- Why do you need foundation waterproofing
- Indoor waterproofing methods
- The essence of the injection waterproofing method
- Injection waterproofing device technology
The construction process necessarily provides for the waterproofing of the foundation and walls. Much attention has been paid to this stage in the past few decades. You can protect a house from moisture ingress in different ways, and one of them – injection waterproofing – we will consider in this article.
Why do you need foundation waterproofing
Few people know that concrete itself is not afraid of moisture, it only becomes stronger from it. But concrete is not a water repellent and perfectly passes water through itself. Therefore, you should not neglect waterproofing. You can do without it only when building non-residential premises, and even then, if the groundwater level is low.
Indoor waterproofing methods
Usually, work on waterproofing foundations and walls is performed from the outside of the room. But in some cases it is impossible or impractical to do this. For example, it is not always possible to dig the foundation of an already operated building. In this case, waterproofing work is performed in the basement..
There are several ways to waterproof the interior walls of a room. The most common:
Impregnation waterproofing of the basement and basement walls is performed relatively quickly. The material for its device is a mixture, which includes a special type of cement, sand and special additives that give the mixture waterproofing properties. The components of the composition, applied to a damp surface, react with water. As a result, crystals are formed that stop the penetration of moisture. And the wetter the surface of the walls, the stronger the effect of the mixture.
The coating and painting methods are similar. For them, bitumen-polymer or bituminous mastics, polymer paints or oil paints and varnishes are used. This type of insulation is quite effective in basements, but the compounds used for the water-stopping coating are very toxic. The minimum layer thickness of coating insulation is 3 mm, paint insulation is 1–2 mm.
The injection method is the most expensive, but with its help the greatest efficiency is achieved. Most often, acrylate mixtures and gels are used as material. The injected barrier can withstand a water pressure of several tens of atmospheres. This method is used not only for waterproofing foundations and walls, but also in metro tunnels..
The essence of the injection waterproofing method
This method of protecting foundations and basement walls from moisture and leaks has been used in Europe for over 30 years. In our country it became known relatively recently and is considered promising. The cost of materials and work is slightly higher than the cost of more traditional methods of waterproofing, but the effect of the work performed is several times higher. Using the injection method, even cracks and chips on the surface of walls and foundations can be repaired, and active water leaks through concrete can be stopped. It can be used not only for concrete surfaces, but also for porous materials such as brickwork.
The peculiarity of this method is that the prepared polymer mixtures are pumped under pressure into the pores, seams and cracks of the walls, floor and ceiling of the structure. In hard-to-reach places, special types of injectors are used, with which the mixture is pumped under high pressure.
The materials used for injection insulation are made on a mineral or polyurethane base. Their density is approximately equal to the density of water, which allows them to penetrate almost unhindered even into subtle cracks that could have formed in the walls of the foundation.
The use of the injection method of waterproofing is advisable in the following cases:
- it is necessary to increase the limit of the working loads of the supporting structures of the foundations made of brick and rubble;
- if necessary, eliminate active leaks in the walls of the foundations;
- when installing cut-off insulation between the foundation and the main wall of the house;
- when sealing joints between the ground and the foundation wall.
Injection waterproofing device technology
The work on the isolation device begins with the preparatory stage. In new buildings, it consists in cleaning the surface of the walls from dust and dirt, as well as eliminating irregularities. In the case of repairing already used surfaces, the amount of work is slightly larger. It is necessary, if possible, to remove the old waterproofing, clean the walls from mold and mildew, remove salts using special means.
The next stage is drawing up a project, which indicates the density of future holes, and the amount of waterproofing mixture that is needed to complete the entire volume of work. The number of holes and material required depends on the thickness of the foundation and the type of mix. Consumption of a mixture based on polyurethane per square meter is not less than 1.5 liters. The amount of acrylic-based material required is significantly less.
A hammer drill or drill is used to drill the holes. The hole diameter should be 25–32 mm, depending on the diameter of the injection packers or capsules. Holes are made under the sharp boom up to 45 degrees. Depending on the tasks set, the depth of the holes can vary, usually it reaches 2/3 of the wall thickness. When filling joints between the ground and the foundation, it is necessary to drill through the wall. The holes are washed with a stream of water.
Packers are inserted into the holes obtained, which serve as nozzles for the pump. Through these nozzles, the finished waterproofing mass will be pumped into the wall. For this process, a small pump is sufficient, which creates a pressure of 0.5 MPa. For critical components of industrial facilities, an electric diaphragm or piston pump is used. With the help of such equipment, the mixture is fed into the holes together with the hardener, which allows you to evenly distribute the waterproofing material throughout the entire thickness of the wall..
If the wall is made of “dry masonry” you can do without a pump. But in this case, the packers will need to be filled several times a day. Without a pump, the mixture disperses more slowly through the void in the concrete and the process must be repeated several times.
After completion of the injection work, all drilled holes are sealed with a conventional cement-sand mixture..
Important! Work should be carried out at an ambient temperature of +5 degrees. At lower temperatures, the spread of the mixture through the concrete will be very difficult..