Walls of aerated concrete blocks

Building using aerated concrete and gas silicate blocks has many advantages. This is the speed of walling, significant cost savings, excellent thermal insulation characteristics of the material, reducing the total weight of the structure being constructed. However, there are a number of features that must be taken into account when working with aerated concrete and gas silicate: requirements for the foundation or base, mandatory reinforcement of walls of gas silicate blocks, the subtleties of their masonry, protection from external influences Wednesday.

Advantages of aerated concrete

The use of cellular concrete, as this material is also called, gives a lot of advantages during construction:

• Since gas silicate blocks are quite light, the whole structure will weigh much less than when using brick or ordinary concrete. This allows you to dispense with a more modest foundation during the construction of the house, and if we are talking about partitions in the apartment - do not exceed the permissible load on the floor slabs.
• At a price this material will be cheaper than brick or cinder block. Savings can reach up to 30%.
• After masonry, it is not necessary to plaster the walls due to the smooth surface of the blocks. Smooth seams also contribute to surface evenness. If you use a glue solution, then their thickness should not exceed 3 mm.
• Due to the high air content, aerated concrete has excellent thermal insulation characteristics. This allows you to save on wall insulation.
• In terms of environmental friendliness and vapor permeability, gas silicate blocks are similar to such a building material as wood. But they are resistant to fires, unlike the latter, so their use in the apartment is safer.
• Walls of aerated concrete and gas silicate provide good sound insulation.
• Blocks are easy to process, no specialized tools required.

The disadvantages of aerated concrete

The characteristics of the material will not be complete without taking into account its shortcomings. Like any other building material, cellular concrete has its weak points:

• The porosity of the material reduces its strength. Aerated concrete is not used in the construction of multi-storey buildings, a mandatory procedure is the strengthening of gas silicate masonry with metal fittings at the level of window and door openings, as well as in the upper row of blocks around the entire perimeter of the erected walls.
• Aerated concrete is extremely resistant to bending or torsion. Therefore, the construction of walls will require a reliable strip foundation. When using a columnar base, there is a good chance that such a wall will soon crack due to the most insignificant movements of the soil.
• Aerated concrete and gas silicate walls absorb moisture from the environment well. Therefore, obligatory exterior wall decoration. In its process, it is necessary to create a barrier to prevent moisture from entering. Silicate blocks are not recommended for use in rooms with high humidity, such as a bathroom.
• The process of laying on the adhesive solution is quite specific and requires certain skills and a special tool. For such work, it is better to hire a specialist, which, in turn, leads to higher construction costs. The use of cement mortar makes the process similar to the construction of walls made of brick or cinder block, but in this case because of more of thick seams, peculiar cold bridges arise, and the thermal insulation characteristics of the erected partition are significantly reduced.

Types of aerated concrete blocks

The strength of aerated concrete and gas silicate blocks is inversely proportional to their thermal insulation characteristics. The greater the porosity of the material, the better it retains heat, but is able to withstand significantly less load.

The strength of gas silicate blocks is indicated by the letter "D" in the marking and shows their density:

• Blocks marked D1000 – D1200 are the most durable. They are used for the construction of load-bearing walls.
• Blocks marked D400 – D900 have average strength and thermal insulation indicators.
• Aerated concrete marked D300 – D400 is suitable for the construction of interior partitions, as it has good thermal insulation characteristics at low strength.

By shape, the blocks are divided into three main groups:

• Smooth.
• Narrower blocks for partitions.
• U-shaped. They are used for laying jumpers.

The height of all types of aerated concrete blocks is 200 mm, length - 600 mm. An exception is the U-shaped variety having a length of 500 mm. If necessary, the aerated concrete block can be easily cut with an ordinary hacksaw, but there is also a special tool for processing this material.

Wall masonry made of aerated concrete

Walls of aerated concrete can be erected with a thickness of one or two blocks. When using the second option, you can put the blocks on a cement mortar, since the cold bridges will overlap the second row.

Single-row laying during the construction of partitions is best done using a special adhesive solution prepared from a dry mixture according to the manufacturer's recommendation. The lowest row is laid on a waterproofing pad made of roofing material, bitumen mastic or glassizol. The seam between the foundation or floor slab and the first row should be at least 20 mm thick. The finished solution is applied using a tool such as a notched trowel. It is convenient to use special carriages whose sizes coincide with the thickness of the building material.

Blocks are placed on top of the adhesive, and horizontal movements should be avoided. This can lead to uneven thickness of the seam or to incomplete filling with glue. The seam should be no more than 3 mm thick, otherwise the heat and sound insulation characteristics of the aerated concrete wall can deteriorate significantly.

Vertical seams can not be closed if they have profiles and are inserted into each other according to the "groove-protrusion" system. As a rule, well-known manufacturers use this principle, which entails an increase in the cost of work. When laying from cheaper material, the vertical joints must be filled with glue. You may even have to grind the surfaces of the blocks to produce thin seams.

When laying, it is imperative to dress the rows, while the blocks must be displaced by at least 100 mm.

Silicate masonry reinforcement

Reinforcement of the wall with reinforcement is preferably carried out every four rows of blocks. Be sure to reinforce the top row at the level of ceilings and the rows under the window openings. Valves with a diameter of at least 8 mm, pre-treated with an anti-corrosion compound, are placed in specially cut grooves. In each block, two such grooves are made at the same distance from the edge. After laying the reinforcement, they are filled with a solution so that it does not protrude beyond the surface of the block.

To form door and window openings, U-shaped blocks are used, inside of which supporting elements, for example, reinforced concrete beams, are laid. So the entire surface of the wall will look uniform.

Interior and exterior wall decoration

In order for the wall of gas silicate blocks to retain their characteristics for a long time, it is necessary to protect it from the effects of the external environment, especially from moisture. Outside, aerated concrete walls are plastered, bricked or covered with siding. In a harsh climate, an additional layer of insulation is placed between the finish and the aerated concrete wall. It is important to comply with all manufacturer's recommendations.

From the inside for decoration more often drywall, or simply plaster for painting or wallpapering.