Internal insulation of walls with foam

In order not to knock your teeth in a cold apartment or private house, you need to think about insulation in a timely manner.

The first and most significant source of heat loss in homes is the walls. But, if in a country house, in a country house or in a garage the issue of insulation is most often decided in favor of outdoor work, then in the apartment, especially if it is facade and located in areas of the city, where it is forbidden to change the architectural appearance of the building, preference is given to internal insulation.

Insulation of the attic is also possible only from the inside. Although, in fairness, it should be noted that the insulation of the walls with foam inside the apartment requires further repair and finishing work.

In addition to Styrofoam, for internal insulation can be used: mineral wool, Styrofoam or even spraying polyurethane foam. However, the majority of owners prefer Styrofoam. Why this insulation material?.

Benefits of Styrofoam insulation from the inside:

Low cost
non-toxicity. This is especially important because the walls are insulated internally with foam;

Simple, intuitive technology

The ability to warm up with your own hands;

excellent insulation properties of Styrofoam (heat conductivity ratio of 0.038 w/mS).
It is better to illustrate this indicator by example. To get the same result you need to use 100 mm foam and 160 mm. mineral waby. Comparison with other materials is presented in the diagram.

It is clear from the diagram that the most effective thing will be to use Styrofoam to insulate the walls from the inside.

Choosing Styrofoam to insulate walls

The basic requirements taken into account when choosing Styrofoam are: density and the required thickness. As for density, it is easier to work with denser material. It will not fly in the form of balls all over the room.

According to the norms of dSTU B.V.2.7-8-94 “Styrofoam plates. TU” Styrofoam is divided into four groups and has the following order markings: PSB-C 15, PSB-C 25, PSB-C 35 and PSB-C 50. Properties of each brand are listed in the table

Table – choice of foam for wall insulation – markings and properties
Letters PSB-C mean the way styrofoam is made – a non-pressmethod method. The properties of these brands are unchanged for a long period of time (up to 40 years).

At the same time, many mistakenly believe that the numbers at the end of the marking indicate the actual density of the material. However, this is not the case. After all, according to the aforementioned DSTU

Extract from DSTU on Styrofoam density

Therefore, in fact, it turns out that PSB-C -15 has a density of 9 kg/m3. And PSB-C 50 – q/-30 kg/m3. Consider this when calculating!.

Instructions for insulating walls with foam from the inside

The work will require building material and a tool.

Material:
Styrofoam;
tape-sickle for the snout of joints;
Polymer mesh
Cement-based glue;
umbrellas (special dowels for fixing styrofoam);
The primer is universal.
Tool:
roller or mackere brush for primer and container for it;
punch and drills;
Spatula;
Sandpaper;
level, ruler and pencil for marking.
The technology of internal insulation of walls with Foam involves the performance of work in several stages:

1. Pre-preparation stage

The importance of this stage cannot be overstated. Because the quality of the base also depends on the quality of the sheet’s grip with the wall and the ability of Styrofoam to maintain its insulation properties.

Before you get to work, you need:

replace the windows if necessary. Otherwise, the insulation performance will be reduced to zero;
Clean the wall of wallpaper, clogged nails, etc.;
Make all the cracks;
Remove the fungus. If it is not washed away, it should be cleaned with sandpaper;
Dismantle the plinth;
trim the flooring to the thickness of the sheet. The material is mounted only on the carrier coating;
align the possible roughness of the wall. Otherwise, there will be air between the sheets, which is fraught with displacement of the dew point.
Tip: To eliminate minor defects, use a putty to level the wall with passages of more than 10 mm – only plaster.

2. Preparatory stage

At this point, the following steps are being done:

The prepared wall is handled by a primer. From a wide variety of primer solutions, give preference to the universal mixture of the proven manufacturer. For example, good reviews about The Seresit CT-17. After application on the wall formed a thin film, which will provide both bioprotection, and better grip of the adhesive mixture with the wall;

Tip: Do not use a sprayer to apply a primer. So it is applied and dries unevenly, and this reduces its properties.

The wall should dry. It is enough to provide good ventilation in the room;
markings are applied. As practice shows, the walls of most apartments of the period of construction (slaps and panel houses), uneven. If you have the same, draw a line as close to the floor as possible. You’ll be leveling at it. Then the subsequent rows of sheets will lie down relatively smoothly. Why relative? Yes, because dSTU provided deviation of 10 mm on a sheet measuring 1×1 m. Bottom and on the sides do with pruning foam. For the same reason, you do not need to make a large number of blanks and put the drawing on the entire wall – only on the corner.

3. Main Stage

There are two ways to insulate walls with foam from the inside:

Frame method. This method is used if it is planned to finish further with drywall or wagon. This is mainly due to the fact that the thickness of walled UD and SD profiles are 27 mm. Styrofoam fits between them. And 27 mm thick. clearly not enough to perform a high-quality insulation of walls with foam inside the house. But, under the wagon frame method fits as best as possible. This is due to the fact that under it is arranged a wooden frame with a thickness of a beam at least 50 mm.
It’s a frameless way. If you plan to finish the walls with a putty.

How to insulate walls with foam from the inside – a sequence of execution in a frameless way of insulation under a putty or plaster
We begin to install foam on the wall. The work starts from below, from a remote angle.

adhesive solution is applied to the sheet. The way it is applied is shown in the diagram.

The sheet is applied to the wall and floor (if it is uneven, then to the drawn strip) and snuggles;

Council:
Don’t push too hard, otherwise the sheet will be squeezed.
a hole for an umbrella dowel (mushroom) is drilled in the center of the sheet;
Umbrella fixes sheet;
Tip: The umbrella hat should be slightly drowned in styrene or be level with the sheet. Otherwise, there may be difficulties with the finish.
Umbrellas are also clogged at the corners of the sheet for more reliable fixation.

If the styrofoam slabs of polystyrene are even, you can mount on such a scheme.

Such a device allows you to save on umbrellas, but makes the installation somewhat “flimsy.”

To insulate the walls with foam from the inside was better, the second row sheets are shifted. Such a scheme of installation will ensure the absence of perpendicular joints.

That the design does not miss heat, at the junction of sheets there should be no cracks;

To settle the top row, you need to adjust the sheets by size. Styrofoam is cut with a regular knife or a construction knife (if its thickness does not exceed 50 mm);

stitches. The seams are more than 10 mm thick and need to be trimmed with foam. those that are less than 10 mm. You can blow out the foam.

Council:
To keep the piece tight, on its back side you need to apply foam.

“Sickle tape. The tape is good because it has one side treated with glue. It’s easy to glue. The price of the tape is insignificant, in that value is difficult to overestimate, because it protects the seam from deformation. Without the use of the tape, cracks will go down the seams;

Council:
Protruding joints are eliminated with a grater for styrofoam.

smearing umbrella hats. Only those that are drowned in Styrofoam. In principle, hats “hide” and during the putty wall. But, then the subsequent mixture will be applied with a thick layer, and will dry out longer

4. Finishing stage

glue is applied to the surface of the top sheet. The width of the layer is equal to the width of the arching grid.

Applied mesh and hides under a layer of mixture.

After the wall is completely dry you can proceed to decorative finishes.

Tip: Try not to allow folds on the grid. They are poorly disguised in the future

Insulation of walls from inside foam

In conclusion, I would like to note, on what it is not necessary to save on internal insulation foam:

on ventilation. To do this, you need to make special holes in the frames of the windows. Metal-plastic windows are equipped with them by default, but in wooden frames of holes are not provided. Ventilation is needed to avoid condensation.

at the thickness of the insulation. The picture shows how the dew point is shifting.

on the density of the insulation. A low-density insulation will not allow you to get the planned effect of insulation of walls with foam from the inside.

on the quality of a primer. Poor primer will not protect you from mold and fungi development.

For the record, the insulation of styrofoam balconies and loggias has its own specifics, which need to be familiarized with additionally.