Heat insulation of walls with polystyrene

Polyfoam, or more correctly - expanded polystyrene, belongs to the category of one of the most popular building materials. In addition to other applications, it is widely used for warming the walls of houses from the inside and outside. Due to its structure and characteristics, the material is capable of good insulation and protect from the external noise of the premises of houses and apartments.

The polystyrene foam has become popular and because it is lightweight in weight and very easy to install. 100% method for insulation of the walls from the inside with polystyrene, which will provide silence and protect the living quarters from the cold, will be presented below, but before purchasing this material, simply it is necessary to have information about its types and basic performance characteristics.

Styrofoam varieties used for insulation

All kinds of foam are produced in a convenient form for installation, in the form of slabs of various sizes and thicknesses, which varies from 10 to 100 mm or more. All expanded polystyrene can be divided into two main classes - is a conventional non-pressed foam and extruded. They differ significantly in their characteristics due to the structural structure, so it is worthwhile to consider each of them separately.

This table presents the comparative characteristics of two insulation classes. Particular attention in this case should be paid to the thermal conductivity of - the less it will be, the better:

Comparative characteristics of conventional expanded polystyrene and extruded polystyrene foam:

Material values ​​	Extruded polystyrene foam	Usual foam
Water absorption in% by volume for 30 days, notmore	0.4	4
Water absorption in% by volume for 24 hours, no more	0.2	2
Water vapor permeability, mg / m × h × Pa	0,018	-
Thermal conductivity in dry condition at temperatureUre 25 ± 5 ° С, W /( mхСС) no more than	0,028	0,036 ÷ 0,050
Limit of compressive strength at static bending,( kgf / m²) MPa	0,4-1,0	0,07 ÷0,20
Compressive strength at 10% linear strain, MPa, N / mm², not less than	0,25-0,50	0,05 ÷ 0,20
Density, kg / m³, within	28 ÷ 45	15 ÷ 35
Operating temperature range, ° C	-50 to +75	-50 to +70

Conventional( non-pressed ) expanded plastic

This type of insulation is labeled PSB-C( EPS-122D EPS-free self-extinguishing polystyrene).It is produced by the method of sintering individual granules by means of high temperature. On , the granular structure of such polystyrene can be seen on the - the pellets can have a slightly larger or smaller size, so the material density can be different in the defined by the range. The density of the foam, which is indicated by a two-digit number following the letters of the label, also depends on the size of the granule fraction.

Basic characteristics of ordinary foam plastic of different density:

Foam grade PSB-C	15	25	35	50
Density, kg / m³	15	15-25	25-35	35-50
Compressive strength at 10% linear strain, MPa, not less than	0.05	0.1	0.2
Flexural strength, MPa, not less than	0,07	0.18	0.25	0.35
Thermal conductivity at 25 ° C, W /( m × ° C) not more than	0,042	0,035	0,033	0.04

This also includes a variety of foam, which is used in bulk, that is, Ranuli backfilled, for example, a concrete mix as the insulation material screed. Apply this type of insulation and for backfilling in the piers or between the beams of the attic floor.

Extruded polystyrene foam

Extruded polystyrene foam differs from ordinary polystyrene with higher strength and structural density, as it is produced by pressing and squeezing in molten state through forming nozzles using extrusion technology - continuous hot forming.

"spike-groove" joints. They are made in the form of boards, which often have an - "comb-groove" joint profile connection, which facilitates the installation of a heater on the wall surface and when laying on the floor. This kind of expanded polystyrene has a somewhat higher thermal conductivity, since it has a dense, less " air-blown " structure, but nevertheless , also very well will suit for insulation of walls from the inside.

Pros and cons of the foam for internal insulation

Any of the types of expanded polystyrene has a general, more or less pronounced positive and negative qualities in terms of application for insulation of the walls of the house or apartment from the inside.

The following qualities are attributed to the merits of this heater:

• Light weight, which allows you to easily raise the heater to any floor of a high-rise building.
• Resistance to the formation of any type of microflora - fungus or mold, provided it is properly installed.
• The material is almost waterproof - at high humidity it is able to absorb no more than 0,4% of its volume for 10 ÷ 12 days .
• For polystyrene foam is characterized by very low thermal conductivity. The ratio in the average is 0.030 - 0.035 W /( m × ° With ) - is 30 ÷ 45% lower than most other insulation materials.
• Extruded polystyrene foam has a sufficiently high shock resistance and compressive strength. The usual foam, however, can not boast of this.
• Simplicity and ease of mounting, especially those panels that have a "groove-groove" connection.
• Polyfoam, simultaneously with heat insulation, helps to smooth the surfaces of walls.
• Affordable price, compared to other heaters.

The following features of the foam can be attributed to the negative qualities of the foam:

• If the mounting is incorrectly mounted to an external wall, a mold may appear under the foam plastic, which is able to penetrate the structure of the material and continue to propagate therein.
• The ignition temperature is 490 ÷ 500 degrees, that is, it can ignite from the of the covered fire. Therefore, styrofoam can not be attributed to fireproof materials, although it has the property of self-extinguishing. When exposed to an open flame, the foam stems and drains away, continuing to burn and itself becoming a possible source of fire propagation.

• material. With thermal decomposition, foam generates corrosive smoke containing toxic substances that are dangerous to the human respiratory system. - is phosgene, hydrogen cyanide and others. They cause burns to the respiratory tract and severe poisoning, often leading to death.
• For prolonged use, ordinary foam begins to decompose gradually into components, also releasing substances hazardous to health, such as hydrocyanic acid, nitrogen oxides, hydrogen halides and others. Therefore, foam AS all is also better for external insulation, and for interior use it is better to choose a more environmentally friendly insulation, for example, stone wool in mats, eco-wool and , .From the point of view of chemical resistance, extruded polystyrene foam is far ahead of its "colleague".

However, if in spite of everything it is decided to stop your choice on foam, then you need to at least correctly prepare and correctly carry out the necessary operations for warming the walls.

Process of wall insulation with foam

Tools and materials required for the operation of

For work it is necessary to prepare the following simple tools :

• Wide brush and roller for applying antiseptic and primer.
• Roulette and construction level - for marking and controlling the verticality of the installation of expanded polystyrene plates.
• Hammer for clogging fastening elements.
• Electric impact drill or perforator, concrete drill bit - if the work will be done in a brick or panel house.
• Nozzle-mixer for electric drill for mixing putty and plaster mixes.
• Construction knife for cutting reinforcing mesh.
• Spatulas of various widths for application and leveling putty and plaster mixtures. For gluing foam blocks it is required, including, and notched spatula.
• Grate and sandpaper or abrasive mesh of varying degrees of granularity.
• Capacities for mixing mortars and a bath for priming.

From materials required:

• The foam itself, calculated by the area of ​​the walls.
• Fiberglass reinforcing mesh - its the total area must also cover completely all the insulated walls.

• Filler and plaster mix on a cement base.
• Antiseptic composition.

• Primer mixture of deep penetration. Sometimes the primer combines the function of an antiseptic in itself.
• Fasteners elements - plastic dowels - "fungi".

• Special metal or polymeric corners for reinforcing and finishing corners premises.

• Dry construction mortar is an adhesive for foam.

Prepare in the se necessary, it is possible to proceed to the preliminary stage of warming works.

Preparatory work for

You do not have to disregard the preparatory measures, since the life of the insulating material and its functionality depend on how well they are carried out.

The preparatory work includes the following technological operations:

• Obligatory cleaning of the walls from the old paint or wallpaper, otherwise there will not be enough adhesion to bond the foam, glue and wall surface. In addition, as the old finish is removed, cracks and chips may appear on the surface, which must be sealed, or fungal colonies, which should be neutralized.
• Elimination of cracks and cracks consists of several stages - this is their extension, dust removal, priming treatment and sealing with putty mixture. If too large gaps are detected, for example, in the area of ​​the corners, they can be sealed with a mounting foam or sealant. After hardening or drying of the materials of the seal, their protruding fragments must necessarily be sheared off or cleaned up to the level of the wall.

• repair filler If molds or obvious damp spots are found in the corners, they must be cleaned, and the entire damaged area should be treated at least twice with an antifungal compound.

• If linoleum or other decorative material is placed on the floor, it must be cut and removed from the wall by the thickness of the foam, as it is recommended to install a heater on the floor, not on the top finish.
• Further, the walls are checked for flatness. If there are small flaws, they will be closed with foam plates, only you will need to impose on some of them a bit more adhesive mass. Therefore, after discovering small indentations, they are marked with chalk to know on what slabs it is necessary to apply over to lei.
• If the surfaces are skewed, their should be aligned with the , otherwise there may be air between the walls and slabs of the expanded polystyrene, which will help to shift the "dew point", wet the walls from the condensate and, as the consequence, reduce the overall of the insulation.

• The final stage in the preparatory work will be the treatment of the entire wall with antiseptic primer, which will prevent the occurrence of mold between the internal surfaces of the walls and foam polystyrene panels.
• After completion of the preparatory work, the wall needs to be dried dry - for this you can open all the windows and doors, ensuring a good airflow.

If the floor in the room is uneven, then in order for the first row of plates to stand perfectly horizontally, you can repulse a flat top line of the first row of the on the wall using a colored cord, under which the panels will fit. If necessary, some of them are cut from below.

Another option for leveling the first row can be to fix the bottom of the wall of the profiled corner, which is set strictly on a horizontal level. If the first row of foam laying is installed on the fixed exactly corner, then all the rest of the masonry will also remain even. Corner should have a width equal to the thickness of the polystyrene boards used.

Installation of foam on the walls

First of all, the glue mass is mixed, on which the foam blocks will be glued to the wall.

• In the capacity is filled with the required amount of water, depending on the adhesive to be mixed, from for calculating for 25 kg of dry approximately , 9 ÷ 10 liters( the instruction is necessarily printed on the dry construction mix).Then a little bit of water is added, a dry mix is ​​added portion by piece and mixed with a drill with a mixer.

The glue will be ready when its consistency reaches a paste-like homogeneous state. Usually is given by for 3 ÷ 5 minutes for ripening, then is still once the mixture is mixed, and it is possible to consider its completely ready for operation, and can begin to fix the foam blocks to the wall.

• The foam is installed from the floor, from the corner of the room. The rows of plates are set according to the principle of brickwork, " in the dressing".

To ensure that the plate is easy and is secure is adhered to the with the wall, before applying the adhesive to the surface of the foam, its is lightly treated with coarse-grained abrasive paper and several scratching lines are applied with a conventional nail.

• Next, the adhesive is applied to the entire plane of the plate and distributed using a notched trowel, so that the same comb thickness is obtained. If the plate falls on the previously marked cavity in the wall, then the foam is applied to the with a conventional spatula, in the area where the irregularity is located.

• Then the plate is pressed firmly against the surface with the hands, so that the proper grip is formed. Next next to it is installed the second plate - and so the entire first row.

It is important to make sure that the glue does not get between the plates, as it can break the seal of the insulation layer.

• Masonry of the second row starts with the half of the plate, which is set in the level, measuring its vertically and horizontally.
• After is installed the first two rows of plates, they must be fixed with dowels-fungi.

For their installation, it is necessary to drill directly through the polystyrene blocks in the wall of the hole, with a depth of 60 ÷ 70 mm( without accounting for thickness of the insulation).Then the dowel - " fungus " is installed in the hole and is clogged so that the cap is "drowned" in the foam plastic. After this, a plastic spacer rod is inserted into the dowel and the plastic nail-rod is driven in.

One "fungus" can fix three panels at once on their joint , if it is properly fixed. On each of the panels it is necessary to provide 5 ÷ 7 dowels.

Completing wall warming operations for

• When the entire foam is installed on one of the walls, the is finished, and on the sides of the masonry between the sides of the heating layer and the , the wall will remain gapmounting foam. It will become a kind of damping layer that will allow the layer of foam to shrink when shrinking walls or when thermal linear vibrations remain unscathed.

• Further, external joints between plates are recommended, if necessary, to seal with .

• The next stage of the is the reinforcement of the foam layer. For this, the is also kneaded with one portion of the glue paste, to which the gluing of the mesh will be made.
• Surface reinforcement begins at angles, as they are the - most vulnerable to mechanical damage to the site. At the corners of the adhesive mixture is applied, and in it perforated metal or plastic corners with fiberglass mesh on both sides. The corners are tightly pressed, and the is removed to the by a spatula.

• Further, from the roll of the reinforcing mesh, a web is cut, equal in length to the height of the wall from floor to ceiling.

On the top of the wall, approximately 500 mm , the glue mixture is applied to the width of the fiberglass mesh. The mesh is fixed to on on worn on the wall of glue and pressed with a spatula, so that it completely "drowned" and pressed firmly against the surface of the foam panels. The surplus mixture is removed.

The adhesive mixture can then be applied on top of the mesh and distribute the of its over the surface using a wide spatula. So is reinforced with all insulated foam wall. The glue should close as much as possible the mesh and hats of the fungi, but they can slightly penetrate through it. The main thing is that the mixture should be distributed as evenly as possible, without lumps, growths and "bald spots".

Video: how to properly paste the plaster reinforcing mesh

• In order to finally make sure of the smoothness of the surface, after setting the adhesive layer, it must be treated with with a grater with an abrasive screen of average grain size installed on it. Alignment is performed in a circular motion counter-clockwise, with a slight pressure on the grater .

• The leveled reinforced surface must be plastered with a thin layer of plaster( starting putty), which completely closes the mesh and hats of the fungi. This layer should not be thick - its maximum thickness is 1.5 ÷ 2 mm.
• Further, the primary plaster layer after its drying is also rubbed in the same way for the same - technology with smooth movements, counter-clockwise.

The last stage, before the wall is finished with decorative material, the surface is leveled to the ideal with a thin, finish putty compound, which can be applied to in one or two layers. In order for this work to be performed properly, it is necessary to carry out the of its with additional illumination. However, putty of walls is a subject for separate consideration in a special article, which is easy to find on the pages of our portal by following the link.

Video: one of the options for insulation of the internal surface of the wall with polystyrene

It is quite possible to insulate the walls with polystyrene foam with a 100% effect, without resorting to the help of a construction team, if you carry out the entire process carefully and without haste. However, it must be remembered that in order for the room to become warm , it is necessary to start with the replacement of windows with systems with double-glazed windows, which will not allow cold air to enter the room. If in an apartment or house there are old withered wooden frames, blown out by all winds, the insulation of the walls with polystyrene foam will not help to keep the housing comfortable during cold weather or windy weather.