Basement waterproofing from the inside from groundwater - methods
DRoot water is contained in the upper soil layer and can occur at a depth of one meter or more. The layered structure of the soil and the alternation of aquifers with clayey layers does not allow us to confidently exclude the appearance of groundwater in a particular area. The rise of groundwater is fraught with rapid and irreversible destruction of the building, therefore, all building structures and basements must be protected from moisture, and waterproofing the basement from the inside from groundwater is a mandatory construction requirement.
The content of the article
Soil - aggressive environment
Regardless of whether the basement is used or not, the outside of its walls must be protected from moisture, this is the requirement of SNiP. Groundwater contributes to the rapid destruction of the walls of the foundation, regardless of what material this foundation is made of.
Video: basement waterproofing
Consequences of moisture penetration
The water itself does not harm concrete and brick structures. Moisture becomes hazardous at low temperatures. Penetrating into the pores of concrete, into the seams between slabs and bricks, water fills all voids, rises through the capillaries and enters the above-ground structures. During frosts, water turns into ice, increases in volume and begins to expand the walls of pores and capillaries. After thawing, the volume of moisture returns to its original value, water fills other voids and new capillaries, and then freezes again. The stress in the thickness of the structure gradually accumulates, and after several cycles of freezing and thawing, the walls of the foundation and above-ground elements begin to crumble.
Concrete and brick in terms of frost resistance, they differ little from each other, under equal conditions they are able to withstand without destruction on average from 30 to 50 freeze-thaw cycles.For the conditions of central Russia, such a number of thaws may well happen within one calendar winter, therefore, in the spring, one can notice the beginning of destruction. In addition to freezing, there is a danger of colonization of the basement walls by mold fungi, which release enzymes that destroy concrete and brick.
Types of waterproofing
Special polymer compounds are used as waterproofing, which are applied to the walls of the structure from the inside and outside. Waterproofing the walls of the basement from the inside from groundwater is a laborious and costly process, but it is intended to extend the service life of the building several times. There are several types of insulation:
- coating insulation - application of liquid polymer (bitumen) to the surface;
- penetrating - the introduction of special additives into the plaster mixture, which then acquires hydrophobic properties;
- membrane or roll - insulation using special materials that are fixed to the surface of the basement walls;
- injection - injection of a polymer solution into the pores and capillaries of the concrete layer;
- liquid rubber - a special composition based on bitumen, rubber and plasticizers.
Related article:
Bituminous mastic for foundation waterproofing: price. Types of mastics, cost, brands, DIY and proper application in a special publication.
Waterproofing layer device
From waterproofing quality depends on the duration of the building and the microclimate in the basement and first floor. When choosing an isolation method, you should not focus on the cost of the procedure, but the main criterion should be efficiency.
Traditional bitumen sealants have been widespread and have proven to be ineffective. The composition is prepared as follows: pieces of bitumen are melted over a fire, diesel fuel or used engine oil is added to the melt to the consistency of liquid sour cream. This mixture is constantly heated to keep it liquid and applied to the dry surface of the concrete wall. GOST requires that at least 2 layers be applied from the inside, but even in this case, after one or two years, the layer cracks and partially crumbles.
Roll insulation is more perfect, since the main obstacle is a sheet of roofing material or rubemast, which is attached to bituminous mastic. The heated and prepared bitumen is applied to the basement wall, sheets of roofing material are glued to it with an overlap. For better adhesion, it is recommended to heat the finished layers with a gas burner, thus, the bitumen melts and the coating becomes practically airtight. This method is very reliable, but laborious and highly skilled.
Liquid rubber is bitumen to which special plasticizers are added. Unlike the traditional recipe given above, such a layer remains plastic even after hardening, which means that it performs its functions longer. Such compositions are not cheap, but their properties are unique: they are plastic, have very high adhesion, are not afraid of low temperatures and aggressive environments.
Waterproofing plaster mixes are good for use in rooms with constant positive temperatures, therefore, penetrating basement waterproofing from the inside from groundwater is used indoors. To achieve the required level of protection, a layer 1.5 - 2 cm thick is required. There are special additives that are introduced into concrete and give it hydrophobic properties. If desired, concrete basement walls and foundation elements can be completely made from such a composition.
Basement injection waterproofing from the inside from groundwater is used relatively recently and belongs to the latest developments. For its device, holes are made in the walls of the foundation in a certain order, metal needles are immersed there and a polymer composition is injected through them under a pressure of 85 - 160 atmospheres. It penetrates into the pores and capillaries of concrete, filling them and thus creating a waterproof layer.
Application features
In private and multi-storey construction, basement waterproofing technologies do not differ much. Most often, preference is given to the following types:
- roll - due to low cost and high efficiency;
- penetrating - due to high reliability and ease of application;
- liquid rubber - due to its exceptional reliability.
Such a method as injection waterproofing is used at large facilities, since its installation requires an expensive composition, highly qualified specialists and sophisticated equipment.
How to protect a basement from groundwater
Waterproofing work must be performed in strict accordance with the chosen technology, however, there are general rules:
- it is necessary to start insulation work only after the concrete has fully matured - on the 28th - 30th day after pouring;
- do not waterproof in a humid environment, the basement must be thoroughly dried;
- waterproofing work must be carried out at positive temperatures, otherwise the polymerization process of the binders will be disrupted and the layer will be ineffective.