Horizontal insulation of the foundation with polystyrene foam technology. How to properly insulate the foundation and blind area with foam plastic from the outside

In order for the house to stand for a long time, without sagging or letting in heat, it is necessary to think about high-quality insulation of its foundation. 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. U quality material The granules are of the same size and their breakdown occurs “alive.” 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 the high density of the 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 benefits for many are offset by significant drawback– 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:

Not needed ideally flat surface for work
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 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 expanded polystyrene is done in areas with cold winters, two layers of material are laid.

You might also be interested to know in a wooden house

To insulate the foundation or basement, it is recommended to use 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– 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 one made of material that will not collapse 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 has completely dried, it is necessary to make additional fixation polystyrene foam boards using special dowels with a wider cap.

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 quality properties, which provide foundation insulation with polystyrene foam, also insulate the soil. 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.

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 provide for lower distribution of pipes for heating systems, hot water supply, as well as pipes for water supply and sewerage systems.

When planning to place utility rooms in the basements: a garage, a laundry room, a boiler room, a 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 bricks or stones 510 mm thick or concrete blocks 500 mm thick with 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, household appliances, when constructing highways, runways, and laying pipelines. IN 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 necessary measure. According to the climatic zoning map, only in southern regions The Russian Federation can 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, the 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.

A 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 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. Well-known 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. Stated characteristics this insulation are characteristic of EPPS, however, the thermal conductivity coefficient is slightly higher - 0.03-0.032 W/m*ºС.

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

Watch the video how it is used this type material 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 polystyrene foam for external use requires reliable sealing plaster mixtures based on cement.

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 expanded 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 groundwater level.

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 bitumen mastic.
It is not advisable to use foamed polystyrene at elevated groundwater levels.
On difficult soils, mechanical damage (compression) of the foam is real. 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, such material can be used without any hesitation.

Moreover, insulating the external foundation with polystyrene foam is considered a 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 the 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 that will be covered with soil are installed 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 foam plastic 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.

Indicator	Unit of measurement	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, PSB-S-35 grade foam is best suited. 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. Counterfeit expanded polystyrene panels are increasingly found on the construction market. 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, the fake PSB-15 slab under a lateral load equal to 1 ton bends by 20 mm, while high quality stove– only by 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 thing.

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

Disadvantages of internal foundation insulation.

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

Types of expanded polystyrene, pros and cons of the material

Unpressed
Pressed
Extruded

Suspension or unpressed polystyrene foam is one of the most common due to its cost. In high-quality material, the granules have the same size and their breakdown occurs “alive.” The density of the material varies from 15 to 50 kg/m3. It does not freeze in the ground.

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, the simplest scheme of which is as follows:

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.

Let's start insulating the foundation

Material selection

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

Thermal insulation layer thickness
Density

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

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

You don’t need to pay much attention to the flammability class, 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.

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.

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 and follow a similar procedure for completing the work.

Additional fixation of insulation

After two or three days, when the glue has completely dried, it is necessary to make additional fixation of the 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

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 a cheaper type of 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, it’s not very suitable for insulating a foundation. large number heat insulators. 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. With their help, you can insulate columnar, shallow, strip, pile and other types of foundations.

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 the roll waterproofing, 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 useful term heat insulator services. 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.

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. 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 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 the underground part of the foundation from freezing.

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

Because 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. 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 areas of the house (roof, walls, foundation) require various types PPP. Each modification of the teaching staff has different characteristics, therefore it can be used when insulating only a certain area of the house.

Markets building materials They sell polystyrene foam in 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 the one that suits all technical characteristics material.

The thickness of the EPS is selected depending on climatic conditions in the construction region. 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 with 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 polystyrene foam insulation does not have special locks, then after 3 days polyurethane foam is introduced 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.

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 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.

DIY columnar foundation made from asbestos pipes

Against the backdrop of constantly rising energy prices, people are increasingly beginning to think about high-quality insulation housing. Insulating a home with expanded polystyrene has long become the norm. This technology multifaceted and consists of several stages. One of the most important areas is the thermal insulation of the foundation, and in this article I will tell you why you need to insulate the foundation at all and will dwell in detail on how to independently insulate your foundation with extruded polystyrene foam.

General information about materials or the role of insulation in the arrangement of the foundation

First, let's understand the terms. Expanded polystyrene is commonly called a lightweight cellular material created on the basis of styrene.

Now there are 2 types of this popular material most widely represented on the market:

Well-known polystyrene foam in technical language is called cellular polystyrene foam. This material was developed in the first half of the last century and is now one of the most popular insulation materials;
Extruded polystyrene foam has the same base, but is produced using a different technology. Its characteristics are an order of magnitude higher, but the price of its extruded counterpart is at least 2 to 3 times higher than the cost of good polystyrene foam.

Why extruded polystyrene foam

Those owners who were already interested in prices probably noticed that insulating a house with extruded polystyrene foam is a rather expensive idea. It is much cheaper to sheathe a house simple polystyrene foam, for example, PSB-S25, which, by the way, is done in most cases.

But here anyone normal person a reasonable question arises: if the whole house can be insulated inexpensive foam plastic, then why pay more for extruded polystyrene foam for foundation? At one time I also thought about this, and it turned out that there were several reasons.

Let's start with the fact that polystyrene foam is not called a cellular material for nothing; everyone has noticed that the balls can be easily crushed with your own hands, the connection between them is loose.

Consequently, where there are gaps, water will definitely penetrate and as soon as frost hits, the slabs will slowly begin to crumble, which means that they need to be well protected from above, while extruded polystyrene foam is a dense, monolithic material, the structure of which, in principle, contains moisture cannot penetrate.

If we take the tabular data, the water permeability of polystyrene foam is 3–4%, and expanded polystyrene has a maximum rate of 0.4%. And then this 0.4% is given for water permeability in the cut areas of the sheets, that is, where the integrity of the cells is compromised.

At one time, extruded lightweight polystyrene foam was developed for the needs of the navy; life jackets and other similar products were supposed to be made from it. But it soon became clear that these slabs have phenomenal strength and are much more in demand in the construction industry.

Nowadays, not a single decent highway or airfield runway can do without insulation of the road surface. And here exclusively extruded polystyrene foam is used.

Extruded plates can withstand pressure up to several tens of tons per square meter. By the way, the foam begins to crumple already at a pressure exceeding 100 - 200 kg. And this, as you understand, is very small when planting it in the ground.

Now let's move on to more banal things. The owners of private houses know very well that polystyrene foam is a favorite habitat for mice; these creatures feel warm and cozy there. Insulating the house with extruded polystyrene foam completely eliminates this problem.

The maximum service life of foam plastic insulation according to standards does not exceed 25 years. And the warranty for extruded polystyrene foam only starts at 40 years.

And finally, if we compare materials in terms of thermal conductivity, then foam plastic is inferior to its to a young relative by about a third. That is, where you need a foam thickness of 100 mm, you can get by with 70 mm polystyrene foam.

I know of only one way to use thick foam to insulate a foundation below ground level. This is when brickwork is installed on top of the foam to protect it. But the price of this option is several times higher than the most expensive extruded polystyrene foam.

Is it necessary to insulate the foundation?

Even 20 - 30 years ago it was believed that monolithic reinforced concrete foundations should not be protected, much less insulated. Allegedly, with such heavy, durable structures, nothing will happen.

Now the concept has changed, and for the following reasons:

Indeed, a monolith laid below the freezing level of the soil is quite capable of withstanding soil movements during frost heaving. But no matter how strong the concrete is, it will sooner or later begin to deteriorate due to constant freezing. External thermal insulation of the foundation with polystyrene foam completely eliminates the problem of freezing of the monolith and increases its service life several times;
For shallowly buried structures, frost heaving is worst enemy. There have been cases when such tapes not only cracked, but were completely torn out. It turned out that if you “wrap” a shallowly buried concrete foundation in a shirt made of extruded polystyrene foam, then he is no longer afraid of soil movements. Please note that polystyrene foam is not able to withstand such pressure; it will simply be crushed;
A modern capital house is unthinkable without a good basement, and sometimes even an entire technical floor with a garage, laundry room and other premises. So, insulating the foundation with polystyrene foam automatically relieves the owners of constant condensation on the walls of the basement rooms. You get a cool yet dry basement;

Such a newfangled technology as the “Swedish Stove”, which is designed for the construction of energy-saving houses in the north and on unstable soils, was initially developed using extruded polystyrene foam. It cannot be realized with other insulation.

But perhaps the most important reason proving the need to insulate the foundation is the serious loss of heat, and therefore money, during the cold period. Which, by the way, on most of the territory of our great power lasts at least six months. So, if we turn to hard numbers, it turns out that in a house with a conventional strip foundation, heat loss from the foundation is about 20%, and in cottages with a recessed basement, the losses reach 25%. Agree, taking into account current fuel prices, the amount accumulates in six months is substantial.

How to insulate a foundation with extruded polystyrene foam

So, we found out that insulating the foundation with polystyrene foam is not a newfangled trend, but an urgent necessity, and it cannot be replaced with anything else. Now let's look at the practical side of the issue and, like all normal builders, let's start with calculations.

Calculations for insulating the foundation

Naturally, in order to make accurate engineering calculations you need, at a minimum, to have a technical education. Now there is such a useful thing on the Internet as an electronic calculator.

But if both of these options are not available to you for some reason, then you can use a simpler formula. An experienced construction engineer once suggested it to me.

H = (R – h/K1)K2

H – the required thickness of extruded polystyrene foam for the foundation;
R – heat transfer resistance. If we omit the exact table values, then on average for Russia we take about 3.5 m²K/W;
h – thickness of the foundation tape;
K1 – thermal conductivity coefficient of the material from which the foundation is made. For concrete it ranges from 1.3 – 1.7 W/mK, on average you can take 1.5 W/mK;
K2 is the thermal conductivity coefficient of the insulation you have chosen. The instructions on the packaging will help you here; this information will definitely be there.

Calculation required quantity extruded polystyrene foam slabs are even simpler: calculate the quadrature of the foundation, that is, multiply the length by the height, divide the final figure by the quadrature of the sheet, then round up and add 10 - 15% for trimming and arranging corners.

With the number of sheets, everything seems to be clear, but regarding the thickness of the sheets, I usually advise that if you have the means, it is better to take 100 mm. If you don’t have enough money, then 50 mm. In general, it is believed that for middle zone In Russia, 50 mm is enough, and the further north the region, the thicker the insulation, the maximum is 150 mm.

A few words about the instrument

The number of tools depends on the technology you choose. What you need is a hammer drill, several metal spatulas with a blade width from 10 to 40 cm and a knife for cutting polystyrene foam boards.

To install good roll waterproofing you will need gas burner, in extreme cases, you can get by with a blowtorch, but it will work worse. Naturally, tools such as a tape measure, level, hammer, etc. should be in the kit of any self-respecting owner.

External foundation insulation

Insulation of the foundation from the outside is deservedly considered the most in an efficient way arrangement load-bearing structures. IN in this case the concrete monolith itself remains in the positive sector. The dew point (the place where the temperature is 0ºC) will be located in the insulation, in our case in extruded polystyrene foam.

In the vast majority of cases, the foundation is insulated during the construction stage of the building. Although no one is stopping you from insulating the capital foundation of an old house, only to do this you will have to dig around it.

The technology involves laying insulation just below the freezing point of the soil. Of course, if you don’t mind the money, then you can completely cover the base with slabs of extruded polystyrene foam, but there is little point in this, because below the freezing point of the soil, waterproofing alone is enough.

Theoretically, such expanded polystyrene is already waterproofing in itself, but there is a high probability of movement in the soil and so that in a couple of years the moisture, and with it the cold, does not reach the foundation, it is necessary to apply a starting waterproofing layer to the monolith.

In order for the waterproofing to take place as expected, the concrete base should be well prepared. At the first stage, you will need to clean the monolith from any remaining soil. Of course, if the foundation has just been poured, then there is nothing to clean there. This procedure is only needed for old foundations that were already in the ground.

Now to increase adhesion you will need to coat the monolith with a primer. There are special bitumen-based primers for this, but if you don’t want to spend money on them, then mix bitumen with gasoline or diesel fuel in a 1:1 ratio and coat your foundation. The composition is not expensive, tested and dries within an hour.

I do not recommend saving on waterproofing for the foundation. I, like most experts, believe that the highest quality results are obtained by rolled waterproofing, which is installed with heating. Rolled materials from the Technonikol brand have proven themselves well in this sector.

To fix such rolls you will need a gas torch or blowtorch(working worse with a lamp). The tapes are mounted vertically. First, roll out a large roll, cut required quantity ribbons and roll them into small rolls.

Then you heat the edge of each small roll and attach it to the foundation from below. Then gradually roll it out from the bottom up and at the same time heat the canvas.

The sector heated by the burner is slightly pressed against the monolith, there is no need to be zealous, such waterproofing sticks well after heating. The tapes are laid with a slight overlap.

But this is not the only option. A coating made of liquid rubber gives a fairly high-quality result. Here it is better, of course, to call professionals with special equipment and they will cover your entire foundation with rubber in a day. Although if you don’t mind the effort and time, you can buy liquid rubber in the form of a coating and apply it to the monolith with your own hands using a spatula.

After waterproofing layer Once it has completely hardened, you can begin fixing extruded polystyrene foam on it. This type of insulation is produced by several leading world brands; in our country, Penoplex is usually used. Plates from this manufacturer are equipped with L-shaped grooves around the perimeter, which provides a tighter and higher-quality connection.

Extruded polystyrene foam below the ground level, that is, underground to the foundation, more precisely to the waterproofing, can only be glued. No dowels or other through fixation options are used here. In the ground, the integrity of the slabs and waterproofing layer must not be compromised under any circumstances.

For gluing to the waterproofing layer, it is better to use polymer-based glue. You can do it even simpler: if you heat the waterproofing with a torch at several points and apply a slab to it, the slab will stick perfectly.

The only thing that is strictly forbidden to use are adhesives made with organic solvents, such as gasoline, toluene, acetone and others. The fact is that organic solvents corrode both polystyrene foam and extruded polystyrene foam.

The slabs are glued from any angle, by analogy with brickwork, that is, with a shift between the rows. The weakest point in the foundation is considered to be the corner, so it is recommended to insulate it in 2 layers, with a 1m overlap on the wall planes.

For those owners who like to do everything with a significant margin of safety, there is a two-layer technology for installing insulation. It consists in gluing the same one on top of the first layer of 50 mm thick slabs.

Only the joints between the slabs of the first and second layers should not coincide. This technology is also good because it does not require additional reinforcement of the corners.

When the insulation is finished, you can fill the trench, but there is a small nuance here: extruded polystyrene foam can withstand serious pressure along the plane, but large point loads can damage the insulation.

To prevent random stones or any other hard objects that sometimes appear in the ground from pushing through your polystyrene foam for the foundation, sand should be the first layer about 20 cm thick.

Therefore, the trench must be dug carefully, at the same time throwing a layer of sand towards the foundation wall and adding regular soil further. Plus, this layer cake needs to be compacted every half meter.

Warm blind area and drainage as additional protection for the foundation

As you know, prevention of a problem has always been an equally important part of its solution. Serious freezing of the soil in the area of the foundation can be, if not completely eliminated, then significantly reduced by insulating the blind area around the perimeter of the house with extruded polystyrene foam.

If you strictly follow the technology, then the size of the blind area should be equal to the depth of soil freezing in a given region. But I can say from myself that this rule should be observed only on heaving soils. In the case where the house stands on stable soils, a blind area of about a meter in size is sufficient.

It’s not difficult to equip it with your own hands. To insulate the blind area, slabs 50 mm thick are sufficient. Initially, soil is selected for the structure to a depth of about 200 mm. The bottom of the pit is well compacted and covered with geotextile or roofing felt.

A sand cushion about 50 mm thick is poured onto it and also compacted. A layer of extruded polystyrene foam is laid on this pillow with a slope of 20–30 mm per 1 meter.

A reinforcing frame will need to be tied on top of the insulation. Too thick reinforcement is not needed here enough steel wire diameter 6 mm (wire rod). Although, in order not to bother with the knitting of the reinforcement frame, I lay a regular steel mesh chain-link in 2 layers with a gap of 30 mm. In the area of the blind area, the load is negligible and great strength is not required there.

After this, again ensuring a slope of 20 - 30 mm, the whole thing is filled with concrete. The thickness of the concrete layer is around 100 mm. The slope is needed so that water flows freely from the blind area.

But all this is good if the groundwater runs much lower than your foundation. In cases where there is a high probability of flooding of the building, in order to drain groundwater from the monolith and insulation, you will have to install drainage.

If you have completed the installation of the insulation, then arranging the drainage system should not cause you any difficulties. In this case, a small layer of gravel is poured onto the bottom of the trench around the house and a plastic drainage pipe with a cross-section of 100 mm or more (a pipe with many holes) is laid on it.

Keep in mind that the drainage pipework must be laid below the freezing level of the soil, pass no closer than 300 mm from the border of the insulation and be installed with a slope towards the central well, the slope is 10 - 20 mm per 1 linear meter.

Plus, at all pipe turns it is necessary to make intermediate inspection wells. The central well is needed to collect water and naturally it is made larger and deeper. The water is either pumped out or taken to another place.

In the standard version, we have a layer of sand behind the insulation and then soil, and to arrange drainage instead of soil on top drainage pipe a layer of crushed stone is poured, the thickness of such a layer ranges from half a meter to a meter.

The general structure of the system is shown in the diagram. The foundation and the blind area bordering it are insulated with extruded polystyrene foam. And to prevent water from breaking through to the insulation, a drainage system is installed.

Insulation of the foundation from the inside

I’ll tell you honestly, insulating the foundation with polystyrene foam from the inside is not the best option. In this case, the concrete monolith itself has frozen and will continue to freeze, but you get a dry basement and a relatively warm floor.

The technology is extremely simple. The insulation boards are glued to the wall in the same way as we glued them on the outside for waterproofing. To install extruded polystyrene foam on bare concrete, I use the Ceresit CT83 building mixture; by the way, it was developed precisely for these purposes.

But glue alone will not be enough here; the insulation will need to be additionally secured and plastered. When the insulation is installed, the same construction adhesive with a thickness of 2–3 mm is applied to it.

While the glue is still wet, a fiberglass reinforcing mesh is embedded into it using a spatula, after which holes in the concrete are drilled through the insulation and plastic umbrella dowels are driven into them.

Next you will need to wait for it all to dry, lightly sand the surface with coarse sandpaper and apply a layer of cement-based finishing putty. That's basically all. Remember that from the inside, in the basement, it is enough to insulate the outer walls and ceiling.

Conclusion

Thermal insulation of the foundation with polystyrene foam is the most effective way to get rid of cold floors and protect the concrete monolith from destruction. The photos and videos in this article show some practical points arrangement process. If you have any questions, write them in the comments and we’ll talk.

Many owners, trying to insulate their house, forget that a significant part of the heat escapes through an uninsulated foundation.

It’s one thing if the floor is well insulated, but quite another if it’s not. Therefore, it is necessary to ensure thermal insulation of the base of the house - to protect the foundation from freezing.

Insulating the foundation allows you to solve two important problems:

reduction of heat loss;

protection of the foundation of the house from freezing and deformation. Let's clarify this point. Most of the soil in our country can be classified as heaving. It tends to freeze to a considerable depth, and during the process of thawing, change its original volume. When the soil plays, it has a detrimental effect on the foundation that is located on this soil.

For external insulation of the foundation, various thermal insulation materials can be used. But the most effective is the use of rigid insulation - polystyrene foam. And to be precise, one of its two types - polystyrene foam.

Insulating the foundation with foam plastic from the outside

Foam insulation can be considered the most popular method of foundation insulation. This is due to the characteristics of the material:

cheapness;

absolute non-hygroscopicity;

durability. Important parameter, since insulating the foundation from the outside with polystyrene foam is a rather labor-intensive process;

polystyrene foam does not deform or change its size under the influence of moisture or chemical compounds;

resistance to any ambient temperatures;

the lowest thermal conductivity coefficient among known insulation materials. This is due to the structure of the material itself. After all, polystyrene foam is 98% air. Which is known to be a poor conductor of heat.

The main physical and mechanical properties of different brands of polystyrene foam are presented in the table

The only significant disadvantage of polystyrene foam is its fragility. To minimize the appearance of cracks and damage, you need to quickly cover the area with an adhesive mixture.

Before proceeding with installation, please note that insulating the foundation with foam plastic from the outside is carried out only in the warm season. The foam itself can withstand low temperatures. But the time it takes to dry the base and the properties of the glue may change.

How to insulate a foundation with foam plastic

The sequence of work on insulating the foundation with foam plastic can be presented as follows:

1. Goal setting

That is, the decision for what purpose the insulation will be carried out. For example, reduce heat loss from the living space, insulate the basement under the house from the outside, or turn the basement into a living room. Depending on this, the thickness of the foam for insulating the foundation will be selected.

2. Planning

2.1 Material selection

In this case, the insulation is polystyrene foam, and you can choose glue or adhesive foam as the adhesive composition.

Each foam adhesive has its own advantages and disadvantages. As well as different costs and setting times. Therefore, the budget and construction time have a direct impact on the choice.

2.2. Calculation of foam thickness for insulation

Before starting work, you need to determine what thickness of foam plastic will be sufficient to insulate the foundation in accordance with the goal.

The calculation can be carried out based on the data in the table below (parameters for polystyrene foam brand PSB-S-25).

For clarity, we present some signs. Foam plastic 50 mm thick. corresponds to the heat saving parameter with brickwork 250 mm thick. (one brick).

It is worth noting that when planning to convert a basement into a living space, you need to not only insulate the foundation, but also the basement and the ground floors.

2.3 Calculation of the amount of foam for insulation

You can determine the amount of material by multiplying the height of the cladding (sheet of foam) by the perimeter of the house. And dividing by 0.5 (the area of one sheet.) The resulting result will reflect the required amount of foam in the sheets. The amount of adhesive composition depends on its type and consumption. Which is indicated by the manufacturer on the packaging.

2.4. Budgeting

Even if you do not pay builders, but insulate the foundation yourself, you will inevitably incur some costs. Drawing up an estimate will allow you to understand what budget will be sufficient for the planned work. It must include: the costs of purchasing materials, their delivery, and removal of construction waste.

3. Choosing foam for foundation insulation

When purchasing polystyrene foam, pay attention not only to its density, but also to the geometry of the sheet. Tolerance along the length and width of the foam - 10 mm. Otherwise, you will have to adjust each sheet on site, which is not very convenient. Well-known manufacturers ensure that this parameter is observed, but the “shrubs” can make any cutting. Accordingly, both the quality and durability of such foam should raise doubts.

The second aspect that allows you to determine the suitability of polystyrene foam for insulation is its color. The color of high-quality foam is snowy white. If it has a yellowish or grayish tint, we can conclude that low-quality raw materials were used or there were violations in technology. But, most likely, such material was exposed to ultraviolet radiation as a result of improper storage. That is, its surface layer is destroyed under the influence of the sun. Such insulation can be used, but provided that the depth of the damage is not great, and the damaged area is treated with a foam grater.

4. Excavation of the foundation

It is advisable to insulate the foundation at the construction stage of the building. This way the work is easier to complete because it is not duplicated. Modern developers do just that.
But what about those whose house was built several decades ago? In this case, you have to dig out the foundation almost to the ground. Ideally, to the depth of soil freezing in a given region (usually 1-1.5 m). Or at least the length of a sheet of foam plastic. That is, about half a meter.

In this case, the width of the trench is determined by adding the thickness of the sheet and the space required for the work. That is, it should be 350-500 mm. Making it wider is impractical, especially if you are insulating the foundation with polystyrene foam yourself, without using construction equipment, and a narrower trench will be inconvenient for work.

When choosing soil from a trench, you should think about where to put it. Insulation work lasts more than one day, and the sale of excavated earth should not affect movement around the site.

5. Filling a trench near the foundation

The bottom of the trench, or at least that part of it where the foam plastic will be laid (50-100 mm), must be covered with sand. Layer thickness is about 200 mm. The sand must be compacted, maintaining a slight slope. This will allow the water to flow away from the foundation. If the groundwater level is high, you need to take care of drainage around the house - pour a gravel bed, lay geotexile on it, and wrap the pipes in it.

6. Preparing the foundation base

The excavated foundation should dry well. That is why it is better to carry out work in the warm season.

Taking this opportunity (while the foundation is being dug), it is worth paying attention to utilities that are inspected, isolated, repaired or restored.

Next, all peelings are removed from the foundation, and unevenness is leveled - this will prevent the appearance of voids. Then a level is struck; this line will serve as a guide to the height of the foam sheet.

Moisture-proof mastic or bitumen mastic is applied to the prepared foundation. Its purpose is to protect the foundation from moisture.

As for bitumen mastic, there is a controversial situation; according to the laws of chemistry, bitumen (based on solvents) has a detrimental effect on the structure of the foam. At the same time, there is practical evidence that the foundations of private houses, treated with bitumen and insulated with foam plastic, last for many years. Probably, everything depends on the chemical composition of a certain bitumen mastic and the method of fixing the foam.

7. Attaching foam plastic to concrete (foundation)

Installation of foam plastic is carried out using adhesive solution or foam glue.

Material prepared for the website www.site

The adhesive solution is applied in blots or with a notched trowel to reduce the possible gap between the sheet and the base.

Advice. If you choose glue for foam plastic, it is better to take foam in cylinders under the gun, this way it is more convenient to use and costs less.

During installation, the sheets are laid at a minimum distance from each other.

If there are two rows, the sheets in them should be located in checkerboard pattern. The sheets are stacked on sand cushion and leveled.

Advice. If you need to achieve a sheet thickness of 100 mm. use two 50 mm sheets. The overlap between the rows will prevent the appearance of cold bridges. Work on installing the next layer can begin only after the glue in the previous one has completely dried.

The reinforced mesh is designed to protect the foam from mechanical damage if the insulation protrudes beyond the trench and may be damaged.

The mesh is applied to the top of the sheet and fixed with adhesive.

9. Finishing

If the house has a low base, i.e. the foundation of the building is flush with the ground and the foam plastic is completely covered with soil, then installation of the mesh and finishing are naturally not needed. In this case, it is enough to fill the trench with expanded clay, it will serve additional insulation, sand or soil.

Insulating the foundation with foam plastic from the inside

Internal insulation is carried out using a similar technology, excluding trench digging. But it has a number of features.

mandatory fastening to an umbrella dowel (fungus). The dowel is attached to the corners of the sheet and one in the center;

insulation is carried out on the floor (if it is planned to adapt the basement into a living space). In this case, polystyrene foam is placed between the joists;

the need to use a membrane that will protect the base of the foundation from moisture;

mandatory ventilation device, through a system of ventilation ducts, through a through hole in the foundation or forced. Otherwise, moisture will accumulate in the basement, which will ultimately lead to the destruction of the foundation base, the appearance of mold and rot.

In general, insulating the foundation with foam plastic with your own hands does not require special knowledge and tools, but will entail time and physical costs.

Scope of application

EPPS is used in civil and industrial construction, greenhouse farming, in household appliances, in the construction of highways, runways, and pipeline laying. 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 greater the layer of insulation that must be laid.

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

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.

How to choose

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.

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

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

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 of slab foundations, 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

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.

Types of expanded polystyrene, pros and cons of the material

Introductory video instructions

Insulation schemes and their features

Let's start insulating the foundation

Advantages

How to choose

Types and characteristics of EPS

Penoplex

TechnoNikol

URSA Eurasia

Roll waterproofing

Waterproofing mastics

Waterproofing mixtures

Penetrating waterproofing

Injection waterproofing

Waterproofing with clay

Scope of application

Advantages

How to choose

Types and characteristics of EPS

Penoplex

TechnoNikol

URSA Eurasia

We insulate the foundation of the house with expanded polystyrene

Is polystyrene foam suitable for insulation?

Use of extruded polystyrene foam

How to choose the best type of polystyrene foam?

Video on foundation insulation with XPS polystyrene foam from TechnoNIKOL

How to identify fake PSB foam

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

Advantages

Flaws

Types of expanded polystyrene, pros and cons of the material

Introductory video instructions

Insulation schemes and their features

Let's start insulating the foundation

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Warm blind area and drainage as additional protection for the foundation

Insulation of the foundation from the inside

Conclusion

Insulating the foundation with foam plastic from the outside

How to insulate a foundation with foam plastic

1. Goal setting

2. Planning

2.1 Material selection

2.2. Calculation of foam thickness for insulation

2.3 Calculation of the amount of foam for insulation

2.4. Budgeting

3. Choosing foam for foundation insulation

4. Excavation of the foundation

5. Filling a trench near the foundation

6. Preparing the foundation base

7. Attaching foam plastic to concrete (foundation)

9. Finishing

Insulating the foundation with foam plastic from the inside

Scope of application

Advantages

How to choose

Types and characteristics of EPS

Penoplex

TechnoNikol

URSA Eurasia