Please tell me when laying the walls of the bathroom from aerated blocks, do you need to process them with something? As I understand it, gas blocks absorb moisture well, can they generally be put in the bathroom? Thanks in advance for your reply!
Answer: Yes, you are right, aerated concrete blocks have a high vapor permeability, and in the bathroom you yourself know there is always high humidity. Having such a high ability to absorb moisture, aerated concrete blocks can be used for the construction of walls and partitions in bathrooms only after protective waterproofing measures have been taken after the walls have been erected.
The first thing you have to do is prime the entire surface of the bathroom walls with a deep-penetrating primer, such as ST-17 from Cerezit. The primer will provide you with the preparation of walls from aerated blocks for applying a leveling layer of putty, for example ST-29.
The filling of the walls must be done very carefully, since the layer of putty will protect your aerated concrete from moisture. After the layer of putty has dried, it is necessary to treat the floor and the surface of the walls to a height of 200 mm from the floor level with Ceresit CR 65 cement-based waterproofing. Well, then the moisture-resistant CM-17 tile adhesive from the same company and calmly lay the ceramic tiles on the walls of your bathroom. After completing such work, you will reliably protect the bathroom walls made of gas blocks from moisture.
Please tell me when laying the walls of the bathroom from aerated blocks, do you need to process them with something? As I understand it, gas blocks absorb moisture well, can they generally be put in the bathroom? Thanks in advance for your reply!
Answer: Yes, you are right, aerated concrete blocks have a high vapor permeability, and in the bathroom you yourself know there is always high humidity. Having such a high ability to absorb moisture, aerated concrete blocks can be used for the construction of walls and partitions in bathrooms only after protective waterproofing measures have been taken after the walls have been erected.
The first thing you have to do is prime the entire surface of the bathroom walls with a deep-penetrating primer, such as ST-17 from Cerezit. The primer will provide you with the preparation of walls from aerated blocks for applying a leveling layer of putty, for example ST-29.
The filling of the walls must be done very carefully, since the layer of putty will protect your aerated concrete from moisture. After the layer of putty has dried, it is necessary to treat the floor and the surface of the walls to a height of 200 mm from the floor level with Ceresit CR 65 cement-based waterproofing. Well, then the moisture-resistant CM-17 tile adhesive from the same company and calmly lay the ceramic tiles on the walls of your bathroom. After completing such work, you will reliably protect the bathroom walls made of gas blocks from moisture.
The widespread opinion that aerated concrete absorbs some of the water, like a sponge, is due to its porous structure, which is formed during the production process. At the same time, aerated concrete keeps the accumulated volume of water in itself.
The insignificant level of water absorption of aerated concrete is due to the fact that the pores in this material are not only closed, but also open. Cellular aerated concrete absorbs moisture by 6-8%, as it has the property of hygroscopicity. Given this property of the blocks, it is necessary to create additional protection against moisture. Material protection is provided not only for the constructed walls, but also during transportation and storage.
According to experts, in order to thoroughly destroy aerated concrete, it is necessary that aerated concrete remains in direct contact with water for a long time, i.e., aerated concrete must lie in water.
The finished aerated concrete block consists of approximately 75% of pores. Moreover, the largest volume falls on macropores, which form rounded voids and interpore partitions.
The operational humidity of aerated concrete products is 4-5%. At the same time, the critical humidity for the material, entailing its destruction, for aerated concrete with a density of 400 kg / m³ is 45-50%. Similar indicators for aerated concrete with a density of 500 kg / m³ - 40%.
Due to the porous structure, the material "breathes" and, accordingly, has high thermal insulation and sound insulation properties. Absorption of a large amount of moisture leads to a change in these properties for the worse. In order for aerated concrete not to absorb moisture, additional processing is carried out.
It actively absorbs moisture from the environment during rain, sleet, and in spring when the snow melts. If you do not create protection, aerated concrete can absorb up to 35% moisture relative to its mass. This percentage of moisture dramatically reduces heat resistance, and it becomes damp and cold indoors. Aerated concrete can crack in winter if the premises are not warmed up in the fall and the material has absorbed a large amount of moisture.
The moisture content of aerated concrete used for the construction of a building wall depends on the number of seasons of house operation, on what the wall design and sorption capacity are. For example, the moisture content of aerated concrete walls of a country house, which is not used for residential purposes in the cold season, does not play any important role. If the mineral material aerated concrete is protected from precipitation by a reliable roof, then in this mode of using the building it will always be unharmed.
Moisture can enter the room from below from a poor-quality foundation or from the junction of walls with the ground; outside, when the season changes, precipitation; from the inside in case of improper operation of the air conditioning system, flooding.
According to the manufacturers, a certain amount of water can penetrate shallowly into the material, however, it is the capillary-porous structure of the block that allows it to quickly and easily give back moisture, that is, the liquid does not linger for a long time in the structure of wetted aerated concrete.
Aerated concrete easily gives up the accumulated part of the water to the outside, when the air in the room becomes excessively dry, a wall made of this material will provide humidification.
The amount of water that has penetrated into aerated concrete, first of all, worsens its thermal insulation properties. The higher the water absorption, the lower the actual thermal insulation properties of the material.
Aerated concrete walls, being saturated with water, create additional weight loads in the structures in which they are used. Accordingly, the higher the water absorption of aerated concrete, the greater the risk of an emergency.
The sphere of water itself is a destructive factor. The constant presence of water in aerated concrete can lead, at least, to a decrease in strength.
Currently, two methods of how to protect aerated concrete from water have found the greatest practical application - these are waterproofing and hydrophobization.
Water repellents - formulations that are supplied in the form of concentrates or ready-to-use solutions, aqueous or organic solvents. They do not create a surface film, but form a water-repellent (hydrophobic) layer up to several millimeters deep. The vapor permeability of the treated surface is almost not reduced, that is, some of the water evaporates, but does not get inside. The surface treated with a water repellent, as a rule, does not change color. The hydrophobic coating significantly increases the frost resistance of any material.
These properties allow the use of water repellents on silicate and ceramic bricks, concrete and aerated concrete, limestone, travertine, shell rock, granite, marble, and even on paving slabs.
The water-repellent effect is due to the penetration of the water repellent into the aerated concrete to a depth of 5 to 50 mm, depending on its density and humidity. The water repellent is fixed after 12-24 hours. In this case, crystals are formed in the capillaries of the material, which prevent the penetration of water into aerated concrete. But this does not prevent air from entering.
As for waterproofing, experts note: the wall device helps to largely eliminate the negative impact of water on aerated concrete. Ideally, the "pie" of the wall structure should be such that the outer layer is significantly more vapor permeable than the inner one. This will allow not only to effectively remove some of the water from the premises, but also to prevent water from entering the house from the street. For example, the Indastro Renoart RSi240 will help solve this problem.
To prevent the blocks from absorbing moisture, various protection methods are used. Osnovit SSL15 SafeScreen insulation with antiseptic properties has also performed well.
Treatment of the inner surface of the walls with a deep penetration primer (acrylic primer Ekorum) followed by treatment with a putty for interior work. This creates a vapor barrier. To create such a barrier, traditional plaster cannot be used without priming and gluing to the surface of the wallpaper. When using traditional plaster, aerated concrete is dampened from moisture from inside the room. The plaster will crack and flake off. The outer side of the wall is treated with gypsum plaster, cement-sand is not suitable, as it exfoliates. Plaster plastering is carried out once every 2-3 years.
The use of decorating the outside of walls with decorative materials, such as tiles, stone, and so on. Decorating will protect the layer of plaster on the surface of the aerated concrete. Large selection of decorative coatings.
The outside is lined with bricks. Pick up a brick. Since the cement-sand mortar passes steam well between the brickwork and the aerated concrete wall, an air gap is left. The gap width is approximately half a brick. In construction in this way, one small problem arises: how to fix the front wall if it is being erected with a gap. The problem is solved by using anchor elements that are installed every 5 rows of laid bricks. It is not recommended to use ordinary reinforcement or steel angle as anchors, as these elements are susceptible to corrosion. Over time, there will be no rigid connection between the load-bearing wall and the facade. The front wall will collapse. Fiberglass or stainless steel, which is popular on the building materials market, is used as anchors.
Facade decoration with siding. The method is much worse than brickwork, it is not recommended to use it, since at the end of the work there are a lot of hidden problems. Of course, maybe the finish looks beautiful and the price is several times less, but the durability of the aerated concrete structure will decrease.
The use of reinforced concrete sandwich panels based on shipbuilding concrete with a water resistance value W.
Together with the finishing of the inner and outer walls made of aerated concrete, work is being carried out to waterproof the foundation, since moisture can penetrate through an improperly constructed foundation. To do this, when building walls, aerated concrete blocks are laid out above ground level from 30 to 50 cm.
With high-quality equipment of window openings, decorative protrusions and roofs with drainage systems, as well as high-quality waterproofing of the basement, a house made of aerated concrete can stand for more than a dozen years without the occurrence of any structural defects.
When carrying out construction work, do not leave aerated concrete in the open, since moisture is very quickly absorbed in the rain and its properties deteriorate. It is not recommended to completely unpack aerated concrete.
It is not recommended to build aerated concrete structures from November to March. In the same period, it is inappropriate to plaster the surfaces of the walls. Excessive moisture will deteriorate the properties of the block, and the plaster, when dried in a hotter, drier period, will flake off and crumble. In this case, all plastering work must be repeated.
Gas and foam concretes are distinguished by high vapor permeability, and this is the reason for the nuances of the selection of building materials for the interior cladding of buildings. In a warm room, there is always water vapor in the air, which easily penetrates deep into the aerated concrete wall, cool there and condense. The block is damp. To prevent this, it is important to scrupulously select finishing building materials for the interior, whose performance vapor permeability should be much lower than the walls. The same determines the choice of the facade cladding material, which should have an even greater vapor permeability, so as not to impede the free exit of moisture vapor accumulated by the walls to the outside.
Attention: The vapor barrier of walls made of aerated concrete or gas silicate is carried out indoors, and not along the facade. In this case, it does not matter: there is insulation of the building outside or inside, or it is not, as well as the facade is faced or it was abandoned.
Correctly laid tiles on a foam block or gas block can increase the strength and moisture resistance of the structure. And they perform such works most often on the walls of bathrooms and kitchens, providing also the decoration of their interior.
Foam blocks are a building material characterized by high heat and sound insulating properties, lightness and relatively affordable price. That is why they are increasingly used for housing construction. However, in addition to its advantages, the material also has a small drawback - the need for a finish that can preserve its characteristics and increase its operational life. The inner surfaces of blocks in living rooms require plastering and painting. And sometimes it becomes necessary to put tiles on the foam block - both in order to protect the enclosing structures from high humidity, and to decorate the interior.
Possibility of stacking
Homeowners making repairs in a foam block house often have a question whether it is possible to lay tiles on a foam block. The answer to it is positive - however, due to the increased fragility of such a base, pieces of material may eventually begin to fall off along with the tile. Prevent this situation by using first a primer, and then plaster or special tile adhesive.
Most often, the need for laying tiles on foam blocks arises when finishing the enclosing structures of the bathroom and kitchen. Indeed, in addition to the fact that the humidity here is noticeably higher than in other rooms, there is a likelihood of water getting on the foam concrete and, as a result, the destruction of blocks and the appearance of mold. It is worth noting that ceramics can also be laid in such rooms on the floor, however, work with foam blocks is carried out only when decorating the walls.
Tile selection
An important nuance when laying tiles on foam blocks in the bathroom or in the kitchen is the correct choice of finishing materials and finishing area. So, giving preference to the option with ceramic cladding up to the ceiling itself, you can visually reduce the room, creating the illusion of a lower ceiling. Therefore, in small bathrooms or kitchens, it is advisable to lay tiles, leaving at least 30-40 cm to the ceiling. And at the same time choose smooth materials in cold colors. For a large bathroom and kitchen area, tiles in warm colors will be an excellent option for tiling a foam block.
The dimensions of the tiles should depend on the filling of the premises with furniture and other items (household appliances and plumbing fixtures), their area and height:
- if there are a lot of interior elements, it is worth choosing large tiles or plain light mosaic;
- for a small bathtub in a minimalist style (with the installation of only the essentials, without a washing machine and wall cabinets), an ideal option is a small square tile with a size of 100 x 100 mm;
- for low rooms, a vertically rectangular tile is suitable, for low rooms - square-shaped products.
Adhesive selection
Before buying tile glue, you should pay attention to its increased elasticity. And when choosing a way to put tiles on foam blocks in the bathroom, they pay attention to such characteristics as resistance to increased moisture. For the working wall in front of the kitchen stove, preference should be given to tiles, the operation of which is possible in conditions of high temperatures.
As materials with which dry rooms are finished (corridors, living rooms or offices), compositions based on a conventional cement-sand mixture of the CM9 type are suitable. And among the special options for tile glue, a mosaic glue stands out separately, designed for sticking mosaics on the walls. Due to the presence of white cement in the composition, this material does not have its own shade and provides increased strength of the cladding.
Preparation for styling
Before preparing foam blocks for tiles, you should evaluate the evenness of the wall surface. If the laying of foam concrete was done correctly, almost no additional finishing is required. In the presence of significant irregularities, the performer has serious work to prepare the foundation and.
Since the foam block strongly absorbs moisture, ideally for wet rooms to produce
Application of a primer under the plaster.
The next stage is the priming of the blocks. For this, specialized materials are used, a wide range is presented. When decorating bathrooms, it is worth completing additionally; such work is not required in the kitchen. Having finished with the preparation, they go directly to the question of whether it is necessary to plaster the foam block under the tile - as a rule, they choose the option with plaster, which is more costly, but also provides increased wall strength. For these purposes, tile glue is quite suitable. , on which the tile will be laid, go to the main part of the work.
The main stages of work
The first step in laying tiles on a foam block or aerated block (the principle of gluing ceramics to both materials is the same) is to prepare the solution. To do this, add a dry glue mixture and water to a previously prepared container, mixing them using a perforator with a special nozzle. The mixing ratio is usually indicated on the packaging of the adhesive.
Despite the instructions for preparing the adhesive mixture, it is advisable to independently control the mixing process. The finished substance should not be too liquid and free of lumps, but also not very hard, so as not to impair the adhesion of the tile and wall.
Continuing the work, you should:
- Apply the ready-made adhesive mixture with a notched trowel;
- Attach the first tile to the wall and press firmly;
- Check the horizontalness of the material with a level and, if necessary, level the tile. Alignment of tiles is given no more than 10-15 minutes after applying the glue. If this time is over, the glue should be removed and re-applied;
- Repeat the same steps for the next tiles. In order to leave the tile joints of the same thickness, use plastic crosses;
- If it is necessary to cut the tiles, use a tile cutter, holding the cutting part of the tool along the marked surface of the tile;
- Plastic corners are laid in the corners of the room, with the help of which even seams are provided. And to bypass the pipelines of water, gas and heat supply, they are cut out in the tiles.
After laying all the tiles and drying the material (about 24 hours), the crosses are removed, and. The material for these works is selected to match the tile. Excess grout is removed with a sponge. And after 2-3 hours, the cladding is wiped again, removing traces of the grout mixture. On this, the facing of the foam block with tiles ends.
When deciding whether it is possible to glue tiles on foam blocks, and giving preference to this option, they get high-quality finished walls, the repair of which can not be done for many more years. At the same time, the surface of the enclosing structures is reliably protected from external influences using both plaster and tiles. And such a result can be achieved only with the help of a responsible attitude to work and strict adherence to all requirements.