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Foam concrete blocks: dimensions, characteristics. Calculation and standards for the thickness of a foam block wall

External walls made of foam blocks during the construction of buildings are becoming increasingly popular. Feature of the material - availability large quantity pores, which is achieved by using special impurities in the manufacture of blocks. The proposed article describes the technology for constructing a wall from foam blocks and how to cover it.

Advice: When purchasing for the construction of walls foam concrete blocks, it is necessary to find out the technology of their production. The option of laying the material will depend on this.

Foam concrete is a type of cellular concrete of small mass.

In its production the following are used:

Cement.
Sand.
Foaming agent that promotes the appearance of air cells in concrete closed type.

After hardening, you can obtain a material with quite attractive properties, which include:

Low specific gravity.
Low thermal conductivity.
Low hygroscopicity.
Democratic price.
Ecological cleanliness.
Long service life.

Disadvantages of foam block:

Lack of high strength characteristics.
The construction of walls from it is carried out using reinforcement to increase the reliability of the structure.

Foam blocks are made in two ways:

Molded or bulk. In this case, the foamed mixture enters prepared forms, in which, after drying, they are ready for the construction of walls. Construction Materials. The laying of such blocks must be done using cement-sand mortar.
Split. In this case, a large monolith of foam concrete is made, dried in an industrial oven, after which the blocks are cut standard sizes string saws. The clear geometry of the products allows installation on an adhesive mixture.

The advantages of foam concrete are:

Excellent thermal insulation properties. The structure of the material allows you to keep the room warm in winter and cool in the summer heat.
Good sound insulation. This is ensured by the rather large width of the blocks and their porous structure.
Safety. The material is completely environmentally friendly.
Reliability and durability.
Economical. Foam concrete uses components whose price is not too high.
Lightweight, which significantly reduces the load on the foundation.

Disadvantages of blocks:

Increased absorption of condensate and moisture or hygroscopicity, because of this, a lot of moisture will accumulate in the room.
Buildings made of foam concrete are not very aesthetically pleasing appearance. More often the material is used in the construction of standard buildings.
Poor resistance to point loads.

Features of laying walls made of foam blocks

Before starting construction, it is necessary to determine the brand of foam blocks.

They differ in:

Thickness.
Densities.
Sizes.

For the construction of partitions and interior walls Usually thinner foam blocks are used.

Wherein:

If the product is 100 millimeters thick, maximum height walls made of foam blocks can be 4.5 meters. High altitude requires strengthening walls made of foam blocks - reinforcing the structure.
To hang heavy objects on the walls, blocks over 150 millimeters thick are selected, the permissible load on them is up to 50 kilograms (see).

Instructions for laying blocks:

Corner blocks are installed.
A mooring cord is stretched and fixed between them.
The first row is laid out.
It is used for cement-sand mortar, applied in a layer of at least three centimeters to the waterproofing for the foundation.
The quality of the work is checked by level; if necessary, the location of the blocks is leveled with a rubber hammer.

Tip: Laying the next row must begin after at least three hours.

The thickness of the seam should not exceed 5 millimeters.
Window openings are laid out using hollow foam blocks U shape, connected reinforcement is inserted into them and concrete is poured.
How to strengthen walls made of foam blocks? To do this, every 3-4 rows must be reinforced with reinforcement or reinforcing mesh. The reinforcement must be laid in special grooves, which are cut into the blocks with wall cutters or a grinder.
Installation of floor slabs is done after installing a concrete reinforced belt with a height of 200 millimeters.

Advice: When constructing floors or roofs made of wood, you should not make an armored belt, but limit yourself to constructing special platforms for beams.

When deciding to use foam concrete for the construction of walls, you must keep in mind:

The cement mortar should be prepared in small portions. When using special glue when laying foam blocks, it must be used within 15 minutes after application.
The optimal temperature for laying foam blocks should be from (+5°C) to (+25°C). If the temperature is higher, the foam blocks will need to be moistened periodically.
To apply glue or cement, it is more convenient to use a special trowel or a toothed comb. In this case, the seams can be made smoother and thinner. Glue must be applied to the horizontal and side parts of the foam block.

The foam block is carefully pressed. A level is placed on it, and the part is leveled vertically and horizontally by tapping with a rubber hammer. Excess solution is removed with a regular spatula.
After installing every third row, the deviation from the vertical is checked with a plumb line and level, and the corners with a level.
Every third row is reinforced. The reinforcement is placed on the mortar in the grooves, the mortar is applied again on top and the next row of materials is placed.
Each laid row is carefully cleaned with a construction float to remove any possible irregularities, and the dust is swept away with a brush or vacuumed.
If necessary, the foam block is sawn to the right size Using a regular hacksaw, the cut is cleaned of dust.
Laying foam blocks should be done with bandaging. Each subsequent row must be shifted relative to the previous one by at least 10 centimeters, perfect option– 1/2 the length of the block.

What mistakes should be avoided when laying

To prevent the dismantling of a wall made of foam blocks due to improper installation of the material, it is necessary to take into account some nuances:

It is necessary to lay the first row well. Mistakes that were made when laying the first row will add problems for the next ones and lead to deviations of the walls from the vertical.
Do not lay foam blocks in the rain or high humidity when the temperature is below 10°C below zero.
High-quality filling of all seams must be ensured, which can affect the strength and thermal insulation properties of the wall.
Dust removal of blocks should not be neglected. Dust will interfere with the quality connection of the elements, this can lead to the appearance of cracks.
Lack of reinforcement can lead to a decrease in the strength of the structure.
When laying floor slabs directly on foam blocks, a point load is created that exceeds the tensile strength of the material, which can lead to destruction of the walls.

How to install the partition

When building a wall made of foam blocks, the construction technology is as follows:

When laying partitions indoors or walls made of foam blocks in a bathroom, products are used whose thickness is from 5 to 15 centimeters.
Masonry is done in the same way as external walls.
The line of the future partition is drawn on the ceiling, walls and floor using a dye thread.
Guides are made, a rope is stretched, or a frame is made from the drawn lines.

The connecting surfaces are cleaned and dust is thoroughly removed.
The abutment surface is treated with a primer.
A layer of mortar is applied to the marking line located on the floor and the first row is laid out.
The level checks the quality of the masonry and corrects it with a rubber hammer.
The second row starts from half a block, as in the photo.

Tip: To increase structural strength in load-bearing walls At home, you should install anchors in advance or attach every third row of the partition to the load-bearing wall with anchors.

The gap between the last blocks and the ceiling is sealed after 48 hours polyurethane foam along the perimeter of the masonry.

Laying walls from foam blocks, arranging and designing structures is quite easy to do even by non-specialists. The video in this article will show you how to do it correctly.

Foam block structures are easy to erect, and such work is completed quickly. Laying foam blocks can be done with your own hands. But foam concrete and aerated concrete (cellular concrete, which is included in the concept of “foam blocks”) are not plastic and not durable. This circumstance creates increased demands on the building foundation. Especially if the building is built on soft and heaving soils. The foundation should not bend under the influence of ground movement in such a way that this would lead to cracking of the foam blocks. It must be built in accordance with the design and satisfy the rigidity requirements.

Foam blocks can be easily processed by hand. They can be sawed with a regular hacksaw, planed with a plane, and grooves can be made into them. hand tools. You can hammer a nail into them with a hammer, or you can stick this nail in with your hands... This circumstance will most likely indicate a discrepancy between the characteristics of the foam blocks and the requirements of the standards...

Features of purchasing foam blocks

IN overall quality foam blocks, you need to check them during the purchase process. The seller must have all accompanying documentation confirming the compliance of the goods being sold with GOST requirements. Particular attention should be paid to the quality of foam concrete blocks, the manufacturing technology of which is simple, and which, unlike aerated concrete, can be made in “any basement.”

It is also not permissible to purchase blocks with a lower density than those designed. Although they are naturally cheaper, they have much less strength.

Adhesive for masonry must be used.

Glue for foam blocks is approximately 2.5 times more expensive than conventional cement-sand mortar. But you still need to use glue. The blocks are very smooth and relatively smooth surfaces, which, according to the laying technology, must be fastened together with special glue. Due to its fluidity, the adhesive creates a uniformly thick and very thin layer, which ensures uniform load transfer and therefore gives strength to the entire structure.

It is completely unacceptable to lay these foam blocks “as usual” on a thick 10 - 20 mm layer of cement-sand mortar. Then there will be nothing to talk about preserving the thermal insulation properties of the wall. Yes and strength indicators walls in bending and compression will sharply decrease, which will most likely lead to cracking of the blocks without movement of the foundation. In addition, such an amount of solution will cost twice as much as if glue were used. After all, only a little glue will be used - for a seam 2 mm thick, i.e. 5 – 6 times less than the solution.

First row in the wall

Before laying the first row of the wall, the base must be perfectly (!) aligned horizontally. This must be taken care of at the construction stage. If necessary, the finishing of the base is done with a thin layer of strong cement-sand screed.

The geometry of the entire building and the strength properties of the wall depend on how the first row of foam blocks is laid. It should be taken into account that the thickness of the seams cannot compensate for the unevenness of the first row.

In addition to a very clear horizontal line, vertical unevenness in the row is also strictly controlled. Sometimes, to set one level of blocks, the first row is laid on a cement-sand mixture. The placement of each element is carefully checked according to the level and the mooring cord.

Laying begins from the corners in solid blocks. Bandaging the rows in the corners is carried out as usual. But this creates the need to insert a cutting (additional) block in the middle of the wall. It is important that its side surfaces are lubricated with glue in sufficient quantities, and that the seams with adjacent blocks in the row are completely filled.

But it is natural that there is no ideal. When building walls from foam blocks, a grater will help out, because foam concrete and aerated concrete are very easy to process manually.

The upper part of the blocks of the first row should be aligned so that there are no vertical differences in height between them. Also, there should not be a wave - a smooth decrease or increase in the level of the masonry. A laser level will help when adjusting the horizontal position.

So painstaking work It is also important because when ligating the seams, in subsequent rows, no zones of increased stress should arise in the blocks. Those. There should be no block edges left hanging in the air. If this is allowed, then cracking of the wall is inevitable.

Vertical seam - what to do with it?

Should I fill the vertical seam between the foam blocks with glue? The question arises for two reasons.
Firstly, at the ends of the blocks (usually) there are tongue-and-groove locks, which already ensures redistribution of the load horizontally between the blocks without an adhesive solution.
And secondly, each seam is still a bridge of cold, and the fewer there are, the better.

Possible options:

if the blocks are covered with solid plaster, then the vertical seam does not need to be filled with glue;
if there is no plaster on any side, then the seam on that side is filled halfway to avoid blowing through the wall;
if the masonry is carried out in the stiffeners, or the calculated load on the wall is more than 69 percent of the strength of the foam blocks, then the vertical seam is filled completely, i.e. The blocks are glued together in a row.

By the way, about the horizontal seam. If the wall is thick (and this is a typical situation), there is a desire to save glue and increase the thermal insulation properties of the wall by laying glue only along the edges of the foam blocks, and leaving their middle empty. Of course, this is unacceptable, because overstressing of the blocks in the edge parts will occur from the vertical compressive load. The horizontal seam must be completely filled with glue, and each block must be placed on the glue over its entire area.

We are laying a wall of foam blocks.

To make it easier to control the geometry of the wall masonry, you can install guide beams near the corners. Any flat planks will do. It is only important to accurately align them vertically and secure them firmly.

Then it will be possible to stretch cords between them, along which the wall can be oriented by taking measurements to the blocks. Gradually the cords move up to the level of the row being laid. It is convenient to apply the corresponding row level marks on the guides.

In subsequent rows, just like in the first, the horizontal line is adjusted, using a grater if necessary.

Of course, we cannot forget about ligating the seams vertically. But foam blocks have their own tolerances - the vertical seam in the overlying row must be shifted away from the vertical seam of the underlying row by at least 12 cm.

Is reinforcement necessary?

Reinforcement prevents cracking of walls when loads occur on the walls in the horizontal plane. But it does not actually increase the load-bearing capacity of foam blocks.

Where and how the walls should be reinforced, this question actually does not exist, because everything is determined by the project. However, sometimes it has to be addressed.

For walls made of foam blocks, the following immutable rules apply regarding their reinforcement:

a number of foam blocks under the windows must be reinforced, and in places where lintels above the openings rest on the wall, and the reinforcement should be placed at least 0.5 meters beyond the dimensions of the opening;
under rafter system reinforced ring beams (belts) are installed on the roofs and under the ceilings;

Reinforcement of the wall as a whole can be done according to this scheme. Reinforcement is laid in every fourth or fifth row of blocks, starting from the first. Typically a rod with a diameter of 8 - 10 mm is used. The number of rods along the width of the masonry depends on the thickness of the wall and load requirements. More often these are two rods equidistant from the edges of the blocks.

To lay the reinforcement, grooves are made on top of the row in the blocks. They can be made with hand tools, because the strength of the material is not great. Then rods on a cement-sand mortar are laid in the grooves ( lightweight concrete) or on glue. To increase the thermal resistance of the wall in places of reinforcement, a layer of foam plastic 2-5 cm thick is also placed in the grooves of the blocks closer to the outside.

The following is important. You can't just lay it down reinforcing rod into the groove and fill it with solution. First, a solution is poured into the groove, then a rod is sunk into it, and then the solution is added to the groove to be level with the surface.

Design of openings, construction of partitions

Manufacturers of foam block products also make special elongated blocks for lintels and as partition bases. In cross section they resemble the letter P. But naturally, they are installed like an inverted P. One side wall is usually thicker - it is installed from the outside of the building.

These elongated blocks have standard width ordinary blocks, and can be used as lintels over openings. During installation, be temporarily supported by spacers.

They can also serve permanent formwork to create durable reinforced structures, for example, under the bases of internal partitions.

In this case, a reinforcing frame is mounted in the gutter of the block, but so that it is inside the block and does not extend beyond its boundaries. This frame is then filled with concrete up to the level of the upper edges of the side walls. For this, you can use cheaper heavy concrete, but with a very fine fraction of crushed stone. In general, the reinforcement and grade of concrete are determined by calculation, i.e. house project.

Jumpers made of foam blocks are erected without any special features. It is important that such partitions cannot be too thin at a large height - the limit load on the blocks will be exceeded. In some cases, the lintel can be strengthened by using fiberglass reinforcement.

To improve the acoustics of rooms, partitions are sometimes made sound-vibration-insulated from load-bearing walls and ceilings. To do this, the partition is placed on a vibration-damping pad. Chipboard can be used as it, min. plate, polyethylene... etc. Also, between the pier and the load-bearing walls, a vibration damping joint is left, filled with polyurethane foam.

Load-bearing walls are those walls that form the main frame of the structure. They bear the load from the roof, partitions, ceilings and their own weight. That is why materials for the construction of load-bearing walls should be used durable products. For these purposes you can use brick, ceramic blocks, foam concrete, wood. A foam concrete wall can withstand the load of slabs and own weight. In this case, the density of the material should be D600. For large structures the density will be greater: D800 or D1200. Due to their lightness, the blocks are used as insulation and for filling monolithic frames.

Why foam blocks?

Cellular concrete is artificial stone which is different:
- greater thickness compared to brick;
- high fire resistance;
- it is easier to make channels for engineering systems in foam block walls;
- comparative cheapness of the material;
- the ability to erect buildings on any type of soil.
But along with this, some disadvantages cannot be ignored. Walls made of foam blocks require mandatory protection.

Requirements for load-bearing walls

Load-bearing walls must be durable, strong and reliable. Foam concrete walls fully meet all technical requirements and are suitable for individual low-rise construction. Concrete blocks thanks to small sizes allow you to construct walls of any configuration that are not subject to rot, moisture or pests.

Cellular concrete has a porous structure and therefore foam concrete blocks have good thermal insulation properties. A foam concrete wall up to 30 cm thick does not need additional insulation, and the sound insulation performance of foam blocks is several times higher than that of other materials, including brick. Wooden houses are much more environmentally friendly, but in terms of fire resistance, foam concrete walls are able to retain their original load-bearing capacity after exposure to high temperatures.

In large country houses stagnation of air masses occurs. Thanks to such properties as vapor permeability, an optimal microclimate will be created in the house, but unlike wooden house, houses made of mineral raw materials do not rot, do not burn, and do not get wet in water. The size of foam concrete blocks makes it possible to speed up the pace of construction significantly. For example, there are 15 standard bricks per standard block. As for the price of products, the same volume of concrete blocks costs 1.5 - 2 times cheaper than ceramic bricks.

Foam block masonry has a certain specificity associated with the characteristics of the material. Its low strength requires reinforcement of the rows and installation of an armored belt under the floors. Foam concrete blocks are used for the construction of structures for various purposes. Load-bearing walls and partitions are quickly erected from them, and they also provide good thermal insulation. But for this you need to know how to lay the foam block, otherwise the expected effect will not work.

Differences in foam block manufacturing technology

When purchasing foam concrete blocks for further construction of walls, it is recommended to find out exactly what technology they were used to produce. The installation option directly depends on this.

Foam concrete is a type of lightweight cellular concrete. When producing blocks, a foaming agent is added to the mixture of cement, sand and water, which promotes the appearance of closed air cells in the concrete. As a result of hardening, a material with very attractive properties is obtained:

low specific gravity;
low thermal conductivity;
low hygroscopicity;
affordable price;
environmental cleanliness;
long service life.

Among the disadvantages of foam block, it should be noted the lack of high-strength characteristics, as a result of which walls should be built from it using reinforcement, which will increase the reliability of the structure as a whole.

There are two ways to make foam blocks:

casting (or bulk) - the foamed mixture is fed into prepared molds, where after drying a ready-to-use building material is obtained;
cutting (or slitting) - a large monolith of foam concrete dried in an industrial oven is cut into blocks of standard sizes using string saws.

In the first case, foam blocks are laid on a cement-sand mortar, thus leveling permissible deviations by size. In the second case, the blocks have a clearer geometry, so installation is carried out using adhesive mixtures.

Let's start from the foundation

The reliability of the masonry and the durability of walls made of foam blocks are possible only if they are based on a strong and high-quality foundation. It is poured as a solid monolith, or mounted from concrete blocks with the obligatory installation of a reinforced concrete belt.

Although foam blocks have a low hygroscopicity rate, due to the closed structure of the air cells, they react negatively to the appearance of moisture, absorbing and accumulating it. Therefore, even during the design, it is necessary to provide measures to protect the walls from possible capillary rise of water. At the foundation construction stage, both horizontal and vertical external waterproofing is carried out, and the level of the base above the blind area is raised by at least half a meter.

a layer of cement-sand mortar 1-2 cm thick is laid on the foundation;
waterproofing is arranged;
a layer of cement mortar is laid.

Only after this can you begin to build walls.

Rules for laying a foam concrete block

Every mason knows that walls made of foam blocks are built much faster than walls made of brick. This happens due to significantly bigger size block with less weight, even compared to one-and-a-half bricks (ratio is 1:13). Thanks to this, the process of laying foam blocks is much easier and simpler.

In addition, foam concrete is excellent for processing, which is very important when constructing complex structures. What technology will be used to build the walls and how to lay the foam block largely depends on the method of its manufacture.

Laying should begin from any angle, observing maximum accuracy when laying the foundation block.
There should be no voids between the seams.
To increase the strength of the walls, the masonry is reinforced.
Before installing the ceiling, a reinforced concrete belt is laid.
The first row of foam blocks, regardless of their manufacturing technology, is laid out on cement mortar.
When laying, it is necessary to bandage at least 0.4 times the height of the foam block.

The initial row must be checked by level and, if necessary, adjusted. We should not forget that the shape of the future building depends on its evenness.

Cast foam block

Masonry material made by injection molding does not have clear lines, so the blocks must be prepared before starting work:

clear out sharp corners and too large hangnails;
cut off significant irregularities;
remove chips.

Cast foam blocks are laid on a cement-sand mortar, which is applied notched trowel or a trowel for automatic regulation height of the applied layer. Vertical seams, as a rule, should be 8-15mm, and horizontal ones - from 10 to 15mm.

Cut foam block

The laying of blocks made using cutting technology is carried out on glue mixture. The wall turns out smooth, which facilitates its subsequent finishing.

Advantages of using glue:

minimum size of seams (1-2mm) – low mixture consumption;
the absence of so-called “cold bridges”, which has a positive effect on thermal insulation;
the ability to select a mixture based on characteristics and manufacturer.

Wall reinforcement

Foam block masonry must be reinforced. To do this, after three or four rows the seams are reinforced with welded wire mesh(diameter 4-5mm), which performs the function additional protection from the formation of cracks, increases the stability and strength of walls. Reinforcement is also carried out in the area where the lintels support.

The rapid development and global modernization of technologies for the production of materials and raw materials for construction have led to the emergence of a new class of products ideal for the rapid and economical construction of walls - cellular concrete. One of the varieties of such an innovative product is foam concrete. However, the method of obtaining it has been known for more than 50 years, but only with the development and implementation of highly effective artificial foaming agents did manufacturing companies have a unique opportunity to supply production universal material to the stream.

Foam concrete: features and technology of its production

To accurately calculate thermal resistance, use the thermal conductivity coefficient of foam concrete D600, equal to 0.14 Kcal/m 2 h o C. To ensure the required level of thermal insulation, the wall must have a thermal resistance of R = 3.14.

Using the formula R = d/λ, where d is the calculated wall thickness, and λ is the thermal conductivity, it is easy to determine d. In our case, the calculated wall thickness is approximately 450 mm. However, such thermal resistance is calculated based on a temperature of 40 o C. Moreover, if we take into account the use additional funds thermal insulation and fairly rare frosts, then a wall thickness of 300 mm will be the most optimal.