Do we need air holes in the basement?

By Admin | Recommendations
18 April 2016

in a dispute over whether to air holes in the base, and whether they close for the winter, broken a lot of copies.It would seem, what is there to say?

air holes in the base are required for ventilation of the underground space, which facilitates the removal of excess moisture from the socket.

produhi usually made in the construction of strip foundation.It would seem that the technology worked before melochey.Tem however, often appear on threads with questions: there are air holes and wooden beams and floor joists still rotting;insulation gets wet or the inside walls of the strip foundation in the winter frost forms.So whether you want produhi?

That opinion forumchanin with the nickname chicken-A :

- With the advent of modern materials and construction methods produhi become an anachronism.And if a closed underground additionally how to insulate, it will significantly increase the energy efficiency of the house.

interests of the Western experience.For example, in the United Sta

tes until recently it was considered economically feasible to build houses with air holes and low underground, which were laid all the utilities.

In America, built about 30 million homes similar houses.

But in recent years overseas builders are moving away from the construction base with air holes.It turned out that in freely ventilated underground in the majority of cases still retained humidity.

This is due to violation of temperature and humidity conditions.For example, the warm summer air gets colder in the underground, but because of the temperature difference between the water contained in the air condenses and falls as dew on the inner walls of the cap and floor.Over time this leads to rotting structures.

dampness of the underground space is for two main reasons:

1. The constant evaporation of water vapor from the soil under the house.This contributes to the high level of ground water or flooding cap precipitation.

2. Insufficient area of ​​the air holes.In accordance with SNIP 2.08.01-89 1.47, within the walls of basements and underground, with no ventilation, the total area of ​​the air holes must be at least 1/400 of floor space underground or basement.And do produhi be evenly distributed around the perimeter of the exterior walls of the basement or ground floor.

The minimum area of ​​0.05 square meters equals produhiAccordingly, the sub-floor ventilation for a total area of ​​100 square meters will need about 25 air holes with a diameter of 110 mm.

In addition, it is believed that the air holes need to be closed for the winter.


- I think that the habit of closing the air holes in the winter there was more because of the possibility to store food in the cellar.When fully open produhi potatoes and canned winter freeze and spoil.

Under the premises normally do ventilated cellar (basement or semi-basement) with air holes on the outside and the air holes through the floor and ventilation ducts in the walls.In summer, ventilation is due to warm air entering through the external air holes.In winter, the air holes are closed and the flow of air into the cellar goes through the holes in the floor.These holes are covered with small reshёtochkami.

According SNIP II-3-79, the temperature difference between the air in the underground and surface temperature of the underground floors should not exceed two degrees.And to the floor with open winter produhi vymerz not, it must be properly insulated.

minimum thickness of the insulation in the floor (for example, mineral wool) is 200 mm.Since

These requirements are often not respected or carried out with violations, then the next logical step is the construction of the cap without air holes.

well insulated and isolated from the air in the underground during the whole year remains dry, warm, and it does not form mold.

How to make a closed underground?

In teplotehnicheskom against a closed underground differs from the floor on the ground only by the presence of the air gap between the floor and the ground.

When closed underground, because the air layer, which is not open to the atmosphere, the floors are heated indoor heat quickly.Therefore, the floor under a closed underground and permanent mode, you can not insulate.And the process of creating a closed underground can be broken down into a series of sequential steps:

1.Obespechivaem foundation drainage.It contributes to efficient removal of excess moisture from the construction site, which reduces soil moisture underground.

2. Insulate the outside wall of the cap.This keeps the heat underground.

3. Insulate blind area around the perimeter of the foundation.This reduces the heat leakage through the bottom part of the foundation.Besides, warmed otmostka reduces frost heaving forces acting on the foundation.

4. Paroizoliruem ground in the base, that is,block the flow of moisture from the soil in the underground.For this stele on the ground thick, not less than 150 micron, polyethylene film.It is laid with an overlap and mandatory sizing joints.For reliability film can fill the screed from the "skinny" concrete (2-3 cm thick).The ends of the film (20-30 cm) plant on the basement wall and presses bar on the dowel.

5. Mount the ventilation system of the underground space.


- air holes in the basement is best to replace the exhaust riser, going inside the house from the underground to the roof or the attic, and the supply air hole somewhere in the floor non-residential premises, for example, from the vestibule.

vent stack can be made from a tube with a diameter of 50-80 mm.Sinceriser connects the underground room and cold attic, then because of the temperature difference between the riser creates a small thrust, the intake air from the underground.The natural circulation of the cellar is well ventilated.


- I would make ventilation holes in the corners of the house and chimney set at the center.In my case, ventilation of underground space is provided due to the heating furnace.This underground space integrated with the living room, and the air for the furnace is taken from under the floor.

Thus, warmed and closed underground space could become a component of energy-efficient homes .

Hot discussion is needed whether the base with air holes, is conducted in this subject.Reviews

owners floors on the ground are collected here.How to repair a communication under the slab foundation, look at this topic.

In this video explains how to replace the rotten lower crown in a wooden house.