Waterproofing a brick plinth with TechnoNIKOL mastic

Brick intensively absorbs moisture, being constantly exposed to it. Therefore, waterproofing a brick base is a prerequisite when building a brick house. Without the use of this measure, it is impossible to avoid its premature destruction, which is caused by the constant presence of the basement masonry in dampness due to contact with the ground.

Why do you need to protect the foundation of your house from water?

Waterproofing the base helps reduce or completely eliminate the ingress of moisture onto parts of the building and keep building materials intact. The main task of the procedure is to preserve the integrity of the building’s foundation for as long as possible and prevent destruction due to exposure to temperatures.

It is noteworthy that waterproofing work can be carried out both in advance, during the construction process, and after its completion.

The plinth is the external protection of the foundation; it creates a level for the lower floor, guides the laying of walls, and allows for the creation of additional basement rooms.

Basement waterproofing is necessary for:

  1. Preservation of the building, durability of the building. Groundwater can wash away building materials, causing cracks to appear under pressure. As a result, the entire structure will be in danger of collapse.

  2. When building materials come into contact with the ground, they enter into a chemical reaction, wear out faster, and the service life of the structure is reduced.
  3. Getting into microcracks and free cavities of the base (and then into the foundation), water molecules expand under the influence of low temperatures. This leads to disruption of the integrity of materials and cracks.
  4. The protection prevents moisture from entering the interior. Otherwise, the basement or basement rooms become damp, mold and other problems appear, reducing comfort and making it uninhabitable. The fungus quickly invades other spaces and can be dangerous to the health of residents.
  5. There are a lot of salts in groundwater and stormwater. They are deposited on the base, weaken the building mixtures, and lead to delamination and destruction of the structure. Salts leave a white coating that changes the appearance of the house and artificially ages it.

Site drainage is also important ; the foundation must be laid in soil freed from groundwater (a trench or hole for the foundation must be prepared before installing building materials), for which it is necessary to carry out geological development of the soil in advance.

Necessity of execution

Waterproofing the base, which is an element of the building structure that ensures the interface between the foundation and the external elements of the building (structure), such as its walls. In addition, waterproofing work is carried out to protect the basement floor, which is a semi-buried room in relation to the surface of the earth.

Waterproofing the basement and basement is necessary to protect them from the effects of harmful negative factors, which are:

  • groundwater and melt water;
  • precipitation.

Under the influence of such external factors, the foundation is destroyed, regardless of what materials it is made of (concrete, brick, etc.), which is due to the physical properties of water: it expands when freezing and promotes the formation of microorganisms.

The presence of high-quality waterproofing allows you to use the basement floor for arranging technical premises (garage, bathhouse, auxiliary rooms), as well as protect the enclosing structures (walls) from moisture.

These measures make it possible to extend the service life of all building elements of the building (structure) and help create an optimal microclimate inside the premises of the first floor and the building as a whole.

External waterproofing of the basement of a brick house

Consequences of not insulating your home from moisture

The basement of the building is exposed to water from both the soil and the atmosphere. This is the wettest part of the building. The lack of waterproofing affects not only the foundation, but also the walls of the building.

What are the consequences of lack of basement waterproofing:

  1. If this part of the building is made of brick, it absorbs moisture very well. It rises from the ground up the structure and destroys it from the inside. Finishing materials (tiles, panels, etc.) split and fall off in pieces. The external attractiveness of the building is lost.
  2. Penetration of moisture into the walls threatens to damage the thermal insulation of the room (the insulation gets wet, begins to rot and collapse). Heating the house will become difficult and will require a lot of resources.
  3. Water penetrates the cracks in the concrete foundation, erodes it and destroys it. It’s good if the base mixture initially contains waterproofing elements, the appearance of cracks will be delayed for some time. But such a building will wear out faster.
  4. The concrete base also splits and is torn from the inside by moisture entering through the cracks. The reliability of the building is lost, traces of salt remain on the outer part, the paint falls off along with the plaster.
  5. It becomes impossible to stay or store anything inside the basement floor. Biological microorganisms are difficult to remove; they spread throughout all rooms, the first floor and walls of the house are especially affected.

Waterproofing the base must be done in three places: in contact with the foundation, with the ground and with the wall. Then the structure will be reliably protected.

Why do you need waterproofing of a brick plinth?

The basement is the part of the house that connects the base of the building and the load-bearing walls. It is installed directly on the foundation located in the ground and is located at a close distance from the source of moisture. In contact with moist soil, brick absorbs water well due to its porous structure. Moisture is retained in a brick block and at sub-zero temperatures it becomes ice, thereby destroying its structure from the inside. To protect the building from soil moisture and premature destruction, you need to waterproof the brick base outside and inside the house.

What materials are used, how to choose them correctly?

Materials for basement waterproofing differ in properties. The choice is made based on performance characteristics:

  1. Polymer compositions .
    Their physical properties are similar to rubber; they are used more often on the outside, where the base comes into contact with the ground and the atmosphere. Advantages: tolerates temperature changes well, does not crack in the cold, it is not necessary to clean the surface before application, they are inexpensive.

  2. Mixtures and primers .
    These materials are able to penetrate into the deep layers of the base, making them considered the best option for porous concrete and brick. Used for internal and external work. Apply using painting supplies (brushes, rollers). The base with it becomes heat-resistant and is not susceptible to external influences. It can only be applied at above-zero temperatures; before the procedure, you need to protect your respiratory system and exposed skin. The compounds are applied to the cleaned surface. For better penetration into concrete or brick, the surfaces are leveled.
  3. Coating, mastics . Cement-polymer based materials. It is applied from above to the base, suitable for any surface, no preliminary preparation is required. Disadvantage: bitumen-based waterproofing is short-lived and needs to be updated periodically. Based on cement and polymers, it lasts longer and tolerates temperature changes well.
  4. Rolls: roofing felt, roofing felt, film, membrane . They are convenient to use when laying the foundation. The material is left in reserve in a trench or hole, and then the base is covered with it. This way the entire base of the building is protected from water, even if it is very close. Rolled coverings can withstand the pressure of melt water, are inexpensive and environmentally friendly. The most popular option is “Izospan A base”. This waterproofing is capable of releasing vapors to the surface, maintaining fresh air inside the basement.
  5. Injections. This is a special type of basement waterproofing; the solution is injected into the surface. Such work is carried out exclusively by specialists; the method is effective if the waterproofing procedure has not been carried out in advance; it is more expensive than others.

A brick base requires waterproofing, since the porous material absorbs a lot of moisture and quickly collapses.

Suitable for:

  • mixtures,
  • coating,
  • processing with polymer compounds.

This way the brick will retain its useful properties: breathability, heat retention and visual appeal. It is recommended to carry out the procedure in advance and begin preparing from the moment the foundation is laid.

In what cases is the construction of a brick foundation justified?

  1. The construction of a brick foundation is justified in cases where the planned structure will be small in size and light in weight. These can be small wooden country houses, bathhouses, sheds, gazebos, garages and other objects.
  2. If the soil on the site is dense and low-heaving, then a brick foundation can last 50 years or more.
  3. A brick foundation can only be laid if the groundwater level is low.
  4. If you have enough bricks or can buy them cheaply.
  5. In cramped conditions that make access for construction equipment impossible.

But the main incentive for building a brick foundation may be the desire of the owner of a summer cottage to build a house or bathhouse on his own. Coming from the bustle of the city to their dacha, not everyone wants to see noisy construction vehicles and workers scurrying around the construction site.

Therefore, building a brick foundation is an ideal way to take a break from the busy city life and find an outlet for your creative energy.

Processing methods

There are two types: horizontal and vertical waterproofing. Horizontal waterproofing between the plinth and the foundation is necessary if the plinth is also the base of the wall. It protects against moisture penetration from the foundation above and preserves the integrity of the walls for a long time. If the base is a continuation of the foundation, the procedure is optional.

This can be done if the base of the building is made of:

  • stone,
  • bricks,
  • blocks,
  • Concrete products

If the base and foundation are a monolithic concrete or rubble concrete structure, it cannot be waterproofed horizontally.

The moisture protection on the basement floor must be connected to the base protection, the seam between them is treated with a torch or mastic. Rolled materials are used here: roofing felt or roofing felt.

Vertical waterproofing - covering the outside and inside of the base , protection from moisture from the soil and atmospheric phenomena. You can use any of the materials listed above; mixtures, coatings or polymers are most convenient. Apply from the bottom of the soil to the beginning of the wall.

It is carried out together with horizontal waterproofing; at the junction, the materials are carefully combined.

Technology of work from inside and outside

Comprehensive moisture protection is carried out inside and outside the base. External insulation is more important, since the threat here is higher; from the inside, water penetration into the surface of the base occurs during the operation of the room.

Horizontal installation

Rolled materials are laid on the foundation before laying the base. How to make a coating with your own hands:

  1. Level the surface, remove all debris, seal cracks and crevices with connecting material.
  2. Cover a flat surface with bitumen mastic.
  3. Lay out the roofing material evenly, pressing it tightly against the mastic. Keep the overlap approximately 20 cm; there should be no air under the coating layer.
  4. At the joints, melt the roofing material with a gas burner; the seams are tight, without holes.

Vertical coating

You will need: bitumen mastic, bitumen primer. Instructions:

  • clean the surface from dust and debris, level it;

  • walk over the surface with a primer (bitumen primer) so that the materials adhere successfully;
  • when the primer has dried, apply the mastic evenly and uniformly - the first layer should dry completely;
  • apply a second coat.

After about 10 years, mastic may crack under the influence of temperatures. It is necessary to monitor the condition and carry out repairs on time.

Vertical roll

Often the coating is combined with rolled masonry, so the waterproofing layer is more reliable. You will need: rolled roofing felt, mastic, primer.


  1. Clean and level the surface.
  2. Apply primer and wait until dry.
  3. Apply the first even layer of mastic.
  4. Before joining the roofing felt and mastic, heat the rolled material on a gas burner until soft. This way it will adhere better to the coating.
  5. Apply roofing felt overlapping and melt the seams using a torch. There should be no gaps left.
  6. For reliability, it is recommended to apply 2-3 layers of roofing felt. Treat all joints with a torch or mastic.

In an already built house, waterproofing can be laid on top. First you need to clean the surface and degrease it with a primer. After applying all the layers sequentially, cover the top with facing materials (tiles, bricks). Reliably process joints.

But more often they use injection waterproofing, which is carried out by professional construction teams. The solution is injected into the finished base, fills the cracks and hardens.

Internal using mixtures

Inside the base, mixtures and primers are often used. They penetrate into microcracks in the coating, harden there and prevent moisture from seeping through.


  1. Level the surface and degrease with primer.
  2. Moisten the surface for better penetration of the mixtures.
  3. Apply penetrating material.

The penetrating material is suitable for concrete plinth walls; an adhesive primer (concrete contact) is used.

For bricks, silicon-based compounds are used, applied with a roller or brush. If you plan to apply coating to the brick, you first need to plaster the surface.

Horizontal waterproofing of cladding

The brick base of the house and subsequent floors must be separated from the foundation by an insurmountable barrier to capillary moisture. To do this, the upper surface of the foundation is cleaned of dirt and dust, leveled and lubricated with bitumen mastic.

TechnoNIKOL roll material made from new types of roofing material is laid on top of this layer, so that the edges of the insulating material extend beyond the walls. After this, the waterproofing layer is evenly pressed onto the mastic so that these layers touch everywhere. If a simple roofing material is used, there should be two such layers. When building a house with a low foundation in an area of ​​high humidity, ordinary roofing felt is laid in five layers. This insulation cannot be done during renovation.

Possible process errors and ways to eliminate them

Common mistakes:

  1. External waterproofing was not carried out in advance. To do this after construction, when damage has already begun, you will need to open up part of the soil to the base of the base and drain groundwater (if it has reached the surface). Next, clean the damaged surfaces and strengthen them with reinforcement and cement. Apply waterproofing and cover with facing materials (or paint).
  2. No stripping or priming. These important process elements should not be skipped. The fact that a mistake has been made will become known with the appearance of leaks or damage to the base. Waterproofing will need to be repeated on the finished structure.
  3. Selection of low-quality materials. The suitability and interoperability of materials must be considered in advance.

The result of errors is the appearance of cracks.

They are eliminated like this: the crack is cleaned from the inside with an iron brush and filled with primer. If the crevice is wide, bitumen mastic is used. Afterwards it is treated with cement until it dries, and waterproofing is carried out over the entire surface of the base.

Drainage system

Installing a drainage system
If this was not done during the construction of the foundation, during repairs you need to dig a trench to the depth of the foundation along the entire outer perimeter. Place a system of plastic pipes with holes in the trench to drain incoming water. Fill the trench with soil. The top layer is made of compacted clay.

Then a sand layer about 10 cm thick is added, reinforcement is laid on it and a cement blind area 1 meter wide is poured. The blind area is made with a slope of 2 cm. When the blind area structure hardens, seal the seam between the foundation and the blind area with polyurethane sealant.

Average prices for the country

The price depends on the type of work. Average cost of work in Russian cities:

Type of workMoscow, r/m2St. Petersburg, r/m2Regions, r/m2
Vertical using roll materials, coating, penetrating650600500

The final price depends on the complexity, volume, materials and qualifications of the workers.


  1. All work on the construction of a brick foundation can be done on your own, even alone.
  2. The brick foundation, along with the necessary rigidity, has a very good quality - flexibility. When soil moves, it does not collapse, which can happen with monolithic structures.
  3. If some part of the foundation is destroyed, part of the brickwork can be replaced.
  4. A foundation of any complex shape can be very easily laid out of brick, without the need to construct specialized formwork

You will learn how to build a strip foundation from FBS blocks by reading our article. And here is an article about how to lay bricks on a foundation.

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