Floor waterproofing
Basement waterproofing
Waterproofing a bomb shelter
Basement leaking, what to do?
Many of us face a constant problem in underground structures: water and dampness in the basement, in the cellar, and more recently in the bomb shelter. This issue is especially relevant in autumn, winter or spring.
We will analyze the main problems associated with moisture in the basement and methods for its elimination.
Damp walls in the basement and cellar
We are often approached by customers with the question of the dampness of the walls in the basement, inspection pit, cellar. There seems to be no water, and the walls are damp.
The plaster begins to collapse, tiles and paint peel off. A fungus, efflorescence, the smell of dampness are formed.
As a rule, this is a complex problem, consisting of the absence of:
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external (external) and cut-off (horizontal) waterproofing;
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the foundation is not insulated along the perimeter of the building, from the outside;
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lack of heating and ventilation in the basement or cellar.
Fungus in the basement
Ineffective or damaged waterproofing
Capillary moisture migrates inside the foundation wall and negatively affects the finishing materials, systematically destroying their structure, integrity, and appearance.
The plaster “blows” and disappears, and the paint and putty bubbles, peels off.
No foundation insulation
Foundation freezing.
Lack of ventilation and heating
High humidity, low temperature, leads to the formation of condensation on the walls.
Moisture collects in the coldest places in the form of "dew point" water.
Condensation with high humidity in the basement
What to do?
We solve this problem comprehensively.
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First, we solve the issue of ventilation and heating.
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We increase the temperature in the room and remove excess moisture to the outside, using exhaust ventilation.
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The walls will dry out, the condensate will go away, we will improve the microclimate in the room.
If these actions did not help and moisture collects on the walls in the form of water, then this is already a problem with external or horizontal (cut-off) waterproofing.
If it is not possible to carry out waterproofing work outside the basement, we carry out internal waterproofing of the basement.
Such types of work are classified as waterproofing under negative moisture pressure.
Basement waterproofing from the inside
Basement waterproofing from the inside
Unpleasant situation. I went into the basement, and there was knee-deep water.
In summer, such questions arise less frequently, but there are: a high level of groundwater, the rainy season, a pipe burst and a lake in the basement.
In autumn, winter and spring, such tasks are more common: rains, snow melts, poor drainage of surface water, ineffective blind area.
Internal basement waterproofing
Internal waterproofing occurs in several stages.
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Determination of places of leakage;
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Foundation repair and waterproofing;
- Ventilation, heating, insulation.
First of all, we pump out water and determine the weak points through which water penetrates into the basement or cellar.
Water penetration into the basement
The main places where moisture enters the basement
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Places of interface wall * floor, wall * wall (corners);
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Interblock seams, if the walls are made of blocks;
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Places of inputs of communications, pipes;
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Seams in brickwork;
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Cold or expansion joints in concrete;
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Cracks, shells, potholes, any destruction of the base;
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Technological holes from formwork rods.
- There are times when water filters through the body of blocks and concrete. This is due to the formation of voids, large and small cracks in them. Due to the old age of the base, poor vibration or compaction of concrete during pouring, shrinkage of the building.
Moisture penetration points in the basement
Active leak in basement
If there is a constant penetration of water (fistula, fountain), usually, an economical option, use a cement hydraulic repair mortar with a quick set of strength and expansion.
The people "Hydroplomba". This composition is able to set from 30 seconds to 3 minutes.
There are cases when the pressure is so strong that the seal does not have time to react with water and washes it out.
In this case, it is necessary to perform parietal drainage.
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Using a perforator, we make holes in the base.
- We insert a tube into the hole, and attach a hose to the tube.
Water will look for the most convenient place to exit and go through these holes, and you, in turn, will relieve the water pressure on the wall and will be able to control the drainage of water into the pit or into the sewer.
When the water pressure on the underground structure decreases, the main problem areas for leaks can be closed.
After performing waterproofing work, close the drainage holes or leave them to facilitate the operation of the internal waterproofing system, since the cause of the occurrence of water behind the wall has not been resolved, and moisture will continue to press on the foundation walls.
Stop active leaks
Another option to stop the active penetration of water, more expensive - injection.
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Holes are made in the base with a puncher.
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The packer is installed in the hole and a hose is connected.
- With the help of specialized equipment, a polymer composition is pumped into the body of the structure.
Reacting with water, the polymer turns into a solid state, such as a gel or a state of mounting foam, after expansion, sealing the smallest microcracks.
Also, you can inject current liquid cement compositions, but this is in case you have large voids inside the wall.
A cementitious flowable compound fills the main cavity, and then, after curing, gel or liquid waterproofing compounds can be injected to seal the micropores.
Injection of polyurethane resin in the basement
When the active leak is stopped, we proceed to repair work on the base.
We embroider cracks, adjunctions, seams, shells.
With the help of waterproofing, non-shrinking repair compounds, we fill all the seams, cracks, shells.
In the corners we carry out the device of fillets (plinth), at 45 degrees. Waterproofing does not tolerate right angles.
Joint stitching
Another option for sealing joints, when it is not possible to make fillets, is the use of elastic waterproofing tapes between two layers of polymer cement waterproofing.
Right angles create additional stress, which can lead to cracks in the waterproofing coating and a potential weak point for moisture to penetrate.
Basement waterproofing
When waterproofing basements for negative pressure, cement waterproofing is mainly used.
One-component, hard coating with a protective effect
Usually, such cementitious waterproofing is used for positive moisture pressure. But if the negative pressure of the water is not strong, this type of protective system can work to "separate", due to the adhesion force with the base (adhesion). On average, the adhesive force is 1.5 MPa.
Basement waterproofing
One-component cement-based penetrating waterproofing
Cement-based penetrating waterproofing withstands negative moisture pressure due to good adhesion to the base, creation of an armoring layer and penetration into the concrete body, with the help of chemically active substances, forming water-insoluble crystals in concrete capillaries. Thereby stopping the water inside the wall.
I note right away that “Penetrating waterproofing” works only with cement stone (concrete, cement plaster, concrete blocks). It will not work on brick, except perhaps along cement joints or in the form of a 2-3 mm armor layer.
Two-component or one-component elastic polymer-cement mixture
This type of waterproofing system is used on a horizontal plane, in corners, on walls.
Elastic 2-3 mm coating, capable of covering microcracks up to 1.5 mm.
Can withstand dynamic loads and temperature differences.
Roll and polymer basement waterproofing
There are projects when under negative pressure, when waterproofing basements, roll or mastic waterproofing materials are used.
This is possible, but only if there is a pressure retaining wall or floor install.
Otherwise, water will extrude the coating (formation of bubbles), which will lead to a violation of the integrity of the protective coating.
In our projects, we try to use a combined approach for waterproofing.
In the corners, at the junctions, in the seams, deformation movements are possible. Therefore, here we use elastic polymer cement waterproofing.
On the basis of concrete, plaster, brick, in a static state, we use cement coating waterproofing compounds with an armoring layer.
And penetrating waterproofing, as mentioned earlier, only on cement-containing bases and more dense.
On a chemical level, it only closes microcracks up to 0.5 mm. And if the base is loose, thin, deformed, the penetrating waterproofing will not be effective, the process of tightening microcracks, the growth of crystals in the concrete body, will last a long time.
Penetrating waterproofing
On top of the waterproofing, you can lay tiles on glue or make a screed, thereby preventing wear and destruction of the waterproofing layer.
Walls can also be plastered, with the addition of waterproofing additives to improve water resistance, as can screeds.
Most importantly, no mechanical fasteners in the base on which the waterproofing is applied. Immediately promising place for a leak.
Basement ventilation
After we have made repairs to the base and applied waterproofing, we proceed to the device of the microclimate in the room.
There are cases when they made waterproofing, and the walls or corners are wet. This may be due to a violation of the waterproofing layer, because the water will look for a weak spot in the system and find it. Such places require additional protection.
Or condensation forms on the base, since there is no ventilation, the foundation freezes, and the temperature is low.
On sites, we often check, as follows, the cause of moisture.
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We put a fan or heater next to this place. If the place dries up, it means condensation. If not, then there is moisture pressure.
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Or wipe off the drops of water and apply acrylic paint. After polymerization, if it bubbles, then the pressure of moisture, if drops, condensate form on it.
- On a horizontal surface, you can lay a square meter of film and secure it with tape around the perimeter. A day later, if there is moisture on the film, we work with ventilation, and if inside, then the inside of the concrete floor is wet.
Even in summer, in hot weather, condensation forms in the basement, in cold areas, so insulate the foundations from the outside and ventilation will help you.
Basement ventilation