Gypsum plaster for tiles - myth or reality? Plaster waterproofing Is it possible to apply penetrating waterproofing to plaster.

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 call them compositions special purpose, 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 is used as a filler quartz sand, stone flour, finely ground coal, bituminous additives. 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 the greatest efficiency the thickness of the coating should be 25 mm, provided that the plaster is applied from the water side. 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 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

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 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 processing sandblasting machine.

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 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.

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 carried out with ordinary cement mortar, it is possible to apply waterproofing plaster not 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. Optimum humidity air - 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 high consumption 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. Poured into the container clean water room temperature, add a dry mixture and stir 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, giving Special attention 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 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. Continue Finishing work possible in 3-7 days, depending on the composition of the plaster. For example, a Barralastic coating can be tiled within 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.

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

Step 1. Work surface slightly moisturize.

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.

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 done correctly, the coating after drying has an even color, smooth hard surface, when tapped wooden hammer makes ringing sounds.

Video - Plasterer Robot PlasteRUS SPERO

Video - Waterproofing plaster

15.05.2008, 21:45

There is concrete ground floor(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.

21.05.2008, 16:32

It is best to do waterproofing outside the house. Dig up, grease, dry, cover with extruded polystyrene foam and bury. And it will be warm and dry in the basement. : D

21.05.2008, 19:33

Agree. The problem is that waterproofing was done on the outside with HYDROTEX, but the result was zero. In addition, a blind area was made around the house, quite wide, up to 3 m. In this case, it will have to be destroyed.
So far, they started to make waterproofing inside with a two-component component GIDROLAST. Then we put the beacons under the plaster, and after plastering, we will once again coat it with waterproofing, just in case.
I am worried about the question: the layer of plaster will in places reach 5-7 cm. Will it fall off over time? It's on the walls.
There's a special song about the ceiling. There, too, drops of up to 5 cm. To keep everything and not fall on your head, we decided to do this: beacons, cement plaster, mesh, Fügenfüler, Vetonit VH putty.
Can any of the plasterers advise: is this the right decision?

AnatolyK

22.05.2008, 16:08

the best waterproofing is rolled - you have already seen the effectiveness of the tacks, now it's the turn for the fins. On thick plaster: it is advisable to apply on a reinforcing mesh screwed to the wall, even if it exfoliates in some place, it will stick to the mesh. Look in stores for a hardening accelerator for concrete - it will work faster with it because you have to wait for the setting of the previous layer. A perforated mesh will also go to the walls, and welded mesh to the ceiling is better - it will be more reliable
---- first the grid and then the rest.

23.05.2008, 11:34

And what can be the thickness of the plaster layer (not total, but layer-by-layer)? I must have several layers by 5 cm and each must set before applying the next one?
They also recommended strengthening soil before plastering the ceiling.

AnatolyK

23.05.2008, 22:37

the thickness of the layer depends more on the skill of the plasterer - by eye it will determine what will once again throw the solution and the entire layer will slide. it looks like this: throw a solution of medium density with a ladle on the entire wall - it will turn out uneven surface, on the lighthouses, remove the excess solution in thin places and wait for the setting. 5cm - 3-4 times, roughly a layer in the morning, the second in the evening, the third for grouting.

Strengthening primer before plastering the ceiling.
V the latest technologies and I'm not very good at materials: D (Soviet hardening), therefore, on the forum I try to pick up something useful from modern materials (it's better to learn from other people's mistakes), if this is another impregnation, then write the name - who can use it.

23.05.2008, 23:00

Clearly, now there is little left - to find plasterers. The brigades living in St. Petersburg are looking for large volumes, and I have 60 meters of plaster and 150 meters of screeds. Do not lure anyone to the object!

AnatolyK

24.05.2008, 12:45

the volume pulls only on " renovation work"You need to look for such people. For those who are building the" main bread ", of course, a small object is certainly not profitable.

24.05.2008, 19:10

Yes, it's a shame you're far from Peter.

28.05.2008, 22:13

I brought a plasterer to my facility. At the base, it was advised to take plaster for ceilings in a wet room cement mix KNAUF-UNTERPUTS, which is also used for building facades. Have taken. Today the plasterer is calling almost crying, saying that he sprayed four bags and everything fell to the floor! It turns out that the base was not warned that one more VP 332 mixture of the same Knauf had to be applied before UNTERPUT! We have lost more than 2000 rubles on this experience.
It seems we need to stop at gypsum ROTBANT, which at first they didn’t want to do because of the humidity in the room. Everyone seems to be praising this mixture.

AnatolyK

28.05.2008, 22:41

and everything fell to the floor. He immediately collected it and again on the ceiling with a thinner layer. Gypsum can be made more or less moisture resistant, but in our country where all the mixtures are prepared in one concrete mixer: cry :, and supertechnology 2e cannot be bought until 1e. : D

28.05.2008, 22:46

But in general, the ceiling on concrete can be plastered in the old fashioned way: cement, sand, gartsovka, for example?

AnatolyK

29.05.2008, 12:34

So I wrote about the "Soviet hardening", i.e. You compose yourself what you need for a given place, using additives, which you know, or which you will find. Buying ready-made dry mixes just comes out more expensive and you have to overpay only for the promoted name. That is why I mentioned the hardening accelerator: cement-sand 1-3 (4) and the addition of% to cement (a bit of plasticizer). Gartsovka is the simplest lime-sand mortar used since ancient times for internal plastering of walls and ceilings, for masonry. But before the lime was kept in the pit for three years, so the quality was different. For the basement, add cement, or ask for a ready-to-use quick-setting for wet rooms.
If the hard worker did not find where to use the solution, then take off his last pants, shame on the jungle.

29.05.2008, 15:33

I called the KNAUF company today (manufacturer cement plaster UNTERPUTS). I say, so they say and so, your product falls from the ceiling and does not dry for a day. They thought for a long time, then they passed a verdict: that my room is poorly ventilated and therefore the solution does not dry, and the second, that we used the soil not of their production, but of PLITONIT.
We decided to try ROTBANT on the ceilings (although the KNAUFT technologists dissuade, they say, it will only stand for a year in a damp room), and on the walls, cement-sand and a plasticizer. Let's see what happens.

02.06.2008, 22:20

Here she came from the village. In general, on the walls it turned out fine. Ceilings have not been done yet.
We decided to use a racer. We make the solution like this: 1 hour cement + 2 hours. prancing + 2 hours of sand. I refused from the plasticizer, because. it is for faster drying of the solution, and the solution is stronger when it dries for a long time. Even moistening seems to be necessary.
Here is the question: in the next room to prepare previously plastered (smooth) walls for additional plastering (the walls themselves were plastered three years ago, but not leveled), what should be done?
1. Is it necessary to cover with a primer? And which one is better?
2. Put a thin metal plate. mesh? Will there be air cushions under it?
3. Make notches?

AnatolyK

02.06.2008, 22:55

previously plastered (smooth) walls, depending on how much you need to align:?:, maybe just putty will be enough. If you need a layer of plaster, then a notch with a grinder centimes every 5-10 with a rhombus.
For those familiar with this chemistry, we do not use a primer - for me, the primer is the first layer of the solution: oops:

02.06.2008, 22:58

It is necessary to align in places up to 7 cm. Horror, of course, but you need it under the tiles. And if you put a grid, maybe the notches are not needed then?
My plasterer doesn't want to work with a grinder.

AnatolyK

03.06.2008, 07:25

Not a very smooth wall - 7cm brick thickness per edge. it is imperative to make some notch, in it the solution "as if with your fingers" holds, the mesh is of course also stronger. The wall is simply leveled under the tiles.

03.06.2008, 13:11

Yes, in some places you will have to put a brick on the corners.
Worse, there are still places where the old plaster crumbles. They will beat it off, of course, but they may not notice something and cover it on a weak basis with a new one ...

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. Bedding 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 roofing not made 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, aggression external environment, factors from which you need to additionally carry out protection:

• 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, holding only internal waterproofing not quite the right decision.
• External insulation is the isolation from moisture of the external surfaces of the walls and foundations of the house, sometimes flat roofs.
• Vertical insulation is plastering, coating, painting, spraying, pasting, reinforcement, penetrating waterproofing.
• Horizontal - usually the same, but already defending horizontal surfaces... 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 plasters are prepared from a mixture of sand and cement with an additive in the form liquid glass, ceresin, 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 the grip plaster mix with a 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.