Insulation of the foundation slab with polystyrene foam. How to properly insulate the foundation and blind area with foam plastic from the outside. The procedure for internal insulation of the foundation

Advantages

How to choose

δ – foundation thickness (m);

Types and characteristics of EPS

Penoplex

TechnoNikol

URSA Eurasia

Waterproofing mastics

Waterproofing mixtures

Penetrating waterproofing

Injection waterproofing

Waterproofing with clay

According to their purpose, the buildings under consideration form three groups:

Residential, medical and preventive care and children's institutions, schools, boarding schools
Public, except for those listed above, administrative and domestic, with the exception of rooms with wet conditions
Production with dry and normal modes

The thickness of insulation of basement walls (foundation) is calculated only for “warm” basements, which have bottom wiring pipes of heating systems, hot water supply, as well as pipes of water supply and sewerage systems.

When planning to place utility rooms in the basements: garage, laundry room, boiler room, pantry for products that will be heated slightly or not at all, you can use extruded polystyrene foam of a smaller thickness. The main thing is that the thermal insulation laid on the basement walls is tightly connected to the thermal insulation of the above-ground walls.

The basement walls have a load-bearing part made of brick or stones 510 mm thick or concrete blocks 500 mm thick with a finishing plaster layer 20 mm thick on the room side.

Thermal conductivity coefficient of EPPS under operating conditions, λA W/(m K),
no more than – 0.031

Thermal conductivity coefficient of EPPS under operating conditions, λB W/(m K),
no more than – 0.032

1	Arkhangelsk	B	1	90	70
			2	70	50
			3	50	40
2	Astrakhan	A	1	60	70
			2	50	40
			3	30	20
3	Anadyr	B	1	130	100
			2	100	80
			3	70	50
4	Barnaul	A	1	90	70
			2	70	50
			3	50	40
5	Belgorod	A	1	70	50
			2	50	40
			3	40	30
6	Blagoveshchensk	B	1	100	80
			2	80	60
			3	50	40
7	Bryansk	B	1	70	50
			2	60	50
			3	40	30
8	Volgograd	A	1	70	50
			2	50	40
			3	40	30
9	Vologda	B	1	90	70
			2	70	50
			3	50	40
10	Voronezh	A	1	80	60
			2	60	50
			3	40	30
11	Vladimir	B	1	80	60
			2	60	50
			3	40	30
12	Vladivostok	B	1	70	50
			2	60	50
			3	40	30
13	Vladikavkaz	A	1	60	50
			2	40	30
			3	30	20
14	Grozny	A	1	60	50
			2	40	30
			3	30	20
15	Ekaterinburg	A	1	90	70
			2	70	50
			3	50	40
16	Ivanovo	B	1	80	60
			2	60	50
			3	40	30
17	Igarka	B	1	130	100
			2	100	80
			3	70	50
18	Irkutsk	A	1	100	80
			2	80	60
			3	50	40
19	Izhevsk	B	1	80	60
			2	70	50
			3	40	30
20	Yoshkar-Ola	B	1	80	60
			2	60	50
			3	40	30
21	Kazan	B	1	80	60
			2	60	50
			3	40	30
22	Kaliningrad	B	1	60	50
			2	50	40
			3	30	20
23	Kaluga	B	1	80	60
			2	60	50
			3	40	30
24	Kemerovo	A	1	90	70
			2	70	50
			3	50	40
25	Vyatka	B	1	90	70
			2	70	50
			3	50	40
26	Kostroma	B	1	80	60
			2	60	50
			3	40	30
27	Krasnodar	A	1	50	40
			2	30	20
			3	30	20
28	Krasnoyarsk	A	1	90	70
			2	70	50
			3	50	40
29	Mound	A	1	90	70
			2	70	50
			3	50	40
30	Kursk	B	1	70	50
			2	60	50
			3	40	30
31	Kyzyl	A	1	110	90
			2	90	70
			3	60	50
32	Lipetsk	A	1	80	60
			2	60	50
			3	40	30
33	Magadan	B	1	110	90
			2	80	60
			3	60	50
34	Makhachkala	A	1	50	40
			2	30	20
			3	30	20
35	Moscow	B	1	80	60
			2	60	50
			3	40	30
36	Murmansk	B	1	90	70
			2	70	60
			3	50	40
37	Nalchik	A	1	60	50
			2	40	30
			3	30	20
38	Lower Novgorod	B	1	80	60
			2	60	50
			3	40	30
39	Novgorod	B	1	80	60
			2	60	50
			3	40	30
40	Novosibirsk	A	1	90	70
			2	70	60
			3	50	40
41	Omsk	A	1	90	70
			2	70	60
			3	50	40
42	Orenburg	A	1	80	60
			2	60	50
			3	40	30
43	Eagle	B	1	70	50
			2	60	50
			3	40	30
44	Penza	A	1	80	60
			2	60	50
			3	40	30
45	Permian	B	1	90	70
			2	70	50
			3	50	40
46	Petrozavodsk	B	1	80	60
			2	70	50
			3	40	30
47	Petropavlovsk- Kamchatsky	B	1	70	50
			2	60	50
			3	40	30
48	Pskov	B	1	70	50
			2	60	50
			3	40	30
49	Rostov-on-Don	A	1	60	50
			2	40	30
			3	30	20
50	Ryazan	B	1	80	60
			2	60	50
			3	40	30
51	Samara	B	1	80	60
			2	60	50
			3	40	30
52	Saint- Petersburg	B	1	70	50
			2	60	50
			3	40	30
53	Saransk	A	1	80	60
			2	60	50
			3	40	30
54	Saratov	A	1	70	50
			2	60	50
			3	40	30
55	Salekhard	B	1	120	100
			2	100	80
			3	60	50
56	Smolensk	B	1	80	60
			2	60	50
			3	40	30
57	Stavropol	A	1	60	50
			2	40	30
			3	30	20
58	Syktyvkar	B	1	90	70
			2	70	50
			3	50	40
59	Tambov	A	1	80	60
			2	60	50
			3	40	30
60	Tver	B	1	80	60
			2	60	50
			3	40	30
61	Tomsk	B	1	100	80
			2	70	50
			3	50	40
62	Tula	B	1	80	60
			2	60	50
			3	40	30
63	Tyumen	A	1	90	70
			2	70	50
			3	50	40
64	Ulyanovsk	A	1	80	60
			2	60	50
			3	40	30
65	Ulan-Ude	A	1	100	80
			2	80	60
			3	50	40
66	Ufa	A	1	80	60
			2	70	50
			3	40	30
67	Khabarovsk	B	1	90	70
			2	70	50
			3	50	40
68	Cheboksary	B	1	80	60
			2	60	50
			3	40	30
69	Chelyabinsk	A	1	90	70
			2	70	50
			3	50	40
70	Chita	A	1	110	90
			2	80	60
			3	60	50
71	Elista	A	1	60	50
			2	50	40
			3	30	20
72	South Sakhalinsk	B	1	80	60
			2	60	50
			3	40	30
73	Yakutsk	A	1	140	110
			2	110	90
			3	70	50
74	Yaroslavl	B	1	80	60
			2	60	50
			3	40	30

Nowadays, many people independently build and repair their homes. For anyone who has encountered insulation, EPS means only one thing - extruded polystyrene foam. The range of applications of this material is very wide; in particular, it is widely used for insulating foundations. Extruded polystyrene foam is produced by extruding polystyrene foam through an extruder. Extrusion imparts new qualities to polystyrene that are not possessed by material produced by non-press or press methods.

Scope of application

EPPS is used in civil and industrial construction, greenhouse farming, in household appliances, when constructing highways, runways, and laying pipelines. In the construction industry, EPS is used to insulate all house structures: from the foundation to the roof.

EPPS is one of the best materials for insulation

Insulation of foundations for almost all buildings in Russia is a necessary measure. According to the climatic zoning map, only in the southern regions of the Russian Federation can one do without this work. In the rest of the area, thermal insulation of the foundations must be carried out, and the further north you go, the larger the layer of insulation must be laid.

Since expanded polystyrene is produced in sheets, it is convenient for thermal insulation of all types of foundations - strip, pile, slab.

Moreover strip foundation can be insulated both from the inside and outside. For ease of installation, polystyrene foam sheets have a groove along the edge. For strip foundations, in addition to insulating the foundation itself, insulating the blind area is also important, especially on heaving and moist soils. Therefore, first of all, you need to take care of drainage.

Advantages

Polyurethane foam, polystyrene foam, foam glass and expanded clay are suitable for insulating the foundation. The best is polyurethane foam, but it is more expensive and requires a spraying unit. Among expanded polystyrene foams, the advantage is on the side of EPS.

EPPS has many advantages

There are several reasons for this:

good thermal insulation properties. Thermal conductivity is at the level of polyurethane and is 0.029-0.031 W/m*ºС. Moreover, in a humid environment these properties practically do not change;
low vapor permeability – 0.005 mg/m*h*Pa. This is not enough for walls, but just right for the foundation;
minimum water absorption – 0.4%. The walls of the basement and foundation will be dry;
compressive strength and bending strength are quite high compared to other foams;
frost resistance – more than 50 cycles. It is used at temperature differences from -70 to +75;
durability – declared service life is 45 years;
ease of use. Absolutely light, with a special edge, sheets that can be cut with a knife.

Extruded polystyrene foam is competitive in terms of price. However, it is always worth remembering that EPS is flammable, so you should try to use it outside in places with minimal risks of ignition, and also be sure to insulate it with non-flammable material.

How to choose

When buying EPS, you must definitely ask for a quality certificate. The sheets themselves also need to be inspected. They can be of different colors, but the color must be uniform. It is advisable to break a piece of the sheet; a characteristic crack should be heard. Then look at the structure; regular polyhedra will be visible on the fault lines. When you press on the sheet with your finger, it should spring back, but a small dent may remain.

All insulation sheets must be the same thickness

When choosing EPS for foundation insulation, you need to pay attention to the density. For these works, the density of polystyrene foam must be at least 35 kg/cubic meter. m.

Very important point, how thick should the EPS sheet be? The answer to this question can be found in SP 50.13330.2012, which provides indicators and requirements for thermal protection of buildings.

A key indicator of the thermal protection of a structure is heat transfer resistance. For ease of use, the Rules provide the values of the reduced resistance to heat transfer of enclosing structures, broken down by degree-day of the heating period. For each construction area, the normalized heat transfer resistance is calculated, adjusted by a coefficient that takes into account the conditions of the region.

The heat transfer resistance of the enclosing structure consists of the sum of the thermal resistances of each material (layer) of the structure, taking into account the heat transfer coefficients of the internal and external surfaces of the structure. Thermal resistance is the ratio of the thickness of the structure to the thermal conductivity coefficient of the material of the structure (sq. m*ºС/W), i.e. the structure is homogeneous.

Returning to the question of choosing the thickness of the EPS for the base, you need to use the formula:

The thickness of the sheet must be selected depending on the conditions

δth – thickness of the insulation layer (m);

R0 – reduced heat transfer resistance of the building envelope of the construction area, according to the table taking into account GSOP (sq. m*ºС/W);

δ – foundation thickness (m);

λ – thermal conductivity coefficient of the foundation material (W/m*ºС);

λth is the thermal conductivity coefficient of the insulation (W/m*ºС).

Types and characteristics of EPS

For some time now in Russia extruded polystyrene foam has been called by the name of the company that produces this material. This is how Penoplex, Technoplex, TechnoNIKOL and Ursa appeared. Famous manufacturers Penoplex, TechnoNikol, URSA Eurasia supply high-quality thermal insulation to the construction market.

Penoplex

Especially for underground structures and structures, the company produces a type of insulation called Penoplex Foundation. The manufacturer guarantees increased strength and ability to withstand loads for 50 years. The declared characteristics of this insulation are characteristic of EPS, however, the thermal conductivity coefficient is slightly higher - 0.03-0.032 W/m*ºС.

The sheets have dimensions of 1200x600 mm with a standard thickness of 20 to 150 mm. The average cost of one sheet 50 mm thick is 199 rubles.

Watch the video to see how this type of material is used for insulation.

TechnoNikol

For insulation slab foundation The TechnoNIKOL CARBON ECO SP brand of EPPS is produced. It is characterized by strength, stability in a biologically aggressive environment, and thermal inertia. Service life – 40 years.

The company produces one standard size of this brand - 2360x580x100 mm. The price of one sheet fluctuates around 740 rubles.

URSA Eurasia

The company produces three grades of URSA XPS extruded polystyrene foam. The most suitable for foundation insulation is URSA XPS N-V, since it has the highest compressive strength - 50 t/sq.m. m. However, reduced temperature regime: -50 to +75.

URSA calls its products slabs, and the dimensions of this material are as follows: 1250x600 with a thickness of 50.60, 80, 100 mm. The cost of one slab with a thickness of 50 mm is 192 rubles.

The use of expanded polystyrene for exterior work requires reliable sealing with cement-based plaster mixtures.

Expanded polystyrene will certainly be one of the most effective heat insulators. This material is also used for foundation insulation.

An indisputable advantage of using polystyrene foam for such a task is the ability to do all the work yourself without spending much money. Let’s try to find out in more detail how to properly insulate the foundation not only outside, but also inside.

We insulate the foundation of the house with expanded polystyrene

To insulate the foundation with foam plastic, in our time, as a rule, 2 types of such material are used: extruded (XPS) or foamed (EPS). In addition to production technology, these types are distinguished by their qualities.

According to the experience of professionals, it is preferable to use extruded polystyrene foam.

Compared to foam, it is characterized by the lowest heat transfer coefficient, is stronger and more hygroscopic. Meanwhile, extruded polystyrene foam is not cheap.

Extruded polystyrene foam is an excellent choice for insulating the foundation in the basement.

The disadvantages of foamed polystyrene foam are easy to minimize: this requires an auxiliary layer of waterproofing that protects the material from the harmful effects of wet soil, as well as equipment for a foundation drainage system, which makes it possible to lower the level groundwater.

Polystyrene foam can be attached directly through to a concrete wall.

Here are a few key tips of a collective nature that must be followed when insulating the foundation with polystyrene foam.

When using foamed polystyrene foam for external thermal insulation, it is advisable to waterproof the surface with 2 layers of bitumen mastic.
It is not advisable to use foamed foam at elevated groundwater levels.
Damage is real on difficult soils mechanical type(compression) of foam. The material can be protected using profiled membranes or a brick wall.
At the final stage of the work, a blind area is always implemented. For shallow foundations, it is also advisable to insulate the blind area with extruded polystyrene foam.

Is polystyrene foam suitable for insulation?

Foamed polystyrene foam (foam) is one of the most popular thermal insulation materials used in modern construction.

Expanded polystyrene foam board is at the peak of fashion.

The use of foam plastic for insulation of ground elements of a building raises doubts, taking into account fire safety, however, for external thermal insulation of the foundation, you can use such material without any hesitation.

Moreover, insulation of the external foundation with polystyrene foam is considered good method. Polystyrene foam is comfortable for installation; the surface insulated with this material can be finished and covered with plaster without any problems.

Using expanded polystyrene foam to insulate the foundation of a house.

Polystyrene foam is produced in the form of slabs; the material is very inexpensive, but at the same time it has very low thermal conductivity. The disadvantages of expanded polystyrene foam are listed below.

The ability to accumulate water (which reduces thermal insulation properties).
Low stability.
High deformation factor.

That's why when we're talking about On how to insulate a foundation with polystyrene foam, professionals advise covering foamed polystyrene foam with a waterproofing layer (bitumen-polymer, roll, etc.), covering the insulated foundation with a narrow brick wall (half a brick) or specialized profiled polyethylene membranes.

Use of extruded polystyrene foam

In general, the method of insulating the foundation with extruded polystyrene foam looks very specific.

The foundation must be dug. The depth of the pit is at the level where the base of the foundation is located. It is advisable to surround each side with trenches 1 to 1.5 meters wide.

The foundation plane can be properly cleaned of collapsing or chipping parts of concrete or soil.

The polystyrene foam layer is applied after waterproofing work. The foundation plane is covered with bitumen-based mastic, roll materials or penetrating compounds.

In the photo, polystyrene foam is used to insulate the base and blind area.

In a situation where the height of the underground part of the foundation exceeds the freezing depth of the soil, it is advisable to cover the lower part of the dug trench with sand. The remaining surface will be covered with foam.

Polystyrene foam is the simplest method of waterproofing and insulation, which does not require special skills.

Layers for thermal insulation, which will be covered with soil, are mounted using glue without the main enemy of polystyrene foam - an organic solvent. The use of hot bitumen is not allowed (the limiting temperature of the composition is 70 degrees). Hot bitumen, organic solvent, and dowels will certainly damage the integrity of the waterproofing layer.

Strengthening the walls of the strip foundation with expanded polystyrene.

It is advisable to apply glue to the slabs point by point. It is recommended to apply at least 8 strokes of a centimeter thick and 10 cm in diameter to a 120 by 60 polystyrene foam slab. Just a minute after completing the application of the composition, the slab must be pressed to the foundation and held for some time.

The foundation of the future cottage insulated with foam plastic slabs.

When the 1st row is glued, it is advisable to fill the trench with earth or sand up to half the height of the polystyrene foam slabs. In this way, you can increase convenience during subsequent work.

In most cases, the slabs have a special recess along the entire perimeter, which allows for the interlocking of all components. To transfer greater density to the insulation layer, it is necessary to coat the joints with a bitumen composition.

Thermal insulation of the foundation using specialized polystyrene foam mounted with glue.

The weakest element of the foundation, taking into account heat loss, will be the corners. They need the most effective insulation. It is advisable to implement an auxiliary layer of thermal insulation with a width of 0.5 meters on each side of the corner. Attach the material to the first layer. Bitumen mastic can be used as glue.

Expanded polystyrene for organizing thermal protection of the foundation of a wooden gazebo.

Often, to install foam plastic to the foundation, it is not glue that is used, but mechanical fasteners, for example, disc-shaped dowels with a plastic shell. 1 slab requires 4 similar dowels.

How to choose the best type of polystyrene foam?

This kind of material, such as polystyrene foam, can be used to insulate the entire building: from the foundation to the roof. Consequently, there are materials available on the market with different qualities suitable for a particular place of use. There are three main brands of foam: PSB-S-15 foam, PSB-S-25 foam and PSB-S-35 foam.

Table of main indicators of PSB-S foam plastic.

Table of the main properties of Divinycell H foam from DIAB.

Index	Unit	H35	H45	H60	H80	H100	H130	H160	H200	H250
Compressive strength	MPa	0,45	0,6	0,9	1,4	2,0	3,0	3,4	5,4	7,2
Compression module	MPa	40	50	70	90	135	170	200	310	400
Tensile strength	MPa	1,0	1,4	1,8	2,5	3,5	4,8	5,4	7,1	9,2
Tensile modulus	MPa	49	55	75	95	130	175	205	250	320
Shear strength	MPa	0,4	0,56	0,76	1,15	1,6	2,2	2,6	3,5	4,5
Slicer module	MPa	12	15	20	27	35	50	73	73	97
Nominal Density	kg/m3	38	48	60	80	100	130	160	200	250

For proper insulation of the foundation the best way PSB-S-35 grade foam is suitable. Since foundation slabs must have protective sealed layers. Penoplast-S-35 is also called hybrid; it is more than resistant to the influence of water.

Expanded polystyrene suspension, pressless, self-extinguishing type, made in accordance with GOST 15588-86.

Plates PSB-S-25 F.

Plate brand PSB-S-35.

When choosing expanded polystyrene for the foundation, it is advisable to look for a special brand “Foundation” on the label. This type of foam is also used for thermal insulation of attics and floors.

Many experts believe that only extruded polystyrene foam is suitable for insulating foundations. This material does not rot and does not collect water. XPS is often used to insulate soils around foundations (to avoid freezing).

An obvious drawback that the creators of XPS like to keep silent about is that insulating the foundation with extruded polystyrene foam is quite expensive.

Video on foundation insulation with XPS polystyrene foam from TechnoNIKOL

The insulation method using polystyrene foam allows you to achieve remarkable results in as soon as possible, as evidenced by this indicative video.

How to identify fake PSB foam

It turns out that polystyrene foam can also be counterfeited. On construction market Counterfeit expanded polystyrene panels are becoming increasingly common. Their testing showed the strength to be almost 2 times less than that of real industrial models. As you can see in the photo below, the more granules a PSB board has, the less durable this board is.

As a result, a fake PSB-15 slab under a lateral load of 1 ton bends by 20 mm, while a high-quality slab bends by only 9 mm.

On the left is a fake slab (large granules), on the right is a real one.

Moreover, with a load of 2 tons, the fake PSB-15 plate cannot withstand the load at all - it simply breaks. Keep this in mind and learn to distinguish fake foam boards from the real ones.

External and internal insulation of the foundation with foam plastic: key features

Experts adhere to established ideas regarding foundation insulation methods. They give their preference to the external and put forward several relevant arguments in favor of this method.

External thermal insulation, regardless of the heat insulator used and the type of foundation, blocks low temperatures from entering the structure, eliminating the possibility of freezing.
A heat insulator mounted outside has an effect on the concrete, increasing the service life of the house.
External insulation prevents the penetration of water and groundwater, guaranteeing reliable waterproofing properties of the foundation.
An external heat insulator makes it possible to compensate for temperature changes and protect not only the upper (basement) part of the building, but also the lower section of the foundation.

Expanded polystyrene has excellent thermal insulation, excellent strength and environmental friendliness.

Advantages

However, properly executed internal insulation also has a number of positive features:

internal insulation of the foundation creates a good local climate in the basement and in the building;
The internal heat insulator prevents condensation from accumulating in the basements.

Flaws

Flaws internal insulation foundation.

Lack of adequate protection against external freezing.
Possibility of destruction and deformation of the foundation, formation of cracks, heaving of the soil.

It is clear that a new space with more or less normal indicators will not hurt anyone. Owners of mansions and private buildings often turn basements into gyms or laundries. To make the room easy to settle in, it is recommended to carefully insulate the foundation.

By the way, if the means allow, it is best to insulate the foundation both outside and inside.

31.08.2014

In order for the house to stand for a long time, without sagging or letting in heat, you need to think about high-quality insulation its foundations. Among the variety of materials offered on the market, it is very difficult to choose. But many experts prefer insulating the foundation with polystyrene foam - not the cheapest, but reliable option.

Types of expanded polystyrene, pros and cons of the material

In terms of the thermal insulation properties of one of the most popular types of foam plastic, expanded polystyrene can only compete with mineral wool. Depending on the production method, it is divided into three types:

Unpressed
Pressed
Extruded

Suspension or unpressed polystyrene foam is one of the most common due to its cost. High-quality material has granules same size and their breaking occurs “in a living manner.” The density of the material varies from 15 to 50 kg/m3. It does not freeze in the ground.

Pressed polystyrene foam It is manufactured by pressing on the basis of latex polyvinyl chloride with the addition of a blowing agent. The closed cellular structure determined high density material and its resistance to physical stress. It absorbs moisture worse and has electrical insulating properties.

Homogeneous fine-cell structure extruded polystyrene foam made this material one of the best types of foam. High density and minimal water resistance - all this is achieved thanks to extrusion during the production process. However, the advantages for many are offset by a significant disadvantage - cost.

All the considered types of material are nothing more than polystyrene foam. This means that they share, to some extent, all its pros and cons.

Advantages of polystyrene foam insulation:

No need for a perfectly flat surface to work with
The slabs are easy to cut and set with glue, which speeds up the work
Low vapor permeability coefficient
Frost resistance
Excellent thermal insulation properties

Disadvantages of polystyrene foam insulation:

Flammability of the material
Not the highest mechanical strength
High hygroscopic ability to absorb moisture
Susceptible to rodent infestation without proper protection

Read also about insulating the base of the house with penoplex

Introductory video instructions

Insulation schemes and their features

When choosing one of the schemes for insulating the foundation with polystyrene foam, you need to decide between two varieties:

External thermal insulation
Internal

The second option can be discarded, since it is ineffective. In 90% of cases, they resort to external insulation, simplest scheme which is the following:

Foundation
Waterproofing layer
Expanded polystyrene
Waterproofing layer
Reinforcing mesh
External finishing of the plinth

A possible diagram is presented in more detail in the figure below.

Depending on the climate of the area and the wishes of the waterproofing layer, some changes can be made to the design. For example, instead of one layer of insulation, two are laid, and instead of reinforcing mesh, brickwork is made on the outside.

Let's start insulating the foundation

The durability and functionality of foundation thermal insulation depends largely on the quality of foundation preparation. It is necessary to remove any protruding elements and structures from the surfaces and eliminate depressions.

The next step is to check the verticality of the base. Using a plumb line, you need to walk along the walls and mark the discovered irregularities. Small differences can be eliminated with a thicker layer of glue.

Material selection

At the next stage, you need to decide on polystyrene foam, taking into account two main factors:

Thermal insulation layer thickness
Density

The standard thickness of slabs sold on the market may vary from 3 to 10 cm. When foundation insulation with polystyrene foam is done in areas with cold winters, two layers of material are laid.

You might also be interested in learning how to insulate a floor in a wooden house

To insulate the foundation or ground floor, it is recommended to take polystyrene foam with a density of at least 35 kg/m3.

Flammability class may not be assigned special attention, but higher is better. Material with anti-feather additives is slightly more expensive, but better.

Waterproofing

One of the most important stages is the preparation of a waterproofing layer that will protect the foundation from groundwater. Almost any of the materials sold on the market can be applied under the insulation, but the most common of them is considered to be roofing felt.

Bitumen mastics containing organic solvents should be avoided. They, penetrating into the polystyrene foam, begin to destroy it from the inside. Thermal insulation quickly loses its properties. If coating waterproofing is selected, preference is given to water-based or polymer-based mastics.

Attaching the insulation

Attaching polystyrene foam to the foundation must be done in a combined way:

On glue
Dowels with a wide head

Glue on the slabs must be applied in longitudinal strips along the perimeter and in the center. After maintaining 1-2 minutes in this state, the plate is pressed tightly to the base.

Be sure to check the horizontal and vertical levels to prevent distortions. A thermal insulation layer that is too thick is placed in two slabs (one on top). In this case, the joints of the first row must completely overlap the second. If the gaps remain, they foam.

Protecting the insulation

The next stage, which requires responsibility, is protecting the insulation from moisture and other destroyers. Expanded polystyrene has low mechanical strength and can be inhabited by rodents.

The simplest option to make foundation insulation with polystyrene foam more reliable is to apply a reinforcing mesh. It is stretched well and secured with dowel-nails around the perimeter at certain intervals. A cement solution is applied to the top, to which waterproofing additives are added. It should protect the insulation from freezing and water.

Drainage system

Foundation insulation is not only a high-quality and reliable application of polystyrene foam. It is necessary to lay drainage pipes around the perimeter of the house that will drain groundwater.

Drainage must be discharged into a specially dug hole or septic tank. It is recommended to use a perforated pipe made of a material that will not break down in the ground. At the same time, it is laid on a bed of crushed stone and gravel. The backfill must be uniform and done carefully so as not to damage the insulation.

Let's get to the base

The base, like the underground part of the foundation, must be insulated and protected from moisture. The surface is prepared and waterproofed using the method described above. It is recommended to use the same materials, adhere to in a similar manner performance of work.

Additional fixation of insulation

After two or three days, when the glue is completely dry, you need to make additional fixation polystyrene foam boards using special dowels with a wider head.

Each slab must be fastened in at least 4 places - in the corners. If it is necessary to save money and reduce the number of nails used, they are installed at the joints:

Using a drill and a suitable drill, carefully make a hole in the wall a couple of millimeters larger than the nail itself.
Use a hammer to hammer in the dowels (be careful not to damage the insulation)
The nail itself is installed and achieved

We insulate the soil

To improve the quality properties provided by foundation insulation with polystyrene foam, the soil is also insulated. A blind area is made along the entire perimeter of the walls, thanks to which it is possible to distance the soil freezing line.

It is performed according to the following instructions:

A sand cushion is placed at the bottom
Then a layer of polystyrene foam boards is laid
Reinforcing formwork is installed
The solution is poured with a slight slope from the outside so that water can drain after precipitation.

The final stage is finishing the base. Here you can give free rein to your imagination, purchase the desired materials and get to work.

The most common option is tiles, which are laid on a reinforcing mesh and special glue. Those who want to save money can plaster the surfaces and paint them in the desired color.

Video tutorial on how to insulate a foundation with your own hands

Conclusion

Insulating the foundation with expanded polystyrene with your own hands is not a difficult job. But if in doubt, you should seek the help of a specialist and ask him for clear recommendations and advice.

Types of polystyrene foam materials

Foundation insulation with polystyrene foam is a common method of thermal insulation of the base of a building. Expanded polystyrene materials have a foamed structure. Foundation walls protected by these thermal insulators retain heat well and virtually do not allow water to pass through.

Polystyrene foam is more cheap look polystyrene.

The most expensive thing is to insulate the foundation with extruded polystyrene foam.

Polystyrenes are produced in the form of slabs of different thicknesses. You can choose the appropriate size of material taking into account the type of foundation of the house, the presence of a basement or basement. When choosing, you should also take into account the characteristics of the local climate.

In Russian conditions, it is considered more acceptable to insulate the foundation with polystyrene foam 5 cm thick. If a wine cellar is equipped in the basement of the premises, the temperature in which is about 10 ° C, then it will be better if the thickness of the polystyrene foam is 10 cm.

Increased attention is paid to gluing the corners of the foundation, since freezing of the entire structure begins precisely from them. For this purpose, slabs approximately 3-4 cm thicker than the main heat insulator are used.

In fact, not too many heat insulators are suitable for insulating the foundation. The choice is made according to the rule that the thermal insulation layer must have a service life approaching the durability of the structure itself. Based on this, we can conclude that it is better not to use polystyrene foam for insulating the foundation.

Considering that the service life of reinforced concrete is at least 100 years, and foam plastic is about 20-25 years, it is almost impossible to control the condition of PPS buried in the ground.

After using polystyrene foam, a problem will certainly arise associated with re-insulating the foundation. Despite the fact that thermal insulation with polystyrene foam is performed more often than insulating the foundation with polystyrene foam, this approach is not considered rational among professionals.

Properties of polymer insulation

IN modern construction For foundation insulation work, the most suitable polymer materials are used:

penoplex;
extruded polystyrene foam.

There are no fundamental differences between these polymer-type heat-insulating materials. This is explained by the fact that they are made on the basis of polystyrene. There are minor differences in the production technology of these heat insulators related to foaming. Penoplex and extruded polystyrene foam for the foundation have properties such as low thermal conductivity and high strength. These heat insulators are excellent for insulating the foundation of a cottage or private house. They can be used to provide insulation columnar foundation, shallow, strip, pile and other types.

The materials are similar in composition, which is reflected in their durability and quality. They do not absorb water, but polystyrene foam, which has lower thermal conductivity than polystyrene foam, is more durable.

The cost of expanded polystyrene is higher than that of polystyrene foam. Consequently, prices for insulation with these materials vary. These thermal insulators have an attractive appearance. According to some information circulating among builders, foam plastic is considered a material that can replace 50 cm of brickwork. No one has conducted any experiments to compare the density of brick and foam plastic, but this indicator is lower for PPS, so the insulation has less thermal conductivity than brick.

Insulation of the foundation from the outside with polystyrene foam

Carrying out installation work for foundation insulation with polystyrene foam does not amount to special labor. Insulation should be applied to the waterproofing. Insulation of a strip foundation with polystyrene foam is carried out as follows:

the wall is treated with a heat-insulating coating;
the surface of the wall is covered with a waterproofing layer;
measurements are taken of the freezing depth, to which 5-10 cm is added;
the container (bucket) is filled 1/4 with water and foam glue is added;
the composition is thoroughly mixed with a mixer until the consistency of thick sour cream;
glue is applied to the foam sheet in several places and leveled using a notched trowel;
the insulation sheet is pressed tightly against the foundation wall;
the subsequent sheet is inserted into the lock of the previous one, if provided;
the sheet is glued to the wall by pressing the material;
the foam is covered with a PVC membrane;
the dug trench is filled with sand.

All steps to insulate the foundation with foam plastic are not complicated. At the same time, experts do not recommend nailing the insulation to the foundation wall with nails, since you can break through the waterproofing.

The foam installation method is most suitable for beginners. This method cannot be compared in cost to spraying polyurethane foam. It is best to carry out insulation with an assistant, so that one person can cut and feed the sheets, and the second can apply glue and mount the insulation on the wall.

Application of thermal insulation in construction

The best method of thermal insulation of the base of a house is considered to be insulation of the foundation with penoplex. This method is used mainly at the stage of building a house. Fastening polystyrene foam to concrete in most cases involves the use of special bitumen mastic.

The entire surface is pre-leveled cement composition, and then the smooth foundation wall is cleaned. After this, the first layer of mastic is applied, that is, a bitumen primer, onto which a roll of waterproofing is glued, and a heat insulator is attached on top. An additional layer of geotextile is laid on top as a protective covering. Often, penoplex is simply covered with soil.

For creating additional protection will not require significant expenses Money, but geotextiles can significantly extend the useful life of the heat insulator. The technology of foundation insulation using expanded polystyrene can be studied by watching the video.

Another method of insulating the base of a house where there is no basement is used to insulate foundations in the form of a solid concrete slab.

The essence of the method is that polystyrene foam is laid on a sand cushion and poured on top concrete base. At the same time, it remains possible to immediately put into monolithic foundation heating circuit of the "warm floor" system. The name of this design is Swedish stove. It refers to shallow foundations, which are insulated not only from below, but also along the entire perimeter.

Based on the beliefs of energy efficiency, this development is one of the best, but it requires scrupulous work. Otherwise, failure to comply with the technology can lead to cracks in the slab and subsequent damage to the “warm floor” system.

Options for insulating a shallow foundation

The main disadvantage of the Swedish stove is the inability to carry out repairs after it cracks. A solid slab can be mounted on different soils, so it successfully replaces a strip foundation. Correct laying of the heat insulator should ensure long term foundation design services.

Insulating the structure of a Swedish stove is appropriate if the owner personal plot I decided to build my house from wood, planning to lay heated floors in the foundation of the building. This problem requires a serious approach, since after the house has already been built, it is impossible to do without dismantling work. In this case it is necessary to do:

removal of plinth cladding;
opening of the old blind area around the building.

If the foundation of the house is a shallow strip foundation, then you will have to dig a trench to its base in order to install heat-insulating material over the entire surface of the foundation. Another common option is to insulate the base and lay penoplex under the blind area. This will protect against freezing underground part grounds.

Thermal insulation throughout the foundation and the soil under the blind area is the most The best way insulation of the base of the house. If you decide not to dig to the foundation, you can dig a hole that runs along the entire perimeter of the foundation. The width of the pit should be more than 1 m of the entire wall, and its depth should be 200-300 mm. The soil near the base must be compacted properly. Next you will need to do the following:

clean the base;
remove all sagging;
seal cracks;
dilute the glue in water;
strengthen polystyrene boards to the base;
fix the slabs with umbrella dowels;
pour a layer of sand more than 10 cm wide into the hole;
level and compact the sand;
lay out slabs of penoplex (expanded polystyrene);
strengthen geotextiles;
refill the blind area;
install the plinth cladding.

Choosing polystyrene foam for foundation insulation

Because the technological process The production of extruded polystyrene foam is carried out under pressure, this makes it possible to produce insulation, the structure of which includes molecular bonds of high strength. XPS has more high quality than polystyrene foam (PSB). Often, extruded polystyrene foam becomes a material that is almost irreplaceable in cases where ordinary foam plastic simply cannot withstand the load.

Before choosing EPS, you need to understand what technical characteristics it has. Expanded polystyrene is manufactured in several modifications, since different types of EPS are required for different areas of the house (roof, walls, foundation). Each modification of the teaching staff has different characteristics, therefore it can be used when insulating only a certain area of the house.

Building materials markets sell polystyrene foam of 3 main brands:

PSB-S-15.
PSB-S-25.
PSB-S-35.

For insulating the foundation, the last option is considered the most suitable, because this brand of heat insulator has protective sealed layers, so it does not absorb water. When purchasing expanded polystyrene, you should make sure that the material is marked with the “Foundation” mark. This will allow you to choose a material that is suitable for all technical characteristics.

The thickness of the EPS is selected depending on the climatic conditions in the region of construction. The width of this material can vary from 1 to 10 cm. For middle latitudes, a heat insulator 5 cm wide is suitable. Each manufacturer produces similar heat insulation boards various sizes, so you must first determine how much they will be needed.

Polystyrene can be strengthened to the foundation using either special glue or bitumen. It is worth considering: after gluing, polystyrene foam slabs remain movable for more than 20 minutes. Therefore, they need to be strengthened not only with glue, but also with plastic dowels, selected with a margin of length.

If polystyrene with a width of 5 cm is mounted, then the dowels must have a length of more than 10 cm. To attach the slabs, glue of the Bitumast brand, Ceresit ST-84, cement-polymer, bitumen adhesives that do not contain gasoline, ether and acetone are used.

Properties of extruded polystyrene foam

Many home owners use foam plastic to insulate the foundation, which is considered good thermal insulation material. Professionals believe that polystyrene foam is more suitable for thermal insulation of external walls than for insulating the foundation.

Foam plastic can be damaged by rodents, and its shelf life is not very long, since this heat insulator absorbs water, while having low strength and a very high deformation coefficient. Pressless expanded polystyrene (foam) begins to crumble into individual balls after just a few seasons. This occurs due to the hygroscopicity of the material.

Extruded polystyrene foam (EPS) is more durable than polystyrene foam. The duration of its operation significantly exceeds the shelf life of polystyrene foam. Builders often call EPPS Polpan. The technology for its production differs from the production process of polystyrene foam, since EPS is produced under pressure, initially representing a semi-liquid viscous foam mixture fed through a nozzle with a certain cross-section.

As a result, slabs of various sizes are produced. Modern developers often have to insulate the outside of houses with penoplex slabs, that is, extruded polystyrene foam. The material is orange in color.

Thermal insulation of a columnar foundation with polystyrene foam

Before you insulate a columnar foundation with your own hands, you will need to purchase a heat insulator and suitable glue for it. Then you should perform all the following types of operations in turn:

Dig the foundation to its depth, making a trench around it.
Cover the foundation with EPS at least to the depth of freezing of the soil.
Clean the foundation, removing all crumbling or chipping concrete particles.
Cover the surface of the foundation with a penetrating primer (2 layers) and let it dry until it is completely absorbed into the concrete.
Waterproof the foundation bitumen mastic.
Apply glue onto the slab in spots.

The polystyrene foam is attached to the foundation 1 minute after applying the glue. If the size of the polystyrene board is 120x60 cm, you need to apply more than 8 strips of glue 1 cm wide. For this, a comb spatula is used. You need to start from the bottom, rising in rows.

If the polystyrene foam insulation does not have special locks, then after 3 days polyurethane foam is injected into the seams between its plates for sealing. Dowels can be used for fastening, so holes for them are drilled along the edges of the slabs and in the center of each of them.

When insulating a columnar foundation with your own hands, coating waterproofing can be used if protection from capillary water is required. The level of hydrostatic pressure can reach up to 0.1 MPa.

Technique coating waterproofing quite simple. It is performed using bitumen or polymer mastics that cover the surface of the foundation with a film with waterproof properties. The use of coating technologies is typical for vertical waterproofing of foundations.

When carrying out horizontal coating waterproofing, it is necessary to take into account the fact that due to their low strength they are used only as auxiliary waterproofing layers. After processing each hole a small amount polyurethane foam dowel-nails are driven into them. Then waterproofing is applied to the heat insulator with polymer mastic, and after it dries, the trench is covered with earth.

DIY columnar foundation made from asbestos pipes

Polystyrene foam is a cheaper type of polystyrene.

The most expensive thing is to insulate the foundation with extruded polystyrene foam.

Considering that the service life of reinforced concrete is at least 100 years, and foam plastic is about 20-25 years, it is almost impossible to control the condition of PPS buried in the ground.

Properties of polymer insulation

In modern construction, the most suitable polymer materials are used to carry out foundation insulation work:

penoplex;
extruded polystyrene foam.

There are no fundamental differences between these polymer-type heat-insulating materials. This is explained by the fact that they are made on the basis of polystyrene. There are minor differences in the production technology of these heat insulators related to foaming. Penoplex and extruded polystyrene foam for the foundation have properties such as low thermal conductivity and high strength. These heat insulators are excellent for insulating the foundation of a cottage or private house. With their help, you can insulate columnar, shallow, strip, pile and other types of foundations.

The cost of expanded polystyrene is higher than that of polystyrene foam. Consequently, prices for insulation with these materials vary. These heat insulators have an attractive appearance. According to some information circulating among builders, foam plastic is considered a material that can replace 50 cm of brickwork. No one has conducted any experiments to compare the density of brick and foam plastic, but this indicator is lower for PPS, so the insulation has less thermal conductivity than brick.

Insulation of the foundation from the outside with polystyrene foam

Carrying out installation work on insulating the foundation with foam plastic is not difficult. Insulation should be applied to the waterproofing. Insulation of a strip foundation with polystyrene foam is carried out as follows:

the wall is treated with a heat-insulating coating;
the surface of the wall is covered with a waterproofing layer;
measurements are taken of the freezing depth, to which 5-10 cm is added;
the container (bucket) is filled 1/4 with water and foam glue is added;
the composition is thoroughly mixed with a mixer until the consistency of thick sour cream;
glue is applied to the foam sheet in several places and leveled using a notched trowel;
the insulation sheet is pressed tightly against the foundation wall;
the subsequent sheet is inserted into the lock of the previous one, if provided;
the sheet is glued to the wall by pressing the material;
the foam is covered with a PVC membrane;
the dug trench is filled with sand.

Application of thermal insulation in construction

The entire surface is first leveled with a cement composition, and then the even wall of the foundation is cleaned. After this, the first layer of mastic is applied, that is, a bitumen primer, onto which a roll of waterproofing is glued, and a heat insulator is attached on top. An additional layer of geotextile is laid on top as a protective covering. Often, penoplex is simply covered with soil.

To create additional protection, significant expenditures of money will not be required, but geotextiles can significantly extend the useful life of the heat insulator. The technology of foundation insulation using expanded polystyrene can be studied by watching the video.

Another method of insulating the base of a house where there is no basement is used to insulate foundations in the form of a solid concrete slab.

The essence of the method is that polystyrene foam is laid on a sand bed, and a concrete base is poured on top. At the same time, it remains possible to immediately install the heating circuit of the “warm floor” system into the monolithic foundation. The name of this design is Swedish stove. It refers to shallow foundations, which are insulated not only from below, but also along the entire perimeter.

The main disadvantage of the Swedish stove is the inability to carry out repairs after it cracks. A solid slab can be mounted on different soils, so it successfully replaces a strip foundation. Proper installation of the heat insulator should ensure a long service life of the base structure.

Insulating the structure of a Swedish stove is appropriate if the owner of a personal plot has decided to build his house from wood, planning to lay heated floors in the foundation of the building. This problem requires a serious approach, since after the house has already been built, it is impossible to do without dismantling work. In this case it is necessary to do:

removal of plinth cladding;
opening of the old blind area around the building.

Thermal insulation throughout the foundation and the soil under the blind area is the best way to insulate the foundation of a house. If you decide not to dig to the foundation, you can dig a hole that runs along the entire perimeter of the foundation. The width of the pit should be more than 1 m of the entire wall, and its depth should be 200-300 mm. The soil near the base must be compacted properly. Next you will need to do the following:

clean the base;
remove all sagging;
seal cracks;
dilute the glue in water;
strengthen polystyrene boards to the base;
fix the slabs with umbrella dowels;
pour a layer of sand more than 10 cm wide into the hole;
level and compact the sand;
lay out slabs of penoplex (expanded polystyrene);
strengthen geotextiles;
refill the blind area;
install the plinth cladding.

Choosing polystyrene foam for foundation insulation

Since the technological process for the production of extruded polystyrene foam is carried out under pressure, this makes it possible to produce insulation whose structure includes high-strength molecular bonds. EPPS is of higher quality than polystyrene foam (PSB). Often, extruded polystyrene foam becomes a material that is almost irreplaceable in cases where ordinary foam plastic simply cannot withstand the load.

Before choosing EPS, you need to understand what technical characteristics it has. Expanded polystyrene is manufactured in several modifications, since different types of EPS are required for different areas of the house (roof, walls, foundation). Each modification of PPS has different characteristics, so it can be used to insulate only a certain area of the house.

Building materials markets sell polystyrene foam of 3 main brands:

PSB-S-15.
PSB-S-35.

The thickness of the EPS is selected depending on the climatic conditions in the region of construction. The width of this material can vary from 1 to 10 cm. For middle latitudes, a heat insulator 5 cm wide is suitable. Each manufacturer produces similar heat insulation boards of various sizes, so you must first determine how many of them will be needed.

Properties of extruded polystyrene foam

Many home owners use foam plastic to insulate the foundation, which is considered a good thermal insulation material. Professionals believe that polystyrene foam is more suitable for thermal insulation of external walls than for insulating the foundation.

Thermal insulation of a columnar foundation with polystyrene foam

Dig the foundation to its depth, making a trench around it.
Cover the foundation with EPS at least to the depth of freezing of the soil.
Clean the foundation, removing all crumbling or chipping concrete particles.
Cover the surface of the foundation with a penetrating primer (2 layers) and let it dry until it is completely absorbed into the concrete.
Waterproof the foundation with bitumen mastic.
Apply glue onto the slab in spots.

When insulating a columnar foundation with your own hands, coating waterproofing can be used if protection from capillary water is required. The level of hydrostatic pressure can reach up to 0.1 MPa.

The technique of coating waterproofing is quite simple. It is performed using bitumen or polymer mastics that cover the surface of the foundation with a film with waterproof properties. The use of coating technologies is typical for vertical waterproofing of foundations.

When carrying out horizontal coating waterproofing, it is necessary to take into account the fact that due to their low strength they are used only as auxiliary waterproofing layers. After treating each hole with a small amount of foam, dowel nails are driven into them. Then waterproofing is applied to the heat insulator with polymer mastic, and after it dries, the trench is covered with earth.

Insulating the foundation with polystyrene foam is a popular way to improve thermal insulation performance and prevent freezing of the foundation. Expanded polystyrene is nothing more than polystyrene foam made using more modern technologies. Extruded polystyrene foam has greater strength compared to conventional foam, as well as a more convenient form of plates for installation.

Advantages of insulation using expanded polystyrene:

High thermal insulation characteristics, frost resistance;
Low vapor permeability;
Expanded polystyrene slabs are easy to install and cut to the required size;
Surface does not require additional training, irregularities are allowed;
The price of the material is low.

Disadvantages of polystyrene foam:

The material is flammable, therefore, when installed on the base part of the foundation, it requires finishing with non-combustible materials;
Expanded polystyrene is often damaged by rodents and requires the installation of reinforcing mesh;
Expanded polystyrene absorbs moisture, which contributes to its destruction, therefore, when insulating foundations in damp soil, additional waterproofing is necessary;
The mechanical strength of the material is also low, therefore, when backfilling with soil containing solid inclusions, additional mechanical protection in the form of shields is required.

Technology of foundation insulation with polystyrene foam

Preparing the foundation. Foam insulation is possible both for objects under construction and for those already in operation. The foundation must be completely excavated, cleaned of soil, dust, construction debris, grease stains and rust. Leftovers roll waterproofing it also needs to be removed from the foundation. You can insulate the foundation with polystyrene foam both from the outside and from the inside, but the most effective is external insulation, when the foundation itself is included in the heat-insulated zone.
Selection of polystyrene foam. When choosing, two factors should be taken into account - the density and the calculated thickness of the insulation layer. Expanded polystyrene slabs have a thickness of 30 to 100 mm; if it is necessary to make a thicker layer of insulation, they are attached in two layers. The density of expanded polystyrene for foundation insulation must be selected from 35 kg/m 3, the flammability class for the underground part of the foundation does not matter; for the base it is better to choose expanded polystyrene with fire-retardant additives, or to isolate it from the structural combustible parts of the building with a layer of non-combustible material.
Foundation waterproofing. This important stage will allow you to avoid the foundation getting wet from groundwater if the insulation layer passes through it. under the insulation can be carried out in any way, with the exception of waterproofing with bitumen mastic on organic solvents - expanded polystyrene in contact with solvents quickly loses its properties and is destroyed. Therefore, when performing coating waterproofing, it is better to choose polymer or water-based mastics.
Fastening polystyrene foam to the underground part of the foundation. The insulation boards are attached to the foundation using contact adhesive for polystyrene foam. The glue is applied around the perimeter of the slab and in several stripes in its center, left for 1 minute and pressed firmly to the foundation. Wait a few minutes, then attach the next slab. It is better to fasten the plates level to avoid distortions at the joints. If, according to the calculation results, an insulation layer of greater thickness is required than the maximum standard thickness of polystyrene foam, then the insulation is attached in two layers, one on top. In this case, the slabs are positioned so that the second row completely overlaps the joints of the first with the center of the slab. If after the sticker there are still gaps, they are foamed with polyurethane foam.
An important step is protecting the insulation. The disadvantages of expanded polystyrene include its low mechanical strength and the likelihood of damage by rodents. Therefore, to maintain the integrity of the thermal insulation layer, it is necessary to protect it with reinforcing mesh or wooden panels. The mesh or panels are attached along the perimeter of the foundation to the height of the backfill using dowel nails. You can plaster the foundation on top of the mesh cement mortar with the addition of waterproofing components, which will also help to avoid the insulation getting wet and being destroyed when freezing.
Drainage. This stage is mandatory for buildings installed on wet soils With high level groundwater. Drainage is carried out along the entire perimeter of the foundation and leads into a natural depression, reservoir or specially dug drainage well. The drainage is a perforated pipe made of any material, laid on a specially prepared bed of crushed stone and sand. The foundation is backfilled with soft soil or sand, carefully so as not to damage the polystyrene foam slabs.
Basement insulation. The basement part of the foundation is also subject to insulation. The prepared and waterproofed foundation surface is ready for laying insulation boards. The polystyrene foam boards are attached to the same glue, the gluing procedure is similar.
After the glue has dried, that is, after a day or two, the insulation boards are additionally fixed to the base using special fasteners - dowel-nails with a wide head. Each slab must have at least 4 fastening points, and to reduce their total number, dowels can be installed at the joints of the slabs. They pre-drill a hole in the slab and foundation a couple of centimeters deep than the length of the dowels, after which the dowels are carefully hammered in, followed by the nail. Plastic dowels, due to their wide caps, perfectly hold polystyrene foam boards and at the same time do not create cold bridges.
Soil insulation. Effective reception, which allows not only to improve the temperature in the building, but also protects the foundation itself from destruction. Its operating principle is that the soil around the foundation is isolated from subzero temperatures with the help of an insulated blind area, and the frost line moves away from the foundation walls to the distance of insulation. Usually the width of the blind area is no more than a meter. The blind area is insulated with polystyrene foam slabs laid in formwork on a prepared sand bed, after which the blind area is reinforced with rods and filled with concrete. When pouring, it is necessary to make a slight slope outward so that precipitation did not stagnate on the blind area.
Basement finishing. Finishing is necessary to protect the insulation from mechanical damage and give decorative look the basement part of the foundation. Reinforcing painting mesh is attached to the insulation boards using cement-based glue, after which they wait for the glue to dry and plaster the base. You can attach any type of material to plaster facing material, or paint the base with paint.

Insulating the foundation with polystyrene foam is not the best effective method for buildings experiencing large mechanical loads from the ground. Expanded polystyrene has more durable analogues, for example, insulation with polyurethane foam or slabs. To perform thermal insulation of the foundations of buildings built on highly heaving soils, it is more reliable to use these materials.

Many owners of private housing prefer to insulate the basement and foundation by covering the outside with polystyrene foam. This allows you not only to save heat in the house, but also to protect the foundation of the building from premature destruction and cracking. In addition, the walls of the basement, if there is one in the project, will always remain dry.

The technology for performing such work is not very complicated. The main thing is to adhere to all the main stages of insulation and not to disturb the sequence of operations.

Before choosing expanded polystyrene as the main insulation material, you should find out all its qualities.

The unambiguous pleasant properties that extruded polystyrene foam has are:

high frost resistance;
excellent thermal insulation;
no toxins;
low response to chemical influences;
vapor tightness;
minimal moisture absorption;
durability in operation;
resistant to fungi and rotting.

But there are also several not very pleasant qualities that the material has:

Flammability - additional treatment with special mastics is required in basement areas.
Low resistance to physical impacts - requires protection from rodents in the form of a metal mesh.
Mechanical damage - when backfilling there should be no hard rocks in the soil.

But, despite this, the material is highly valued by professionals, as it is easy to install, convenient to use, and can be easily cut into small pieces. And it costs quite a bit.

Selection of polystyrenes for insulation

When choosing a material for insulation, it is worth considering its three main properties:

density characteristic;
the size of the slab layer;
flammability classes.

It is thanks to these parameters that you can effectively insulate any foundation with polystyrene.

Since expanded polystyrene boards are used as insulation, manufacturers, for the convenience of users, produce products whose thickness is not less than 30 mm and not more than 100 mm. This allows you to combine materials in such a way that the resulting insulation thickness is most suitable for each individual case.

Density characteristics also have their significance. For foundations, it is better to use sheets with a density of at least 35 kg/m3.

Flammability classes are only important for insulating the base and basement. After all, the underground part doesn’t care what kind of polystyrene foam will be used. But for the basement and plinth it is worth purchasing slabs with the addition of fire retardants. This will provide some insulation from combustible elements of the home structure.

Preparatory work before insulation

Initially, it is worth preparing the foundation of the building for insulation operations. And for this you need:

Clean the base from soil and debris.
Treat with protective mastics.

If the foundation has just been laid, you just need to expand the trench (pit, place on all sides of the pit) by 45 cm. This will allow you to carry out work on insulating the base from the outside with polystyrene without interference. True, after digging ditches, it is necessary to remove the formwork from the foundation.

The same operations should be carried out for the foundation that has long been used under the building. But the difference here will be the additional cleaning work.

You will have to not only remove soil and adhering remains of vegetation from the foundation walls, but also completely clear it of rust, chipped parts of the mortar, and pieces of external waterproofing.

Now you can start priming external walls foundation. The technology is quite simple and resembles conventional priming of any surface. The difference here is the mastic compositions themselves.

Since the primer at this stage of work is waterproofing before laying the insulation, you should approach the choice of mastic responsibly.

It must be remembered that mastics with organic solvents should not come into contact with polystyrene. Otherwise, it will immediately deteriorate. It is better to use water-based primers.

Foundation insulation with polystyrene

After the primer has dried, you can begin the process of insulating the underground area of the foundation with polystyrene foam. Here, too, the technology is simple. The main thing is to perform all operations as the instructions suggest:

dilute the adhesive mass in the proportions indicated on the container and let it sit;
apply the mixture to ready-made cut polystyrene foam slabs, and not to the foundation walls;
give time for the glue to set on the slab;
press the prepared sheet to the foundation;
Check the correct position of the sheet using a level.

You need to start attaching the slab to the base of the house from one of the corners. And only from below. This will make it possible to lay out the sheets more evenly and without large seams.

It is better to use extruded polystyrene foam for such work. Its properties are much better than its analogues.

It is always easier to insulate the base of a building from the outside in pairs. After all, it is often necessary to lay the material in several layers.

It is worth remembering that working with polystyrene requires care and attention. Before you start insulating, it is better to prepare sheets of the optimal size by cutting them in advance.

Now it’s worth protecting the insulation from external mechanical damage (rodents, sharp stones). To do this, a fiberglass mesh is placed on the outside of the insulation. It is also coated with adhesive solutions.

Can be used metal mesh or just wooden panels. They need to be secured with dowels from the very bottom of the foundation to the ground level. For maximum effect the network (boards) are plastered with ordinary mortar of small thickness. After the plaster has dried, you can backfill.

Don't forget about drainage. It is always performed when insulating base walls with extruded polystyrene foam.

Insulation of the base and basement with polystyrene

Thermal insulation of the basement floor is not difficult. It is performed in the same way as insulating the foundation of a house. But there are some differences here.

After all, the base is above the ground, and it is also affected by external factors. And besides, in some houses there is no basement in the basement. Therefore, the finishing of such buildings will be simpler.

After the slabs are glued to the walls of the basement, you should let them dry thoroughly. And now it is necessary to strengthen the polystyrene sheets with additional dowels, which have a fairly wide head. Such fasteners will hold the plates on the surface of the base without damaging the sheets themselves.

To ensure that the dowel fits tightly but does not damage the insulation, you need to drill small holes at the joints between the sheets. The length of the holes should be slightly longer than the length of the fastener.

Next, carefully drive a dowel into the hole and insert a nail into it. Hammer the resulting structure into the basement wall. It doesn’t matter whether the basement is with a basement or without a basement - the technological process for attaching the slab is the same.

It is important not to miss: for each slab there should be 3-4 fastenings. This will additionally protect the material from damage during further finishing.

Now it’s worth throwing a painting net over the insulated wall of the plinth. And you can throw a solution on it thin layer. As the solution dries, unevenness will be visible. They can be removed with plaster. And only after that you can perform Finishing work With outside basement

In order for the functions of the basement to serve as best as possible, it is better to finish the base with ventilation material.

Build highly effective thermal insulation of a stone house, perform insulation basement or the foundation of a building without the use of modern insulating materials is almost impossible. Of all the options available at cost and do-it-yourself, owners of new buildings and old houses most often choose the foundation insulation scheme with polystyrene foam. The main argument decision taken there was durability and high efficiency polystyrene foam with a relatively simple method of installing it yourself. At the same time, the craftsmen, without going into the subtleties of technology, simply glue the base and foundation polystyrene foam board followed by sealing the insulation with a layer of thin plaster, as in the video:

Foundation insulation with extruded polystyrene foam - EPS

Expanded polystyrene itself is a type of foam that has undergone hot extrusion, resulting in a stronger and denser structure. EPPS has gained wild popularity as an insulation material due to a number of positive qualities:

The highest ratio between price and insulation efficiency;
The material is very light, a cubic meter weighs no more than 35 kg, which allows you to perform most insulation operations with your own hands without helpers;
Expanded polystyrene does not rot and is not affected by microflora, it has high strength, which makes it possible to insulate the foundation with relatively large sheets.

Important! The most common mistake in using extruded polystyrene foam as foundation insulation is the refusal to apply an additional waterproofing system.

The manufacturer states that the water absorption of EPS is about 0.8% per month of the sample being in water. In fact, the cells of expanded polystyrene are quite large and collect water vapor well, which means that the material, allowing diffusion moisture to pass through, will swell, thereby reducing the effectiveness of insulation to a minimum.

To install sheets of extruded polystyrene foam, a flat surface is required, without protrusions, seams and traces of formwork, which are always sufficient on foundation walls. However, when proper insulation foundation with expanded polystyrene, the technology of EPS stickers allows for thermal insulation much more efficiently and cheaper than using backfill methods, installing blocks of foam glass, foam concrete, polyurethane foam.

Effective insulation of the foundation with polystyrene foam

To insulate the foundation of a small private house, polystyrene foam in the form of small sheets of 60x100 cm, 30 mm thick, is best suited. This size of material allows you to work with a foundation with a height of 120 cm. They are simpler and more convenient to use. There are groove elements at the long ends of the sheet, which make it possible to obtain a “blind” joint without losing the thermal insulation properties of the joint.

Each sheet has inside, which is adjacent to the foundation, longitudinal grooves measuring 5x3 mm. If the extruded polystyrene foam sheet is installed correctly, the resulting water condensation will flow through the grooves into the lower part of the insulation system and be removed by drainage. Dried soil increases the effectiveness of foundation thermal insulation.

Methods of fastening extruded polystyrene foam

All methods and recipes for foundation insulation using sheets of extruded polystyrene foam can be divided into two main groups:

The classic scheme for installing the material on the insulated surface using glue or adhesives;
Easier and cheaper fastening of EPS using dowels.

The latter option is most often used for cladding facades; dowels provide strong fastening of extruded polystyrene foam boards to any surface. Most often, the facade, walls, and basement of the building are insulated in this way, and often, in order not to change the method of fastening, they install sheet insulation polystyrene foam and concrete blocks foundation. It is believed that fastening the sheets in one way on the base and on the foundation avoids the destruction of polystyrene foam boards due to temperature changes.

This method can only be used if concrete walls foundations do not have waterproofing or are covered with a fresh, undried layer of mastic coating, liquid rubber or a similar composition. It is clear that it can be installed over film or roll waterproofing only as a last resort, and only with obligatory coating of the dowel installation sites. Otherwise, pinpoint tears in the waterproofing film will lead to soaking and failure of the entire foundation insulation system.

Insulation by gluing polystyrene foam onto foundation concrete

Gluing insulation boards onto a concrete foundation base with your own hands is actually no more difficult than using dowels. The whole technological process is very similar to gluing facing tiles, with the only difference that when installing a heat insulator it is necessary to achieve the tightest possible joints of individual sheets.

Insulation is carried out in three stages:

Carefully clean and level the concrete surface of the foundation using a grinder and cutting wheels over the stone, we pass with a brush with metal bristles and blow air on the walls;
We coat the walls with a liquid waterproofing compound, and you can install insulation boards. If waterproofing is carried out in a double layer, for example, by coating with bitumen mastic and rolling with roll material, it is best to use a special glue that allows you to obtain good adhesion to polystyrene foam without dissolving the insulation;
The laid polystyrene foam is covered with a reinforcing mesh and plastered with a waterproof compound.

Advice! IN professional version For insulation, the laid layer of thermal insulation must be covered with film waterproofing, thin steel mesh, a layer of geotextile and covered with grated clay.

Popular adhesive compositions for polystyrene foam insulation

In the professional version, bitumen-rubber or silicone adhesive mastic with the addition of rubber and special substances that enhance adhesion is most often used. It is enough to open a jar of the composition, apply it to the foundation, lay a sheet of extruded polystyrene foam and carefully press the slab to the concrete surface. The mass consumption is in the range of 1.5 kg/m2.

After about 10 hours, the installed insulation must be treated over the surface of the glued heat insulator with another layer of mastic, and dense polyethylene film and geotextiles must be laid. Thus, you get a “warm” cake that is not afraid of moisture, open water, temperature changes and even mechanical contacts with stones or gravel. To avoid damage to the insulation by rodents, before filling with soil, you can lay a steel mesh or pour a layer of foam glass granules.

In addition to bitumen-rubber mastic, slabs can be strengthened using polyurethane foam, as in the video:

For work, use frost-resistant foam options that do not have secondary expansion due to the deep dissolution of the foaming agent in the polyurethane mass. Otherwise, rising layers of foam can distort and lift the edges of the slabs and expose the joints. One of the most commonly used foam for gluing insulation boards is Ceresit ST84 foam.

For direct laying of extruded polystyrene foam on a concrete surface the best option there will be a mixture of “SK 106P” “Aqualit” or “Ceresit ST85” or “ST83”. Both options are diluted with water and have a relatively short hardening period, so prepare the adhesive mass immediately before laying the insulation.

Insulating the foundation of the blind area with polystyrene foam

Insulation of the foundation is unthinkable without additional measures for thermal insulation of the blind areas of the walls. About 30% of the heat from the concrete base of the foundation system is lost in the near-surface layers of the soil. Installing even a relatively thin layer of extruded material under a concrete base will reduce the depth of soil freezing by 15-20%. Extruded polystyrene foam is best suited for these purposes due to the high strength and elasticity of the sheets.

The blind area is made in the form of a wide concrete strip, 8-10 cm thick, with a reinforcement frame. Most often, the function of the foundation blind area is protection from moisture and compensation for heaving of the soil under the walls.

The easiest way to do the insulation yourself is at the stage of building the blind area. To do this, you will need to dig a mini-pit the width of the blind area, to a depth of at least 30 cm. A thick waterproofing film will need to be laid at the bottom of the pit, which will drain water from under the blind area to the drainage area. Next, a 5-7 cm layer of sand and crushed stone is poured, geotextiles are laid and sand is re-filled. Before laying the insulation, the base is carefully compacted and leveled.

At the next stage, a layer of extruded polystyrene foam is laid out. Two or three layers of 30 mm sheet are best suited, depending on the required insulation power. Next, a separating membrane, reinforcement and formwork are laid to form a concrete layer of the blind area. The outer edge of the foundation blind area should overlap the edges of the insulation by at least 10 cm.

Conclusion

Today, foundation insulation using foam materials is the most effective and inexpensive compared to using silicate blocks, filling with expanded clay, or laying aerated concrete slabs. The material of expanded polystyrene boards is calculated for cyclic strength when the temperature changes “winter-summer” for 80 years, therefore, if the installation technology is followed, the service life of the foundation insulation will be more than sufficient.

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