How thick should the walls of the house be?

It is important to understand that the outer walls of a house are subject to two types of loads:

1. Horizontal. This is the influence of winds, as well as a thrust from the roof truss structure;
2. Vertical. This is the own weight of the wall, as well as the weight of the floors and loads during operation..

It is clear that the thicker, the more massive the wall, the more weight it will bear, the better it will cope with the loads. However, making walls too thick is impractical. These are unnecessary costs for building materials, loss of usable space inside the house. Therefore, you need to determine with the optimal indicator, taking into account future loads, the climate of your region and the selected building material.

External walls should not only be strong, but also warm. Therefore, their thickness is regulated by SNiP 23-02-2003 “Thermal protection of buildings”. To calculate the optimal wall thickness for your region, you first have to use SP 131.13330.2012 “Construction climatology”. In this document, we are interested in a table where the minimum, maximum temperatures in each region are indicated, the number of days when the temperature is below +8 ° C.

Let’s take Moscow for our calculations, as not the coldest, of course, but also not the warmest region of our country. It turns out that in the capital the temperature below +8 ° C lasts on average 205 days.

This indicator is important for us in order to calculate the degree-day of the heating period: GSOP = (t_v-t₈) z₈

In this formula, tv means the calculated average temperature inside the house, t₈ Is the average temperature of the heating season (in our case, less than + 8 ° C), and z₈ – the duration of the heating period, which we have already found in the table.

We carry out calculations, then we find in SNiP 23-02-2003 in table 4 the indicator that corresponds to them. For Moscow, the normalized value of the resistance to heat transfer of walls is at the level of 3.16 m ° C / W.

Now we take the formula R = s /? (m²* ° С / W).

Where we have R will be an indicator of resistance to heat transfer, s is the thickness of the wall, in meters, eh? – thermal conductivity index.

However, if you strictly follow all the calculations, coefficients and norms of SNiP, it turns out that in the Moscow region, for example, walls made of brick should be about two meters! It’s hard to imagine, so let’s go the other way and deal with the thickness of the walls, guided by construction practice and expert advice.

Brick

The standard dimensions of bricks, silicate or ceramic, are 250x120x65 mm. The length is the same for single, one and a half, and double bricks – 250 mm. That is, the maximum wall thickness of one brick will be exactly that much. Of course, this is not enough to ensure optimal thermal insulation at home..

Experts point out that at a temperature of -20 ° C, the thickness of the brick wall should be 510 mm. There is only one way out for cold regions – to make two walls of brickwork, and between them to lay insulation with a thickness of at least 100 mm, for example, stone or mineral wool. Or fill the void with penoizol. The end result is a wall 600 mm thick. This is more than enough, given that the interior will still be finished..

Aerated concrete

The dimensions of aerated concrete blocks are usually 600 mm in length and 200 mm in height. But the width can vary from 300 to 500 mm. For the Moscow region, the optimal wall thickness of aerated concrete is 450 mm. That is, for the outer wall of the house, it is advisable to choose blocks with a width of at least 400 mm, plus finishing inside and along the facade – you get the optimal thickness without unnecessary insulation.

Shell rock

This natural material has high heat retention rates, shell rock is four times warmer than concrete. However, in order to provide warmth in a house located in the middle lane, experts advise building external walls made of shell rock in one and a half stones. In this case, the wall thickness will be 600 mm..

Expanded clay blocks

Popular and affordable building material. The width of the expanded clay block varies from 190 to 450 mm. The optimal wall thickness of this material, according to SNiP, is 380 mm, that is, the masonry goes into two blocks of minimum width. If external brick cladding is supposed, and this is a very common case, the width of the block wall can be reduced.

Bar

Wooden beams with a section of more than 220 mm are extremely rare. However, according to SNiP, the thickness of such a wall for the Moscow region should be 480 mm. Since there is simply no bar of such a section, insulation is necessarily used to achieve the required heat preservation indicators.

Log

The most sturdy, warm and reliable houses are made of large-diameter logs – from 350 mm. But such massive logs are expensive, construction is expensive. According to experts, for a country house or a bath, it is enough to choose logs with a diameter of 200-220 mm, and for permanent residence – at least 230-300 mm. The costs of massive logs are further paid off by savings on heating and building insulation.

Frame house

In this case, the wall thickness will depend on the “pie”, the number of layers of the frame house, the filler, the selected insulation. According to experts, the inner layer of thermal insulation of the frame should be 150-200 mm. Plus, for example, drywall for interior decoration and cement-bonded particle boards, OSB for exterior. Plus siding for finishing the facade, lathing under it, membrane films for protection from wind and moisture, vapor barrier. As a result, for the capital region, the wall thickness of a frame house should be at least 220 mm.

Let’s talk separately about the width of partitions, walls inside the house. In this case, it is not so much heat that is important as sound insulation. The simplest and thinnest option is two sheets of gypsum cardboard 12.5 mm thick with a layer of sound insulation. From materials such as aerated concrete, expanded clay block, ceramic block or brick, partitions are most often erected in one row. That is, the thickness of the wall will directly depend on the size of the block plus the interior decoration, at least plaster.

Do not forget about the tongue-and-groove slabs, which are not suitable for the construction of the external walls of the house, but just for the partitions. Their thickness ranges from 80 to 100 mm. We recommend taking a beam for partitions with a cross section of at least 100 mm.

Important! If the partition is load-bearing, you should take care of its reliability, make it in two bricks, for example. The same is true if a kitchen unit is hung on a plasterboard wall – these places should be strengthened.

Construction experience shows that modern insulation allows making walls thinner without losing heat in the house. A multi-layer wall turns out to be thinner than just a brick, but at the same time as warm, remember this when thinking about the thickness of the walls of your future home.