Insulating the foundation from the outside is a necessary measure to create a comfortable temperature in the house and basement. Thermal insulation of the foundation and basement allows you to save on energy costs for heating the house, which will please any owner.

Insulating the foundation from the outside - a rational solution or a waste of time?

The foundation is the basis of any house, building or structure. High-quality construction of this foundation will help to avoid future problems such as wall cracks, building subsidence, etc. Proper operation of the foundation, in turn, will solve the problems of wear and loss of structural strength. Therefore, thermal insulation is a necessary measure to protect the foundation and base of a house from the influence of the external environment.

Insulation of a concrete base is usually carried out on the outside of the house. An option is possible when the foundation is insulated from the inside, but this is done if it is impossible to insulate the building from the outside for some reason. Insulation from the outside is more profitable, since freezing and the formation of condensation moisture occurs from the street. For greater efficiency, you can combine these two options by isolating the foundation from the outside and inside.

Proper and timely insulation of the foundation will help avoid the following problems:

• formation of condensation on the walls of the basement. The basement must be dry to ensure the safety of supplies, and condensation leads to the formation of mold and mildew. Thus, not only food, but also building materials deteriorate;
• cold floor in the house. Waking up in the morning and standing on an icy floor straight from a warm bed is invigorating, but very unpleasant. As you know, your feet should be warm. Therefore, cold floors not only conduct cold into the room with impunity, but can also easily cause colds;
• cracks in the foundation. Cracks form due to frost heaving of the soil. Soil heaving occurs when wet ground suddenly freezes, and at this moment it is able to exert strong pressure on the foundation. Therefore, waterproofing in the insulation process is a very important stage.

So, the need for external thermal insulation comes down to the following points:

1. protection of the foundation from freezing and temperature changes;
2. increasing the service life of communications;
3. increasing the service life of the foundation structure;
4. protection from moisture and soil heaving;
5. absolute savings in energy costs.

Stages and options for insulating the foundation from the outside

Ideally, the foundation should be insulated at the stage of building a house when there is free access to the entire surface. To isolate the foundation of an already built house, you will have to carefully dig it out and clear it of soil. Work will need to be carried out carefully to prevent cracks from occurring. But, nevertheless, in both cases the thermal insulation will be effective.

When insulating the external foundation, polystyrene foam, extruded polystyrene foam, polyurethane foam and expanded clay are used. The most popular insulation material is polystyrene foam, which is probably due to its advantages: affordable price, resistance to moisture and ease of use. At the same time, it is necessary to remember about its low degree of fire resistance.

Insulation of the foundation from the outside is divided into several stages:

1. Preparatory work. It is necessary to remove the soil to the freezing depth and to a width of about 50 cm. The foundation is cleared of soil and dust. Next, you need to seal all the seams and cracks in the foundation with primer and construction foam.

The depth of soil freezing is an indicator whose value varies depending on the climatic zone and soil composition. The lower the temperature drops, the greater the freezing depth. The value of this indicator by region and region can be found in SNiP (building codes and regulations).

1. Waterproofing. To insulate from moisture, you can use rolled bitumen or liquid rubber. Liquid rubber is applied with a spatula to the primed surface, and rolled materials are secured by heating them with a torch.
2. Insulation of the foundation. After the waterproofing layer has taken its place, you can begin direct thermal insulation.

• Polystyrene foam and polystyrene foam. If the waterproofing was done with bitumen, then it must be heated with a burner and foam plastic/expanded polystyrene boards attached to it. In the case of liquid rubber, you can use mastics. They are applied pointwise or stripwise onto the foam and attached to the foundation. In both cases, you can install the insulation using mushroom dowels (4–5 pieces per sheet). The seams between the sheets are closed with reinforced mesh and cemented.
• Polyurethane foam. It is applied by spraying, thanks to which it fills all cracks and leaves no seams. Clings well to any surface. The required layer of polyurethane foam is from 5 cm. Spraying requires special equipment and the help of specialists.
• Expanded clay. In this version of thermal insulation, it is necessary to simply pour expanded clay into the prepared trench. The dimensions of the trench for this insulation should be 1 m wide. Roofing felt is also useful to cover the expanded clay on top and lay it on the bottom of the ditch as waterproofing.

1. Before filling everything with earth, it is recommended to apply another layer of waterproofing material if the insulation was done with polystyrene foam or polyurethane foam.

How is the basement insulated from the outside?

The base is the upper part of the foundation, which is in contact with both the floor of the building and the underground part of its base. An uninsulated base is a good conductor for cold air and dampness. Therefore, the comfortable temperature in the house directly depends on the level of thermal insulation of this area of ​​the exterior of the house. The role of insulation for the base will be taken over by the already familiar polystyrene foam and extruded polystyrene foam. Perhaps there is something left after insulating the foundation, then it will be profitable to purchase the required amount of material, and you can get to work.

Thermal insulation of the base from the outside consists of several stages:

• First you need to make markings. You need to use a level (laser or water) to determine the top point of the basement finishing and stretch horizontal ropes around the perimeter of the building.
• Prepare the surface. Cleaning from dirt and priming with a deep penetration compound.
• Prepare sheets of polystyrene foam/expanded polystyrene. If the wall protrudes further than the base and vice versa, then the sheets must be cut in accordance with the size of the protrusion.
• Insulation of the basement from the outside. It is better to start thermal insulation from the corner of the house. Glue is applied to the foam sheet with a notched trowel and pressed tightly against the surface of the base along the line of the stretched rope. To prevent the insulation board from moving, it can be secured with dowels or screws.

The dowels must be plastic, since, unlike metal ones, they do not conduct cold air, i.e. do not create cold bridges in the places where the insulation is attached.

• Insulation finishing. After the entire base has been insulated, it needs to be treated with a primer, and the façade corners must be attached to the corners. You need to glue a reinforcing mesh onto the surface of the foam plastic; cement glue is useful for this. When the glue has dried, you can putty the surface with a solution for exterior use. Apply another layer of primer to the dried putty and you can finish lining the base (painting, fastening decorative elements).

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Thermal insulation of the foundation is no less important than the thermal insulation of the walls, especially in areas with a harsh climate. Frozen soil cannot protect the foundation of a house from moisture and cold, and the foundation itself, after repeated freezing, begins to collapse faster. To get rid of these problems and reduce the cost of heating your home, you need to know how to insulate the foundation of a house from the outside, and how you can do it yourself.

The foundation of a house is regularly exposed to moisture, increased load, and temperature changes. After the onset of frost, the accumulated moisture freezes, destroying the material, and through cracks in the concrete the cold penetrates into the home. As a result, the house always has cold floors, dampness emanates from under the baseboards, and condensation or frost appears on the basement walls (in severe frosts). For thermal insulation to be effective, the insulation must have the following characteristics:

• low thermal conductivity;
• waterproof;
• good mechanical strength;
• resistance to temperature changes.

There are no strict requirements for the vapor permeability of the material, but insulation materials with low vapor permeability are usually used, just like the concrete foundation itself. The flammability of the material is not of great importance, because the underground part of the building is least susceptible to fire risks.

Which insulation to choose

Mineral wool insulation for foundations is not the most suitable option: they tend to accumulate moisture, losing their thermal insulation properties, and are not sufficiently resistant to mechanical loads. Soil pressure will lead to shrinkage of the material, and the effectiveness of insulation will decrease to zero.

Prices for mineral wool

But polymer insulation does not have such disadvantages and fully meets the necessary requirements.

Let's take a closer look at their characteristics.

Expanded polystyrene

Expanded polystyrene, or polystyrene foam, is very widely used in thermal insulation. It is lightweight, its sheets have the correct shape, and therefore installation is not a problem even for a novice master. The material is available in various densities and thicknesses, and depending on this has certain areas of application. Only the densest sheets with a thickness of at least 50 mm are suitable for foundations; the rest are best used for insulating walls and partitions.

In terms of thermal conductivity, foam plastic is much more effective than wood, expanded clay, and mineral wool insulation. It almost does not absorb water, is not prone to shrinkage and deformation, and serves as an excellent sound insulator. In addition, polystyrene foam boards fully retain their properties when exposed to salt and chlorinated water, soap solutions, and weak acids. The insulation can come into contact with bitumen mastics, lime, water-soluble adhesive solutions and cement plaster.

For slab foundations, as well as deeply buried foundations, it is necessary to use polystyrene foam marked PSB-S-50, which is able to withstand heavy mechanical loads and provide reliable protection against soil swelling. For columnar and standard strip foundations, PSB-S-35 grade foam is used.

All other varieties are not suitable for foundations due to the low density and fragility of the sheets.

Expanded polystyrene made by extrusion is significantly superior to polystyrene foam in all respects. It is many times stronger, absolutely moisture-proof, and has the lowest vapor permeability and thermal conductivity. Microorganisms also do not develop in it, even under conditions of prolonged exposure to dampness.

Foundation insulation with extruded polystyrene foam - EPS

EPS boards with a smaller thickness have a much greater effect. To thermally insulate the foundation in a temperate climate, an insulation thickness of 40 mm is sufficient, in northern conditions - about 60 mm (a two-layer laying of slabs with a thickness of 30 mm is recommended). For ease of installation and greater packing density, the slabs are equipped with tongue-and-groove joints.

They are attached to the base using an adhesive solution and disc-shaped dowels.

Laying of EPS slabs can be done vertically (when insulating columnar and strip foundations) and horizontally (when installing a slab foundation).

Due to its increased strength, the material perfectly tolerates the load from the concrete layer, does not flatten or shrink, unlike polystyrene foam and polyurethane foam. The most popular brands of extruded polystyrene foam are Penoplex and TechnoNIKOL.

Main characteristics

Sprayed thermal insulation, or PPU, is increasingly used to insulate foundations. Polyurethane foam forms a very durable seamless coating that is resistant to adverse influences. At the same time, it simultaneously performs the functions of vapor and waterproofing, which greatly simplifies the work process. Another useful property of this insulation is its high adhesion to the base. It adheres equally firmly to stone, concrete, brickwork, and wooden structures, is easily applied to hard-to-reach areas, and fills the slightest cracks.

Polyurethane foam is applied in two ways - pouring and spraying. The first option is more labor-intensive and expensive, so it is rarely used when insulating private houses. The second method is actively used to insulate the entire building - from the roof to the foundation. Before application, the components are mixed in a foam generating unit with air and the finished mass is sprayed under pressure onto the working surface. Within a few seconds, the composition hardens, and upon completion of the work, you can immediately begin finishing. The only disadvantage of such insulation is that it is impossible to do without installation, and this is an additional cost.

In addition to the described insulation materials, bulk materials, in particular expanded clay, can be used for foundations. It is environmentally friendly, inexpensive, has good thermal insulation characteristics, and is suitable for both vertical and horizontal insulation. But since expanded clay can absorb moisture, losing some of its properties, and the work process requires more effort and time, this insulation is used less and less, giving way to more modern and effective materials.

Prices for expanded polystyrene

Expanded polystyrene

Foundation thermal insulation technology

Insulation of pile, columnar and strip foundations can be carried out both during the construction process and during the operation of the house. Before installing the insulation, the base must be prepared, which includes cleaning, sealing cracks, and installing waterproofing. The better the preparation, the more effective and durable the result. Slab foundations are insulated directly during construction, because thermal insulation slabs are located horizontally under a layer of reinforced concrete.

Strip foundation

The most labor-intensive stage in insulating such a foundation is excavation work. The foundation must be excavated to its base or to the level of soil freezing. If possible, it is better to hire special equipment, because digging by hand will take a lot of time and require a lot of physical effort. The foundation is dug around the entire perimeter to a width of at least 1 m, then the bottom of the trench is compacted and covered with a layer of sand and crushed stone.

The foundation walls are cleaned of soil with a stiff brush and left open for 10 days to allow the moisture to evaporate. For this reason, work must be carried out in the warm and dry season.

Step 1. The dried walls are carefully inspected for damage, and any identified defects are eliminated. Before sealing, cracks are opened and cleaned of dust; if necessary, the surface is leveled with cement-sand plaster. If unevenness exceeds 20 mm, the plaster is additionally reinforced with metal mesh. After plastering, you must wait until the surface is completely dry.

Step 2. Waterproof the foundation. It is most convenient to use coating waterproofing, for example, polymer, rubber or bitumen water-soluble mastics. Compositions containing organic solvents cannot be used, since polystyrene foam boards are destroyed upon contact with them.

To improve adhesion, the surface is pre-treated with a bitumen primer, applying it in a thin continuous layer. It takes about a day for the primer to dry, after which you can begin applying mastic.

Step 3. Stir the mastic; if the mass is too thick, add a little water.

Prices for bitumen mastic

For application use a wide brush with dense bristles or a roller. The composition is evenly distributed over the walls in a continuous layer, very carefully coating the corners. The layer should not be transparent, but it should not be made too thick, so that streaks do not form. The mixture is rubbed well over the surface, filling the smallest pores of the depression. When the first layer has hardened, apply the second in the same way. Usually two layers are enough, but if the area is often flooded with groundwater, it is recommended to apply 3 layers of mastic.

Step 4. After the waterproofing has dried (after 5-7 days), you can begin installing foam plastic or EPS. To attach the plates, a special adhesive composition is used, for example, ALLFIX, Ceresit CT 83, Titan.

Installation of insulation is carried out from the bottom up, in horizontal rows, with mandatory bandaging of the vertical seams. Apply glue, press the slab to the surface and check its position with a level. When installing the next slab, it is necessary to align the mounting grooves as tightly as possible so that the joints are barely noticeable.

Advice. When laying thermal insulation slabs in two layers, the joints of the lower layer must be completely covered by the slabs of the upper layer. Combining joints will lead to the formation of cold bridges, which means that the effect of insulation will be lower than planned.

Step 5. As a rule, the underground part of the insulation does not need additional fixation, because after backfilling the material is tightly pressed with soil. But in the above-ground part of the slab it is recommended to strengthen it with dowel nails with wide heads. Fastening is carried out after the adhesive solution has completely dried. To do this, through holes are drilled in the slabs (in the center of the slab and in the corners) and buried 40-50 mm into the base. Next, insert the dowels and hammer them in until they stop.

Step 6 To protect the surface of the slabs from accidental damage, plastering is performed with a fiberglass reinforcing mesh. Apply the adhesive solution to the insulation, spread it in an even layer 40-50 mm thick, lay a mesh on top and forcefully smooth it with a spatula, deepening it into the solution. For convenience, it is recommended to cut the mesh into pieces and overlap them by 10 cm.

Step 7 After a day, a final leveling is carried out, and when this layer dries, the surface is treated with a grater and emery cloth.

Step 8 Fill the trench with soil, leaving a distance of about 30 cm to the top. The soil is compacted well to reduce shrinkage. A layer of sand 10-15 cm thick is poured on top, which is also carefully compacted, and then a waterproofing membrane and a layer of insulation are laid at a slight slope from the wall. The final stage is the arrangement of the blind area by pouring a concrete screed.

If it is decided to insulate the foundation with polyurethane foam, there is no need for leveling and waterproofing. After digging a trench and clearing the base of the earth, it is only necessary to eliminate cracks and also remove peelings, if any. When the foundation walls are dry from moisture, you can begin applying polyurethane foam. You can rent a spraying installation from a construction company or buy it, but if you do not have the skills to work with such equipment, it is better to turn to specialists. After the material has hardened, the trench is filled with soil, and a blind area is made on top, as described above.

Columnar foundation

Thermal insulation of columnar and pile foundations is performed a little differently. To thermally insulate the space between the grillage and the ground, it is necessary to build a fence that acts as a plinth. This design does not carry a load, so there are no special requirements for the mechanical strength of materials.

Step 1. A narrow trench up to half a meter deep is dug between the foundation pillars, and a third of it is covered with a layer of sand and small crushed stone.

Step 2. A frame of metal rods is laid on top and a layer of concrete mortar is poured.

Step 3. After the concrete has hardened, the space is bricked around the entire perimeter, leaving small vents in the opposite walls for ventilation.

Step 4. When the masonry is dry, insulation boards are glued to the outside and then plastered using reinforcing mesh. After the plaster has dried, the trench is filled with soil and compacted.

Finally, decorative finishing of the base is carried out - this can be painting, applying decorative plaster, or facing with artificial stone.

Instead of a brick fence, you can install a frame made of timber or a metal profile between the foundation supports. Before installation, the timber must be treated with antiseptic impregnation and dried well. The beams are fastened using metal corners, bolts 65-80 mm long and self-tapping screws; it is preferable to use welding to assemble a metal frame. After installation, the frame is sheathed with EPS or foam plastic boards, and corrugated sheets or plinth panels are attached on top.

Slab foundation

With horizontal insulation, the slabs can also be laid in one or two layers. Most often, insulation with a thickness of 50 or 100 mm is chosen for slab foundations. Thermal insulation begins after the foundation pit has been prepared and the sand cushion has been backfilled.

Step 1. The sand layer is thoroughly compacted over the entire area and leveled horizontally. The smoother the base, the denser the insulation will lie.

Step 2. Film and heat-insulating boards are laid on the sand cushion, joining the mounting grooves. In each subsequent row, the joints are shifted by the width of half the sheet.

Advice. When laying insulation in two layers, the lower slabs are placed in rows along the long side of the foundation, and the upper slabs are placed in rows along the short side. This will not only eliminate cold bridges, but will also further strengthen the strength of the thermal insulation layer.

Step 3. Along the perimeter of the foundation, close to the slabs, formwork is installed, inside which a reinforcing frame made of steel rods is mounted. Concrete is mixed and poured.

Step 4. After the concrete has hardened, a blind area is made. Carefully level and compact the sand with a slight slope from the foundation. The slabs are laid tightly and covered with a waterproofing membrane on top. The membrane sheets are overlapped by 10-15 cm. Next, they are backfilled with sand, again everything is leveled and compacted.

Prices for thermal insulation materials

Thermal insulation materials

Video - How to insulate the foundation of a house from the outside

Video - Insulating the foundation with polyurethane foam

Video - Insulating a slab foundation

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

Do I need to insulate the foundation?

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

So, insulating the floor prevents cold from penetrating into the room through the ceiling.

Thermal insulation of the foundation performs the following functions:

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

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

External insulation of strip foundation

First of all, let's look at how to insulate a strip foundation, which is the most common.

There are two ways to insulate such a base:

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

Often, internal insulation is performed together with external insulation. Next, we will consider both thermal insulation options.

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

Preparation of materials

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

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

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

The only drawback of expanded polystyrene is the high price, which averages 4,500 rubles per 1 m2.

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

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

• drainage;
• adhesive foam for penoplex;
• roll waterproofing, for example, roofing felt;
• materials for pouring the screed (needed for arranging the blind area).

Excavation work

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

Excavation work is carried out as follows:

1. First of all, you need to dig out the strip foundation. To do this, dig a trench to the entire depth of the foundation, about one and a half meters wide. After that the foundation should be left for some time to dry thoroughly;

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

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

It is necessary to start excavation work in dry, warm conditions. Therefore, it is best to insulate the foundation in late spring or summer.

The excavation work has now been completed.

Foundation preparation

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

The work is performed in the following sequence:

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

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

It is necessary to fill all the depressions, cracks, etc. with mastic to form a continuous coating with a thickness of about 2-4 mm.

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

Installation of insulation

The installation instructions for penoplex look like this:

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

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

1. As a rule, it is impossible to perfectly cover the foundation with insulation boards. Therefore, you need to inspect the walls and fill the existing cracks with adhesive foam.

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

Arrangement of the blind area

Now you need to make an insulated blind area by following these steps:

1. the pit around the perimeter of the house must be filled with earth so that a trench about 30 cm deep from the ground level remains;
2. then fill the trench with sand about ten centimeters thick and compact it thoroughly;

1. roofing material should be laid over the trench close to the walls of the house. Glue the roofing felt joints that should overlap each other with bitumen mastic;

1. then penoplex is laid on the waterproofing;
2. A screed is poured over the penoplex according to the standard scheme.

At this point, the insulation of the foundation from the outside is completed.

Thermal insulation of strip foundation from the inside

Do-it-yourself foundation insulation from the inside can also be divided into several stages:

The basement can only be insulated after it has been thoroughly waterproofed, since the room must be dry.

Preparation of materials

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

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

Preparing the walls

Before insulating the foundation of a house from the inside, you must prepare it:

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

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

Before insulating the foundation, you need to insulate the floor. This operation is carried out according to the same scheme as the thermal insulation of the blind area - waterproofing and insulation are laid, after which the screed is poured.

Installation of insulation

After the walls have dried, we begin installing the insulation:

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

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

1. Then the plate is glued to the wall. In this case, adjust its position using a level. The entire first row of insulation is covered using this principle;
2. the second and all subsequent rows should be staggered so that the seams of the slabs do not coincide. During the installation process, use a level and rule to ensure that the surface of the walls is level.;

1. After the glue has hardened, you need to drill holes and install dowels. Each slab must be additionally secured with five dowels. Slightly recess the fastener caps so that they do not interfere with further finishing.

This completes the installation of insulation.

Reinforcement

Insulation reinforcement is carried out as follows:

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

In this way, cover the entire surface of the walls with mesh. In this case, it is important to position it so that each subsequent strip overlaps the previous one by 10 cm;

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

This completes the work. Now you can prime the walls and putty them to apply the finishing touch.

Thermal insulation of pile-type foundations

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

Preparation of materials

To insulate the pile foundation, you need to prepare the following materials:

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

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

Frame installation and insulation

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

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

The work begins with the arrangement of the cladding, which is performed as follows:

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

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

1. After this, penoplex should be fixed to the frame. To do this, you can use ordinary nails and nails, to which the panels will subsequently be attached;
2. Fill the gaps between the foam boards with foam;
3. near the bottom edge of the structure along the perimeter of the house you need to install a starting profile for attaching the panels. Make sure that the panka is positioned vertically;

1. Install corner profiles at all corners using self-tapping screws. Make sure the corners are installed vertically.

Arrangement of the blind area

The blind area is performed as follows:

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

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

Try to make the screed as close to the foundation as possible, so that after covering it, there will be a gap of about 5-7 mm between the blind area and the foundation.

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

Frame covering

The foundation cladding is done as follows:

1. The bottom of the panels is inserted into the starting bar, with which they are connected into a hook. The panels outermost from the corner are inserted into corner profiles. The top panels are attached to the sheathing with self-tapping screws, as shown in the diagram above.
   The entire frame is sheathed in this way;

1. An ebb is mounted on top of the casing, which allows water to be drained onto the blind area. The ebb should be such a width that it covers the gap between the base and the blind area;
2. At the end of the work, the gap between the blind area and the foundation sheathing should be filled with isolon. Construction sealant can be applied on top. Thanks to this, water will not seep under the foundation.

This completes the process of insulating the foundation.

Conclusion

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

Insulating the foundation from the outside is necessary work to ensure the preservation of heat in the room, protection from moisture, and saving energy resources.

The optimal solution is to carry out all the manipulations during the construction of the building, but it is possible to implement the plan after the construction of the building is completed.

For each individual case, we have developed our own most convenient algorithm, according to which the foundation of a private house should be insulated from the outside, and materials have been selected that allow us to achieve the highest quality and most effective insulation of the foundation.

Variety of materials for thermal insulation

Insulation of the foundation base from the outside is carried out:

Each of the listed materials is ideal for providing high-quality insulation of the foundation of a house from the outside.

In all cases, it should be remembered that thermal insulation of the foundation is not necessary in order to increase the flow of warm air entering the room. Every effort should be made to prevent the cold from penetrating into the building.

If they want to avoid material costs and save as much as possible on arranging a warm foundation for a house, many owners of private buildings carry out all the work using the ground. The backfill method allows you to achieve a positive result, but modern materials guarantee that a reliable and high-quality warm foundation will be created.

When deciding how to insulate the foundation, you must first choose the method of performing the work, because the thermal insulation material can be fixed on the outside of the building or on the inner surface of the base.

Depending on which insulation was chosen and on the method of insulation, materials for insulating the foundation necessary to achieve the goal are selected.

You can purchase everything you need if you know how to properly insulate the foundation of a residential building in order to provide the owners with comfortable living conditions. The materials used should not be deformed under the influence of aggressive environments or allow moisture to pass through. They must be characterized by a long service life, resistance to temperature changes, low weight, strength and high density.

Taking into account all the requirements, experts recommend using the following as insulation:

• penoplex;
• extruded polystyrene foam;
• sprayed polyurethane foam.

Before insulating the foundation of a house from the outside with your own hands, it is necessary, in strict accordance with all requirements, to prepare the base surface on which the thermal insulation material will later be fixed.

Spraying polyurethane foam requires the participation of craftsmen and the use of special equipment; in addition, such a coating is resistant to exposure to ultraviolet rays.

That is why owners of country buildings strive to insulate the foundation of a private house using penoplex, which is cheaper, but quite durable and of high quality.

Insulating the outside of a house with polystyrene foam is also popular because it does not require the use of special fasteners. To securely fix it, it is enough to use an adhesive composition similar to polyurethane foam. This is foam cement.

Execution of work

Knowing how to insulate a foundation from the outside, you can correctly select the most suitable material and prepare the foundation.

This stage requires special attention, since the algorithm for performing the work depends on the characteristics of the constructed frame. In cases where we are talking about piles or pillars, then the construction of a brick wall will be required to fill the gaps between already installed piles or pillars:

1. You will have to dig a trench around the entire perimeter of the house and place a sand cushion at the bottom, which will need to be thoroughly compacted.
2. The second stage is laying the reinforcing mesh, on top of which the concrete base is poured.
3. After 10 days, the concrete will gain strength and laying can begin.

Another option that is considered when deciding what and how to make a warm foundation is to use slag or expanded clay. Having decided how to insulate the foundation of the house, you can begin making calculations and purchasing materials.

Surface preparation begins with sealing all detected defects on the outer surface of the foundation base of an already constructed building.

For this purpose, you can use a sand-based plaster mixture, and the largest cracks can be filled with polyurethane foam. Primer is applied on top of the plaster. This should be a deep-penetrating composition that ensures high-quality adhesion of materials. For more information about insulating the base, watch this video:

Having made the final decision on how to insulate the foundation from the outside, you need to take care of arranging high-quality waterproofing. To treat the foundation from the outside, coating materials such as bitumen mastic are needed.

Now it's time to attach the first layer of polystyrene foam. It is necessary to apply an adhesive composition to it and press it tightly to the surface that is being insulated.

All seams and joints are foamed and after the foam has hardened, it is cut off and the entire covered area is covered with reinforcing mesh to create a second layer of plaster.

To insulate the foundation from the outside, two layers of polystyrene foam are required. The final decoration will be:

• slabs;
• panels;
• plaster and paint;
• tile.

Before choosing the best way to insulate the foundation of a built house, you need to decide what and how to insulate the area underneath it. To do this, you should know how to insulate the foundation, given that much depends on the quality of the floor. Penetration of cold air is possible from the underground or basement. Treatment of old floors, during which it is good to use modern insulating materials. For more information about the stages of work, watch this video:

By considering various methods and options for foundation insulation, you can see that this process is not as simple as it might seem.

Failure to comply with the nuances of the technological process causes disruption of the microclimate in the room, heat loss, and unjustified energy costs.

However, knowledge of the features of each individual structure and the building materials used for its construction will help to achieve success. So, for example, a concrete base is insulated only from the outside, because practically no cold air passes through it, but the false base of a pile foundation requires mandatory insulation of the inner surface.

Many owners of wooden houses are faced with the fact that in winter the floor freezes on the 1st floor. This phenomenon can only be eliminated in one way - to insulate the foundation of a wooden house from the outside. The foundation of a wooden house is built from different materials. The method of insulating the foundation of a wooden house depends on the type of supporting structure of the building. Modern thermal insulation materials are used to insulate the foundation of the house. This article presents options for insulating foundations of various designs.

Why do you need to insulate the foundation from the outside?

The foundation of a wooden house is a supporting structure that is in direct contact with the natural foundation and the structure itself. In addition to its supporting function, the foundation protects housing from the negative influences of the soil. It is important that the base of a wooden house does not cause heat leakage from the home.

The foundation of the house is constantly exposed to moisture penetration from the soil and changes in ambient temperature. In winter, moisture that gets into the body of the base of the structure freezes and destroys the supporting mass. The cold begins to penetrate into the home through cracks. As a result, the floors in the house will always be cold in winter. That is why it is necessary to insulate the base of a wooden house.

It is impossible to insulate an old foundation from below, but its walls are quite accessible for thermal insulation. Since supporting structures can be of different types, the thermal insulation of the foundation from the outside is carried out in different ways.

Materials for foundation insulation

Insulation of the foundation must be done at the stage of its construction. Although there are circumstances when careless builders did not take care of this in due time. And now the owners of the house have to re-insulate the base of the wooden house.

The time comes, and homeowners think about which insulation to choose. Among the wide variety of heat-insulating materials, it is necessary to highlight materials suitable for insulating foundations:

• expanded polystyrene;
• polyurethane foam;
• expanded clay;
• Styrofoam.

All these materials have low thermal conductivity and high resistance to temperature changes.

Expanded polystyrene

This material has high thermal insulation properties, moisture resistance and insusceptibility to low temperatures. Thanks to these qualities, extruded polystyrene foam has gained great popularity as external insulation for the foundations of wooden houses. Expanded polystyrene is convenient for insulating strip foundations and plinths.

The material has a fine-cell structure. It is produced by exposing polymer granules to high temperature and pressure in carbon dioxide. Insulation comes on sale in the form of a slab material called penoplex. The service life of polystyrene is about 40 years.

Manufacturers often call expanded polystyrene boards penoplex. Penoplex with a thickness of 50 mm corresponds in heat-shielding properties to 75 mm of foam plastic and 95 mm of mineral wool.

Video on insulating the foundation with penoplex:

Polyurethane foam

The polymer is sprayed onto the foundation walls using special equipment. Once on the surface to be treated, polyurethane foam greatly increases in volume. In terms of its thermal insulation properties, a 50 mm layer of polymer is similar to a 120 mm thick sheet of expanded polystyrene.

The hardened foam on the walls of the base of the building forms a seamless, dense coating. Unlike sheet insulation, the sprayed outer covering does not require additional sealing of the seams. In addition, the polymer has high adhesion and “sticks” to almost any surface.

Expanded clay

Expanded clay granules are obtained by firing a foamed clay solution. Expanded clay has high thermal insulation qualities. This is one of the cheapest thermal insulation building materials.

Lining the external walls of the foundation with expanded clay prevents the base of a wooden house from freezing, even in the conditions of the Far North. The only drawback of the material is its low commercial availability.

Styrofoam

Polystyrene foam is essentially the same polystyrene foam, but has not been extruded (pressure treated at high temperatures). Foam boards are used to insulate the foundation and basement of a house. To prevent heat leakage from a wooden house from below, foam plastic with a thickness of 40 to 120 mm is used.

Polymer boards are easy to process. Most often they are attached to the foundation walls using bitumen mastic. Foam plastic is also fixed to the wall with dowels - fungi.

Polystyrene foam, along with its high thermal insulation qualities, is a very fragile material, so the outside walls of the foundation lined with foam plastic necessarily need a final protective coating.

Methods for insulating the foundation of a wooden house

Mostly wooden houses are built on strip, column and pile foundations. In each case, it is necessary to cover the base and basement of the house with insulation.

Strip foundation

This type of foundation can be made monolithic or constructed from prefabricated reinforced concrete blocks. Also, the support strip under a wooden house is made of rubble stone or flagstone.

The technology for how to insulate the foundation of a wooden house from the outside with your own hands is as follows:

1. A trench is dug along the perimeter of a wooden house to the depth of soil freezing.
2. The foundation walls are cleaned of soil residues and covered with bitumen mastic.
3. The insulation boards are installed on a vertical surface, heating the bitumen waterproofing layer with a burner.
4. A reinforcing metal or polymer mesh is fixed to the insulation.
5. All surfaces are primed, puttied and plastered.
6. Insulation is laid on the sandy cushion of the blind area.
7. The blind area is concreted, asphalted, lined with ceramics or stone.

The concrete monolith of the house support strip with a thickness of 40 - 50 cm does not need insulation. The physical characteristics of such a reinforced concrete mass have sufficient heat-insulating properties.

Columnar foundation

As a matter of fact, it makes no sense to insulate the columnar foundation itself. The main heat leakage occurs through the space between the bottom of a wooden house and the ground. The constant movement of air masses underground creates an outflow of heat from the lower floor of the building.

To prevent this negative phenomenon, the outer perimeter of the underground is covered with vertical fences. Fences can be made from a variety of materials: from wooden panels to reinforced concrete slabs. Enclose the base with siding (thin-sheet metal or polymer panels). Siding performs a purely enclosing function.

Due to the enclosed space, drafts stop and the underground air temperature stabilizes in the positive range, and this ultimately leads to effective insulation of a wooden house.

The basement fence is erected from brick, wild stone or other masonry material. It is important that the masonry of the fence is not rigidly connected to the columnar supports. Due to various geological movements, the pillars can move the masonry of the fence. In this case, the wall of the base may crack and collapse.

A hermetically sealed space inside the base can lead to increased air humidity. This in turn will create a favorable environment for the growth of fungi and mold. To prevent the air in the underground from stagnating, it is imperative to make vents in the basement enclosure - small openings that provide natural ventilation for the underground.

For greater reliability of thermal insulation of the base of the house, polyurethane foam is sprayed onto the internal surfaces of the fence.

Pile foundation

The principle of insulating the pile foundation of a wooden house is the same as in the previous case. The house, located on stilts, also has an open underground, which must be closed from the outside environment.

Wooden houses are supported on both wooden and reinforced concrete and screw piles. To insulate the basement of a house on a pile foundation, wooden panels, polymer or metal siding are most often used.

Features of foundation insulation with expanded clay

The method of insulating the foundation with expanded clay has its own characteristics. Since, unlike slab insulation, expanded clay is a bulk material, they do it this way:

• a trench around a wooden house is made 20 - 30 cm wide; the depth of the ditch is made just below the soil freezing mark;
• sand 10 cm thick is poured onto the bottom of the trench; then make a layer of crushed stone or gravel of the same thickness;
• sheets of roofing material are attached to the walls along the outer perimeter of the trench;
• the ditch is filled with expanded clay; pour the granules in layers of 30-40 cm; each layer is compacted;
• the top of the insulation is covered with a cement screed;
• a half-brick thick wall is placed along the screed; masonry is carried out to the height of the building’s base;
• a metal mesh is laid across three rows of bricks, connecting the masonry and the base of the house;
• the space between the masonry and the base is filled with expanded clay;
• a blind area made of cement mortar is installed on top of the masonry; The screed is covered with a galvanized sheet.

If the roof insulation is not done simultaneously with the thermal insulation of the supporting structures of the building, then the thermal insulation of the foundation will not bring the desired result. The heat will go up, the floors and walls in the home will remain cold.

The base of a wooden house must be insulated, since the owners try to eliminate the cold in living quarters by increasing the load on the heating system of the house, and this results in exorbitant financial costs for heating the home. In this regard, it is better to properly insulate the foundation once and live in a warm house for many winters without incurring unnecessary expenses on heating the house.