different problems:

blind area - an EPS tape laid under it moves the freezing zone outward from the house, swelling is impossible in the soil layers adjacent to the foundation;
outer vertical surface of the tape - protection of waterproofing, elimination of cold bridges, reduction of heat loss through the floor/floor of the house, shifting the dew point outward for normal operation of the underground floor;
horizontal layer under the base of the MZLF - if the building does not have heating or is heated during periodic visits, to eliminate freezing of the soil underneath it is necessary to retain the heat of the subsoil with a continuous layer of polystyrene foam.

Important! A set of works to eliminate swelling must be carried out only on clay soils. However, heat loss in a complex plinth assembly with multilayer cladding, adjoining various designs from unequal material can only be prevented by external thermal insulation vertical surfaces of the foundation.

Materials and technology for foundation insulation

With the existing diversity thermal insulation materials Foundation insulation is most often made with extruded high-density polystyrene foam EPS, XPS, Carbon SP from TechnoNIKOL, Penoplex Foundation. Unlike mineral, glass and ecowool, polystyrene foam retains its heat-insulating properties, even when completely immersed in water. For comparison - basalt wool loses 30% of its properties when wet and begins to slide off vertical surfaces under its own weight. Rely on soft insulation concrete structures prohibited.

Insulation materials

To protect the foundation of a private cottage, the following thermal insulation materials are most effective:

polyurethane foam - marked PPU, sprayed onto the surface, also available in the form of slabs, density 50 - 60 kg/m3, thermal conductivity corresponds to 0.028 units, costs twice as much as expanded polystyrene;
extruded polystyrene foam - various designations among manufacturers, boards different sizes, density 35 - 45 kg/m3, thermal conductivity 0.03, costs less than the previous option.

Insulation of the foundation with extruded polystyrene foam.

The polyurethane foam used to fill the seams of insulation is made of polyurethane foam. Therefore, when using Penoplex, EPS, the quality of the joints is higher than that of the main surface.

The main disadvantage of expanded polystyrene is its low chemical resistance - the material is dissolved by petroleum products. Therefore, it is not recommended to paste over concrete surfaces, treated with bituminous mastics, welded roll materials having a bitumen layer. It is better to use polymer mastics, membranes or polyethylene films. Polyurethane foam is inert to petroleum products, acids, alkalis and salt solutions.

Budget foam plastic PSB-S has a density of 15 - 25 kg/m3, thermal conductivity of 0.04 units, and vapor permeability of 0.05. This insulation is used in the following cases:

outer layer of vertical crushable insulation;
permanent formwork for a low grillage (lower horizontal deck).

In the first case, insulation is necessary to protect the main layer of heat insulation. In the second option, the foam remains after pouring the grillage under reinforced concrete structure, is crushed by soil during heaving so that heaving forces cannot tear the grillage beams away from the pillars or piles, the heads of which are embedded in the structure.

Technology overview

Insulation of the foundation is carried out according to different schemes depending on the operating mode and design. Anti-swelling protection is required for columnar, strip and slab foundations. Heaving forces practically do not affect the piles, however, with a low grillage on bored piles, screw piles the beams must be positioned at least 10 cm above the ground.

Scheme for insulating the foundation and outside blind area for a house with constant heating.

There are three main operating modes at home:

constant heating - insulation reduces heat loss, expands the zone of non-freezing soil around the building and protects the foundation from the effects of negative temperatures;
heating is completely absent - eliminating heat loss in this case is pointless, however, it is necessary to preserve geothermal heat under the building to prevent soil freezing, so the blind area + the entire perimeter of the garden house under the sole is insulated;
heating is turned on periodically (baths and cottages) - since episodic heating is present, it is necessary to reduce heat loss in the ceilings and floors, the outer surface of the grillage, strip, slab and blind area is insulated; when there is no heating, there is a need to preserve the heat of the subsoil, so the entire perimeter of the house under the sole is insulated foundation.

IN garden houses without heating, laying polystyrene foam at the level of the foundation base is not always economically profitable:

If the depth of the pillars or MZLF is within 40 cm, it makes sense to make a pit, since the fertile layer will still have to be completely removed in order to make floors on the ground.

If the tape or columnar foundation lie deeper earthworks can be avoided by laying insulation according to a different scheme:

under the blind area - the perimeter of soil freezing moves away;
under the base of the foundation – protection against swelling;
on the inner surface of the tape + under the floor along the ground - preservation geothermal heat under the entire foundation structure.

If for some reason it is impossible to fill the pit openings with non-metallic material that does not contain clay and, accordingly, frost swelling, instead of the standard insulation of the outer surfaces of the strip foundation, a crush-sliding thermal insulation scheme should be used:

pasting external concrete vertical surfaces with high-density polystyrene foam;
covering it with polyethylene (attached only in the base part);
installation of low-density polystyrene foam PSB-S close to the film without fastening (pressed with backfill material).

This option is especially relevant for deep-laying belts. Contact area of the side surfaces of the tape with clay soils is huge, the pulling loads are very significant. When heaving forces occur, the soil crushes the foam and moves it upward along the slippery film. The main layer of insulation is not harmed; after the spring thawing of the soil, the outer layer moves down again.

Important! Insulation is only one method of eliminating swelling in a set of measures. Therefore, drainage and nonmetallic materials in the underlying layer and backfilling of sinuses cannot be canceled.

In classical technologies monolithic foundations(slab, tape, pillars) to reduce the lower protective layer of concrete, level the base, and eliminate leaks of cement laitance from the concrete at the time of pouring, a concrete screed is used.

If a building for seasonal, periodic operation is insulated with a layer of expanded polystyrene along the entire perimeter of the pit, then there is no need to make a concrete footing. This allows us to slightly reduce the construction budget.

Errors in foundation insulation

Due to lack of experience, individual developers often make mistakes when insulating foundations:

cold bridges - the thermal insulation contour must be continuous, the seams must be foamed, the joints of the slabs must be displaced in the case of a multilayer contour in adjacent layers;
the use of low-density materials - PSB-S is allowed only for the lower deck of the grillage, the outer layer of crushable thermal insulation;
violation of thermal insulation schemes - for basements, MZLF buildings with constant heating, it is necessary to insulate the tape from the outside, without heating and when the heating is periodically turned on - from the inside;

Cold bridges, which negate the effectiveness of insulation work, usually occur at the junction points of the base elements:

lack of lateral vertical thermal insulation along the perimeter of the floor screed on the ground;
uninsulated concrete preparation;
absence of polystyrene foam on the upper horizontal edge of the protruding base;
incorrect combination of basement insulation and façade insulation.

Errors in pairing the insulation of the base and façade.

Important! It is impossible to correct the cold bridge created as a result of facing the facade with brick, the bottom row of which is installed directly on the protruding plinth.

Thus, despite the fact that it is recommended to install insulation on the outer surfaces of the foundation, this scheme correct only for homes with constant heating mode. In garden houses, thermal insulation is made along the inner edges of the tape. The blind area is always insulated; crushable thermal insulation is usually necessary for deep-lying tapes.

Owners of private houses, in an effort to make their home warm, sometimes pay attention only to the walls and ceilings. At the same time, they forget that insulating the foundation is an equally important point.

As a result, problems arise with cold floors and excessive heating costs. Once you invest effort and money in insulating the load-bearing base, you can save an impressive amount on heating costs.

What causes the need for thermal insulation?

A significant portion of the cool air enters the room through the foundation. Therefore, many building designs are designed to raise the floors above ground level. Warm, heated air rushes upward. When the roof is not insulated, heat leaks out. And the room is filled with cold air, which penetrates through the floors of the building. Therefore, the need for thermal insulation of the load-bearing base is obvious. If the walls are in frozen ground, the room will have to be constantly heated.

When it comes to preserving heat in an old house, you should remember that all components of the system must retain heat: the foundation, walls, ceilings and roof. If just one thing releases heat, the entire building will not be able to keep it at a high level.

High-quality foundation insulation can reduce the impact groundwater and cold on the base of both wooden and stone buildings.

Insulation methods

All insulation methods are usually divided into two types. The first is before the foundation is poured, the second is the insulation of the finished structure. The first option is preferable and is the one that is used most often. In harsh winter conditions concrete foundation insulated on both sides.

Concrete is known for its almost complete lack of thermal insulation; it cools easily and heats up just as easily. During construction, they use both insulation, which is mounted directly into the formwork, and special permanent formwork. Such panels cost several times more than simple ones, but the amount of costs is lower than the price of dismantling simple formwork and subsequent insulation.

Insulating the foundation of an already used house is a complex and responsible undertaking. In cases where the building is built with insufficient foundation depth, freezing of the soil underneath will be very strong. In such situations, for thermal insulation, the foundation is dug both inside and outside, and later insulation is laid. At the same time, to prevent freezing of the floor in the basement of an old building, it is sprinkled with expanded clay.

Already long years the most commonly used methods of foundation insulation remain unchanged: using earth, expanded clay or expanded polystyrene.

Earth insulation

This option is the most economical, despite the impressive volumes of sand that will have to be unloaded and leveled. The method consists in filling the earth up to the level of the future floor, as a result the entire basement and foundation are underground.

Soil insulation is carried out before the construction of the house begins. It is imperative to provide a ventilation shaft for the basement.

Advantages of the method:

when insulating with soil, you don’t have to buy insulation;
the house will not freeze through the basement.

Flaws:

large volumes of earth and sand will have to be leveled;
soil is a weak heat insulator;
the foundation walls will let cold into the room, albeit in smaller quantities.

Thermal insulation with expanded clay

One of the cheapest and most effective methods. Sometimes builders combine insulation with soil and expanded clay.

During the process of pouring the foundation, expanded clay is placed in inner part pre-fabricated formwork. This method is used both for insulating walls and floors, in both cases it is quite effective. Unique properties Expanded clay is enclosed in its porous structure, thanks to which it does not allow moisture and cold to pass through and retains heat well. The only losses occur due to the fact that the cavities between the granules are filled with cement, and it is a conductor for cold.

Expanded clay insulation is often used for strip foundations. With a low-depth foundation, the material is used to insulate the floor in order to completely get rid of freezing of the ground in the basement.
If insulation occurs after pouring, then the lightest formwork is usually used, since expanded clay is practically weightless. Sometimes slate sheets are used as formwork.

Expanded clay is a fragile insulation material. When used for floor insulation, lay on expanded clay mineral wool and film to protect against moisture.

What about foam?

When deciding how to properly insulate a foundation, the choice often falls on the foam insulation method. This is a universal and affordable material.

Polystyrene foam is sold in sheets that are easy to install. Therefore, its use allows you to do all the work yourself.

Waterproofing

Before fixing the insulation sheets, it is important to waterproof the surface. There are many methods of waterproofing:

applying several layers bitumen mastic;
waterproofing with roofing felt;
plastering the surface;
application of special penetrating compounds.

Laying slabs

After ensuring waterproofing, sheets of expanded polystyrene are mounted on the insulated surface. The sheets are laid from the bottom of the foundation to the level of the future floor. The insulation is secured using special adhesives that are applied pointwise to its surface. Expanded polystyrene sheets must be laid close to each other to create a monolithic surface. The seams between the insulation boards are sealed with polyurethane foam.

Expanded polystyrene breaks down over time when exposed to sun rays, therefore it should be securely closed from above with cladding panels.

Thermal insulation around the perimeter

Before insulating the foundation around the perimeter, you need to remove the soil along the entire base of the building to a depth of about half a meter and a width of about one and a half meters. After creating the trench, approximately 20 cm of sand is poured in and it is thoroughly compacted.

Expanded polystyrene slabs are installed on the “sand cushion”. For added reliability insulation materials are attached using special adhesives, for example, bitumen mastic. The joints formed between the plates are blown out with foam. You can also fill the gaps using cold-applied bitumen mastic.

After fixing the insulation and completing the remaining related work, sand is again filled with a layer of at least 3 m.

Corner areas of buildings lose more heat than flat surfaces. Therefore, in these places you should use a larger (one and a half times) layer of polystyrene foam.

The advantages of perimeter insulation with expanded polystyrene foam are as follows:

the design of the insulated foundation is protected from deformations and cracks;
the basement is also thermally insulated;
polystyrene foam has good operational properties, which makes it a fairly durable material.

Expanded polystyrene can also be used for internal insulation old house if it is impossible to carry out external insulation. To do this, the walls are glued from the inside foam boards. A room insulated in this way can become a full-fledged room.

Using penoplex

Penoplex material is more advanced than polystyrene foam. prevents its deformation, the building will last longer.

Penoplex has a closed-cell structure, so it is not susceptible to the destructive effects of water. Other important advantages of the material are its strength and low thermal conductivity.

How is installation carried out?

Penoplex can be installed only a week after waterproofing, the methods of which were described above.

Penoplex is produced in the form of slabs with grooves of a certain configuration. These grooves ensure a very tight fit of the plates to each other without gaps.

Fastening is carried out with special adhesives. You need to choose only those compounds that are not capable of destroying the insulation. The glue is applied pointwise, gradually treating small surface areas. The slab is applied to the foundation and pressed for 40 seconds. After gluing the slabs, proceed to the next section. The process continues until the entire surface of the base of the building is insulated.

The slabs must be glued so that they protrude 35–50 cm upward. After installation is completed, the resulting voids are filled with non-heaving materials. At the end they carry out thermal insulation soil around the perimeter.

High strength sealed board using PU foam

Polyurethane foam or PPU - modern construction material with many advantages. It is characterized by low thermal conductivity, strength, durability and environmental friendliness. Working with polyurethane foam is easy - no additional fasteners are required for installation, and it is applied to the surface quickly. PPU has high waterproofing properties, which prevent moisture from entering, thereby protecting the building.

The main advantage of using polyurethane foam as insulation is the inability to spoil the result - the final coating is always obtained without cracks, irregularities and joints.

How to work with polyurethane foam?

It occurs by spraying insulation onto the surface using special installations. The resulting foam is firmly connected to the base of the structure, filling all cavities. The result is a high-strength slab, very hard and airtight. Since the material has a closed structure and air gap is absent, then condensation cannot appear in such a product.

Thermal insulation of the foundation with polyurethane foam is the most effective method. It is suitable for both new buildings and for thermal protection of an old house. But the cost of such insulation is high and it is impossible to carry out the work yourself, since special equipment is required.

There are many options for waterproofing and insulating the foundation; all you have to do is choose which one is most suitable.