A basement is needed to protect things from dust, light, moisture and heat. However, what to do if it is wet there? Of course, to insulate the basement. Waterproofing is necessary if the area where the basement is located has a high groundwater level and sometimes it is flooded, if mistakes were made during its construction, if condensation accumulates on its walls, and also in cases where the basement needs to be converted into a living room. In this article, we will consider waterproofing the walls and floor of a basement.
Why is the basement wet?
On the one hand, the basement is great for storing food and other things, but on the other hand, it causes many problems. For example, due to high humidity, fungus and mold often appear on the basement walls, which can cause things, supplies, and food stored in the basement to spoil. Fungus and mold also cause various diseases in humans, so you need to be very careful with them. High humidity in the basement appears due to seasonality, foundation defects and existing insulation, lack of ventilation or its poor performance. All these problems need to be considered in a complex, and better waterproofing should be installed.
Functions of waterproofing
Of course, the main function of waterproofing is to protect the premises from moisture. However, let’s take a closer look at it and figure out what exactly and how exactly it protects:
- Waterproofing protects interior spaces from water and moisture, which contribute to the appearance of fungus and mold, as well as destroy materials and increase metal corrosion.
- Waterproofing increases the durability of the foundation by preventing it from absorbing water. Due to the absence of water in the foundation in winter, it does not crack or deteriorate.
- The procedure eliminates the occurrence of corrosion and rusting of the reinforcement as a whole.
- Waterproofing increases the chances that the concrete will not crack or develop fissures.
Waterproofing also protects everything else that can be damaged by moisture, such as seams. It also reduces the load on the building structure as a whole. Next, we will look at what exactly and how exactly can be waterproofed.
Basement waterproofing from groundwater
This type of work is carried out both inside and outside the premises. If we talk about external changes, then first of all it is necessary to pay attention to the fact that the insulating material has contact with heterogeneous backfill. For this purpose, bitumen mastics, liquid rubber, deep penetration insulation are used, which is covered with insulation or membrane on top.
Basement waterproofing from the inside against groundwater is much more effective than external waterproofing, however, if possible, both types of procedures should be done to ensure maximum protection. Internal finishing is carried out using dry mixtures that are diluted in water. Polymer mastics also cope well with groundwater.
Foundation waterproofing
Foundation waterproofing can be horizontal and vertical. It is very important to work with the base, because the entire main structure is on the foundation. Horizontal insulation is usually carried out after the installation of the slab itself. For it, the floor is pulled together by at least 50 mm. After that, it is covered with polymer-bitumen rolls, roofing felt or PVC film. A metal mesh is usually laid on top.
If we talk about vertical waterproofing, it is done before laying the walls on the foundation base. There are no strict requirements for the material in this case and both roofing felt and bitumen can be used.
Overview of materials used
Cellar waterproofing is carried out using various materials. Below we will consider the features of each of them in more detail.
Penetrating insulation
It is produced using dry mixtures based on cement. It usually includes polymer additives. The service life of the mixture reaches 50 years or more, while the frost resistance of such insulation is up to 100 cycles, and water resistance is 3 stages.
The mixture is applied to wet concrete using a brush or roller, and when it hardens, it fills all the cracks and the concrete structure with special crystals. Also for similar purposes, there are materials of very deep penetration, which are applied not with a brush, but with a sprayer.
Coating insulation
It is bitumen or mastic with the addition of rubber, polymers, or rubber. Usually, this method is used outside, since it is prohibited to use such compositions inside. Before carrying out the work, the walls of the room are dried and treated with a primer, and then the composition itself is applied in several layers.
Mastics are considered the most modern of coatings. Some of them are even approved for indoor use: for example, ceramics can even be laid on them. It is noteworthy that with the help of such mastics, it is possible to seal already formed cracks up to 0.8 mm wide, while they allow to withstand water pressure of 3 or more bars. Such compositions are applied with a brush in 2-3 layers, and to control the quality of work, compositions of different colors are used.
Roll insulation
Bitumen-based rolls are usually used to protect the premises from the outside, and it can be used on both vertical and horizontal surfaces. This material can be laid by gluing, i.e. simply removing the protective film and applying the roll to the desired surface. Installation can also be done by fusion, i.e. using a torch and free laying (can be overlapped). Before starting the installation, it is necessary to check the surface moisture level, and then treat it with a primer.
Liquid rubber
The composition is a mixture of latex or bitumen, as well as polymers. Sometimes other additives are added to it. After drying, liquid rubber is a film with very high adhesive properties (1.5 MPa to concrete and more than 6 MPa to metal). These indicators are much higher than those of mastic. Another advantage of rubber is its resistance to ultraviolet radiation, while the material itself can last up to 30 years or more. It is important to understand that the thickness of the coating should be selected based on the properties you want to get from it. For example, a rubber coating of 3-4 mm allows you to protect the room from capillary moisture, but a coating of 7-8 mm or more is able to withstand serious groundwater pressure. Liquid rubber can be applied not only to horizontal but also to vertical surfaces using a spray gun.
Membrane
Another type of excellent insulation is membrane insulation, which is a special film that is used for roofing, but sometimes it is also used in basements. The membrane is as follows:
Injection insulation
First of all, you need to clean the surface from dirt, and also pump out water from the basement, if there is any. Cracks on the surface of the floor or walls need to be widened and filled with mortar. Then level it, for example, using a primer.
Stages of the procedure
First of all, you need to clean the surface from dirt, and also pump out water from the basement, if there is any. Cracks on the surface of the floor or walls need to be widened and filled with mortar. Then level it, for example, using a primer.
Also, before starting work, it is necessary to take into account the level of groundwater, and the gaps between the walls and the floor should also be sealed with mortar. The waterproofing itself is carried out as follows:
- Inspection of the basement and preparation for work.
- Removing the old insulation layer, if any.
- Drying the surface and the room as a whole.
- Application of waterproofing material.
- Strengthening the material and drying it.
When choosing the means and method of insulation, it is necessary to take into account the cost of the entire layer, taking into account labor. However, it is also worth paying attention to the ease of installation in a particular case, as well as the reliability of the entire structure as a whole.