What is applied first - waterproofing or plastering the walls. Gypsum plaster under tiles - myth or reality? Characteristics and properties of waterproofing plaster

15.05.2008, 21:45

There is a concrete ground floor (with windows, semi-basement). Where the wall comes into contact with the ground, white spots appear (like frost, apparently fungus or efflorescence), and dark spots (moisture). We cleaned the metal. brush and coat with Pufas anti-mold solution.
The walls are all uneven, the sea waves sometimes move forward 3 cm, sometimes they go inward 3 cm. This is how our little brothers made plaster for us!
Now you need to waterproof and level the walls for the tiles.
Please advise how to level out such differences. Who recommends Rotbant (but plaster, and it’s humid here), who cement-sand mixture, and who will use plasterboard (which will reduce the area).
And which is better - first waterproofing or first final plaster, and then waterproofing.
Does anyone have experience with waterproofing? Three years ago we waterproofed it with a mixture of HYDROTEX, there was no effect and the layer gradually fell off.

21.05.2008, 16:32

It is best to waterproof the outside of the house. Dig it up, coat it, dry it, cover it with extruded polystyrene foam and bury it. It will be warm and dry in the basement. :D

21.05.2008, 19:33

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

AnatolyK

22.05.2008, 16:08

The best waterproofing is rolled - you have already seen the effectiveness of tacks, now it’s the turn of the fin. For thick plaster: it is advisable to apply it to a reinforcing mesh screwed to the wall, even if it peels off in some place, it will stick to the mesh. Look in stores for a hardening accelerator for concrete; it will work faster because you have to wait for the previous layer to set. Expanded mesh will also work on the walls, but welded mesh is better for the ceiling - it will be more reliable
---- first the grid then the rest.

23.05.2008, 11:34

What can be the thickness of the plaster layer (not overall, but layer by layer)? I guess I should have several layers per 5 cm and each one should set before applying the next one?
They also recommended that I use a strengthening primer before plastering the ceiling.

AnatolyK

23.05.2008, 22:37

The thickness of the layer depends more on the skill of the plasterer - it will be determined by eye that he will throw the mortar again and the entire layer will slide off. it roughly looks like this: throw a medium-thick mortar over the entire wall with a ladle - you get an uneven surface, remove the excess mortar in thin places along the beacons and wait for it to set. 5cm - 3-4 times, approximately a layer in the morning, a second in the evening, a third for grouting.

Strengthening primer before plastering the ceiling.
IN the latest technologies and I’m not very good with materials: D (Soviet training), so 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 just another impregnation, then write the name - maybe someone has used it.

23.05.2008, 23:00

It’s clear, now all that’s left is to find plasterers. The teams living in St. Petersburg are looking for large volumes, but I have 60 meters of plaster and 150 meters of screeds. I can’t lure anyone to the site!

AnatolyK

24.05.2008, 12:45

the volume only reaches " renovation work“We need to look for people like this. For those whose main bread is construction, a small project is of course not profitable. As a part-time job, just give me something like this, the smaller the volume, the higher the cost per sq.m.

24.05.2008, 19:10

Yes, it’s a pity that you are far from St. Petersburg.

28.05.2008, 22:13

I brought a plasterer to my site. At the base, they advised us to use KNAUF-UNTERPUTS plaster cement mixture for ceilings in damp rooms, which is also used for building facades. Have taken. Today the plasterer calls and is almost crying, saying he sprayed four bags and everything fell on the floor! It turns out that the base did not warn that before UNTERPUTTS it is necessary to apply another mixture of VP 332 of the same KNAUF! We lost more than 2,000 rubles from this experience.
It seems that we should settle on gypsum ROTBANT, which at first they did not want to do because of the humidity of 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 put it back on the ceiling in 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 super technology 2e is not possible until you buy 1e. :D

28.05.2008, 22:46

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

AnatolyK

29.05.2008, 12:34

So I wrote about “Soviet hardening”, i.e. you yourself compose what you need for a given place, using additives - which you know, or which you find. Buying ready-made dry mixtures simply turns out to be more expensive and you have to overpay only for the promoted name. That’s why I mentioned the hardening accelerator: cement-sand 1-3 (4) and the addition of a bit of plasticizer to the cement. Gartsovka is a simple lime-sand solution that has been used since ancient times for interior plastering of walls and ceilings, and for masonry. But before, the lime was kept in a pit for three years, so the quality was different. For the basement, it is better to add cement, or ask for quick-setting ready-made for wet areas.
If the worker has not found where to use the solution, then take off the last of his pants, shame on the jungle.

29.05.2008, 15:33

Today I called the KNAUF company (manufacturer of UNTERPUTS cement plaster). I say, so and so, your product falls from the ceiling and does not dry for a day. They thought for a long time, then they made a verdict: that my room was poorly ventilated and therefore the solution did not dry, and secondly, that we used soil not produced by them, but by the PLITONIT company.
We decided to try ROTBANT on the ceilings (although KNAUFT technologists discouraged it, saying it would only last a year in a damp room), and on the walls cement-sand and plasticizer. Let's see what happens.

02.06.2008, 22:20

I came from the village. In general, it turned out fine on the walls. The ceilings haven't been done yet.
We decided to use a prance. We make the solution like this: 1 tsp cement + 2 tsp. prancing + 2 hours of sand. I refused the plasticizer because... it is for faster drying of the solution, and the solution is stronger when it dries for a long time. It even seems like it needs to be moistened.
Here’s the question: in the next room, to prepare previously plastered (smooth) walls for additional plastering (the walls themselves were plastered about three years ago, but not leveled), what needs to be done?
1. Do I need to coat it with a primer? And which one is better?
2. Place a thin metal grid? Will there be air cushions underneath?
3. Make notches?

AnatolyK

02.06.2008, 22:55

previously plastered (smooth) walls, depending on how much you need to level:?:, maybe just putty will be enough. If you need a layer of plaster, then cut it with a grinder every 5-10 centimeters with a diamond.
For those who are familiar with this chemistry, we don’t use a primer; for me, the primer is the first layer of the solution: oops:

02.06.2008, 22:58

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

AnatolyK

03.06.2008, 07:25

wow, amazingly smooth wall - 7cm brick thickness per edge. It is necessary to make some kind of notch, the solution will be held in it “as if with your fingers”, and the mesh, of course, will also be stronger. The wall is simply leveled under the tiles.

03.06.2008, 13:11

Yes, in some places you will have to put bricks on the corners.
What’s worse is that there are still places where the old plaster is crumbling. They will beat it off, of course, but they may not notice something and cover it with a new one along the weak foundation...

In most modern domestic houses, the walls do not protect against moisture. It is believed that traditional surface cladding is sufficient ceramic tiles or cheap analogue- coloring oil paint. How to waterproof walls and whether it is really needed in the bathroom, whether money is being wasted - this is what our article is about.

That it is necessary to insulate the floor to prevent moisture from entering building construction and as a result, to the neighbors living below - everyone knows. About the walls building codes are silent. However, we recommend doing so. In areas where water flows will fall directly on the wall, we strongly recommend that the walls be properly waterproofed. These are places behind the bathtub and shower stall, if it does not have sealed rear walls.

Bathroom areas that need waterproofing

In most cases, there is no need to specially protect walls from water that remain dry or those where only occasional splashes will reach (for example, behind a washbasin). It is enough to tile it, paint it with waterproof paint and even stick waterproof wallpaper with the appropriate glue. But this is provided that the walls and partitions are built from materials that are resistant to moisture: concrete, brick, effective wall blocks. There is one more condition - good ventilation. If your bathroom is small enough and the ventilation is poor, then not only drops of water, but also steam will settle on the walls and ceiling. As a result, this will lead to the formation of fungus and, at a minimum, damage to everything in the bathroom.

WATERPROOFING FLOWER BEDS.

Which mixture is best for waterproofing?

This issue cannot be resolved right away. There are many manufacturers and each may have several types in stock. So, only “Ceresit” has three of them - Ceresit CR 166 (CR 66), Ceresit CR 65 and Ceresit CL 51 mastic. Not to be confused with the water repellent for the facade “ST 13”. The latter composition does not have waterproofing properties.

Water repellent “s13”

The main thing is to understand the principle (idea) of applying waterproofing mixtures. This can be done using the example of Cerosit products. All manufacturers of construction chemicals adhere to approximately the same technologies based on common physical phenomena.

All mixtures can be divided into hard and elastic. Hard can be applied to fixed surfaces - foundation walls, wells, indoor small pools, showers, bathrooms. From Henkel it is a dry waterproofing mixture “CR 65”.

Terraces, balconies, outdoor swimming pools, heated floor screeds, and plasterboard walls are subject to temperature and mechanical fluctuations, therefore, to protect such objects, an elastic waterproofing mass is needed. This is “CR 166” - a two-component polymer-cement waterproofing mass and elastic polymer mastic Ceresit CL 51. Or hard “CR 65” + elasticizer “CC 83”.

Rigid and plastic waterproofing mixtures.

Also, mixtures are divided into those that can be applied to plaster surface and those that react with gypsum and cannot be used. Chemical reaction accompanied by crystal growth. Then these neoplasms provoke detachment.

Characteristic differences between various waterproofing materials.

And there is one more important difference between “Ceresit” waterproofings - some are suitable only indoors, others can be applied both inside and outside the building.

What else do you need to know about the technology of using waterproofing mixtures?

You cannot make self-leveling floors on the waterproofing layer. It becomes a separating layer and the thickness of the screed, in this case, must be at least 32 mm. Therefore, it is better to apply waterproofing after screeds and self-leveling floors, taking into account the composition of the floor mixture. Some contain gypsum. The screeds must be completely dry (28 days). For concrete this period is 3 months.

Waterproofing on self-leveling floor

How to apply waterproofing.

For dry waterproofing mixtures (“cr 166” and “cr 65”) there is no need to prime the surface. It is enough to moisten it until it is saturated with water. Much like applying plaster to a brick wall. The wall (or floor) should be damp, but not wet, along which the mixture will flow. Can be applied with a brush and spatula.

For elastic polymer “cl 51”, preliminary priming of the surface is required.

For 3 days, the treated surface must be protected from drying out, wind, direct sun rays and frost.

Waterproofing thickness.

The thickness of the waterproofing depends on the conditions in which it will work. It could just be a damp environment, or it could be pressurized water. Based on this, one or more layers are applied. The final thickness can vary from 1 mm to 3 mm (CR 166) and up to 5 mm in CR 65.

The recommendations state that the first layer must be applied with a brush. Second brush or spatula. The thickness of the layer applied in one pass should not exceed 1 mm. This rule applies to two-component Ceresit CR 166 (CR 66) and Ceresit CL 51 mastic.

How thinner layer, the greater the likelihood of making a gap or creating poor-quality insulation. The greater the water pressure, the thicker the insulation layer should be. Application with a spatula gives an increased layer (consumption is correspondingly greater). But this method has a drawback - waves and irregularities appear that interfere with subsequent tiling. And there remains a danger of missing areas when smoothing.

All this can be eliminated if, immediately after the spatula, you coat the protruding ridges with a brush soaked in the solution. The surface is leveled and the pores are guaranteed to be blocked.

Consumption of dry mixes and mastics.

Consumption depends not only on the method of application, but also on the condition of the coating. Yes, if available large number sinks on the floor, consumption may double. Even when applied with a brush. A layer of mixture will accumulate in the recesses. With a significant depth of such pits, the waterproofing may not harden inside the layer for a long time. The crust around the edges will prevent water from evaporating.

Therefore, in such cases, it is necessary to pre-seal all CT 24 or CT 29 sinks. Bases with a non-uniform structure ( brick and stone masonry) plaster with a mixture of CT 24 or CT 29. When applied sparingly with a spatula, on a flat surface (plaster on beacons and without sinks), the consumption is about 3 kg / m2.

Waterproofing under tiles.

The tiles should be glued to a surface treated with hydraulic mixture CL 51 and CR 166, it is necessary only with plastic compounds SM 16, SM 117, SM17 or with glue of a lower class, but with the addition of an elasticizer. And over a layer of CR 65 you can use CM 11 Plus, CM 12 and CM 14 Extra glue (but not earlier than 3 days after applying the waterproofing mass, and no later than 7 days). In this case, priming the surface is not necessary in both cases. Cladding with large-sized porcelain tiles, with or without narrow joints, can create problems on isolated wall or semi due to poor water evaporation.

Protecting the structures of buildings and structures from moisture is one of the important tasks in construction. Every building has risk areas that require close attention.

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

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

Waterproofing works

Waterproofing work, as a necessary technological action, is included in the project. Designers prescribe the method of waterproofing and necessary materials. Developers adapt the project to the actual site and, if necessary, make adjustments taking into account the composition of the soil.

When creating a house project, it is assumed that it will stand on a perfectly dry site. This rarely happens. IN better position the developer whose house will be located on a sandy or rocky area is located. 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 must 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 groundwater. If waters are found below the building's basement floor, then "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 the necessary changes must be made.

Determining the type of waterproofing

Parts of the house located underground are most susceptible to contact with moisture. Unprotected areas of structures, due to the porous structure of concrete, absorb water like a sponge. This phenomenon is called capillary suction. Rising upward, the 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, and mildew appear.

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

An excellent dry roof is the key to a warm, dry home. If roofing were not made according to the rules, or the roof requires repair due to 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 just a few decades ago this was completely impossible, since old methods of waterproofing (roofing felt and plaster) could not insulate buildings well enough.

Waterproofing is distinguished:

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

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

• Internal waterproofing involves carrying out work indoors. Very often this is plastering. But this is often not enough. Let's say we carried out work, plastered the basement, insulated all the cracks with putty. Dry. But outside the house groundwater destroy the foundation and walls of a building through capillary suction. Obviously, holding only internal waterproofing not quite the right decision.
• External insulation is the insulation from moisture of the external surfaces of the walls and foundations of the house, sometimes flat roofs.
• Vertical insulation means plastering, coating, painting, spraying, pasting, reinforcement, penetrating waterproofing.
• Horizontal - usually 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 methods of creating this property differ.
• Coating and plaster waterproofing fundamentally use a similar principle of operation.
• Coating waterproofing is the coating of a surface in several layers with single- or multi-component materials. Apply to brick, concrete, cement structures. Used for external waterproofing - walls, roofs, foundations from moisture and groundwater. In internal waterproofing - basement walls, bathroom or kitchen floors. Works also as an insulating technology for joints and crevices.
• Mineral masses are applied to concrete or cement, brick walls. You can use hot or cold coating.
• To one-component coating materials include bitumen, mastics, sealants. Multicomponent ones include 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 using mixtures prepared directly at the construction site from dry powders and water in the required quantity.

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 resistant to acids.

Solutions based on ceresite, aluminate, are mixed with Portland cement 400 grade and 3 parts sand. Added plasticizers facilitate the work of covering surfaces with the mass.

Plaster based on waterproof cement in a composition of one to three with sand has very good hydrophobic properties. Supplements are not provided here. This type of plaster waterproofing is used to cover the walls of swimming pools, lock chambers, dock rooms, basements, and tunnels, which are attacked by soil water during “heavy” waterproofing.

Separately, it should be noted the group of hydrophobic plaster mixtures. Hydrophobization is when a surface is given the property of repelling water, not drawing it in or becoming covered with it.

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

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

Spraying requires polyethylene parts to avoid reaction with the solution. The solution is applied in two layers until visual detection surface shine. The effect appears after 2-3 days. Waterproofing impregnation does not change the color, texture, or appearance of the surface. After three days, a control wetting is done - when sprayed with water, it should roll off in drops and the material should not become wet.

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

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

The procedure for carrying out plastering work

The surface for work must be cleaned of dirt, crumbling parts of old coatings, paint, bitumen or oil stains, and obvious dirt. There should be no obstructions against traction plaster mixture with the surface.

Work must be carried out in dry air, at a temperature not lower than 5 degrees Celsius. There should be no gaps, cracks or recesses larger than 3 cm on the surface. They must be embroidered and pre-sealed. On walls made of concrete and stone, a reinforcing mesh is pre-installed and a special penetrating primer is applied.

The plaster mixture is prepared on site from the mixture and water at the rate of 6 liters of water per 25 kg of mixture. Plastering is carried out manually traditionally in layers of at least 2 or 3. Each layer should not exceed 2 cm. Dry the layer before re-coating for 24 hours. If 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 in the first two days after application.

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

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.

Many country residents dream of making a full-fledged basement in their cottage. In the basement you can place engineering equipment, set up a workshop, or store household items and household supplies. But, unlike the above-ground part of the cottage, a room completely or partially buried underground is subject to negative influence groundwater and the formation of condensation due to excess humidity. These features must be taken into account when choosing material for plastering interior walls basement and work technology. From this article you will learn:

• Why do the walls in the basement and basement become damp?
• How to solve the problem of excess moisture in the basement.
• How to choose a material for plastering walls in the basement.
• How to prepare basement walls for applying cement plaster mortar.
• How to properly plaster walls ground floor.
• Recommendations and life hacks.

Why do the walls in the basement and basement become damp?

Causes of this problem:

Alexey NikolaevLafargeHolcim specialist

The basement floor is an occupied room under a cottage, the floor level of which is located below the planning level of the ground around the house to a height of no more than half the height of this room. If the floor level is lower, then the room is usually called a basement. Walls in rooms buried in the ground become damp due to the entry of moisture from the ground or its loss in the form of condensation due to the lower temperature of the wall surface.

The main reason for this problem is the developer’s refusal to carry out engineering and geological studies of the soil and erroneously adopted engineering and technical solutions when building a house.

If there is no or poor ventilation in the basement or ground floor, then condensation accumulates abundantly on the walls and ceilings of the premises.

How to get rid of excess moisture in the basement

Before equipping a basement or ground floor, for example, finishing the walls with cement plaster, it is necessary to identify the cause of excess moisture and be sure to eliminate it. In each specific case, a whole range of measures is carried out - pumping out water in case of severe flooding of the basement, additional waterproofing of the floor, walls and seams, arrangement of drainage and ventilation, drying the room with heat guns.

Alexey Nikolaev

Plastering walls in the basement is not only a way to level their surface, but also one of the protective measures wall materials from constant or periodic penetration of moisture and increasing indoor comfort. For this purpose, special types of plaster are used containing various chemical compounds and complexes of mineral additives that allow you to reliably isolate the basement or basement from negative impact excess moisture.

Criteria for selecting materials for plastering walls of basements and ground floors

AStor User FORUMHOUSE

I built a house with a basement. The basement walls were built from FBS blocks. The outside is waterproofed. The basement is residential, heated with underfloor heating. I want to decorate the walls. Builders say it's best to use simple plaster based on sand and cement. Would you like to know how to properly plaster basement walls? What to spend preparatory work? At the bottom of the walls appeared in some places white coating looks like efflorescence, how to remove it?

Before answering these questions, let's tell you:

• In what cases should special sanitizing and waterproofing plasters be used in the basement?
• How do they differ from ordinary cement plaster?

Sanitizing plaster

Sanitizing plaster is also called drying or restoring plaster. Thanks to the porous structure of the material, moisture is evenly distributed throughout the entire layer of plaster and does not go deep, which contributes to its active evaporation. Hydrophobic additives prevent the reverse movement of moisture.

Due to the increased pore area, moisture evaporates faster, and the base (plastered walls) remains dry. That’s why this type of plaster is called dehumidifying plaster. In addition to the drying effect, sanitizing plaster prevents the formation of efflorescence by retaining salts dissolved in water in its pores.

The effect of sanitizing plaster appears only if subsequent layers are vapor-permeable(ideally, the vapor permeability coefficient is greater than that of the plaster itself), i.e. system: wall finishing “breathes”.

Waterproofing plaster

This is the name for cement-based plaster mixtures for waterproofing basement walls and underground premises. The composition of this plaster includes special additives and minerals, providing high degree waterproof after the mixture has hardened.

In addition to damp basements, waterproofing plasters can be used for finishing bathrooms, swimming pools, underground structures, etc.

Alexey Nikolaev

Waterproofing plaster suitable for all types stone walls, but has some limitations in application. Waterproofing plasters are not recommended for use during active shrinkage of the building, as well as on structures prone to deformation, because if the integrity of the plaster layer is violated, namely the formation of deformation cracks and other defects, the waterproofing effect of the material is lost.

Waterproofing plaster only prevents the penetration of moisture from the soil into basement, but moisture still remains in the walls.

General construction cement plaster

In the case when at the construction stage all necessary measures have been taken to prevent the penetration of groundwater into the basement or basement, and it is also equipped effective system ventilation is the same optimal solution there will be application from reliable manufacturer. The use of cement plaster will help reduce financial costs, and will also create a reliable base layer for further finishing work.

Preparing basement walls for applying cement plaster mortar

Preparing the walls of the basement for plastering is divided into a number of sequential steps:

1. The walls are cleaned of dirt, dust, grease and oil stains, traces old decoration, easily separated inclusions, paint, etc.
2. A visual inspection of the walls is carried out. If there are cracks or unsealed seams on the surface through which water can penetrate into the basement, then they should be repaired: jointing and subsequent “caulking” of the defective areas with special repair materials.
3. If there are pockets of mold in the basement, they must be removed mechanically, cleaning the surface down to the base, and then etching the site of infection with antifungal agents. If there is efflorescence on the surface of the walls, then the surface is also treated with special chemical compounds(often these are solutions of weak acids).
4. The walls are primed.

Even if there is no mold in the basement, then the use of primer compositions containing antifungal substances will not be superfluous.

If necessary, measures are taken to create an additional waterproofing layer in the basement.

Technology for plastering basement walls

At this stage, we adhere to the following sequence of work:

• Determine the required thickness of the plaster layer.

Alexey Nikolaev

When the thickness of the plaster layer is more than 15 mm or at the junction of dissimilar materials, for example, concrete and brick, it is recommended to use a plaster mesh. The plaster mesh is mounted in such a way that after applying the mortar mixture it is located in its volume by at least 2/3 of the thickness. This condition can be done by pre-fixing plaster mesh by organizing a distance from the wall by a given amount. The mesh will reduce the likelihood of cracks forming and minimize the opening width when they occur.

• We display beacons.
• Mix the plaster composition strictly according to the manufacturer's instructions. Usually the finished solution has a consistency similar to thick sour cream.

To plaster basement walls, use the usual set of tools.

• First, we fill the unevenness and seams with the solution, after which we apply the first layer of plaster.

Subsequent layers are applied based on the type of plaster and the recommendations of the mixture manufacturer.

During the first 7-14 days after applying the plaster mortar, it is necessary to provide care for the coating, that is, not to allow the material to dry out. For this purpose, the room is maintained temperature regime within +5-30 C° and, if necessary, the plaster layer is moistened. This will minimize the risks associated with the appearance of cracks and provide the plaster composition with a set of strength characteristics specified by the material manufacturer.

If in the basement excess humidity, A obvious signs why it appeared, then you can identify it this way: tightly attach a transparent plastic bag to the wall. We leave it in the basement for several days.

If excess moisture is formed due to condensation, then drops of moisture on the bag will be from the side of the room, and if due to the seepage of groundwater - from the side of the wall.

Users of the portal are also interested in the question: “Is it necessary to use special chemical additives to increase the waterproofing properties of ordinary cement plaster?”

Alexey Nikolaev

The main condition when choosing a plaster mixture is the correct assessment of the tasks facing it.If you buy cement plaster from a reliable manufacturer, then you do not need to add chemical additives to the solution. The components included in the product are selected in such a way as to guarantee that all the characteristics declared by the manufacturer are obtained with minimal labor costs for the consumer. The main points that need to be paid attention to are appropriate preparation of the base, compliance with the manufacturer’s recommendations for the preparation and application of the mortar mixture and proper care of the coating during the period of strengthening.

Summarizing

The space in the basement or ground floor can and should be used effectively by arranging it for your own needs. If groundwater lies below the base of the basement, or a set of waterproofing measures has been carried out, the developer can successfully use ordinary cement plaster without spending money on special mixtures. In this case, ordinary cement plaster is the most affordable and budget solution.