Make ventilation of the foundation of a private house. Air vents in a shallow strip foundation for ventilation of the underground. Location and size of vents

Air vents in the foundation are needed so that the gap under the floor of the first floor is ventilated; for this, special holes are made in the basement ground part of the foundation.

Such ventilation is necessary, since moisture coming out of the ground can accumulate under the floor. This can lead to the fact that building structures will be under the constant influence of moisture, especially since it will constantly accumulate. This problem is very relevant when used during the construction of wooden structures. At high humidity, it can be defeated by rot and mold, as well as the formation of fungus on wooden structures. In addition, radioactive radon gas can accumulate in the underground gap.

In winter, the concentration of moisture and gas rarely increase due to the action of low temperatures, as the probability of evaporation decreases, and they are able to freeze on building structures, remaining, as it were, in a preserved form until the next temperature rise. To get rid of such a serious problem, such holes are made in the ground part.

Are foundation vents always needed? No not always. These holes are made only in cases where there is an underground space. If your floors of the first floor are made on the ground, then you do not need to make air ducts.

Guided by clause 9.10 of the norm SNiP 31-01-2003 (SP 54.13330.2011) “Residential multi-apartment buildings”, the total area of such air vents should be 1/400 of the entire floor area or technical basement. In places where the release of radioactive gases is possible, the size of the vents will be 1/100-1/150 of the floor area, (p. 3.1. MGSN Guide 2.02-97). At the same time, the minimum area of all products must be at least 0.85 m², and one - within 0.05 m². It should be remembered that large ventilation holes require reinforcement, such as, for example, 300x300mm. The shape of the products can be any: rectangle, circle, square, triangle, etc. As a rule, products are made in the form of a rectangle or square, as they look more aesthetically pleasing, and the implementation of such products does not require special technology. The vents are located at the same interval from each other, while the extreme vents from the corners of the foundation should be located at a distance of no more than 900 mm. Ventilation holes must be placed opposite each other for better ventilation, and their number must be even.

The height of their location from the ground level depends on the height of the foundation, but they can be located at a height of 300 mm and not lower, in order to avoid flooding the underground space with melt water. The law of location is this: the higher, the better.

Product calculation

Let's take two options for the location of the air as examples, and also calculate their number.

Option 1

Initial information:

There is a house with a foundation of 5x6 m along the inner walls, built in the city of Nizhny Novgorod. Based on the value of the minimum size of one air 0.05 m², we accept holes of rectangular section 200x250 mm. Now you should consider the required number of such holes and place them accordingly.

Calculation

Calculate the area of all ventilation holes:

S=F/400=30/400=0.075m²,

where F is the total area of the basement space.

Find out the required number of vents:

N=S/P=0.075/0.05=1.5=2pcs,

where P is the area of one hole.

Based on the calculations obtained, 4 air ducts should be organized so that there are no non-ventilated sections of the subfloor. Why not 2, but 4? But because another rule comes into force here, which requires the placement of such holes at a distance of no more than 900 mm from each corner of the foundation. The height of the location from the ground is 300mm.

If housing has internal partitions with a foundation, then such holes should be in all lintels associated with the foundation. Usually, they are mounted for partitions if it is a wooden house. In this case, full ventilation of the underground space will be organized.

Option 2

Initial information:

A house was built in which it was used, dividing the underground space into two equal parts with dimensions of 9x4 m. It is supposed to make rectangular vents with dimensions of 200x250 mm, which corresponds to the minimum size. The house is located in the Irkutsk region. It is necessary to calculate the required number of products and place them in the right places.

Calculation

Total area of vents:

S \u003d (9x4 + 9x4) / 100 \u003d 72 / 100 \u003d 0.72 m².

Due to the fact that radon gas emissions are observed in the Irkutsk region, the number one hundred is put in the numerator.

Required number of holes:

N1=S/p=0.72/0.05=14.4=15pcs.

From the calculations it can be seen that their number is quite large and this may affect the reliability of the foundation. To reduce their number, you need to increase the initial parameters of the vents from 200x250mm to 250x300mm, that is, up to 0.075m².

Based on the new given condition, we again calculate the number of ventilation holes:

N2=S/p=0.72/0.075=9.6pcs=10pcs.

We take the number 10 as a basis and divide it by 2. After dividing, the number 5 is obtained - this is the number of ventilation holes for each half of the underground space. In the foundation, under the inner wall, it is imperative to make 3 ventilation holes for proper ventilation.

Many developers of private houses do not carry out any calculations and carry out airflow when pouring. As formwork, ordinary sewer pipes with a diameter of 110 mm are used. The number of ventilation holes is calculated approximately as follows: one hole per 2-3 linear meters of the foundation.

Is it correct? Not really, but it's better than no air at all. Even if the ventilation holes were not provided for at the stage of foundation construction, then you will subsequently be drilling airflow no more than 100 mm.

Ventilation of the underground device must be carried out all year round, especially in regions where radon gas emissions occur. Therefore, closing the vents for the winter is not recommended. This requirement is described in SNiP 11-3-79 "Construction Heat Engineering". Having opened such a document on the desired page, you can see table No. 2, which indicates that the air temperature in the basement and the temperature of the lower part of the floor should have almost the same value. A difference of only 2°C is allowed, which can only be achieved as a result of proper ventilation.

If the problem is keeping the heat in the room, then it is better to insulate the floor from the inside, but the ventilation openings cannot be closed.

The calculation of the size and number of air vents is carried out at the design stage of the building, and the ventilation holes are formed during the installation of the upper part of the foundation. But it happens that they are forgotten and remembered when the main work on pouring the foundation is completed. What to do in this case, how to make vents in the finished foundation?

There are several options:

Cut or punch ventilation holes of the desired size using a special tool for this: a grinder or a puncher, or maybe both. The complexity of this procedure depends on the material from which the foundation is made. If it is a brick, then there will be no special problems, and if it is reinforced concrete, then you will have to tinker a lot. In this case, forgetfulness can turn into unnecessary material costs. Prices for drilling such holes range from 10-200 rubles per 1 cm of depth, depending on the difficulty of drilling.
If possible, then arrange the floors of the first floor on the ground. This means that there is no space between the ground and the floor, which makes it possible to solve such a problem without additional costs.

Almost all of Europe practices the construction of individual housing without ventilation, laying floors directly on the ground. Such floors do not suffer from the disadvantages inherent in floors that need to be ventilated. Floors laid directly on the ground are able to withstand much more loads, they do not sag, and due to the lack of underground space under the floor, moisture does not form, which adversely affects the floor and wall structures.

If you forgot about the products, then maybe you should reconsider the technology of laying the floor, and save money by lowering the building. Alternatively, you can fill the underground space with construction debris (brick or building materials waste) mixed with sand and compact well, then lay the floor and do not make any ventilation holes.

The minus of the underground is also that some rodents or reptiles can find shelter in it. In such spaces, if they are very warm, many types of insects, bugs and worms can breed, which will certainly be inside the dwelling.

This can happen when, for some reason, the integrity of the basement space is violated, which will entail the penetration of such “animals” under the floor.

I will say right away that it is rather difficult to make ducts in the foundation with your own hands, since the thickness of the tape varies between 40-60 cm. And drilling reinforced concrete of such a thickness is long and costly.

There are several ways to make holes in the foundation:

Basement superstructure made of bricks and with pre-drilled holes. This method is the most correct and quite simple, but applicable in all cases. So, for example, if the walls have already been erected, then, of course, it will not work to build a basement.
Making holes with a puncher is the most popular and affordable way among private developers. Depending on the brand of concrete and the degree of its reinforcement, it will take from several hours to one full working day to complete one blow. In this case, you will have to spend a few drills on concrete. Holes are drilled around the perimeter of the ventilation hole, it is not necessary to work with a perforator at full capacity and periodically moisten the drill with water to avoid overheating.
Use crowns on the bud and drill out the concrete step by step, and then knock out the concrete with a puncher with a pike. Too difficult and not fast way.

With the onset of the first autumn frosts, field rodents begin to look for habitats with more comfortable conditions. Such shelters of mice - voles are found in suburban buildings. There they are not afraid of the piercing wind, which, at sub-zero temperatures, makes the fields unsuitable for existence.

The small size and innate slyness allow mice to penetrate the smallest openings in buildings. Most of all, they are attracted to underground rooms, where the accumulated heat is stored longer.

Air ducts (holes for ventilation of the underground space) are the easiest way for rodents to enter the dwelling. From the underground, they will find opportunities to settle throughout the house.

How and how to close the vents in the foundation from mice?

In order to exclude unwanted neighbors from settling in a country house, it is necessary to securely close the vents in the foundation from mice, that is, to block the paths of their possible penetration. The easiest way to achieve this is by installing gratings on the underground air vents. Grid cells should be no larger than 5 mm. Such products can be searched in stores of building and household goods. It's easy to make them yourself.

If there are no finished products in stores, a wire grate or a rigid mesh will definitely be found. Having estimated the total area of \u200b\u200ball ventilation holes, we acquire the desired material. We cut the lattice with scissors for metal into rectangles of the required size. Next, you need to make the frame details, and arrange the products in their final form.

For the manufacture of the frame, white or canning tin, which can be found on the farm, is used. Tin is cut into strips about 60 mm wide. The strips are folded twice in length, forming a lattice frame. The wire rectangle is framed with the obtained details of the tin strips and fastened by tapping with a hammer. The manufactured frames are installed with dowels and screws into the drilled holes, closing all the vents.

How to get rid of already infiltrated mice?

When access to the house for uninvited guests is blocked, you need to make sure that they have not yet entered the home. To do this, you need to place equipped mousetraps in the house for a while. If traditional mousetraps are unpleasant for their cruelty, you can use the novelty.

New mousetraps are made in the form of slamming plastic cases. It does not injure rodents, but it securely locks inside. For some time in the trap, the mouse will be alive. You can release it into the nearest forest or field.

In this way, you can reliably protect yourself from unwanted neighborhood. It is much safer than using poisonous substances. When using poison, a negative effect on the health and well-being of people and domestic animals cannot be ruled out.

In every house, no matter what materials it is built from, a certain humidity must be maintained. With its redundancy, a fungus may appear, and this harms not only the wooden surfaces of the building, but also its residents. To avoid such unpleasant moments, an air purification system must be installed in each private building, not only indoors, but also for the basement, which is especially relevant wooden house foundation ventilation a.

Dimensions and number of products

Ensuring a good and properly implemented air purification system in the basement of a wooden building is vital. Ventilation in the foundation of the house must be carried out around the entire perimeter of the basement of the building at the stage of construction. Its quantity and dimensions are designed depending on many factors, such as:

nature of the soil
foundation depth
direction of prevailing winds
mean annual temperatures
terrain

If we take average values, then foundation ventilation worked fine, just make a couple of holes on both sides. In this case, the size of the vent should be 100x150 mm. For a strip foundation, the distance of the ventilation hole from the ground level should be about 300 mm, but again taking into account the height of it itself.

Plinth ventilation device

Basement ventilation should provided at the early stage of construction building - its design. And the direct device of the system is made during the reinforcement of the foundation. Most often, the ventilation of the foundation is carried out from asbestos-cement or plastic pipes. To do this, segments of a certain length are installed in the reinforcement structure around the entire perimeter of the building and fixed with a tie wire. To prevent concrete from entering the ventilation openings when pouring the foundation, they must be closed during construction work.

Experts recommend that in order for the basement floor to be normally ventilated, and there was no dampness and mold in it, arrange two holes with a diameter of at least 15 cm from opposite sides. This is quite enough for an ordinary wooden house.

If we are talking about building a building in a lowland area where there is no natural air movement, then it is recommended to make ventilation holes on all sides. At the same time, all foundation ventilation can be adjusted with the help of plugs.

The process of arrangement itself consists of the following steps:

installation site markings
preparation of pipe sections of a certain size
fixing them horizontally in the foundation using knitting wire
filling the prepared holes with dry sand so that cement does not enter during pouring

The pipes in the ventilation openings must be located in such a way that their end faces fit snugly against the inner surface of the formwork. For the most efficient operation of the foundation ventilation system and air flow regulation in the future, it is recommended to make at least one additional hole, the functionality of which can always be limited using a special plug.

It is desirable that the vents in the warm season be covered with a mesh or closed with a special perforated sheet of metal. This is necessary so that rodents cannot enter the house. In cold weather, it is recommended to completely close the ventilation openings, so frosty air will not enter the basement.

It is also necessary to pay attention to radius calculation for round pipes and sections for having a rectangular shape. It is produced according to special formulas for each specific project and is necessary for its correct operation during operation.

Video instruction - how to drill holes in a strip foundation

Competent ventilation in the house is the most important component of a healthy and comfortable life support and is as important as water supply and heating. That is why the ventilation system during the construction of any building should be given special attention. Properly done ventilation will save the house from excess moisture, significantly increasing its service life.

Why ventilate the foundation?

Many "self-builders", having equipped their own home with a good ventilation system, completely forget about the ventilation of the foundation, which is the basis of any structure. But the moisture that forms in the unventilated space of the foundation, penetrating into even the highest quality concrete, destroys the reinforcement cage and leads to the weakening and complete destruction of the foundation. In addition, in autumn, warm air from the underground penetrates into the cold, unventilated space of the basement. At the same time, the moisture in the air falls as condensate on the ceilings and walls of the foundation, penetrating deep into the material. With the advent of frost, the moisture inside the material freezes, and, as is known from school physics lessons, when freezing, water expands, leading to cracks and destroying the foundation of the house. This is still an incomplete list of the detrimental effects of high humidity in the foundation space. You can also recall the harm to the health of the inhabitants of the house from fungi and mold, which develops perfectly in stagnant and humid air. After listing the troubles that arise in the base of a house that is not equipped with ventilation, we hope that no one will have a question: “Do I need foundation ventilation?” Many people think that equipping the base of the house with a ventilation system is a complex and rather expensive process that requires special skills and knowledge. This is by no means the case: arranging the foundation with ventilation will require your desire, understanding of the principle of its operation and the skill of handling the tool.

Arrangement of ventilation of the base of the house

Many people ask how to install ventilation in the foundation of a private house. In order to properly organize the ventilation of the basis of any structure, you should initially do theoretical training. For effective ventilation of the base of the building, it is enough to correctly organize holes, the so-called vents, through which air will enter and exit, saving the foundation space from excessive moisture.

Each vent must have an area of at least 0.05 m 2. In practice, such large holes are rarely made. Each of these holes is replaced by several, but so that the total area of \u200b\u200bthe vent is at least 25 cm 2. A group of such holes is considered to be one vent.
All ventilation openings must be evenly spaced around the perimeter of the plinth, excluding the appearance of stagnant zones. It is better if it will be two vents on each side of the base, located at a distance of no more than 1 m from each dead corner of the base. A hole in the basement of the house for ventilation, located directly under the ceiling, will reliably protect it from any time of the year.
The total area of the holes is calculated from the area of the foundation and should be 1/400 of the part. For example: if the foundation area is 100 m 2, then the airflow area should be 0.25 m 2.

It should be noted that in order to reduce the release of condensate, complex solutions should be used: carefully insulate the foundation itself, before erecting which, make high-quality waterproofing of the free space. To do this, you can use a roofing material, hydrobarrier or ordinary plastic film, which are offered in any hardware or country stores.

After that, the floor in the basement should also be insulated with any material intended for such work. These operations will not allow the soil in the basement to freeze in the winter cold and will not allow the cold to be released when the thaw occurs.

Tip: If the house is located on a plain, and there are no buildings nearby that block the movement of air currents, then two holes, 15 cm in diameter, on each side are enough for good ventilation of a conventional tape base. If the house is in a lowland, then it is necessary to provide additional vents of the same diameter, located along the entire length of each side of the basement.

Stages of work

As a rule, ventilation holes in the foundation are planned at the stage of laying it. These works are carried out when laying the armored belt of the base. In strictly defined places of the base, between the reinforcement, pieces of plastic or asbestos-cement pipes are inserted and carefully fixed so that the ends of the pipes fit snugly against the formwork. In order to prevent the pipes from deforming during the pouring of the armo-belt solution, they should be filled with sand and muffled. After the concrete has hardened, clean the ventilation holes from the remnants of sand and cement that has fallen into the bottom.

Tip: Most experts recommend making additional blowouts on each side of the foundation. The thing is that all owners of suburban real estate must close the vents with a metal mesh, decorative grilles or perforated metal sheets to prevent the penetration of rodents, insects and other "evil spirits". This can significantly reduce the overall cross section of the ventilation openings. An additional hole in this case would be useful. If not needed, such vents can always be closed with plugs, and by opening them, you can regulate the movement of air in the basement.

If the foundation was built without air, then they can be done after, however, this will require a specialized tool, which is not so easy to purchase. You can hire a team that specializes in such work, but it is quite expensive, albeit quickly. You can drill holes using a powerful puncher, a special device to support the tool in a strictly horizontal position and a diamond crown of the required diameter. During this operation, there is a risk of falling into the armature. Of course, it can be cut out, but this will significantly weaken the foundation of the house. Video of drilling air in the finished foundation of the house: https://www.youtube.com/watch?feature=player_detailpage&v=KpVdgFPhN0U

Questions and answers

Question:
Why is it necessary to insulate the foundation, if the ventilation of the strip foundation in the winter will reduce these efforts to zero anyway?

Answer:
If the base of the house and the ground are insulated, then in winter the temperature in the subfield will be above the dew point and condensation will not form. With an insulated base, it is possible to close the vents with plugs, opening only sometimes two, on opposite sides of the base. Thus, the cold will not lower the temperature of the floor in the house, and the level of air humidity will be within normal limits.

Question:
How to make basement ventilation in a wooden house?

Answer:
Ventilation of the basement in a wooden house is no different from ventilation of the base of a brick, reinforced concrete or aerated concrete house. The requirements are the same, the main thing is that all the premises of the basement have openings for the free circulation of air masses.

Answer:
You can use the tables given in the specialized literature, or calculate it yourself using the formula:

de = 1.30 x ((a x b) 0.625 / (a + b) 0.25)

where:
de is the equivalent diameter in mm;
a and b are the sides of the rectangular hole.

We hope that our publication will help you equip the base of your house with a high-quality and efficient natural ventilation system, thanks to which the building will serve you for many years.

Wood is a material prone to damage by fungus and mold with prolonged exposure to moisture. So that the structures that form the lower part of the floor in a wooden house do not collapse ahead of time, it is necessary to provide for ventilation of the foundation base. For this purpose, special products are equipped in the foundation of a wooden house.

Why do you need vents

Holes in the plinth are not required in all cases. The technologies adopted in Europe for the construction of low-rise buildings differ from our traditions. After the installation of the strip foundation, the base is backfilled with soil or sand flush with the surface, a closed reinforced concrete or stone tape. A slab floor of a hanging or floating type is laid on top of the backfill.

In cold weather, such a backfill of soil or sand serves as a conductor of heat from the soil to the concrete floor slab; in the heat, such a floor keeps cool. A monolithic slab laid on a bulk base does not freeze through in a mild European climate.

Capital construction in Russia requires the installation of deep foundations - below the freezing line of the soil. During the construction of private wooden houses, a cellar or basement is often equipped. And in this case, the presence of ventilation holes in the foundation is mandatory.

If you neglect the products, wooden structures will begin to rot. And this is not only the rapid destruction of wood and financial investments in major repairs, including the replacement of the lower rims of the log house. Lack of ventilation under the floor also leads to:

to high humidity on the ground floor of the house due to condensation;
to the appearance of unpleasant musty odors;
to air pollution by mold spores, which can cause allergies or exacerbate asthma, worsen the health of people with chronic lung diseases;
to the appearance in the house of a large number of insects that feed on rotten wood.

Dimensions and location of the products

Vents in the foundation should be provided regardless of the type of foundation. The location of the holes is regulated - the distance to the ground level must be at least 20 cm, otherwise during heavy rains there is a risk of moisture penetrating into the underground of the house.

At least 2 air vents must be placed on each side of the foundation base. The longer the wall, the more vents will be required for high-quality ventilation.

In some cases, the organization of products is not necessary:

if ventilation holes are made in the floor of the house;
in the presence of a high-quality ventilation system in the basement;
when using structures and materials in the construction of the foundation that do not prevent the free penetration of air into the space under the floor;
when the gap between the floor of a wooden house and the ground surface is filled with sand and covered with a vapor-tight material.

To ensure intensive air exchange between the street and the space under the floor, the vents in the foundation are arranged in pairs - opposite each other. A draft draws out moisture, dries out the wood, preventing mold from spreading and condensation from accumulating.

Products in the strip foundation:

must have a diameter corresponding to the dimensions of the building - on average, the size of the vent is from 50 to 100 mm, the larger the perimeter of the building, the larger the diameter of the hole should be;
step of installation of products - from 150 to 300 cm;
if there are jumpers in the strip base for internal load-bearing walls, they must also have air vents.

Arrangement of vents at the stage of foundation installation

Vents in the foundation of a wooden house must be provided at the project preparation stage, so that later the problem of ventilation of the underground space does not have to be solved.

The extreme vents on each side of the foundation base must be located at least a meter from the corner of the structure. This is necessary so that air pockets do not form. Having determined the locations of the extreme holes on the project, they find the optimal places for the rest. It is important to ensure that the holes in opposite walls are strictly opposite each other.

The traditional way of arranging the vents was that at the stage of preparation for pouring the foundation, trimmings of a beam with a section of 100x100 mm were fixed in the marked places. After the concrete had hardened, these wooden mortgages had to be removed. You can try to knock out wood with a sledgehammer, but shock loads are harmful to the concrete base, which is gaining strength.

It is more convenient to make several through holes in the immured trimming of the timber, and then use a chisel to knock out the main part of the wood. A chisel and a hammer will help remove the remains of a wooden mortgage.

Such work takes a lot of time and effort. Today, in order to get neat, even holes, just at the stage of reinforcing the formwork, pipe trimmings of a suitable diameter are fixed in the right places. Ideal sewer polymer pipes that can withstand pressure and temperature extremes.

Pipes with a diameter of about 100-150 mm are inserted into the reinforcing mesh according to the project and securely attached to the mesh with a tie wire. The elements must be horizontal and not move when pouring the concrete mixture.

To prevent concrete from accidentally getting into the pipes during pouring, they are pre-filled with sand or soil and the holes are plugged on both sides. Knot bags made of rags stuffed with sand or soil are suitable as plugs. Filling the pipes with bulk materials also prevents them from deforming or breaking under loads from concrete entering the formwork.

Instead of polymeric sewer pipes, it is allowed to use wooden boxes or asbestos-cement pipes. But these options are more time-consuming, since each box should be put together from a cut board, and after the concrete has hardened, remove the wooden elements from the holes. When cutting an asbestos-cement pipe, harmful dust with asbestos fibers enters the air.

After the concrete dries and gains strength, plugs and poured sand are removed from the pipes. Cleaned ventilation holes are recommended to be closed with metal meshes - this will prevent rodents from penetrating into the underground. The fine mesh also prevents insects and debris from entering the space under the house.

Arrangement of vents after installation of the foundation

If the vents in the foundation were not designed and the appropriate mortgages were not installed before pouring, they can also be made in the finished foundation. This will require the use of a powerful electric drill equipped with a diamond core bit of the appropriate diameter.

Drilling with a crown practically does not exert shock and vibration load on reinforced concrete structures. But it is impossible to punch holes in the foundation with a puncher - microcracks form in concrete, especially if it has not gained strength, which will lead to premature destruction of the foundation structure.

The second option for arranging the vents is to erect a basement of a suitable height on the foundation tape - it is in the basement that the necessary holes can be made. Please note that this will raise the floor of the first floor relative to the original design. They resort to arranging a basement with air vents if, during the installation of the foundation, they forgot to install mortgages for the holes.

If a log or timber frame is erected on a “deaf” foundation, where ventilation holes are not provided, they cannot be cut in the lower crown - this will weaken the support link and the wall structures will not be able to withstand the calculated operational loads.

There is a third option that can be used in this case: ventilation holes are cut into the floor of the first floor. Such vents are closed with decorative grilles that will prevent large things from falling into the underground, and rodents from entering the house.

Furniture should be installed above the ventilation openings so that there are no constant pressure drops in the house. Holes in the floor are not the best way to ventilate. They contribute to the penetration of dampness from the underground, soil odors, harmful gases and fumes into the dwelling. This creates unfavorable conditions for life.

When to close and open the vents

The ventilation of the foundation of a wooden house has different modes of operation depending on how the building is operated. Leaving an unheated house or cottage for the winter, it is advisable to cover the ventilation holes in the foundation - all or only part of them.

If people live in the house all year round, and the building is constantly heated, there is no need to close the vents. Otherwise, the temperature difference will cause condensation to form in the underground, and this is moisture that contributes to the destruction of wood.

So that the house does not lose heat when the air is open, the owners need to heat-insulate the foundation base and the basement in advance, take care of installing the floor of the first floor with lower insulation. This will help maintain an optimal microclimate in the house all year round, save on heating during the cold season and at the same time keep the wooden structures of the lower part of the floor and walls dry.

Conclusion

In order for a wooden house to serve for decades without requiring major repairs, it is important to ventilate the space under the floor, designing it at the stage of preparing the foundation drawings.

The number and location of holes depends on the size and configuration of the building. We must not forget about the holes in the internal lintels of the tape-type foundation base.

The foundation of the building is what the construction of the house begins with, and the destruction of the entire structure can also begin from it. Cracks appear at the base of the building, which will violate its integrity. The reason for their occurrence is improper ventilation of the foundation or its complete absence. If you do not equip the vents at the base of the house, then the wooden elements - walls or floors - will begin to rot, which will entail the irreversible destruction of the entire structure. Often during construction, these small but important holes are forgotten, thereby reducing the life of the building:

In some cases, the arrangement of vents is not necessary

Vents or air vents are important elements of the foundation of the house, which must be considered at the stage of building the foundation. They are small holes. In their organization, there are some rules and parameters that should be followed. This is laid down in the basic rules of construction. These structures are necessary in order to keep the fluctuation of the temperature difference between the floor and the underground at a level of no more than 2 degrees. Such conditions are created in the presence of well-organized ventilation.

But there are cases in which the arrangement of vents is not necessary. This is possible if:

the basement is used as a cellar or food storage;
there is a direct passage between the underground space and the living rooms above it;
the material that was used to finish the basement is a vapor-proof film material laid on top of each other in a layer of at least 15 cm;
in the basement there is a ventilation system that pumps from 0.5 to 1 liter of air per second for every 5 sq. m. area;
when processing the inner surface of the foundation and the soil inside it, heat-insulating materials were used.

The foundation project does not provide for the presence of vents in it in the cases listed above, in the rest it is necessary to design the correct ventilation of the underground spaces.

How many vents to make and what size

The number and size of vents is calculated individually in each individual case. This indicator depends on the conditions in which the building is operated. When calculating, the following factors should be taken into account:

climatic conditions;
the composition of the soil on which the house is being built;
landscape features of the area.

Foundation design technology provides the maximum number of vents for swampy lowland areas or climates with high rainfall. Experienced builders recommend making air ducts in each wall of the foundation, even in those that are laid under the inner wall of the building.

The size of the vents is calculated as follows: the total floor area is measured, then this figure is divided by 400. The resulting value is divided by the number of vents that are planned to be made. This figure will be the size of their optimal area. It is not difficult to calculate how many ducts you need to make - holes should be located every 2-3 meters along the entire length of the walls.

But these calculations are not correct for all climatic zones. For areas with high humidity, experts advise to focus on the following example in calculations: per 100 sq. m of the basement, make 25 ducts with a diameter of 11 cm.

Building regulations state that in a room that is not equipped with exhaust ventilation, vent holes should be sized in a ratio of 1 to 400, relative to the area of \u200b\u200bthe entire basement. Make holes less than 5 square meters. see is not possible. If the area is characterized by a high content of radon, the estimated number of vents should be increased by 3-4 times.

Arrangement of vents

Before you get started, you need to prepare the tools. To equip the vents you will need:

shovel;
sledgehammer and hammer;
perforator or drill;
drill for wooden materials 2.5 cm thick;
drill for metal 1.4 cm;
chisel straight and semicircular;
pipes with a circular cross section, diameter - from 11 to 13 cm, material - plastic or asbestos cement;
sand.

The design of vents must begin at the stage of laying the foundation. For a strip foundation, this process begins during the arrangement of the formwork for pouring concrete. The distance from the soil to the air must be at least 30 cm. This is necessary so that during the melting of snow, moisture does not enter the hole. In parallel walls, all holes must also be parallel.

For the manufacture of vents, round pipes are used, you can use a wooden beam, but in this case it may be difficult to remove it. How to properly remove the timber from the frozen solution, read below.

The process of laying vents looks like this:

The pipes are cut into pieces, the length of each piece must correspond to the size of the formwork and the width of the base of the house.
Sand is poured into each pipe, the ends are covered with rags or paper so that the sand from the pipe does not spill out, and building material does not get inside the pipe.
Prepared pipes are placed in places designated for vents. This must be done so that they rest tightly against the parallel sides of the form.
The pipes are filled with concrete.
In the case of making air from wooden blocks, the process looks about the same, but bars are laid in the concrete, which remain for a month, until the solution is completely dry, and then removed.

How to remove timber from concrete

Wooden beams embedded in raw concrete must be removed. To carry out the work you will need the following tools:

A set of drills for metal.
Electric drill or hammer drill.
Drills for wood.
Semicircular chisel.
Straight chisel.
Sledgehammer or heavy hammer.

Routing:

Using a drill for metal, make two parallel holes along the perimeter of each wooden block. For a thin bar, one hole in the center is enough.
With a drill for wood, make a through hole in the places of the basting.
Take a semicircular chisel and expand the hole towards the side of the beam. With a straight chisel, beat off a part over the hardened concrete. Remove two beam corners in this way.
Take a sledgehammer and beat off the remaining two corners.

For small concrete blocks, in which bars of small section are inserted, you can apply the folk method. Lubricate each bar in advance with any oil. Removing the bar is much easier and does not require the application of physical force. The ends of the vents are freed from paper, sand after the concrete mortar has hardened on the strip foundation. The ventilation of the foundation needs protection; for this, a special grill is installed on each hole for ventilation. A preventive measure necessary to ensure a constant flow of air into any room, including the basement. The mesh will additionally protect the penetration of rodents and insects into the house. The lattice can serve as a decorative element of decoration. Modern industry offers different colors and types of these products.

For efficient air supply to the vegetable storage room, the construction of ventilation ducts is provided. A common version of the system design is the installation of paired pipes. One is placed under the ceiling, the second is lowered to a distance of 0.5-0.7 m from the floor level. Natural traction is created. The hood is able to decorate the exterior of the house and the foundation, photos with interesting, original types of gratings will help determine your need for such a design, choose the option of interest.

Perform seasonal cleaning of ventilation vents. Purchase a long, strong, lightweight stick or pole. Put a polypropylene whisk on one end and stick it into the hole to the maximum possible depth. Turn the tool several times clockwise and counterclockwise. Rinse with clean water and repeat cleaning. Wash protective screens or grills with baking soda, not with soapy water.

What to do if the vents were not designed in advance

There are many reasons for the lack of vents in a built house. There is only one way out of the situation - to correct the defect.

Method one, for the case of an unfinished building.

One of the radical and reliable ways to eliminate the flaw in terms of construction will be the construction of a basement on the foundation. Holes for ventilation are made in the basement. In a brick plinth, it is enough to insert a brick with an edge to form an air vent.
In a concrete, poured basement, a ventilation hole is made according to the method described above for a concrete foundation.
If it is impossible to raise the level of the floor with the help of a plinth, holes for vents are made in the foundation. You will need a special drilling device. It can be a pneumatic hammer, a diamond drill, a hydraulic hammer. The process is difficult and responsible. Impact tools cause dynamic destruction, microcracks are formed, fragments of the base fall off, the structural configuration of the reinforcement is disturbed. The subsequent operation of the building will lead to the penetration of moisture into cracks, oxidation of the metal frame, scree.
It is reasonable to invite a specialist with a modern working tool to perform this section of work. Find a listing of companies, look at several offers, choose from the advice of former clients.
When drilling the foundation, follow the insertion of the frame. This is an important point. The frame will take on the pressure of concrete and will not allow the vent to deform.

Method two for a residential building:

Create a ventilation system not through the foundation, but through the living rooms. A place is selected in the floor that is not subject to a load difference and holes are drilled. Optimal areas are located in the rooms under the legs of furniture, in the corners, under the stairs. The vents are covered with metal mesh.
The implementation of ventilation in the foundation is carried out not so much due to the classics of construction, but for your own comfort. Qualitatively made vents are guaranteed to protect the wooden parts of the building, auxiliary buildings inside the house from moisture, rotting, mold. For strip foundations, the arrangement of vents is a mandatory measure to protect the building from premature deterioration.
The construction of a foundation with holes for vents provided in advance prolongs the life of the building, eliminates the constant repair of basements and cellars, and saves the house from subsidence.