Waterproofing foundations for aerated concrete, varieties

Waterproofing of foundations can be horizontal or vertical. The horizontal one insulates the foundation from the walls so that moisture does not penetrate into the wall blocks by capillary.

Vertical foundation waterproofing serves as a barrier that protects the reinforced concrete foundation from the influence of groundwater. The lack of waterproofing reduces the service life of the foundation, since over time, water enters the concrete and freezes at subzero temperatures.

As a result, the concrete begins to gradually deteriorate, forming microcracks that become larger over time. The solution to this is waterproofing; you will learn about its methods in this article below.

Now regarding specifically aerated concrete. You may be interested in the issue of waterproofing the upper part of the foundation, on which the first row of aerated concrete blocks will be laid; see brief instructions below.

Waterproofing foam blocks: water - come on, goodbye

Moisture is one of the main natural enemies of foam concrete

One of the most significant disadvantages of cellular concrete, and foam concrete in particular, is the increased water absorption of the surface layer, which leads to the development of destructive processes in the material, and sometimes a complete loss of both mechanical properties and consumer qualities.

Thus, high-quality waterproofing of foam blocks is the key to the durability of the object and the absence of unnecessary problems for its owner. What are the basic principles of waterproofing work, what tools and means are involved in working with hydrophobic surfaces - this is what our story is about today.

Laying a foundation for a house made of aerated blocks: possible options

Aerated concrete houses are built on different types of foundations:

• Tape. A popular option due to its reliability. The penetration is made below the depth at which the soil freezes. To lay the first row of aerated concrete on a strip foundation, reinforcement and pouring of concrete are carried out along its perimeter. Then drainage and waterproofing work is carried out.
• Monolithic slabs with stiffeners. When following the technology of laying aerated concrete blocks, it allows you to create a durable building. The slab is reinforced over the entire area. The edges of the foundation must coincide with the height of the base.
• Pile-grillage. The base is piles of concrete or metal, fastened with a monolithic grillage.

Water is the basis of life

Destroyed masonry is one of the most unpleasant surprises

The foam block in its body has an array of connected micropores, which have an intensive and developed network of partitions, localizing each pore as, albeit small, but a separate element.

It is the strength and resistance to external influences of an individual partition that determines the strength and stability of the finished product as a whole. This is also true for the moisture resistance of the block.

Despite the specific structure of the mass, foam concrete is easily processed, maintaining sufficient strength indicators

The foam block production technology involves introducing a foaming agent into the sand-cement mash, which is mechanically distributed throughout the entire mass of future foam concrete. The foaming agent can be of both organic and inorganic origin.

Porous structure is the basis of the positive qualities of concrete

One of the luminaries in the production of classic cellular concrete of various natures is rightfully the Italians. It is the use of Italian protein organic foaming agents that is presented by domestic producers of foam concrete in their advertising brochures as one of the decisive arguments for their quality.

Note: But don’t delude yourself. Any production is, first of all, a system of technological measures, and the use of only one or a few high-quality components does not guarantee a high-quality final product.

Alignment to the West

During the era of widespread industrialization in the Soviet Union, a group of lathes appeared under the DiP brand: DiP-200, DiP-300, DiP-500. The abbreviation DiP meant the banal Let's Catch Up and Overtake. The Soviet Union has long since sunk into oblivion, the vast majority of D&Ps ended their journey at scrap metal depots, and we are still catching up and catching up with world progress.

Suffice it to say that the basic model of European equipment for the production of cellular concrete is digitized inside and out, and its technological controller is capable of simultaneously reading, processing and adjusting at least 12 parameters; similar technological lines of the premium sector simultaneously provide up to 43 /forty-three/ input and current data.

Computerized process control systems - the realities of today

In comparison, the controllers of the same Chinese systems, in the overwhelming majority, only imitate the reading, processing and adjustment of basic technological parameters, such as viscosity, polyzonal mash temperature, alkalization indices, and so on. Thus, given the complexity and responsibility of the technological process for producing foam concrete, it is impossible to obtain a high-quality product without high-quality and expensive equipment.

In many ways, modern equipment is the key to quality

Formed in violation of production technological conditions, pores and their partitions are, in principle, unable to sufficiently resist the destructive effects of moisture, and destruction of the foam block mass is possible even when high-quality waterproofing work is carried out.

Neglect in choosing quality materials can easily turn a building into an ancient Roman ruin

Rule 1. From here follows the first and, perhaps, the main rule when choosing foam blocks and drawing up measures for their waterproofing. Choose the material carefully, and take an equally careful look at the manufacturer. Otherwise, the waterproofing carried out will be a waste of money and time.

Conclusion

If you are building a house from aerated concrete yourself, we strongly recommend that you follow all technological recommendations for masonry. Not only the attractive appearance of the building depends on this, but also its durability and the comfort of your stay in it.

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Laying aerated concrete is a responsible process that requires strict adherence to technology. The porous structure of aerated concrete blocks provides not only the positive qualities of the walls being built (excellent sound and heat insulation properties, good vapor permeability and light weight), but also the negative ones - increased fragility. However, if you use the right mixture and carry out masonry work correctly, this drawback will not affect the quality and service life of your home.

The advertisement is engine of the trade

Recently, very often you can see a lot of advertisements, vying with each other, promising to provide foam blocks with truly unimaginable consumer qualities. One of these qualities is the unique ability to withstand moisture with zero water absorption.

The basis of this miracle is a water repellent for foam blocks, which creates a fatty film at the molecular level that prevents direct contact of foam concrete with water molecules. At the same time, advertising materials cannot do without the use of nanotechnologies, which are very fashionable today.

In addition, the use of special hydrophobic fibers with a diameter of about ten microns is mentioned, which, in addition to the main reinforcing function, also perform the task of accumulating and removing moisture.

Sometimes, if you trust a dishonest advertiser, you can come to such a disastrous result

This leads to Rule 2: Be critical of advertising. When choosing ready-made material, be guided by reason, not emotions. Ask the seller in detail about the features of the technology, objectively evaluate the production culture and remember the school physics course, which teaches that there are laws and no miracles.

Say no to water: basic methods and techniques of waterproofing

Some reagents have a long tradition as waterproofing materials

The main negative point seems to be the price of its implementation. Because truly high-quality materials that can create a durable coating are of imported origin and the resulting high cost.

In addition, this method involves saturation with a reagent and partial polymerization of the surface layer, which in most typical cases entails a very high consumption per square meter of finished surface

Carrying out such work is possible using not only a pneumatic spray gun, but also a bone or roller

In addition, it is necessary to carefully select the composition and overall quality of the paint, since the determining key in this event is the durability of the protective coating. Very often, waterproofing of foam blocks on the balcony is implemented in this way, since it is not easy to combine the protective and decorative functions in any other way.

This type of work is easy to mechanize, as in the photo shown.

Waterproofing of this type allows you to reliably seal not only the structure itself, but also the adjacent areas from moisture.

In addition, in most cases, in the shelter space under a number of conditions, the formation of abundant condensation is possible, which reduces the effectiveness of the measures taken to zero. Steam drainage and condensate removal are provided by membrane materials, which in some cases increase the cost of the finished molding by an order of magnitude.

Surfaces protected in this way cannot be used outdoors, since the ultraviolet rays of the solar spectrum have a destructive effect on film barriers.

The method shown involves the use of specific fasteners and at least one assistant

Plastering requires not only skills, but also dexterity, especially on large areas

When designing this method of protecting cellular concrete, be sure to take into account the increased load on the foundation

Aerated concrete masonry technology

After all preliminary work has been completed to a high standard, you can begin installing the blocks. Laying subsequent rows of aerated concrete begins from the corners. Then a cord is stretched between the opposite corners, which will serve as a beacon - this will ensure that all walls are at the same level.

• A thin layer of glue is applied to the surface of the blocks. The length of application depends on the speed of your work - traditionally no more than 2-3 blocks are covered with the composition. This will allow you to quickly adjust the position of individual elements while the mixture is moving./li{amp}gt;

• The horizontal and vertical plane of each laid block is controlled by the building level. If necessary, the aerated concrete masonry is leveled with a rubber mallet. If there are deviations, freshly laid blocks can be disassembled and laid out again./li{amp}gt;

• The laying of aerated concrete walls is carried out with bandaging - the vertical joints must be offset relative to the previous row by at least 80 mm. The length of blocks near openings, as well as corners, must be at least 115 mm.

The straightness of aerated concrete masonry must be checked after each installed row of blocks. To check the corners of the house, a wooden square is used, and a rule and a building level are used to check the horizontal plane. The rule is placed on a laid row of blocks, and a level is placed on top.

The vertical plane of the masonry is controlled using a plumb line and/or the same building level with the rule. The deviation from the vertical should not exceed 1.5-2 mm per 2 m of wall height.

The technology of each of these processes is discussed in more detail in other articles. Therefore, here we will focus on general points.

If it is necessary to arrange openings, various technological openings or install embedded parts, aerated concrete is cut with a hacksaw. Cellular concrete is easy to process, so there will be no difficulties in preparing elements of the required size.

The installation of overhead lintels can be done using U-shaped blocks, which act as permanent formwork. A reinforcing frame is installed inside the voids, and the structure is filled with concrete. Another option is the use of aerated concrete lintels.

When installing reinforced concrete lintels that are cast in place, it is necessary to subsequently insulate them from the outside.

Important! The laying of aerated concrete walls is accompanied by reinforcement of every 4th row, places under window openings and areas supporting lintels.

The last row of masonry before the attic or interfloor ceiling is made of U-shaped blocks for the subsequent installation of a reinforced monolithic belt. The armored belt binds the aerated concrete masonry and absorbs loads from the upper load-bearing elements, evenly distributing them onto the walls and foundation of the house.

How to protect aerated concrete from moisture

Over the course of 10–15 years, aerated concrete has established itself as an excellent wall material: its share in low-rise construction is close to 50%. It turned out that cellular blocks successfully replace brick. Aerated concrete houses are successfully used in all regions - in the North-West, Siberia, and the Far East.

The reasons for the popularity of silicate cellular concrete are different. Some experts say that interest in gas blocks is due to their ease of use. Others believe that the material is attractive because of its mechanical properties - strength, durability, thermal insulation, environmental friendliness, and vapor permeability. In any case, one conclusion suggests itself: anyone can build an aerated concrete house.

Waterproofing fabric (membrane)

After puttying, you can begin the most important procedure - gluing the canvas or membrane. When cutting on a marking machine, the blade should be stretched without the slightest distortion. Also, when choosing a size, you need to remember the fillet and the protruding part of the foundation.

Pieces of waterproofing fabric are glued overlapping. The approximate size of the latter is approximately 50-100 mm. As with putty, special care is required to insulate areas around pipes. To glue the canvas in these areas, it is divided into squares, in each of which a cutout is made in the middle. The diameter of the cutouts should be slightly smaller (about 2 mm) than the diameter of the pipe.

After completing the waterproofing process, it is necessary to re-check all joints without exception, so that there is not a single crack left through which water can leak.

Why do walls need protection from moisture?

However, all of these advantages also have a downside: the material is hygroscopic. The cellular structure easily absorbs moisture. If the conditions are created for the gas block - placed in water, it will absorb twice as much liquid as it weighs.

This property must be remembered during the construction of the house and in the first year of its operation: the structure of the block resembles a sponge. The pores are filled with moisture during rain, wet snow, and in the autumn-spring season.

However, this property - permeability - also has a downside: the material dries just as quickly. In fresh air in dry weather, the masonry regains normal humidity in just a few weeks.

Moreover: the gas block is capable of removing moisture from the premises. Porous walls are capable of accumulating excess liquid throughout the winter, which is formed during washing and cooking. Summer comes - and all the water is drained outside through a web of capillaries.

A paradox arises. On the one hand, the walls of an aerated concrete house should be protected from moisture, on the other, its unhindered exit from the premises must be ensured.

It turns out that waterproofing materials cannot be used. If the external walls are finished with traditional moisture-proof films or tiles, then the advantages of aerated concrete can easily be turned into disadvantages. All fashionable facing materials - tiles, clinker, thermal panels, plastic - are poorly suited for protecting aerated concrete from moisture. Any coating that “preserves” steam inside the masonry causes harm to the blocks.

More often, problems with excess moisture in walls arise only during construction and during one - the first operational season. Then, in subsequent years, they disappear.

Cracks may appear in undried aerated concrete under the external waterproofing material within a year or two. chips. The increased weight may cause the foundation to sag. Negative consequences arise for two reasons:

Thus, aerated concrete must be protected from excess moisture from the outside. But the masonry must create conditions for removing moisture from inside the premises.

So, are we facing an intractable dilemma? In fact, the way out of the situation is simple. You should choose a protective coating that is more permeable than the wall itself.

Yes, not every material has the necessary properties. However, there is a way out of every situation, and from this one there are several. Walls are easy to protect. Gypsum plaster is also suitable, and ventilated coverings on the surface. However, the fastest and most cost-effective method is hydrophobization of aerated concrete.

Why is it needed?

Cellular blocks, with all their positive characteristics, are highly hygroscopic. If you do not create a moisture-proof layer between the base and the walls, moisture will rise to a considerable height. In winter, it will freeze in the pores and destroy the structure of the material from the inside. As a result, the structure will lose strength and load-bearing capacity, which will lead to its destruction.

Cut-off waterproofing must be done on the horizontal surface of the foundation for the blocks. Its main purpose is to block the access of capillary moisture.

• freezing of walls, deformation of building elements, distortion of windows and doors;
• the appearance of salt deposits as a result of constant exposure to moisture, which not only worsens the appearance of the walls, but also leads to their destruction over time;
• dampness in the rooms, which can lead to damage to decoration, furniture, and household appliances;
• the development of colonies of fungus and black mold, which are hazardous to health and quite difficult to remove.

It also prevents the following negative phenomena:

Types of water repellents

Hydrophobization, speaking in Russian, is the process of imparting water-repellent properties to a material. Water repellents are substances that make the surface non-wettable.

Most moisture repellents can be applied manually, independently. For example, to stop construction, you just need to spray the walls with an impregnating liquid. An ordinary garden sprayer is suitable for applying it.

There are several classifications of moisture-repellent materials. The first is based on the method of introducing water-repellent components. There are bulk and film-forming hydrophobic compounds.

Penetrating substances penetrate 0.5–4.0 cm deep into the masonry. Surface substances - modify a thin layer of external molecules of aerated concrete, giving them water-repellent properties.

The second category is film-forming and penetrating water repellents, which can be used to protect finished concrete products, brickwork, decorative cladding, tiles, etc. After application, they create a thin waterproof layer on the surface. From time to time this coating will have to be renewed, but this is cheaper than subsequently restoring the structure with your own hands.

Another classification system is based on chemical composition. There are organic (polymer) and aqueous, silicon-containing water repellents.

Organic water-repellent coatings are made on the basis of polyurethane, epoxy and other high-molecular compounds. Most of them are penetrating impregnations.

Silicone or silicone moisture-protective substances are aqueous solutions. When applied to a silicate surface, water repellents settle on the surface of the pores. After drying, a film one or two molecules thick forms on the aerated concrete, which prevents moisture from entering.

The peculiarity of aqueous compositions is that they leave the capillaries open: gases and steam pass through them. But water drops, even the smallest ones, roll off the surface without stopping.

Materials for waterproofing

To create a water barrier between the foundation and the masonry, various materials are used: bitumen mastic, sprayed and rolled waterproofing, waterproofing membranes.

For horizontal cut-off waterproofing between the foundation and brickwork, Ondutis D (RV) films are suitable. These are durable films that form a reliable water barrier and at the same time are quite convenient for DIY installation.

An innovative type of membrane - film with applied adhesive tape - Ondutis D (RV) Smart, which greatly simplifies the process of installing waterproofing for building structures.

Preparation of adhesive solution

As an adhesive, it is necessary to use a specially developed “Glue for aerated concrete “VARMIT”. To prepare the adhesive solution, mix the dry mixture with water and mix thoroughly using a mixer (a paddle mixer rotated by an electric drill).

The preparation of the adhesive mixture must be carried out strictly in accordance with the manufacturer's instructions. The consistency of the adhesive mixture is important for adhesive masonry. The mixture is considered to have the required consistency if, when applied to the vertical surface of the block, it does not float away or fall into pieces. When working with glue, you must strictly follow the recommendations for use developed by the manufacturer.

The applied solution on the block should have a groove-like shape.

Classification of hydrophobic water-based compounds.

All water-containing hydrophobes can be divided into three groups.

Concentrates. Saturated solutions have a number of advantages:

The disadvantages include a limited service life - within 2–5 years.

Emulsions are suspended microparticles in an aqueous environment. They have high efficiency and low cost. They require careful handling during storage: the suspension is afraid of frost. After one freeze-thaw cycle, the material loses its beneficial properties. For this reason, we do not recommend buying emulsions in the markets: the risks of purchasing an unusable product are very high.

Colloidal solutions are amorphous compounds. These substances can be considered the most suitable for use at home. Water repellents are not afraid of the sun and cold. They are not afraid of other destructive factors. The only danger that may await the buyer is the risk of purchasing uncertified products. We recommend giving preference to specialized stores.

Aqueous solutions are superior to organic solutions in terms of cheapness and ease of use. However, polymers tend to last longer.

Is laying aerated concrete on cement mortar allowed?

Laying walls made of aerated concrete on a self-prepared cement-sand mortar can be justified only in one case - the use of blocks of the 2nd category. A thick layer of mortar allows you to fill the voids that are formed due to the broken geometry of the masonry material.

1. The increased thickness of the seam (up to 12 mm) leads to the formation of “cold bridges” at the junction of the blocks.
2. Inconsistent composition of the solution - it is very difficult to maintain the most accurate proportions when preparing it yourself.
3. Neglecting the addition of special pigments, plasticizers and other additives or failure to comply with their proportions.
4. The complexity of preparation significantly delays the construction time.

Classification of hydrophobic silicone-based compounds

Silicon-containing polymers are silanes, siloxanes and silicones.

Silanes are deep-penetrating substances. Due to their small molecular size, they are highly volatile, but the most effective. A surface treated with silanes retains its hydrophobic properties almost forever – for centuries. They can be applied to wet substrates. They interact especially well with alkalis, including light and heavy concrete. Helps increase frost resistance.

Disadvantages include the tendency to become dirty, difficult to apply (due to volatility), and high cost.

Siloxanes are surface-type substances. Large molecules react with the surface layer of the material. As a result, the surface tension of minerals decreases and water molecules are rejected. The impregnation is suitable for treating concrete, brick, and wood surfaces. It applies well - it does not evaporate, so it is convenient for self-processing.

Disadvantages: may become partially dirty during prolonged use, darkens. Does not apply well to wet substrates, and practically does not work on painted surfaces. The cost is quite high.

Silicones. Impregnations based on pure silicones are not used for treating concrete.

Putty work

One- or two-component bitumen putty (mastic) is used. The first type is applied in a single layer with a thickness of 5 mm. In the case of two-component putty, the situation is more complicated, since it dries extremely quickly, especially at high air temperatures.

Due to this feature, there is no need to prepare too much putty material. To prevent hardening from happening too quickly, you can, for example, reduce the amount of hardener.

First, the bitumen solution is thoroughly mixed with the hardener. Then a thin initial layer is applied (thickness no more than 2 mm), onto which fiberglass is glued (overlap size is approximately 1 cm). When the first layer is completely dry, you can apply the second, and such a thickness that the fiberglass used for reinforcement is invisible.

Whatever type of putty is used, you need to carefully treat the areas around the fillet and pipes. Builders who have repeatedly dealt with waterproofing advise wrapping pipes with narrow fiberglass strips and applying a layer of putty on top.

Is it possible to prime an aerated block with liquid glass?

Advice on the ability of liquid glass to protect surfaces from moisture can often be heard from home experts. It’s hard to argue with these tips: silicate glue perfectly clogs pores and does not let water through.

There is only one objection: this material completely stops the movement of water and the movement of steam. The aerated concrete surface acquires the properties of a waterproofing agent.

This method is suitable for treating foundations and horizontal waterproofing. However, liquid glass can be used to impregnate walls only after they have completely dried.

In this case, the aerated concrete masonry should be carefully treated on both sides to prevent the wall from becoming wet during the further operation of the house.

Application in multi-storey construction

The main advantage of this type of construction is the light weight of aerated concrete, which reduces the load on the monolithic structure of the building and its foundation, as well as making the premises warm. The thermal insulation properties of aerated concrete allow it to withstand cold weather. The durability of the material is confirmed by a special study, which confirmed that even after 50 years, aerated concrete has an intact structure and shows no signs of destruction, which gives another point in favor of this building material.

How to treat aerated concrete blocks from moisture outside

A popular way to protect the outer surface of aerated concrete is plastering. A thick layer of cement-sand-gypsum plaster will reliably prevent excessive moisture from the walls.

Facing with waterproofing materials is the second effective method. Their choice is large: tiles - tiled or clinker, plastic, siding - are suitable for exterior decoration. However, when working, two conditions must be met:

And the third method is treatment with liquid water-repellent emulsions or solutions. The good thing about technology is that it:

Mistakes when choosing a mixture for laying aerated concrete

Today on the building materials market there is a huge number of masonry mixtures that differ in characteristics, quality and price, and also, almost always, in purpose.
It may be difficult for a person who does not have professional construction knowledge to make the right decision when choosing a material for laying aerated concrete - inside the bag they are all a loose composition, usually gray in color, and perform the function of “gluing” wall materials. Such a superficial view, as well as the unprofessionalism of builders and the dishonesty of a number of sellers, naturally provokes the buyer’s desire to buy a cheaper mixture, believing that “it’s the same thing.”

If this were so, manufacturers would not write the purpose of the mixture on the packaging - from the position of a dry mixture manufacturer, keeping records and maintaining the warehouse availability of one universal product is many times easier than several.

• Application of cement-sand mortar.
• Purchasing a mixture intended for tiles or any other materials.

How to choose the right water repellent

When purchasing a water-repellent agent for aerated concrete, pay attention to the features and functional purpose of a particular composition. In your case, you may need two supplements at once. You will add one additive to the cement masonry mortar to increase its plasticity and waterproofing ability. The second time you will treat the walls after installation.

If you started decorating the walls in late autumn, the most effective remedy will be a silane water repellent: it interacts well with wet aerated concrete and begins to act immediately after application. However, for processing there is a reason for them to hire a worker from a specialized organization: the substance evaporates quickly, and appropriate equipment is needed to apply it.

For small buildings operated in arid areas, you can get by with the most budget-friendly product - a water-soluble silicon-containing composition. If we are talking about temporary protection of a building structure, an inorganic substance is also suitable. It should also be used for finishing white facade walls that are not subject to further cladding: the surface treated with silicon does not become dirty.

Mixtures are also popular. They are prepared if it is necessary to achieve a complex effect - for example, durability, a high degree of purity and deep penetration of the substance.

Approximate costs

The cost of waterproofing work per m2 depends on:

1. location of the object;
2. number of floors of the house;
3. sources of moisture volumes and its intensity;
4. requirements for moisture and vapor protection of aerated concrete;
5. selected thermal protection system: frame or frameless.

The total amount is taken into account the labor costs for all technological operations and the costs of purchasing vapor and waterproof materials, as well as the rental of special welding installations.

The cost of installing waterproofing on houses made of aerated concrete walls in combination with thermal insulation:

Properties of water repellent and antiseptic

Modern water-repellent compounds are multifunctional. They turn out to be useful not only as hydrophobes. Many substances contain fungicides, and therefore have an antibacterial and antifungal effect.

When choosing deep penetration impregnations intended to protect concrete from moisture, the specifics of their application should be taken into account. Solutions for external use are marked accordingly: they are either not recommended for use on interior walls, or are simply prohibited.

There are solutions for universal use. Water repellents of this type are capable of removing mold and destroying other microorganisms on concrete, brick, wood, and asbestos-cement surfaces. These substances are convenient to use indoors - for treating walls, door frames and ceiling beams, and chipboard panels.

There are many impregnations of various brands from different manufacturers on the market today.

Required Tools

1. To clean surfaces, use a spatula, metal and soft brushes.
2. Cleaning of tongues is carried out using a grinding float.
3. A wide brush will be needed to apply the primer.
4. A construction mixer or a regular drill with an appropriate attachment is needed to thoroughly mix the solution.
5. To apply the putty you will need a spatula and a trowel.
6. The trowel is also convenient for pressing fiberglass.
7. A hammer drill will come in handy when working with two-component putty.

Manufacturers of hydrophobic impregnations

Today there is a lot to choose from. The range of brands is endless. This:

Domestic brands are most in demand. The quality of Russian solutions is at a high level, the price is reasonable, and the sales service is decent. All products have been certified. Sellers and suppliers guarantee excellent consumer properties of water repellents. Three brands are of particular interest to builders and developers: Aquasil, Penta, Tiprom.

Aquasil

The manufacturer guarantees that the moisture absorption of aerated concrete will be reduced by 10 times, and that of gypsum-containing solutions by up to 40 times. In addition, the drug strengthens the surface of aerated blocks by a third. After treatment, other parameters also increase - frost resistance, water resistance. The solution protects against efflorescence, dust adhesion, and discoloration.

Impregnation is a concentrate in a canister. The supplier offers containers of 1 l, 5 l, 10 l. Before use, the emulsion is diluted in a ratio of 1: 10. Approximate consumption is 0.5 liters per 1 m². When surface treated, the wall acquires hydrophobic properties 2 hours after application.

The concentrate can be added to concrete and masonry mortars in an amount of 0.04% by weight of cement.

Other products of the Aquasil brand:

Tiprom

Product of JSC "SAZI". For impregnation of aerated concrete, the company produces Tiprom-U concentrate. Its parameters are similar to those of the previous drug:

Not intended for application to dense, non-absorbent materials.

SAZI also produces the following drugs:

Penta

The product range of TM Penta consists of many types of products. Most preparations are specialized and suitable for hydrophobic treatment of a narrow range of materials. There are compositions for impregnating mineral wool, basalt and fiberglass slabs. There are – for processing woven and non-woven fabrics, for wood, leather and other types of raw materials.

The Penta-820 solution is intended for hydrophobization of aerated concrete. The material is applied to wet or dry substrates with a brush or sprayer. The composition has an antifungal, antifreeze and anti-mud effect.

Consumption of working solution – 350 ml per 1 sq. meter of aerated concrete surface. Service life more than 10 years.

Where is aerated concrete waterproofing performed?

Waterproofing of aerated concrete blocks is carried out during the construction process. Only in this case will it be effective and durable. The following structural elements of an aerated concrete house are subject to mandatory insulation from moisture:

Underground parts

All underground parts: foundation, basement, plinth, cellars are treated with adhesive or coating waterproofing, regardless of whether they are made of aerated block or other material. Why do you need to waterproof the foundation before laying aerated concrete? As we remember, aerated concrete blocks attract and absorb moisture from the ground. If there is no insulation, the basement, basement, and first floor floor will be damp. Roll or coating waterproofing is applied to foundation elements outside and inside. On particularly wet, swampy soils, in areas where flooding is possible, in addition to waterproofing, backfilling and drainage are performed.

The first row of blocks in a masonry

In accordance with the TTC. “Masonry of external walls made of foam blocks and concrete blocks” for the first row of blocks, roll-type waterproofing should be performed. The material is laid directly on the surface of the foundation itself in the projection of all load-bearing walls.

Laying blocks on a concrete base without a waterproofing layer is not allowed!

Rooms with high humidity

Such premises include bathrooms, showers, swimming pools, saunas. In the absence of waterproofing, the walls in these rooms begin to become damp, the house becomes cold, and mold appears. Cement-based waterproofing is used for interior spaces. The materials are applied to horizontal and vertical surfaces in contact with water or plumbing equipment.

How to protect aerated concrete walls from the external environment when construction or facade finishing is delayed

The article was written with the participation of PROSEPT specialists

Battles over aerated concrete blocks between their fans and ardent opponents have not stopped for decades, and it is unlikely that one of the sides will ever win. This material has a lot of positive properties, such as low thermal conductivity, good geometry, ease of processing, environmental friendliness and fire resistance. These and other parameters attract private developers, but there are also characteristic features, rather with a minus sign. For example, the need for facade finishing, a large mass of high-density blocks, as well as increased hygroscopicity and the resulting deterioration in frost resistance, which must be taken into account. Most of the copies are broken precisely around the ability of blocks to absorb moisture, which entails an increase in thermal conductivity and a decrease in frost resistance. With the help of PROSEPT specialists, we will try to figure out how to protect aerated concrete from the negative influence of external factors.

In this article we will look at:

Preparation for laying aerated concrete walls

• High-quality foundation waterproofing.
• Properly executed laying of the first row of aerated concrete.
• Reinforcement of the 1st row of aerated concrete blocks.

These processes and the technology for their implementation are discussed in more detail in another article.

After the first row of blocks has hardened, all irregularities, hardened glue and any other contaminants, including dust, must be removed from their surface. Checking straightness is done using a level.

Features of aerated concrete blocks and their operation

Aerated concrete is one of the varieties of cellular concrete characterized by a porous structure; it is characterized not only by high vapor permeability, but also by high moisture saturation. And if the first property is considered an advantage of the material, since houses built and finished in compliance with the technology will have a healthy microclimate, then the second is considered a disadvantage.

Because of this structure, blocks are saturated with moisture more than other masonry materials of their own group and other varieties. And the lower the block density, the more active this process is. Regardless of the brand of blocks, it is difficult to imagine a real situation when the house is completely immersed in water and soaked. But prolonged rains, watering walls even with large overhangs, are the norm for some regions. Therefore, how critical the impact of precipitation is depends on both the parameters of aerated concrete blocks and operating conditions.

Ideally, during the construction process, the outline of the house should be closed before the start of the cold season; at a minimum, the rough roof should already protect the walls. Also, all block manufacturers recommend protecting walls either using a system of ventilated facades, or decorative plasters, or tiles/stones, or something else, depending on the chosen style and financial capabilities. But in practice, this does not always work out - future homeowners lack either time or money, or more often both, and there may be a long interval between construction and facade work. That’s when FORUMHOUSE users have questions: what to do with the unfinished building?

I built an attic house from 30 cm D300 aerated concrete (foundation slab, walls, roof, ceiling, partitions, double-glazed windows). I planned to make a façade with insulation next year, but a crisis arose. The house has been standing for two winters, construction has been suspended. Now the question is - the means do not allow you to do everything at once. What bad can happen to a house made of aerated concrete without finishing the facade? Is it possible and worthwhile to do work on the inside of the house (communications, floors, walls), or the façade first?

Regarding the use of a block considered to be thermal insulation and not structural for the construction of load-bearing walls, Sergey-Spb responded to the participants in the topic who raised this issue that the engineers with whom he consulted considered his solutions to be viable. Regarding the question asked about the facade, the answers from practitioners are as follows.

If the conversation had not been about the D300 and not in St. Petersburg (as I understand), I would have said that it is possible to leave it for more than a year. I'm not saying that the D300 will fall apart - I just don't know how it will behave without finishing. And so, I have a D600, 250 mm, for more than ten years it has been standing fine without exterior decoration, of which a little less than ten have been fully heated (with interior decoration for a long time). In principle, if melt water from a leaky roof does not constantly flow over it (aerated concrete), freezing and thawing alternately, then what will happen to it. At least five years, at least ten.

The house has been standing for eight years without external finishing, the wall thickness is 300 mm, plus internal plaster - the flight is normal. We are already living, this year I will finish the kitchen and next year I will work on a ventilated facade without insulation. So don't be afraid, everything will take its course.

There is a certain algorithm for performing work in aerated concrete houses.

The order was determined a long time ago, and even more so in GB houses. Internal wet work, drying, external work. The recommended drying period is one year. But there are no regulated periods for the presence of aerated concrete without external finishing.

Nevertheless, experts advise to insure yourself, especially since it does not require excessive financial costs.

The main disadvantage of aerated concrete is its low frost resistance in the absence of protection from moisture. Therefore, it is recommended to immediately finish external walls made of aerated concrete. In the case where there is not enough money for facade work, or the priority is interior decoration and occupancy, then facade work can be delayed for several years, protecting the external walls from moisture. The most inexpensive option for preserving aerated concrete is treatment with a water-repellent protective impregnation - a water repellent.

In addition to walls as a whole, there are other risk zones in which excessive moisture accumulation is fraught with, at a minimum, cracking, and at maximum, destruction of the block.

A disaster has occurred (it is not yet clear whether it is big or not). Upon completion of the construction of a house made of aerated concrete, 2 troubles appeared:

In this case, as in many others, the main problem is that the gas blocks easily absorbed moisture, which then destroyed them from the inside. It is important to avoid overmoistening when using aerated concrete. The situation with an abnormally high exposure to moisture on aerated concrete with its subsequent freezing leads to its destruction. To avoid such results, it is worth paying special attention to the arrangement of window sill drains, cornices, each canopy and spillway systems, thereby eliminating the likelihood of constant contact of water with gas blocks. That is, to ensure water drainage from those areas where waterlogging is possible. Particular care must be taken to protect the masonry in the plinth area. If water and snow are not in constant contact with aerated concrete, then precipitation will not cause significant damage to the structure.

According to Evgeniy, solving the problem described will require serious repairs and restoration of the material. However, simple measures should be taken to prevent such incidents in the future. The main thing is to prevent water absorption; you can treat the house with a water-repellent impregnation in the same way as we do, for example, with shoes, treating them during the rainiest season.

The water repellent for aerated concrete is based on silicones, these are organosilicon compounds. They are affordable, inexpensive for the manufacturer, and therefore the price of processing the house for the builder is acceptable.

Another possible problem is mold. Aerated concrete itself is considered biostable, but this is in a dry state; if it is waterlogged, damage by pathogenic microflora is quite possible. There can be a lot of reasons for this phenomenon, and it is necessary to fight, first of all, with them, but it is quite possible to remove traces of the vital activity of microorganisms.

I'm looking for advice on how to combat mold/fungus. The house is made of aerated concrete, 250 mm thick, the 1st floor is aerated concrete, the 2nd floor is an attic with gables made of aerated concrete. Pie of walls from outside to inside: siding, ventilation gap, windproof membrane, insulation, aerated concrete, glued plasterboard sheets, wallpaper. The ceiling between the floors is made of wooden beams, with insulation between them, thickness 200 mm. On the ceiling of the first floor there is a vapor barrier lined with a wooden board. Only the first floor is residential, the second floor is without insulation. The house was built 2 years ago, insulation was done last summer. We started heating in mid-October and moved in in November.

As Evgeny Kuznetsov notes, without a full-time study of the structure, making a “diagnosis” is problematic and incorrect; the appearance of mold is provoked by high humidity, and this phenomenon can have several reasons:

Whatever the reason, it must be eliminated.

Waterproofing the upper part of the strip foundation

To begin with, we check the horizontal level of the foundation with a level; if the horizontal curve is more than 30 mm, we level it with a strong mortar (M200 - M300). If the horizontal level is level, we proceed to waterproofing.

1. We clean and dust the foundation, it must be dry.
2. Next, apply bitumen mastic (for example, TechnoNIKOL) along the perimeter of the tape;
3. We take rolls of special roofing material and, pressing, roll them out onto the tape;
4. The roofing felt overlaps must be at least 150 mm.
5. Next, the first row of aerated concrete is laid on the mortar, but that’s another topic.