Table of Contents
- Types of blocks and their features
- Why and where is waterproofing needed when building foundation made of concrete blocks?
- Horizontal waterproofing of foundation blocks
- Vertical waterproofing of foundation concrete blocks and walls
- The technology of waterproofing walls and foundations made of concrete blocks and best sealers for this
- Waterproofing of foundation concrete blocks from the inside: Technologies and materials for eliminating leaks and restoring waterproofing
- Conclusions and recommendations on the complex solution of problems with leaks of foundation blocks
Today, the foundations and walls of many urban, commercial and private residential buildings are made of various types of concrete and other blocks, such as Solid Foundation Blocks, aerated concrete, gas silicate, expanded clay, etc. This type is practical, relatively inexpensive and popular among builders. However, do not forget that any blocks, whether they are FBS blocks (Solid Foundation Blocks), silicate gas or concrete blocks, all of them are exposed to water and in the absence of high-quality waterproofing can let it pass into the room. In this article we will talk about methods and technologies of waterproofing blocks of underground parts of buildings and structures, such as the foundation of the house and its walls.
Types of blocks and their features
Today, various types of blocks are used for the construction of houses and buildings, varied by the composition, size and purpose.
FBS blocks (Solid Foundation Blocks) – These are solid concrete blocks. FBS blocks are made of a concrete mix and have internal reinforcement, which makes them very strong and able to withstand heavy loads. FBS blocks come in different sizes and are used mainly for the foundations of commercial buildings and private houses.
Aerated concrete blocks are made of cement, quartz sand and components such as aluminum gas generators. Sometimes gypsum, lime and industrial waste, for example, ash or slag from metallurgical industries, are added to the mixture in the manufacture of aerated concrete blocks. Aerated concrete blocks are considered as cheap building materials and, accordingly, mainly budget private houses and buildings are built from it.
Gas Silicate blocks – Gas silicate blocks are an artificial stone made of one of the varieties of cellular concrete. Gas silicate blocks are designed for the construction of budget private houses and do not withstand heavy loads. When constructing a house using gas silicate materials, it is not recommended to build more than 2 floors, since there is a high probability that gas silicate blocks will not withstand the load and will begin to collapse.
Gas silicate blocks
In terms of waterproofing and water resistance, all types of blocks have one weak point and these are the seams formed in the masonry of the blocks. In the absence of good waterproofing from the outside, sooner or later these seams begin to skip moisture or water.
Why and where is waterproofing needed when building foundation made of concrete blocks?
No matter what type of blocks your foundation is made of and walls are erected, all elements of the building located underground should be protected from water exposure.
Where waterproofing is needed:
- The outer side of the foundation;
- Outside walls made of blocks located below ground level;
- Waterproofing is also recommended to be applied up to the end of the first row of blocks at 30-50 sm above ground level.
- Between the wall and the foundation – This type of waterproofing is called cut-off waterproofing; it prevents the capillary rise of moisture from the foundation up the walls.
Why it is necessary to do waterproofing:
Unjustified damage may be caused to your home or building if your concrete foundation is not properly protected from the outside. Without high-quality waterproofing, it will be exposed to an aggressive environment and water and gradually collapse. Do not forget that concrete is a sponge for water and, accordingly, it absorbs it. Water that has penetrated into concrete can freeze at subzero temperatures and thaw when switching to positive temperatures, which destroys concrete, concrete blocks and your foundation, forming cavities and microcracks in it. The formed microcracks and pores in concrete blocks can cause structural damage to the foundation.
Consequences of the lack of high-quality waterproofing:
- Cracks in concrete blocks and foundation;
- Increased humidity in the operated basement or basement (if any);
- Wet spots on the floor-wall junction formed as a result of capillary rise of moisture (in the absence of cut-off waterproofing between the foundation and the walls);
- The growth of mold and mildew inside your home.
Considering the above, when installing a block foundation or a house, you definitely need to do horizontal and vertical waterproofing.
Horizontal waterproofing of foundation blocks
Horizontal protection is applied directly to the horizontal foundation base and serves as a cut-off between the masonry walls and the foundation itself. Thanks to the cut-off waterproofing, the moisture that enters the concrete from the underground part of its occurrence does not rise capillarly up the walls.
Horizontal waterproofing can be made of the following materials:
- Coating mastics;
- Rolled surfaced sheets;
- Pasting;
- Injection waterproofing.
Vertical waterproofing of foundation concrete blocks and walls
Vertical waterproofing is applied to the vertical surface of the foundation and the vertical surface of the walls located below ground level. Its aim is to protect the concrete walls of the basement and the foundation from the effects of moisture and water penetration inside.
When performing vertical waterproofing of walls made of concrete blocks or aerated concrete blocks, it is very important to pay special attention to waterproofing and its quality, since any blocks have a lot of seams when laying, and seams are always a weak point in any structure and in the absence of high-quality waterproofing, water will go through them first.
Vertical waterproofing can be made of the following materials:
- Coating mastics;
- Rolled surfaced sheets;
- Pasting;
- Liquid rubber.
The technology of waterproofing walls and foundations made of concrete blocks and best sealers for this
When building a house of blocks, it is necessary to make both vertical and horizontal protection from water. To do this, you can use a fairly large range of technologies and materials. The following main insulation methods are given below.
Coating mastics
When waterproofing is carried out with the help of various mastics, the work is mainly carried out by the method of its coating (the so-called coating waterproofing). Mastics of various types are mainly applied with a roller or brush. There are several types of mastics for waterproofing installation:
- Bitumen;
- Polyurethane;
- Polymer.
Mastics of various types are chosen for waterproofing of roofs, floors, swimming pools, foundations, balconies and terraces – the tool shows excellent results. A characteristic feature of mastic is that it is presented in a liquid form, but once applied to the surface, the product immediately hardens, forms an elastic, seamless film.
If we talk about the classic bitumen waterproofing, then this is one of the cheapest methods of protecting your structure. Usually, these mixtures are applied with a roller or brush. When performing protection of various structures located below ground level, it is not recommended to use bitumen as the main method of protection. As a rule, bitumen mastic will not be able to serve for a long time as a reliable coating.
Important: before choosing mastic, consult with experienced firms whose specialization is not the sale of materials, but the production of the works themselves. Today, there are a lot of different mastics on the market, but do not forget that each mastic has certain properties and it is absolutely not a fact that it will suit your building and occasion. For high-quality and durable waterproofing of your building, it is necessary to choose the right method and not save on waterproofing materials.
Pasting materials
This is a multi-layer coating made of special polymers that are fixed to the base using various adhesive components.
Installation technology:
The installation of the pasting waterproofing is performed by sticking it on the cleaned and prepared surface manually, after which the pasting membrane should be covered with a special roller in order for its adhesion to the surface to occur. A primer is first applied to the surface where the waterproofing will be applied.
Disadvantages:
- Availability of seams;
- Lack of 100% adhesion to the base;
- The actual service life, in the presence of groundwater, is no more than 3-5 years.
It is not recommended to use pasting insulation for vertical protection, during the construction of a basement or a residential basement made of blocks.
Rolled surfaced membranes
Roll-on surfaced insulation is made of waterproof bitumen-based rolls. For each type of structure there is its own most suitable surfaced insulation. This type of insulation has.
Installation technology:
The installation of surfaced waterproofing is performed using a burner, by rolling the roll over the surface and heating the bitumen layer. Before welding the roll insulation, it is necessary to apply a primer beforehand (to improve adhesion). The rolled sheets should be mounted in at least of 2 layers overlapping the seams of the previous one.
Disadvantages:
- Availability of seams;
- Lack of 100% adhesion to the surface;
- The actual service life, in the presence of groundwater, is no more than 3-5 years.
Surfaced insulation is not recommended for use in the construction of a basement or a residential basement made of blocks.
Liquid rubber
It is made of bitumen-latex emulsion with the addition of various polymers. When applied, liquid rubber forms a homogenious rubber-like membrane without seams and with 100% adhesion to the surface.
Installation technology:
Liquid rubber is applied manually or by spraying on a surface cleaned of dust and dirt. Before applying, the surface should be primed with a primer.
Disadvantages:
- High cost of Liquid Rubber.
Despite the high cost, the absence of seams and 100% adhesion to the base make liquid rubber an ideal composition for waterproofing of underground parts of buildings and structures.
Waterproofing of foundation concrete blocks from the inside: Technologies and materials for eliminating leaks and restoring waterproofing
When using high-quality waterproofing materials and properly executed waterproofing from the outside, it should be comfortable and dry inside of your basement. If you find wet spots or mold in your basement or house, it means that your waterproofing from the outside has become unusable or has been made with violations. To eliminate the consequences of poorly made insulation, you can dig up your house around the perimeter and re-perform waterproofing or make it from the inside using an injection method, sealants, and special polymer-cement compositions.
Important: If leaks are detected in the house or defects in the waterproofing performed, it is recommended to take all possible measures to replace the waterproofing coating from the outside, as this will solve the root of your problem.
Sealants for seams and joints
The weakest points in the foundation made of blocks are the interlocking seams and they should be protected first of all. In the absence of external waterproofing, various non-shrinking and expanding sealants are used to protect the seam zone from water penetration from the inside. Sealants differ in their composition and reactions to water. With an active flow of water, various types of hydraulic seals can be used.
Sealing technology:
To protect concrete blocks from leaks, it is best to embroider the interlocking seams (make a small indent), and layer by layer seals the expanding sealant into it. In case of moisture ingress, this sealant has the properties to expand and does not allow water to pass. Interblocking seams can also be reinforced with injection waterproofing:
Injection method
Injection waterproofing is single-component and double-component polyurethane resins, and helium compositions that differ in viscosity, hardening time, expansion coefficient, reaction to water, fluidity, and other characteristics.
Injection waterproofing is used to seal interblock and cold joints, cracks in concrete, and the body of the structure if it is destroyed or moisture enters through it. For the production of injection works, a special injection pump is used, with which the injection compound is injected into walls or seams.
Injection technology:
- Marking of injection centers in problem areas;
- Drilling holes at 45 degrees;
- Installation of packers or injectors in drilled holes at 45 degrees;
- Injection of polyurethane resin through the packer into the problem area of the interlocking seam or wall;
- Dismantling of packers and sealing of holes with a special sealant.
Scheme of injection waterproofing on foundation and other blocks:
Important: Before injecting cold or interlocking seams, they should be previously pointed with a 3x5sm indent installation, and then protected by a layer-by-layer sealing of a special expanding sealant. This procedure strengthens the seam, and when injected, the resin goes inside the seam, and not through the weak spot to the outside.
You can read more about the injection method in the article – “Injection waterproofing. Features of the injection method of waterproofing“
Polymer cement materials
Polymer cement waterproofing consists of one or two components. As a rule, polymer cement insulation is a cement mixture with polymer fillers and special additives made of liquid polymers.
Today, there are polymer-cement compositions of the HydroPaz Prime type, which work on negative water pressure and are able to withstand water pressure from the outside to the inside, which makes them an ideal composition for applying to walls made of blocks from inside the room.
Application technology:
- Clean the surface from dust and dirt;
- Perform a fillet for the transition of insulation from the horizontal to the vertical;
- Mix the necessary components correctly;
- Apply the resulting mixture to the surface in 2 layers using special brushes and rollers.
As a rule, this type of waterproofing is applied from the inside of the basement or basement to the floor surface with access to the walls up to ground level. Insulation is recommended to be applied after injection work and sealing of interblock and cold joints.
Penetrating waterproofing
Penetrating compositions are supplied in the form of a powder mixture and consist of Portland cement, fillers, and a mixture of active chemical additives.
As a rule, these compositions do not work so well on the basis of FBS (Solid Foundation Blocks) blocks and gas silicate blocks, since they have voids and pores that do not allow crystals to grow in the right volume (crystals do not grow on emptiness).
Important: In most cases, penetrating mixtures will not help to solve the problem of leaks alone.
You can read more about penetrating waterproofing in the article – “Penetrating waterproofing: A detailed description of its work on concrete, types of materials and application technologies“.
Application technology:
- To prepare the base;
- To moisten the surface abundantly;
- To apply a penetrating mixture with a brush;
- To moisten a surface abundantly for 5-6 days.
Operation scheme of penetrating waterproofing:
Conclusions and recommendations on the complex solution of problems with leaks of foundation blocks
If you cannot make high-quality waterproofing from the outside, then in order to eliminate leaks, as well as perform high-quality protection from the inside, you will have to perform a set of measures consisting of the following steps:
- Sealing of interblock joints located below ground level using an expanding sealant;
- Sealing of the cold seam of the abutment plate wall by injection method;
- Application of a special polymer-cement composition capable of withstanding water pressure from the outside to the inside on the floor bases with lifting on the walls to the ground level.
Recommendation: When performing this set of measures by a professional firm specializing in integrated waterproofing, you are guaranteed to get a dry basement for at least the next 15 years.
