Products for foundation ventilation: necessity, standards, organization rules

The service life of many building materials, especially wood, in conditions of high humidity is significantly reduced. In residential buildings, the ground floor floor is in direct contact with the basement, where it is damp and cold all year round. In this regard, many customers ask the question: is it necessary to make airways in the foundation of a wooden house?

Products for foundation ventilation: necessity, standards, organization rules

Products in the basement

What will be the result of a lack of production

Products, or the vents are through openings (holes) located above the ground surface in the foundation, in the walls of the basement or on the floor of the basement room. Apertures made in accordance with building codes provide adequate ventilation of the air, due to which evaporation and moisture release to the street occur.

Lack of airflow in the foundation leads to the following:

  1. Accumulation of a large amount of condensate, 100% humidity.
  2. Condensate settling on wooden beams, ceilings, planks of a rough floor design.
  3. Fungi, mold and other live microorganisms actively proliferate.

The result is rotting and destruction of materials.

Products for foundation ventilation: necessity, standards, organization rules

Rot due to moisture accumulation

As a result of the above, never, including during the cold season , do not close the product. But in order to reduce heat loss, it is necessary to warm the floor with high quality.


Another serious reason for making airs is the accumulation of radon gas in the unventilated basement room, which, sometimes very actively, is released from the soil. If the gas has nowhere to go, it starts to leak through the micro-gaps into the living room.

Radon - natural gas characterized by radioactivity, is dangerous to human health.

On our website you can find contacts of construction companies that offer the service of repair and design of the foundation. Directly to communicate with representatives, you can visit the exhibition of houses "Low-rise Country".

Causes of high humidity in the presence of blow-out

There are enough cases when the holes in the foundation are made, but the humidity in the underground has been kept at an unacceptably high level. This can occur for the following reasons:

  • The equilibrium ratio of temperature-humidity values ​​is disturbed. In the summer, a large amount of warm air through the airways tends to the cold room under the floor. The temperature difference contributes to the process of air condensation and the appearance of water droplets on the inner walls of the foundation. The accumulation of moisture is due to the insufficient total area of ​​existing products, as a result, all the moisture does not have time to disappear.
  • Increased evaporation of water from the soil under the foundation, abundant groundwater, passing high, close to the surface of the earth. A lot of moisture also enters the cellar, which does not erode.
  • Water leaks underground during heavy rains or when snow melts.

Products for foundation ventilation: necessity, standards, organization rules

Water leaks are one of the causes of high humidity

Avoid high humidity by properly arranging vents.

Organization Rules

A sufficient number of air vents of a certain area, especially when combined with an exhaust riser, ensures optimal air movement, which prevents premature destruction of wooden structures, in this case the floor.

First of all, it is necessary to perform calculations correctly.

Products for foundation ventilation: necessity, standards, organization rules

Layout of Products


The number of products is determined per unit volume of the basement premises according to SNiP 31-01-2003. According to this document, in the basement of 400 m 3 it is necessary to form at least one aperture for ventilation. In areas characterized by a climate with high humidity, produce products in the amount of 1 pc. for every 100-150 m 3 .

In the walls of the basement, air ducts are also carried out; in one internal wall, there must be one large through hole, or several, as in external walls.

Products for foundation ventilation: necessity, standards, organization rules

The products are located both in the outer walls of the basement and in the walls

For better ventilation, the vent with the exit to the street is done not only in the walls, but also in the floor. They must ensure the free movement of air, draft.

It may be interesting! In the article on the following link read about building a house on a foundation of screw piles.


When designing products, they take a particularly responsible approach to their location. The calculation of products in the foundation is made on the basis of the following rules:

  1. Through openings have a uniform surface over the entire surface of the walls of the basement room. The distance between two nearby holes is in the range of 2-3 m.
  2. To eliminate the accumulation of moisture and air stagnation provide for air in close proximity to the corners of the building. Experts recommend to maintain the distance from the angle of not less than 0.9 m, measuring the inside of the room.
  3. Depending on the height at which the floor of the first floor of the house is located, a place for air supply is calculated. The distance of 20-30 cm above ground level is the minimum recommended. Holes located lower will allow sewage to flow into the basement. Experts recommend doing products as high as possible.

Good ventilation, ensuring optimum air movement under the floor, creates an even number of symmetrically arranged air vents.

The shape and area of ​​the holes

The shape of the ventilation holes can be round, triangular, square and any other at the request of the owner.

Openings of a rectangular or round shape are most common, when they are formed they often choose sizes:

  • rectangular - 25x20 or 50x10 cm;
  • round - diameter 25 cm.

The normative document recommends organizing a production area in the range of 0.05-0.85 m 2 . A larger area opening, according to the rules, must be reinforced.

Products for foundation ventilation: necessity, standards, organization rules

The total diameter of the vents should comply with the standards

. Private traders prefer to make more holes with minimum dimensions Small vents look more beautiful. The main thing is that the total area of ​​all vents corresponds to the norm.

What you need to know about the creation of products in the strip foundation

Products are created during the construction of the foundation. The complexity of the work depends on the material from which the tape construction is made. Each option has its own nuances.

Concrete foundation

In a concrete foundation, it is easier to make round air-flown. To form them, plastic or asbestos pipes are used, the diameter of which is determined according to the calculation rules presented above.

A plastic pipe is inserted into the reinforcement cage, fastened together with a wire. The main thing is that the resulting assemblies (future produkhy) were installed in the formwork for pouring concrete in the right place and in the required amount.

Products for foundation ventilation: necessity, standards, organization rules

Products in the concrete foundation

The pipe is filled with sand beforehand, it protects it from breakage. After the concrete solution hardens, the sand is removed, a round through hole in the basement wall is obtained.

Sometimes through openings in concrete are made with wooden chocks that are installed in the formwork before pouring mortar. So you can not do! Wooden elements after hardening of concrete is very difficult to remove. They have to be beaten out by applying sufficient force, and the integrity of the foundation itself is damaged.

The foundation is made of brick or blocks

In such a foundation it is advisable to construct a rectangular or square-shaped product.

When organizing openings, you must use a reinforcement cage. Its rods in the foundation are placed on a horizontal plane, in which case it serves as a support for the upper parts of the masonry.

Products for foundation ventilation: necessity, standards, organization rules

Products in the brick

Half or part of the brick is used in the brick foundation for production during laying, the result is a square or rectangular opening.

Is it difficult to make products in the finished foundation

Sometimes there are situations when they did not make products at the construction stage of the foundation. In this case, it is formed in the already finished design.

The main difficulty of the issue is the availability of a specialized tool, because drilling a hole will require diamond drilling. If there is no necessary tool, and its cost is quite high, it is better to turn to professionals - this will allow not only to save on the purchase, but also to ensure better performance of work.

The way to close the openings

The through openings should be closed not with deaf, but with the air passing through the grids. Plugs are installed on a mandatory basis, they protect the underground from the penetration of rodents, cats, birds and other animals.

Products for foundation ventilation: necessity, standards, organization rules

Plastic air grill

Many different types are offered for sale, which are fastened to the outside hole:

  • openings of large sizes are covered with steel reinforcement grids with corners or metal grids, including stainless steel;
  • plastic products differ in shape (including in the form of a branch at an angle of 90), size, have an aesthetic appearance;
  • in the workshops make grilles for individual orders.

When choosing a product, it is necessary to pay attention to the presence of a check valve.To ventilate the foundation, the valve is an unnecessary element (it must always be open, and this will have to be monitored). You should choose options without it.

Products for foundation ventilation: necessity, standards, organization rules

Grilles with decorative decoration

When you do not have to do it,

Conditions are defined , the presence of which allows to do without airs:

  • the inner part of the foundation is filled with sand, while a concrete slab is installed on the walls of the foundation;
  • the soil under the house is covered with a vapor barrier film that prevents moisture from penetrating inside;
  • in the subfield an independent, high-performance ventilation system is equipped, the foundation and the basement are well insulated;
  • the underground is directly connected with the heated room (additional space is created for the storage of objects).

Often the question arises: are we need airways in the basement without a basement? If at least one of the first three points is fulfilled, there is no need for productions. In other situations, vents are required.

It may be interesting! In the article on the following link read about which foundation is better.


Products in the basement are not the most important element of a house. However, the period of operation of the wooden structure depends on the proper ventilation under the floor. It is very important not to make a mistake at the initial stage - to correctly determine the number and area of ​​through openings.


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