The choice of plaster is an age-old question that citizens face when carrying out repairs, but the choice will not be discussed in this article. In our case, preference has already been given to gypsum plaster, but it so happened that the owners wanted to put tiles on such a base. Is it possible or not? Opinions here are diametrically opposite, we will try to understand the problem.

The crux of the dilemma
Gypsum plaster is elastic, does not contain coarse sand grains, like cement-sand, so with its help you can create a coating close to the finish. Such a base is well suited for painting or wallpapering. Plaster has a pleasant White color and dries quickly. At the same time, it is believed that such a coating does not fit under the tiles very well and there are reasons for this:

• High hygroscopicity is a cryptic word that often appears in gypsum-related discussions. Hygroscopicity refers to the ability of a material to absorb water. In a humid environment, gypsum plaster can absorb the smallest particles of water, as a result of which it loses its strength, and pathogenic flora (fungi and mold) can develop inside.

The main reason for the hygroscopicity of gypsum lies in its porous structure.

• Low strength - everyone who has dealt with gypsum knows that the material does not tolerate mechanical damage. For this reason, heavy tiles should be placed on gypsum plaster with great care.

Gypsum plaster does not have a grainy texture, therefore, gives the walls a finished appearance.

• Promotes corrosion - this disadvantage of gypsum does not apply to tiles, but to metal fasteners in general, on which the material has a destructive effect.

If you intend to put a heavy topcoat, then it is recommended to abandon gypsum plaster even at the planning stage. If there is no choice, and the walls are already plastered, then you should use a few tricks to soften the negative features of the gypsum base.

How to prepare gypsum plaster for tiles?
On the question of whether it is possible to glue ceramic tiles on gypsum plaster, you can give a positive answer, but with certain reservations.

Tile adhesive is applied in a thin layer so as not to create unnecessary stress.

• The plaster layer should be twice the thickness of the tile, together with the tile adhesive.
• Do not use tile adhesive to fix irregularities in the plaster. Because of this, the thickness of the glue increases and the weight of the finish coat increases, which is already significant. For leveling, it is best to use gypsum plaster and wait for it to dry. The protrusions on the old surface must be grinded off.

The trowel is used to correct small irregularities.

• The tile should be as light as possible; it is not recommended to use heavy varieties of stone or marble.
• Antiseptic treatment - important stage in the preparation of the room, especially when it comes to a wet room (bathroom, toilet or shower). The compounds are applied to the surface and protect the gypsum from mold growth.

A heat gun will help dry wet rooms.

When working in the bathroom, it is recommended to pre-dry the room. To do this, you can use a heat gun.

Primer - mandatory procedure to strengthen the plaster base.

• The primer partially corrects the disadvantages of gypsum plaster, so this procedure should not be neglected. For this, compositions are suitable deep penetration, which impregnate the base, improve the adhesion of the finished plaster, increase the waterproofing properties of the material, and protect the gypsum from subsequent shedding under the weight of the tile.

For gypsum plaster, use a special primer for surfaces with high hygroscopicity.

• Waterproofing is used not simple, but special, which is designed for laying tiles. Mastic and latex compounds are used as waterproofing. When applying the composition, the manufacturer's recommendations must be followed. Some waterproofing materials are applied in two layers.

Layers of mastic waterproofing can be of different colors to immediately notice unpainted areas

Waterproofing is applied to the abutments of the walls with the floor, and waterproofing tapes are also laid in these places. These tapes are glued at the junctions to pipes and other communications.

• If it was not possible to refuse heavy tiles, then the surface must additionally be covered with a reinforcing mesh. As stated, gypsum is prone to rust and therefore plastic mesh is recommended.

Work progress
Installation of tiles on a plaster base is practically the same as laying tiles on cement-sand plaster.

• Before starting work, marking is done. The approximate location of the tiles can be applied to paper and then to the wall. At this stage, you can install beacons. Do not forget about the presence of seams between the tiles. You can use a plumb line and level to break off even contours and verticals.

Lighthouse markings for tiles.

It is convenient to markup using laser level or beating threads.

• When calculating the height of the tiles, do not leave the halves in contact with the ceiling, this will spoil the appearance of the room.
• It is important when choosing a tile adhesive to choose a composition based on a gypsum binder. The adhesive must have an elastic consistency and provide good adhesion. Avoid using cementitious compounds, as tiles may collapse in the future.

Mixing tile adhesive with a mixer.

• The glue is applied to the wall in a small layer. If you also apply the solution to the tile itself, then the weight of the finish coat will increase, and this is fraught with consequences. To minimize the thickness of the adhesive layer, a notched trowel is used to make the grooves.
• It is not necessary to load the gypsum plaster, therefore, all procedures for sawing or drilling the tiles should be done before fixing on the wall. The tile is mounted on the wall according to the markings. After completing the work, the surface should be washed from the remnants of glue.

Tile adhesive is diluted in containers with the addition of water. It is convenient to use a drill mixer for stirring. After that, you need to give the solution time so that it has time to acquire the desired consistency.

A few words about the bathroom
With all the bold recommendations of manufacturers of various building mixtures, it is better to refrain from using gypsum plaster in bathrooms and other wet rooms. Only the application of gypsum compositions to the ceiling for painting is justified, since such a coating will be lighter than cement plaster, while it will have a smooth, pleasant surface.

Output
Thus, we can conclude that it is possible to lay tiles on gypsum plaster, but only this must be done, observing all the preliminary procedures for preparing the base. Still, the more natural options for the topcoat for gypsum compositions are paint or wallpaper.

The main purpose of plaster mixes is to prepare the base for finishing, that is, in rough leveling and surface hardening. But there are also such plasters that, in addition to the main functions, perform other tasks: they increase heat and sound insulation, protect against harmful radiation, give the base fireproof properties, and so on. They are called special-purpose compounds, and are used taking into account the functional characteristics of these solutions.

Waterproofing plaster

Waterproofing plaster, which is used for finishing surfaces exposed to increased moisture exposure, also belongs to the special ones. First of all, these are foundations, basement floors, basements, outer walls of houses located in damp areas.

Waterproofing plaster on the basement of the house

How does this plaster differ from the usual one, and how should it be applied correctly?

Waterproofing mixtures form a dense hard coating that prevents moisture from penetrating into the thickness of walls or foundations. They are applied manually and by machine, they are used both outside and inside the premises. Depending on the composition of the components, waterproofing plasters are divided into 2 types:

• cement-sand;
• asphalt.

The first type is more common and is widely used in private construction. Cement-sand plaster can be made independently, and the process of their application is almost the same as usual plastering.

Working with cement-sand plaster

To prepare the solution, cement grade M400 and higher is used, and fine quartz sand, stone flour, finely ground coal, bitumen additives are used as a filler. To increase the water resistance, liquid glass, ceresite, sodium aluminate and other water repellents are added to the solution.

The ratio of binder and filler is usually 1: 2, less often 1: 3. For maximum effectiveness, the thickness of the coating should be 25 mm, provided that the plaster is applied from the side of the water pressure. Application is carried out in several layers, minimum thickness- 3 mm. This waterproofing has many advantages:

• high reliability even with prolonged flooding of the foundation and walls of the house;
• resistance to repeated freezing;
• environmental safety - the plaster can be finished inner surfaces drinking water tanks;
• plaster serves as an excellent base for painting and cladding;
• has good adhesion;
• low cost of the solution;
• resistance to mechanical damage.

Applied plaster

In order for the coating to be of high quality and durable, it can be applied only on a carefully prepared base. In addition, the surface must be strong and not prone to shrinkage, otherwise the plaster will be covered with cracks. For work, it is preferable to choose factory mixes with clearly verified proportions of components. They are produced in dry form, and to prepare a solution, it is enough to mix the powder with water in the desired ratio.

Plaster waterproofing

Asphalt plaster used mainly in industrial facilities. Its cost is quite high, and special equipment is required for application, therefore, in private construction, the use of such waterproofing is not always justified. The plaster contains petroleum bitumen, asbestos dust, sand and mineral fillers in the form of powder.

There are two ways to apply asphalt plaster - cold and hot. The cold mortar is applied by hand or by machine and is much easier to work with. The second method involves heating the solution to 180 degrees and applying it using special equipment. In this case, the waterproofing is as reliable and durable as possible.

Popular brands of cement-sand plaster for waterproofing

	The mixture forms a tough waterproof coating with good vapor permeability. Possesses excellent frost resistance (up to 200 cycles), alkaline and salt resistance. Designed for waterproofing external and internal vertical surfaces that are not prone to deformation and shrinkage, not subject to vibration. Used in the decoration of buried structures, water tanks, swimming pools, to fill the voids of old brickwork... Produced in the form of dry powder, packing 5 and 25 kg
Ceresit CR 66 / CR 166	Elastic mixture on a cement-polymer basis. Designed for deformable and shrinkable substrates. Suitable for all gypsum-free mineral surfaces. It is used to protect buried structures, walls and foundations of houses located on the banks of water bodies, decoration of swimming pools and utility tanks. The composition has increased resistance to chemically aggressive substances - alkali, acids, acetone, hydraulic oil and others. Standard packaging contains an emulsion canister (10 l) and a bag of dry plaster mixture (25 kg)
Barralastic	Deep penetration two-component elastic blend. Designed for waterproofing all types of surfaces, including those subject to vibrations and shrinkage deformations. Possesses very high adhesion, after drying it forms an absolutely waterproof coating, but with a vapor permeability. The mortar has good plasticity and can be easily applied with a brush or spatula. Standard kit includes dry mix bag (25 kg) and emulsion canister (5 L)
Penetron	A cement mixture with active additives for waterproofing concrete surfaces. The solution penetrates 40-50 cm into the concrete, completely closing the pores of the material, as a result of which the surface becomes absolutely moisture-proof. The composition is used for finishing foundations and plinths, basements, cellars, wells, swimming pools. When applied to brick or masonry, wood, foam concrete and other materials, the waterproofing effect of the coating is absent. The composition is environmentally friendly, frost-resistant, resistant to alkalis and acids. Packaged in plastic buckets with a capacity of 5, 10, 25 kg
	Penetrating type dry cement mixture for concrete substrates. It is a more budgetary analogue of Penetron, due to which it is in good demand. Apply by brush or spray in two layers. It is resistant to chemically aggressive substances and temperature extremes. Packaged in plastic buckets of 10 and 25 kg

The average consumption of conventional waterproofing plaster is 1.5 kg per m2 in a single layer. The consumption of penetrating compounds is less - about 0.4-0.6 kg / m2. Of course, this indicator directly depends on the quality of the surface, the method of application and the thickness of the layers, therefore, before purchasing the material, everything should be carefully calculated and added in reserve 10-15% of the estimated amount of the mixture.

Ceresit CR 166. Elastic waterproofing compound

Conditions for applying plaster

Waterproofing plaster mortars do not apply to crumbling, loose substrates, coatings containing gypsum, as well as surfaces with efflorescence, traces of bitumen, paint, oil stains. All this reduces adhesion, which means that the plaster will not last long. It is also unacceptable to plaster the bases with cracks, the width of which exceeds 0.5 mm.

Such a wall cannot be plastered without preliminary repair.

To properly prepare the surface, you need to completely remove the layers of paint, old plaster or putty. If the paint is difficult to remove, it is advisable to soften it by heating it with a hairdryer or special chemical washes. After that, it can be easily removed with a spatula. Plaster and putty are cleaned with a metal brush, you can also use a grinder with a nozzle. An excellent result is obtained by sandblasting.

Check the brick for hardness

Use a chisel or chisel, as well as a hammer, to remove old plaster

After removing the old plaster, use a wire brush to get rid of the remaining plaster particles.

The seams of brick and masonry must be cleaned with a metal brush and dedusted. If the masonry is old and the seams are crumbling, they are cleaned out to a solid base and then filled with fresh cement mortar. Cracks must be sewn to a depth of 1-2 cm before sealing and cleaned of dust.

Sealing cracks

Repaired crack

When finishing surfaces with a heterogeneous structure (concrete and brick, brick and stone), the base is pre-plastered with ordinary cement-sand mixture.

As well ordinary plaster, the waterproofing layer needs reinforcement if its thickness exceeds 10 mm. When plastering rough masonry or a surface with numerous defects, when the mortar is applied in a thick layer, a galvanized metal mesh with cells from 10x10 mm to 20x20 mm is used for reinforcement.

Plaster mesh

It is fixed to the base using plastic dowels and self-tapping screws with an attachment pitch of 40-50 cm.

Fastening to masonry using a self-tapping screw with a widened washer

On a flat surface, fiberglass mesh should be used, provided that the layer thickness does not exceed 30 mm.

In the photo - the installation of a reinforcing mesh on the facade of the house

At least 3 months must elapse between the erection of the masonry and its waterproofing. This also applies to concrete foundations. If preliminary leveling is performed with ordinary cement mortar, waterproofing plaster can be applied no earlier than after 28 days. Plastering should be done in dry, windless weather, at a temperature not lower than +5 and not higher than +30 degrees. The optimum air humidity is 60%. Moreover, such conditions must be observed not only during the plastering period, but also within several days after the completion of the work.

Plastering technology

Plastering is carried out manually or by machine. The first option is much more practical, since it does not require equipment and the solution consumption is less. True, it takes more time to work, and the reliability of adhesion to the base is slightly lower. Mechanical method allows you to do everything much faster and without much physical effort, moreover, with this application, the solution adheres very tightly to the surface, and the coating acquires high strength. The disadvantages include the high consumption of the working mixture and the need for a special installation.

Advantages of machine plastering

Manual application method

To work you will need:

• kneading container;
• construction mixer;
• metal spatula;
• paint brush with semi-hard bristles;
• pure water.

Plaster tools

Step 1. The prepared surface is slightly moistened with water using a wide brush. The base must be wet, but not wet, especially since there are no puddles on horizontal surfaces.

You can wet the surface with a brush, dipping it in water and splashing it on the wall

Step 2. Pure water at room temperature is poured into the container, the dry mixture is poured and stirred with a mixer at a speed of 400-800 rpm for 3 minutes. The proportions of water and dry mix are indicated on the package. If this is a two-component composition, first the emulsion is poured into the container, water is added (if indicated in the instructions), stir and only then the dry components are added. For the first layer, the solution is made more liquid: on average, 1 part of water is taken for 2.5 parts of the dry mixture. After mixing, leave the solution for 5 minutes to ripen, then mix again with a mixer.

Mixing solution

Solution consistency

Step 3. The first layer is applied with a brush, performing movements in one direction. The solution is collected a little, carefully rubbed over the surface, paying special attention to the joints. Make sure that the layer remains uniform over the entire area, avoid sagging and sagging. It is not recommended to return to the already treated areas in order to touch up something, this violates the integrity of the layer and reduces the adhesion of the material to the base.

Applying waterproofing plaster

Step 4. After completing the application of the plaster, you must wait until it begins to harden. After that, the next portion of the solution is prepared, but this time less water is added: about 1 part of water to 3 parts of the dry mixture.

Step 5. For the second coat, it is better to use a spatula. Collect the solution in small portions and evenly distribute it over the base with a thin layer from bottom to top, holding the spatula at an angle to the surface. Movements with a spatula must be performed in a direction perpendicular to the direction of the hand. That is, if you applied the first layer with vertical movements, then the second should be applied horizontally. If a third layer is required, this rule must also be followed.

Applying plaster on the wall

Step 6. The plastered surface must be protected from drying out, mechanical stress, direct sunlight. If the weather is too warm, the plaster should be periodically moistened with water using a spray bottle. After 7 days, when the coating gets stronger enough, the plaster is trowelled. To do this, make a liquid solution, throw it in a thin layer on the surface and smooth it in a circular motion using a polyurethane or metal float.

Plastering technology

Grouting the walls after plastering

It is impossible to rub the coating immediately after plastering, since this violates its density and adhesion to the base. You can continue finishing work in 3-7 days, depending on the composition of the plaster. For example, a Barralastic coating can be tiled already 20 hours after the last layer is applied, for Ceresit CR 65 it takes 3 days, for Penetron - from 7 to 14 days.

Mechanical application

Mechanical application, or gunning, is carried out using a special installation with a compressor and a nozzle. Smooth concrete base before gunning, they are treated with a sandblasting machine or small notches are made manually over the entire area.

Sandblasting

On the grounds with rough uneven surface pre-fix the reinforcing mesh made of galvanized metal.

Methods for installing reinforcing meshes

Step 1. The work surface is slightly moistened.

Moisten the wall

Water is poured into the tank of the installation and the dry mixture is poured in the proportions indicated by the manufacturer. Set the pressure in the range of 0.25 ... 0.3, MPa, check the supply of the solution in a separate section of the wall. If the mixture starts to float, slide down, it means that there is an excess of water in the solution, and dry components should be added, but if dry spots form on the plaster layer, you need to add water.

Step 2. For uniform application of the solution, the nozzle is held perpendicular to the wall at a distance of 80-100 cm from the surface, slowly moving it in a circular motion. The thickness of one layer should be between 7-10 mm. After completing the work, the plaster is covered plastic wrap to protect it from drying out.

Machine plastering

Aligning the first layer

Advice. If a forced break is required in the work, the edge of the plaster in the already treated area is cut off at an angle of 45 degrees and scratched with a metal brush over the fresh mortar. After the resumption of the working process, the cut site must be abundantly moistened with water.

Step 3. The next layer is applied one day after the first, the same interval is maintained before applying the third layer. The total thickness of the coating must not exceed 50 mm.

Application and leveling of the second layer

Step 4. After the plaster has hardened, a slurry is prepared, manually applied to the coating and trowelled with a metal or polyurethane float. Next, cover the surface with polyethylene or periodically moisten it with water to avoid cracking.

For 7 days, the plaster must be protected from freezing, direct sunlight, mechanical stress. If everything is done correctly, after drying, the coating has an even color, a smooth hard surface, when tapped with a wooden hammer, it emits ringing sounds.

Video - Plasterer Robot PlasteRUS SPERO

Video - Waterproofing plaster

There is a concrete basement (with windows, semi-basement). Where the wall touches the ground, white spots appear (like frost, apparently fungus or efflorescence), and dark spots(moisture). We carried out a metal sweep. with a brush and smeared with Pufas anti-mildew solution.
The walls are all uneven, the wave of the sea, then they are 3 cm forward, then they go inward by 3 cm. This is how our smaller brothers made plaster!
Now you need to do the waterproofing and alignment of the walls under the tiles.
Advise how to compensate for such differences. Someone advises Rotbant (but gypsum, but here it is wet), some with a cement-sand mixture, and some with plasterboard (which will reduce the area).
And what is better - first waterproofing or first the final plaster, and then waterproofing.
Who has waterproofing experience? About three years ago, we carried out waterproofing with a mixture of GIDROTEKS, the effect is absent and its layer is gradually falling off.

Bathroom without reliable waterproofing can be safely considered the most expensive area of ​​the apartment: very often you have to do redecorating, any rush of the water supply system also leads to payment for the repair of the apartment from the neighbors below. These costs can be minimized only if the walls and floor of the bathroom are waterproofed. For specialists, such an operation is not difficult. But it is also not difficult to do this on your own, you just need to be patient and have the necessary materials.

Tools and materials

Before waterproofing, you need to acquire the following materials and tools:

• waterproofing material (bitumen, bitumen-polymer or cement-polymer composition);
• construction hair dryer;
• reinforcing mesh;
• plaster;
• Decoration Materials;
• silicone;
• putty knife;
• building level.

The scheme of waterproofing the walls in the bathroom.

To begin waterproofing the bathroom, ensure good ventilation in order to avoid the influence of excess moisture on the surface in the future. A built-in hood or direct access to the ventilation well of the building will completely provide a good microclimate in the bathroom and protect the room from fungal aggression. Direct waterproofing in the bathroom should be done from top to bottom.

The main purpose of plaster mixes is to prepare the base for finishing, that is, in rough leveling and surface hardening. But there are also such plasters that, in addition to the main functions, perform other tasks: they increase heat and sound insulation, protect against harmful radiation, give the base fireproof properties, and so on. They are called special-purpose compounds, and are used taking into account the functional characteristics of these solutions.

Waterproofing plaster, which is used for finishing surfaces exposed to increased moisture exposure, also belongs to the special ones. First of all, these are foundations, basements, basements, outer walls of houses located in damp areas.

How does this plaster differ from the usual one, and how should it be applied correctly?

Waterproofing mixtures form a dense hard coating that prevents moisture from penetrating into the thickness of walls or foundations. They are applied manually and by machine, they are used both outside and inside the premises. Depending on the composition of the components, waterproofing plasters are divided into 2 types:

• cement-sand;
• asphalt.

The first type is more common and is widely used in private construction. Cement-sand plaster can be made independently, and the process of their application is almost the same as usual plastering.

To prepare the solution, cement grade M400 and higher is used, and fine quartz sand, stone flour, finely ground coal, bitumen additives are used as a filler. To increase the water resistance, liquid glass, ceresite, sodium aluminate and other water repellents are added to the solution.

The ratio of binder and filler is usually 1: 2, less often 1: 3. For maximum effectiveness, the thickness of the coating should be 25 mm, provided that the plaster is applied from the side of the water pressure. Application is carried out in several layers, the minimum thickness is 3 mm. This waterproofing has many advantages:

• high reliability even with prolonged flooding of the foundation and walls of the house;
• resistance to repeated freezing;
• environmental safety - the plaster can be used to finish the inner surfaces of drinking water tanks;
• plaster serves as an excellent base for painting and cladding;
• has good adhesion;
• low cost of the solution;
• resistance to mechanical damage.

In order for the coating to be of high quality and durable, it can be applied only on a carefully prepared base. In addition, the surface must be strong and not prone to shrinkage, otherwise the plaster will be covered with cracks. For work, it is preferable to choose factory mixes with clearly verified proportions of components. They are produced in dry form, and to prepare a solution, it is enough to mix the powder with water in the desired ratio.

Asphalt plaster used mainly in industrial facilities. Its cost is quite high, and special equipment is required for application, therefore, in private construction, the use of such waterproofing is not always justified. The plaster contains petroleum bitumen, asbestos dust, sand and mineral fillers in the form of powder.

There are two ways to apply asphalt plaster - cold and hot. The cold mortar is applied by hand or by machine and is much easier to work with. The second method involves heating the solution to 180 degrees and applying it using special equipment. In this case, the waterproofing is as reliable and durable as possible.

Popular brands of cement-sand plaster for waterproofing

Name	Brief characteristics
	The mixture forms a tough waterproof coating with good vapor permeability. Possesses excellent frost resistance (up to 200 cycles), alkaline and salt resistance. Designed for waterproofing external and internal vertical surfaces that are not prone to deformation and shrinkage, not subject to vibration. It is used in the decoration of buried structures, water tanks, swimming pools, to fill the voids of old brickwork. Produced in the form of dry powder, packing 5 and 25 kg
	Elastic mixture on a cement-polymer basis. Designed for deformable and shrinkable substrates. Suitable for all gypsum-free mineral surfaces. It is used to protect buried structures, walls and foundations of houses located on the banks of water bodies, decoration of swimming pools and utility tanks. The composition has increased resistance to chemically aggressive substances - alkali, acids, acetone, hydraulic oil and others. Standard packaging contains an emulsion canister (10 l) and a bag of dry plaster mixture (25 kg)
	Deep penetration two-component elastic blend. Designed for waterproofing all types of surfaces, including those subject to vibrations and shrinkage deformations. Possesses very high adhesion, after drying it forms an absolutely waterproof coating, but with a vapor permeability. The mortar has good plasticity and can be easily applied with a brush or spatula. Standard kit includes dry mix bag (25 kg) and emulsion canister (5 L)
	A cement mixture with active additives for waterproofing concrete surfaces. The solution penetrates 40-50 cm into the concrete, completely closing the pores of the material, as a result of which the surface becomes absolutely moisture-proof. The composition is used for finishing foundations and plinths, basements, cellars, wells, swimming pools. When applied to brick or masonry, wood, foam concrete and other materials, the waterproofing effect of the coating is absent. The composition is environmentally friendly, frost-resistant, resistant to alkalis and acids. Packaged in plastic buckets with a capacity of 5, 10, 25 kg
	Penetrating type dry cement mixture for concrete substrates. It is a more budgetary analogue of Penetron, due to which it is in good demand. Apply by brush or spray in two layers. It is resistant to chemically aggressive substances and temperature extremes. Packaged in plastic buckets of 10 and 25 kg

The average consumption of conventional waterproofing plaster is 1.5 kg per m2 in a single layer. The consumption of penetrating compounds is less - about 0.4-0.6 kg / m2. Of course, this indicator directly depends on the quality of the surface, the method of application and the thickness of the layers, therefore, before purchasing the material, everything should be carefully calculated and added in reserve 10-15% of the estimated amount of the mixture.

Prices for waterproofing plasters

Waterproofing plasters

Conditions for applying plaster

Waterproofing plaster mortars must not be applied to crumbling, loose substrates, coatings containing gypsum, as well as surfaces with efflorescence, traces of bitumen, paint, oil stains. All this reduces adhesion, which means that the plaster will not last long. It is also unacceptable to plaster the bases with cracks, the width of which exceeds 0.5 mm.

Such a wall cannot be plastered without preliminary repair.

To properly prepare the surface, you need to completely remove layers of paint, old plaster or putty. If the paint is difficult to remove, it is advisable to soften it by heating it with a hairdryer or special chemical washes. After that, it can be easily removed with a spatula. Plaster and putty are cleaned with a metal brush, you can also use a grinder with a nozzle. An excellent result is obtained by sandblasting.

The seams of brick and masonry must be cleaned with a metal brush and dedusted. If the masonry is old and the seams are crumbling, they are cleaned out to a solid base and then filled with fresh cement mortar. Cracks must be sewn to a depth of 1-2 cm before sealing and cleaned of dust.

When finishing surfaces with a heterogeneous structure (concrete and brick, brick and stone), the base is preliminarily plastered with a conventional cement-sand mixture.

Like ordinary plaster, the waterproofing layer needs to be reinforced if its thickness exceeds 10 mm. When plastering rough masonry or a surface with numerous defects, when the mortar is applied in a thick layer, a galvanized metal mesh with cells from 10x10 mm to 20x20 mm is used for reinforcement.

It is fixed to the base using plastic dowels and self-tapping screws with an attachment pitch of 40-50 cm.

It should be used on a flat surface, provided that the layer thickness does not exceed 30 mm.

At least 3 months must elapse between the erection of the masonry and its waterproofing. This also applies to concrete foundations. If preliminary leveling is performed with ordinary cement mortar, waterproofing plaster can be applied no earlier than after 28 days. Plastering should be done in dry, windless weather, at a temperature not lower than +5 and not higher than +30 degrees. The optimum air humidity is 60%. Moreover, such conditions must be observed not only during the plastering period, but also within several days after the completion of the work.

Prices for plaster nets

Plaster nets

Plastering is carried out manually or by machine. The first option is much more practical, since it does not require equipment and the solution consumption is less. True, it takes more time to work, and the reliability of adhesion to the base is slightly lower. The mechanical method allows you to do everything much faster and without great physical effort, moreover, with this application, the solution adheres very tightly to the surface, and the coating acquires high strength. The disadvantages include the high consumption of the working mixture and the need for a special installation.

Manual application method

To work you will need:

• kneading container;
• construction mixer;
• metal spatula;
• paint brush with semi-hard bristles;
• pure water.

Step 1. The prepared surface is slightly moistened with water using a wide brush. The base must be wet, but not wet, especially since there are no puddles on horizontal surfaces.

Step 2. Pure water at room temperature is poured into the container, the dry mixture is poured and stirred with a mixer at a speed of 400-800 rpm for 3 minutes. The proportions of water and dry mix are indicated on the package. If this is a two-component composition, first the emulsion is poured into the container, water is added (if indicated in the instructions), stir and only then the dry components are added. For the first layer, the solution is made more liquid: on average, 1 part of water is taken for 2.5 parts of the dry mixture. After mixing, leave the solution for 5 minutes to ripen, then mix again with a mixer.

Construction mixer price

Construction mixer

Step 3. The first layer is applied with a brush, performing movements in one direction. The solution is collected a little, carefully rubbed over the surface, paying special attention to the joints. Make sure that the layer remains uniform over the entire area, avoid sagging and sagging. It is not recommended to return to the already treated areas in order to touch up something, this violates the integrity of the layer and reduces the adhesion of the material to the base.

Step 4. After completing the application of the plaster, you must wait until it begins to harden. After that, the next portion of the solution is prepared, but this time less water is added: about 1 part of water to 3 parts of the dry mixture.

Step 5. For the second coat, it is better to use a spatula. Collect the solution in small portions and evenly distribute it over the base with a thin layer from bottom to top, holding the spatula at an angle to the surface. Movements with a spatula must be performed in a direction perpendicular to the direction of the hand. That is, if you applied the first layer with vertical movements, then the second should be applied horizontally. If a third layer is required, this rule must also be followed.

Step 6. The plastered surface must be protected from drying out, mechanical stress, direct sunlight. If the weather is too warm, the plaster should be periodically moistened with water using a spray bottle. After 7 days, when the coating gets stronger enough, the plaster is trowelled. To do this, make a liquid solution, throw it in a thin layer on the surface and smooth it in a circular motion using a polyurethane or metal float.

It is impossible to rub the coating immediately after plastering, since this violates its density and adhesion to the base. You can continue finishing work in 3-7 days, depending on the composition of the plaster. For example, a Barralastic coating can be tiled already 20 hours after the last layer is applied, for Ceresit CR 65 it takes 3 days, for Penetron - from 7 to 14 days.

Mechanical application

Mechanical application, or gunning, is carried out using a special installation with a compressor and a nozzle. Before gunning, a smooth concrete base is treated with a sandblaster or small incisions are made manually over the entire area.

On bases with a rough uneven surface, a reinforcing mesh made of galvanized metal is preliminarily fixed.

Step 1. The work surface is slightly moistened.

Water is poured into the tank of the installation and the dry mixture is poured in the proportions indicated by the manufacturer. Set the pressure in the range of 0.25 ... 0.3, MPa, check the supply of the solution in a separate section of the wall. If the mixture starts to float, slide down, it means that there is an excess of water in the solution, and dry components should be added, but if dry spots form on the plaster layer, you need to add water.

Step 2. For uniform application of the solution, the nozzle is held perpendicular to the wall at a distance of 80-100 cm from the surface, slowly moving it in a circular motion. The thickness of one layer should be between 7-10 mm. After completing the work, the plaster is covered with plastic wrap to protect it from drying out.

Advice. If a forced break is required in the work, the edge of the plaster in the already treated area is cut off at an angle of 45 degrees and scratched with a metal brush over the fresh mortar. After the resumption of the working process, the cut site must be abundantly moistened with water.

Step 3. The next layer is applied one day after the first, the same interval is maintained before applying the third layer. The total thickness of the coating must not exceed 50 mm.

Step 4. After the plaster has hardened, a slurry is prepared, manually applied to the coating and trowelled with a metal or polyurethane float. Next, cover the surface with polyethylene or periodically moisten it with water to avoid cracking.

For 7 days, the plaster must be protected from freezing, direct sunlight, mechanical stress. If everything is done correctly, after drying, the coating has an even color, a smooth hard surface, when tapped with a wooden mallet, it emits sonorous sounds.

Video - Plasterer Robot PlasteRUS SPERO

Video - Waterproofing plaster

Protection of buildings and structures from moisture is one of the important tasks in construction. There are risk areas in every building that require close attention.

In private houses, such places include a foundation, a roof, a basement.

Sometimes a heater is protected from moisture, then waterproofing and thermal insulation are considered as a single complex.

Waterproofing works

Waterproofing works, as necessary technological actions, are included in the project. The designers prescribe a method of waterproofing and necessary materials... The developers adapt the project to the real site, and, if necessary, make adjustments, taking into account the composition of the soil.

When creating a project for a house, it is assumed that it will stand on a perfectly dry area. This rarely happens. The best position is for the developer whose house will be located on a sandy or rocky area. Atmospheric moisture seeping through the soil causes minimal damage to the foundation of the building. Such a house will need light waterproofing.

If the developer is unlucky and the construction has to take place on heavy loamy soils that retain water for a long time, he needs to take care of "heavy" insulation.

It is also necessary to assess the level of occurrence of groundwater. If water is found below the basement floor of the building, then a "light" waterproofing is used. The occurrence of groundwater above the lower roof of the house - then "heavy" waterproofing with the installation of drainage systems should be used. If such drainage is not provided for in the project, then it is imperative to make the necessary changes.

Determining the type of waterproofing

The parts of the house that are underground are most susceptible to moisture contact. Unprotected areas of structures, due to the porous structure of concrete, draw in water like a sponge. This phenomenon is called capillary suction. Rising up, water reacts with the metal of the reinforcement and destroys it. As a result, the foundation loses strength and sags. The house is losing stability. Cracks, moisture on the walls, mold, fungus appear.

Water in the house is no less dangerous. Leaking pipes and cranes destroy the building almost as much as external moisture.

An excellent dry roof is the key to a warm, dry home. If the roofing work was not done according to the rules, or the roof needs repair for its service life, moisture that gets inside the house can destroy it very quickly.

Modern systems and methods of waterproofing make it possible to build and operate houses where it was completely impossible a few decades ago, since the old methods of waterproofing (roofing felt and plaster) could not insulate buildings well enough.

Waterproofing is distinguished:

• internal;
• external;
• vertical;
• horizontal;
• easy;
• medium;
• heavy;
• coating;
• painting;
• plastering;
• penetrating;
• injection;
• pasting;
• sprayed;
• primary;
• secondary;
• anti-pressure (pressure);
• non-pressure;
• capillary;
• sealing;
• complex.

The type of waterproofing depends on the structure of the surface to be protected, the aggression of the external environment, the factors from which additional protection must be carried out:

• Internal waterproofing involves work inside the premises. Very often this is plastering. But this is often not enough. Let's say they have done the work, plaster the basement, insulate all the cracks with putty. Dry. But outside the house, groundwater destroys the foundation and walls of the building through capillary suction. Obviously, carrying out only internal waterproofing is not entirely the right decision.
• External insulation is moisture insulation external surfaces walls and foundations of the house, sometimes flat roofs.
• Vertical insulation is plastering, coating, painting, spraying, pasting, reinforcement, penetrating waterproofing.
• Horizontal - as a rule, the same, but horizontal surfaces are already protected. Very often films and membranes are used for such insulation, which cannot be used on vertical surfaces.
• Technologically, when using all types of insulation, they strive to give structures the ability to repel water, only the ways of creating such a property differ.
• Coating and plastering waterproofing fundamentally use a similar principle of operation.
• Lubricating waterproofing is a coating of the surface in several layers with single or multicomponent materials. It is applied on brick, concrete, cement structures. It is used for external waterproofing - walls, roofs, foundations from moisture and groundwater. Internal waterproofing - basement walls, bathroom or kitchen floor. Also works as an insulating technology for joints and crevices.
• Mineral masses are applied to concrete or cement, brick walls. Hot or cold plaster can be used.
• One-component lubricants include bitumens, mastics, and sealants. For multicomponent - polyurethane mastics.
• Plastering is the covering of walls made of brick, cement, concrete or wood with a layer of mineral mass. Plastering simultaneously performs several functions - waterproofing, thermal insulation, decorative.

It is carried out with mixtures prepared directly at the construction site from dry powders and water in the required amount.

Types and compositions of waterproofing plasters

Waterproofing plaster

Waterproofing plasters are prepared from a mixture of sand and cement with an additive in the form of water glass, ceresin, and various plasticizers.

Liquid glass with a density of 1.40 g / cm3 is dissolved in 10 liters of water. This solution is poured into a mixture of Portland cement and sand in a ratio of one to three. Waterproofing plaster based on this base is acid resistant.

Solutions based on ceresite, aluminate, are mixed with 400 grade Portland cement and 3 parts of sand. The added plasticizers make it easier to coat the surfaces with mass.

Very good hydrophobic properties are possessed by a plaster based on waterproof cement in a composition of one to three with sand. Additives are not given here. Such plaster waterproofing is used to cover the walls of swimming pools, airlock chambers, dock rooms, basements, tunnels, which are attacked by soil water in case of "heavy" waterproofing.

A group of hydrophobic plaster mixes should be noted separately. Hydrophobization is when a surface is given the property of repelling water, not drawing it in and not being covered by it.

To give the plaster water-repellent properties, when dissolving Portland cement of standard 101780, compositions based on silicon and sodium silicones are introduced into its composition and then the plaster is treated with solutions of these agents:

• Additives make up 1.5% of the cement mass.
• After plastering on day 7, the surface is additionally treated.
• Water-repellent impregnation is applied either by hand or by spray.

Spraying requires polyethylene parts to avoid reaction with the solution. The solution is applied in two layers to visually reveal the gloss of the surface. The effect appears after 2-3 days. Waterproofing impregnation does not change color, texture, or type of surface. After three days, a control wetting is done - when sprinkled with water, it should roll down in drops and the material should not be moistened.

Plaster waterproofing is used on facades and buildings, inside buildings. The coating can withstand a water pressure of 7 MP. Withstands temperature differences from -45 to 70 degrees Celsius.

Modern waterproofing plasters are safe, do not emit harmful substances after hardening.

The procedure for plastering work

The work surface must be free of dirt, loose parts of old coatings, paint, bitumen or oil stains, obvious dirt. There should be no obstacles against adhesion of the plaster mixture to the surface.

Work should be carried out in dry air, at a temperature of at least 5 degrees Celsius. There should be no cracks, cracks or grooves more than 3 cm on the surface. They must be embroidered and repaired. Reinforcing mesh is pre-installed on concrete and stone walls and a special penetrating primer is applied.

The plaster mix is ​​prepared on site from the mix and water at the rate of 6 liters of water per 25 kg of the mix. Plastering is carried out by hand traditionally in layers of at least 2 or 3. Each layer should not exceed 2 cm. Drying of the layer before recoating is 24 hours. If the work is carried out in hot weather, the plaster layer is wetted with water. When working outdoors, it is necessary to protect the fresh layer from rain for the first two days after application.

After 20-30 days, signs of water repellency will appear completely.

It should also be noted that decorative acrylic and silicate plasters have signs of water repellency.

The most important thing before starting work is to choose the right type of waterproofing plaster that you need, and then the plastered surface will serve you for many years.