Is it necessary to close the vents in the foundation for the winter in a bathhouse?

Ventilation in a bathhouse is not only comfort, but also an urgent necessity. It is needed both during and after bath procedures:

During the process, it is important that no one gets burned . The danger of carbon monoxide poisoning always exists - this is the result of incomplete combustion of fuel. Therefore, ventilation is necessary for the safety of people in the bathhouse.
In addition, the air that is inhaled and exhaled becomes “waste” and must be removed, replacing it with new air with a higher proportion of oxygen.
regulate the temperature while monitoring the condition of people using ventilation, especially when you need to do this urgently.
Any stove runs on oxygen (combustion is oxidation), so it also needs ventilation. And with the right device, you can also get fuel savings .
And finally, drying after, on which the durability of the structure, especially its wooden parts, directly depends. Ventilation can be a good prevention of fungi and rotting .

At the same time, bath ventilation is quite complex and varied in design. Of course, the issue can be reduced to financial investments, but in reality you just need a good ventilation specialist who will find the optimal solution in each specific case. We will consider all the possibilities and features of the ventilation device in the bathhouse.

Is it worth providing vents?

To put it simply, vents are small holes that are located around the perimeter of the foundation. Through them there is an exit and inflow of air, which is necessary for ventilation. If it is absent, irreversible processes may occur in the base. For example, the air contains moisture, if it is not removed in a timely manner, it begins to condense on various surfaces. In the underground, moisture appears as a result of vital processes that occur in the house. Moist air seeps through the floor covering. There is soil under the house that does not freeze in winter. Since it tolerates moisture well, it begins to evaporate and also settles on surfaces.

In the presence of positive temperatures and humidity, bacteria multiply well and putrefactive processes occur. This also happens in the foundation space. Mold and various fungi begin to multiply at a rapid pace. Over time, mold begins to penetrate from the foundation through the floor into other rooms. This will inevitably lead to damage to beams and wooden floors. In addition, when there is an abundance of moisture, it penetrates into reinforced concrete structures. The reinforcing component loses its strength and may fail. There is another important reason why foundation ventilation is needed.

Radon continuously rises from the soil. It is a gas that, when combined with other substances such as water, can be useful in certain quantities. But with its abundance, the body is poisoned. If the foundation is not properly ventilated, then radon will accumulate in the foundation space and eventually enter the house. To solve these issues, vents are made or ventilation is made. In the second case, a separate ventilation pipe will need to be led outside the roof. For the process to take place, it is important to supply portions of fresh air. This can be easily achieved by constructing cross-ventilation grilles from the rooms. The advantage of this solution is the aesthetic component, because you don’t have to make holes in the foundation.

Why do you need vents in a strip foundation?

In such cases, waterproofing is not able to completely protect against moisture, since groundwater can also affect the structure. Increased humidity in the underground space leads to unpleasant consequences:

Saturation of a concrete structure with moisture. This leads to its gradual destruction. If nothing is done, after some time moisture will get onto the fittings, which will lead to corrosion.
Penetration of water vapor into the house through the floor. This can happen even if the waterproofing layer is created according to all the rules.
Destruction of finishing materials and supporting structure.
The appearance of fungus and mold under the house.
Stale air in the basement.

Ventilation in the foundation.
If a house is built of wood, vents save the material from rotting, because in their absence, the lower crowns can begin to rot. Also, the constant presence of condensation will negatively affect the concrete. It is worth noting that a pile foundation with a low grillage does not require the creation of vents.

When vents are not needed

Some design solutions that were made during the construction of the building make it possible not to construct vents. Among them are:

closed underground space;
presence of vapor barrier;
presence of underground ventilation;
there is a basement or garage under the house.

An underground space can be considered closed when the floor is a solid floor slab. At the same time, the space underneath should be filled with soil or sand. Ventilation will not be required even if a vapor barrier membrane has been laid under the floor. If it is laid in a single contour without gaps at the seams, then gas exchange occurs in one direction and radon does not enter the room. Additional ventilation in the form of vents in the foundation is not required even in cases where the subfloor is already ventilated in passive or active mode. In this case, the air exchange must be at least one liter per second per 10 m2. Air vents will not be required if the basement space contains a basement for storing various things or a garage. Thanks to frequent visits to these rooms, a natural exchange of air masses occurs, which prevents the occurrence of unpleasant situations.

Note! The latter aspect may not require the use of vents, but ventilation for such rooms will still be required. It is constructed by installing two pipes, one is a supply pipe and the other is an exhaust pipe.

Ventilation system in the bathhouse: what could it be like?

Ventilation systems in baths are divided according to several parameters:

Let us explain that forced differs from natural in the presence of fans that force air in or out; local differs from general ventilation in its local character, for example, a chimney above the stove is local ventilation, and vents are part of general ventilation.

As for the supply, exhaust and their combinations, these are designations of what air is directed where: the exhaust drives exhaust air outside, the supply drives fresh air inside, and their combination creates a balanced air exchange inside the room.

These are general terms for any ventilation, but our task is to consider a bathhouse, which has its own specifics. We advise you to also familiarize yourself with the dependence of ventilation on the type of bath (8 types).

Useful video

Watch a short video as one of the options for organizing ventilation in a bathhouse:

Natural ventilation in the bath

It works on the principles of physics, which say that heating makes air lighter and causes it to rise. And an increase in the volume of cold air accelerates the movement of hot air. Knowing about this property, you don’t have to install any appliances at all, just ventilation holes, the location of which will make some of them supply air, and others exhaust.

There is also a stove in the bathhouse, and this is a very favorable circumstance for directing air circulation. If the natural ventilation inlet is located near the floor next to the ash pan, then the stove itself will draw in fresh air, without any fan. Raising the finished floor slightly above the hole under the firebox also improves traction.

The exhaust hole is usually made on the side opposite the wall with the supply hole, but this is not the only option.

Forced ventilation

If you install fans in the same holes, then you don’t have to worry about calmness or other weather conditions that have a bad effect on air circulation in the bathhouse.

In principle, there is no big difference between natural and forced ventilation in the design itself; it is just a matter of which holes the fans are in. Because you can’t install them everywhere, enhancing only the exhaust or only the inflow. But by creating a large difference between the inflow and outflow, we change the pressure in the room. This is easily detected by the way the door slams. The task is to create a balance between outflow and inflow, and the air during bath procedures should circulate slowly, without causing a draft. And when drying, a draft is only beneficial.

What size should the holes be?

Perfumes cannot be made at your own discretion. There are certain standards that regulate their number, as well as the method of location in the foundation. SNiP with serial number 31/01/2003 is taken as the basis. One of its paragraphs (9.10) indicates the area of vents that must be present to ventilate the basement space. The total area of all vents should be more than four hundredth of the subfloor area. That is, you first need to calculate the total area of the subfloor. If it is of the correct shape, then it is enough to multiply the width by the length. For a complex shape, you will need to divide the subfloor into simple shapes and sum up their areas. This does not take into account the area of the foundation.

If the internal area of all rooms is 120 m2, then the total area of the vents will be 0.3 m2. If we translate these values into more visual ones, then round vents should have a diameter of at least 25 cm. For rectangular vents, the minimum dimensions should be 10x50 or 20x25 cm. With a large area, the dimensions of the vents can be significant. For a private one-story house this can be a problem. To solve this, you can make smaller vents, but increase their number around the perimeter of the foundation.

The location of the vents in the foundation strip also has some nuances. Holes cannot be positioned flush against the top edge. The top point of the vent should be at least 15 cm below the top edge of the foundation strip. There are times when the foundation does not rise above the ground surface to the required level, then it is necessary to dig a small pit and fence it off so that the earth does not fall into the underground. The location of the vents should not be chaotic. They should be evenly distributed on each side of the foundation. Those vents that are on opposite sides must be opposite each other so that the air masses can circulate freely.

If the foundation has lintels for partition walls, then holes must also be made in them to allow air to circulate. The minimum distance that should be between vents is 2 meters. There must be at least one vent per partition in the foundation. In addition, if there is only one, then the size of such a vent should be several times larger than that located in the outer wall of the foundation. Instead of one large one, you can provide several with a smaller diameter. The underground is an excellent place that animals and insects will happily choose. To prevent this from happening, the holes must be covered with a metal or plastic grill, which will serve as a barrier to penetration.

Manufacturing process

It is better to lay the basis for making ventilation holes during the construction of the foundation. If this has not been done, then you will have to sweat while making vents in the foundation, which has gained strength.

During installation of the foundation

If the foundation is made of reinforced concrete slabs, then the gap that will be left between several blocks can serve as a vent. In this case, it is important to be careful so that the bearing capacity of the foundation is not damaged. If the foundation is brick, then one of the bricks is installed without mortar so that it can be easily removed. With strip foundations that are completely poured, things are somewhat more complicated. After installing the formwork and lathing, it is necessary to prepare sections of asbestos-cement, plastic or metal pipe in advance. The cavity of the pipe is filled with sand, and it is placed in its place. After the foundation has gained the required strength, the formwork is dismantled, and the sand is blown out of the nozzle hole. Next, the grille is installed.

In the finished foundation

Making vents in a finished foundation entails a lot of hassle and time. You can punch them using a hammer drill. To do this, you will have to acquire a fairly powerful unit and buy drills and peaks for it, the length of which will be equal to the thickness of the foundation wall. You can go the other route and rent a drill press or hire a crew that owns one. It is a special mechanism that is attached directly to the plane and, using a crown, is able to select a hole of the required diameter.

Advice! If expansion of the vents is required due to insufficient ventilation, then you can do differently. To do this, you need to insert a pipe into one of the vents, which will be raised above the roof. A draft will be created through it, which will increase the air flow through the subfloor.

What to do with products in winter

Ventilation is needed all year round, so you need to know what to do with the vents in the foundation for the winter. In winter, less air from the street enters the room than in summer. This is explained by the need to maintain heat and eliminate condensation due to temperature changes. This approach also has negative consequences. The flow of warm and humid air into the underground increases, so the amount of condensation can increase significantly. The situation leads to the conclusion that there is no need to close the vents for the winter, but it is important to make sure that it is possible to cover them in case of strong snowstorms. If this is not done, then snow can fall into the underground and from the warm air it will melt and the amount of moisture will increase. At the stage of constructing ventilation holes, you can install grilles with blinds that will close or install small doors. Additional information about the products can be obtained from the video below.

Note! When there are open vents in winter, it is worth taking care of good floor insulation. Otherwise, coolant consumption may increase by 30 or 50 percent.

Ventilation device in the bath: principles of operation

Bathhouse ventilation can be divided into permanently functioning (roof, foundation, wall) and periodically functioning, during bathing procedures and stove operation. Both are parts of a single ventilation system, which is laid during construction.

The principle of operation of the ventilation system: displacing exhaust air with fresh air. In the most primitive case, two holes are enough for this, but in practice the directions of flows also matter, so the number of supply and exhaust openings can be increased, and they themselves are equipped with dampers, which are a means of controlling flows, their volumes and speed.

Regardless of the location, the supply air is always made lower than the exhaust. Sometimes air flow is provided through the blinds at the bottom of the door to the steam room. But there is one rule: where the air comes from, it must be given there . If we take it from the premises, we need to return not to the street, but also to the premises. Otherwise it won't work.

Calculating the area of ventilation windows is quite simple: we must proceed from the fact that each cubic meter of room volume requires a window with an area of 24 cm². Under no circumstances should the windows be made directly opposite each other at the same height.

To help you, material has also been prepared about ventilation schemes in the bathhouse (10+ different schemes).

Summary

As you can see, vents are an integral part of the structure. Without them, it is impossible to provide the required subfloor ventilation. They must be open at any time of the year. It is better to build them at the stage of laying the foundation. In this case, they can be easily placed at the required level without disturbing the integrity of the base.

To keep the underground of a private house dry, the space must be ventilated. Home owners either create vents in the foundation or install an exhaust pipe that leads to the roof. Before winter, many home owners ask themselves the question: is it worth closing the foundation vents for the winter? To answer this, you need to know the purpose of such holes in the base.

Why do you need vents in a strip foundation?

Saturation of a concrete structure with moisture. This leads to its gradual destruction. If nothing is done, after some time moisture will get onto the fittings, which will lead to corrosion.
Penetration of water vapor into the house through the floor. This can happen even if the waterproofing layer is created according to all the rules.
Destruction of finishing materials and supporting structure.
The appearance of fungus and mold under the house.
Stale air in the basement.

If a house is built of wood, vents save the material from rotting, because in their absence, the lower crowns can begin to rot. Also, the constant presence of condensation will negatively affect the concrete. It is worth noting that a pile foundation with a low grillage does not require the creation of vents.

When can you create a foundation without vents?

It is not always necessary to create vents in the foundation. They are not needed if:

The floor is located in a closed underground space. An example is a building whose underground space is covered with sand. A concrete slab is laid on top of the sand. After completing such work, you don’t have to worry about the appearance of condensation. It is worth noting that such floors are more reliable, since they do not deform under load.
The soil is covered with a layer of vapor barrier film that protects against moisture penetration into the subfloor.
The underground floor is equipped with a ventilation system with a capacity of at least 1 liter/second per 10 meters. It is worth considering that the foundation and base must be insulated. In this case, there is no need to create vents.
The underground space has a constant connection with the heated room. This is possible when the basement is used to store various household items.

In other cases, it is necessary to create vents in the base.

Ventilation without vents

Creating a ventilation system for the subfloor involves a complex set of works. It all starts with creating a drainage system that helps remove moisture from the foundation. It is worth noting that the hygroscopicity of concrete can be reduced by using a special primer.

The next step is to create a waterproofing barrier for the base. Also at this stage the insulation of the subfloor occurs. Waterproofing can be of two types - welded and coated.

Extruded polystyrene foam should be used as insulation. This material is ideal for the described conditions. It does not allow water to pass through and is not attractive to insects. Also, such material does not become a medium for the development of microorganisms and does not rot. Insulation of the blind area occurs when using the same material.

After the described steps, you need to cover the soil with waterproofing material. You can use various materials. The most commonly used film is polyethylene film, but diffusion membranes can also be used. The waterproofing should extend onto the walls by approximately 30 cm.

After this, a ventilation system is created. First, one or more pipes are brought to the roof, and then several supply openings are created in the floor. On the side of the house, the openings are covered with bars.

Methods for installing vents in the foundation

Natural ventilation is easiest to create if the base is made of piece materials. For example, if the foundation is created from concrete blocks or bricks. When creating such a base, it is enough to leave the distance between the two elements that is necessary for ventilating the subfloor. The vent will be blocked from above by the overlying block.

It is worth making careful calculations so that the load on the foundation does not contribute to its destruction in places where there are vents. If the fence is made of wood, holes are cut out in the finished structure.

The creation of vents in a monolithic foundation strip occurs as follows:

First, a tin or asbestos-cement pipe is installed at the desired height perpendicular to the walls. These products should have a cross-section of about 15 cm. To prevent the pipe from collapsing during concrete pouring, it must be filled with sand.
After pouring the solution, the formwork is removed and the sand is blown out.
Then the gratings are installed. This is necessary to protect the subfloor from birds and rodents.

It is not recommended to create vents by installing wooden chocks, since it is enough to knock them out of the finished foundation with a pipe. In addition, the risk of damaging the created structure increases.

If the house is wooden, vents can be created between the first crowns. Also, holes are often created between the crown and the foundation. It happens like this:

first, the contours of the hole are applied to the wall;
after this, cuts are created in the embeds;
then the created holes are lined with boards;
At the final stage, gratings and dampers are installed.

How to insulate vents

Since ventilation is required all year round, it is best to leave the vents open. But in some cases this cannot be avoided. Examples include an increase in heat loss or the appearance of strong winds in the area. It is worth thinking about closing the vents at the stage of creating the foundation. During construction, it is necessary to install special dampers that will prevent cold air from entering from the outside.

You can also use a variety of improvised means for sealing. Home owners often use materials such as tow and rags. Some people fill the holes with foam. But it is worth remembering that it will be quite difficult to completely remove this material.

Why you shouldn't close the vents

The space under the floor is not heated, but the temperature in it is above zero. Since the soil under the house does not freeze, it constantly humidifies the air. The moisture condenses and the beams begin to rot. This does not happen with open airways. They are designed to remove moisture in both summer and winter. It is also worth noting that a damp subfloor contributes to the loss of more heat than a dry subfloor with open vents.

Thus, to create comfortable conditions in the room, it is worth insulating the floor, and not closing the vents in the foundation.

Vents in the finished foundation

In the case when the foundation is already ready, but the walls have not yet been built, a basement wall with holes is erected above the finished structure. If the walls are already built, vents are cut into the foundation. To carry out such work, you should invite specialists, since it will not be possible to create holes yourself without specialized tools.

If you are planning to create your own perfumes, you should follow a few simple rules:

for work it is necessary to use a diamond drill;
during drilling, it is necessary to accurately determine the places where there is no reinforcement;
A reinforcing frame is placed in the created hole, since if it is absent in the place of ventilation, the foundation will be weakened.

If you have experience working with concrete, you can use a grinder or hammer drill. If creating vents is impossible and the house has not yet been built, you should think about installing floors on the ground. After such work there will be no air space left under the floor, so the problem will be solved without additional costs.

It is worth noting that many houses in Europe are built without ventilation, since they do not have underground space. Such floors not only do not suffer from excess moisture, but are also able to withstand heavy loads.

You can also cover the underground space with construction waste and sand, and then compact it well. In this case, ventilation holes will not be required. Another disadvantage of the subfloor is that rodents and reptiles often live in it. Insects and worms may also begin to breed under the floor.

Foundation slab for a house
How to properly pour a strip foundation
DIY strip foundation
How to calculate reinforcement for a foundation

When building a bathhouse, many owners are faced with the question of whether vents are needed in the foundation of the bathhouse. After all, you can simply pour the foundation and build a wooden structure over it. However, such a bathhouse will not last long.

The key to the strength of any wooden structure, especially a bathhouse, is the dry part of the foundation under the floor. Otherwise, high humidity, which is almost 100% in a bathhouse, will promote the growth of fungus, mold and rot. As a result, the wooden frame will simply rot. To prevent such a nuisance, prudent owners make vents or vents - holes in the upper part of the above-ground foundation.

The danger of high humidity in the underground space

The impact of high levels of humidity is deservedly among the most destructive for a significant part of building materials and structures, including the most common wood and concrete in private housing construction. Possible negative consequences of the lack of ventilation at the base of the building include:

Absorption of moisture from the space under the floor by concrete structures of the base. Even high-quality waterproofing is not always able to completely eliminate the saturation of concrete with water vapor at high humidity levels. The result of this negative phenomenon is the gradual destruction of concrete and corrosion of the reinforcement located inside.
Formation of condensation and dampening of wooden structures of the ceiling and floor of the first floor. The logical consequence of this is the appearance of mold, mildew, and rot, which significantly reduces the strength characteristics of the wood and the durability of the entire building, and also leads to the need for repair work. It is important to note that increased humidity levels negatively affect not only wooden structures. Mold and mildew can also appear on brick or gas silicate blocks, as well as concrete and structures made from it.
The entry of stale air and unpleasant odors into the living space, which leads to a decrease in living comfort. In addition to this, do not forget about the gradual increase in radon concentration, which also has a very negative effect on the inhabitants of the building.

Considering such unpleasant consequences of insufficient level or lack of ventilation of the underground space, it is quite logical to ask how effective the vents in the foundation of a wooden house are in winter and whether they need to be sealed or insulated.

Shape and number of vents

The vents in the foundation of the bathhouse can be of any shape: round, rectangular, etc. Currently, vents are increasingly being made from plastic sewer pipes, sections of which are placed in the foundation before it is filled with cement mortar.

Special base deflectors are also used, which provide better removal of moisture and minimize its contact with the wall.

Although some novice craftsmen are confident that the more holes they make in the foundation of the bathhouse, the better. But the number of outlets should also be in moderation. For optimal ventilation of the underground, there are certain rules for the placement of vents:

1. Vents should be evenly spaced. If the strip foundation box does not contain partitions, then symmetrical vents opposite each other are sufficient. If there is a partition - on the three outer sides of the bathhouse foundation and on the partition itself. A distance of 2 meters between the holes will be sufficient.

2. It is recommended to make vents at a distance of about 900mm from the inner edges of the corners of the foundation. The height of placement of vents above the ground surface is at least 20-30 cm

3. Vents measuring 10x12 cm or a radius of 12-14 cm will be quite sufficient for a medium-sized bathhouse.

Using Stubs and Meshes

Open windows attract rodents, especially in the cold season. A self-made mesh or ceiling allows you to avoid the visit of uninvited guests. Making a grid is not difficult, but finding a device that will help control the climate regime is a difficult task.

Numerous reviews indicate an effective solution to the problem using a plastic bottle. These homemade plugs are easy to use: just insert it into the window and the air will stop flowing.

You can close your vents for the winter using plastic bottles

How to construct such a device:

Take a small piece of plastic sewer pipe and cut it to fit the wall thickness.
Place the pipe in the window and fix it there with foam or cement mortar.
Take a plastic bottle, the diameter of which is several millimeters smaller than the pipe used, and cover it with heat-insulating PPE material.
Place the finished plug into the hole.

The plug for vents can be removable or stationary, with or without a mesh (used for open windows). Most models are equipped with doors that close with a slight movement of the hand.

Having created a product from a plastic bottle and put it into operation, the user will notice its effectiveness. Those people who opened the damper (took the plug out of the hole) felt the air bringing freshness into the basement. This indicates good traction of the equipped system.

The answer to the question of how to close vents in the foundation largely depends on what materials the home is made of and how often it is used. Those people who have covered vents with snow are confident in their effectiveness.

But sometimes the disadvantages of this method appear. If a mouse wants to get into the house, there will be no obstacles for it. Along with it, it brings harmful microorganisms and can even gnaw its way to other rooms, so the use of plugs is necessary.

Installation of vents

Vents in the foundations of bathhouses are installed using two methods:

1. Immediately before pouring the strip foundation.

Asbestos-cement or plastic pipes are cut to the width of the strip foundation, filled with sand and laid on the reinforcement between the formwork. After the foundation structure has dried, the pipes are completely free of sand. Less commonly, a foam block is used to create an vent, which is embedded in the foundation in the same way in order to then carefully break it and remove it.

2. Vents are cut out from the foundation with a special tool or knocked out if brick is used for masonry.

Vent protection

If you leave the vents completely open, there is a danger of insects, mice, rats, and cats entering the underground bathhouse. This misfortune can be avoided if you close the openings with homemade metal mesh grilles or special ventilation ones.

Advice

Do not seal the holes in the foundation of the bathhouse with sealed material for the winter. This action negates the entire principle of ventilation. Moisture will constantly accumulate inside the underground, allowing mold to multiply exponentially, and by spring the owner may find a surprise in his bathhouse in the form of rotten wooden floors.

To keep the underground dry, foundation ventilation is necessary. It can be done in two ways - using ventilation holes in the base of the building (vents or vents) or by placing an exhaust pipe on the roof and making several holes for air flow from different sides of the foundation.

Why ventilate the underground?

If ventilation is not provided in an uninsulated foundation, humidity in the underground quickly increases, which sooner or later turns into condensation. Moisture in the form of steam comes through the ceilings from the house, as well as from the ground. Since there is no ventilation of the foundation, there is no way to remove it; it accumulates in the soil under the house, in the walls of the basement, and settles on floor beams, on subfloor boards and/or sheathing materials. Where there is a positive temperature and high humidity (under a heated house, even in severe frosts, the temperature is always above zero), bacteria and fungi always multiply very actively, and materials rot. As a result, very unpleasant odors penetrate into the house and materials are destroyed.

This is what a subfloor without ventilation looks like after a few months.

The second reason why underground ventilation is necessary is radon gas, which is released from the soil, and sometimes in considerable quantities. It is a naturally occurring radioactive gas. Without ventilation, radon accumulates in the upper part of the underground space and gradually seeps into the house. It is probably not necessary to tell what the presence of radioactive gas in residential premises can lead to. So this is another good reason why it is necessary to ventilate the subfloor.

There are two ways to ventilate the underground space:

Make vents in the foundation (also called vents). In this case, moisture is removed due to a draft - ventilation holes are located in opposite walls.
Organize the exhaust of air from the underground - lead the ventilation pipe to the roof, and the supply of air through the grilles in the rooms. In this case, there are no vents in the foundation, but it is necessary to do thorough external insulation of the foundation + basement + blind area. Then cover the soil inside the subfloor with waterproofing.

The second solution makes it possible to improve aesthetics and prevent the subfloor from getting cold due to drafts, but it requires significant material investments. This option is suitable if you are going to build an energy-saving, well-insulated house. In all other cases, it is more appropriate to vent the foundation.

What should be the vents in the foundation and how to position them

Ventilation holes in the foundation are made of round or square cross-section. If desired, it can be triangular or any other shape. If only they were large enough in area to effectively remove moisture from the subfloor.

Dimensions

The dimensions of ventilation holes in the foundation are regulated by SNiP (SNiP 31-01-2003). Paragraph 9.10 states that the area of the vents must be at least 1/400 of the total area of the subfloor. For example, if you have a house measuring 8*9 m, the underground area is 72 square meters. m. Then the total area of vents in the foundation should be 72/400 = 0.18 sq.m. or 18 sq. cm.

The same paragraph of the standard specifies the minimum ventilation area - it should not be less than 0.05 sq.m. If we translate into dimensions, it turns out that rectangular holes should not be less than 25*20 cm or 50*10 cm, and round ones should have a diameter of 25 cm.

Larger holes can be made

In multi-storey buildings this is done, but in private buildings such holes look too large. Usually they are made two times smaller, while increasing the number of vents so that the total area of the vents is not less than the recommended one.

How to position

Make vents in the foundation 15-20 cm below the top edge of the tape. If the base is low, a recess is made in front of the vent - a pit. But ventilation of the underground is required.

The vents in the base are placed evenly on all sides of the foundation opposite each other. This is necessary for the foundation ventilation to work properly. The wind, “flying” into one hole, will fly out into another, taking with it water vapor and radon.

Place the vents in the foundation opposite each other

The distance between two adjacent vents in the basement is about 2-3 m. If there are any partitions inside, at least one vent is needed for each “room”. It is also necessary to make vents in the partitions themselves to allow air masses to move and form a draft. This is exactly what we need. In order for movement to be more or less free, the area or number of holes in the internal partitions must be larger and better, if it is 2-3 times larger. You can make several holes the same size as in the base, or you can make one, but wide one. The second option, by the way, is preferable - the resulting passages can be used to service the underground.

If you don’t find a grate of a suitable diameter, you can do this

Vents in the foundation of any format must be covered with gratings to prevent living creatures from entering the underground. It is desirable that the grilles are metal and the holes are small. For mice, plastic is not a problem, and keeping them out is easier than dealing with them later.

This option improves ventilation conditions and protects against rodents

How to make perfume

Vents are formed at the foundation manufacturing stage. If we are talking about a strip monolithic foundation, then the embedded parts are laid and secured after installing the reinforcing frame. To organize round vents, plastic or asbestos-cement pipes are laid. Their edges are brought flush with the outer edge of the formwork and secured well. If plastic pipes are used, sand is poured into them and the edges are closed with plugs. This is necessary so that the mass of concrete does not flatten them when pouring. These mortgages are not removed after the formwork is removed.

Installed plastic pipes for vents in the basement

Rectangular vents are formed from boards, knocking down a box of the required size. It is also installed in formwork, but after the concrete has set, the wood is removed.

If the base is built of brick, you can periodically trim the bricks or install a half instead of a whole. In concrete block plinths, take several pieces with two large holes and make them through. Installed instead of one of the “normal” ones. If the foundation and plinth are built from reinforced concrete blocks, vents are made at the joints.

The formwork was removed

Vents are organized in approximately the same way in columnar and pile (screw, bored, TISE) foundations. When the gaps between the supports are covered with the selected material, the required number of holes is left, the total area of which is equal to 1/400 of the area of the subfloor.

How to fix the situation

What to do if there is a foundation, but they forgot to make vents or their sizes are insufficient for normal ventilation - fungus, high humidity and other “charms” have begun to multiply in the underground. There are several ways to solve the problem:

Increase the size of existing ones or drill new ones.
Drilling into a monolithic foundation is not an easy task. This can be done either using a crown of a suitable size. If you don’t have a crown, you can take a long, large-diameter drill and use it to drill many small holes around the perimeter of the vent. Then the remaining gaps are drilled, and the uneven surface is then either sanded or simply covered with a grid. Another way is to order diamond drilling. In this case, special equipment is used, holes are drilled much softer, without shock loads. Diamond drilling in the basement of a building
If it is not possible or desirable to make new or expand old vents, you can improve draft by connecting one or more pipes from the vent to the roof. Due to the pressure difference, the draft will be better and the humidity will decrease.
Make forced ventilation. To avoid turning it on/off manually, you can set a timer or a differentiated thermometer. It will turn on the fan when the temperature in the underground is higher than outside (a condition for condensation).
Reduce the amount of moisture entering the subfloor. Most often, the source is soil, especially when the groundwater level is high. It is covered with a vapor barrier. Thick polyethylene film (thickness from 150 microns) is suitable. It is laid so that one sheet overlaps the other by 10-15 cm. The joints are taped with double-sided tape (you can do it twice - at the beginning of the “overlap” and at the end). The film is placed on the walls by 20-30 cm and secured with a strip. To prevent the film from being damaged during further use, a layer of sand is poured over it or a skinny screed 3 cm thick is made. If the foundation, blind area and base are insulated, this gives a good effect - in combination with a ventilation pipe leading to the roof. If there is no insulation, condensation will form on the film. By making a slope in one direction, moisture can be collected and removed outside the subfloor. This option, although worse, works.
For ventilation of the underground in a bathhouse (heated) or in houses with stove heating, there is another solution - install the stove so that the air is drawn from under the floor (make a vent below the level of the finished floor).
Ventilation of the foundation by taking air into the furnace from the underground
No underground floor - no ventilation needed. To implement this axiom, the entire space from the ground to the subfloor is filled up. The most affordable material with good heat-insulating properties is used. Usually this is expanded clay. Its disadvantage is that it is hygroscopic and is capable of “pulling” water from the ground. If the groundwater level is high, if you do not provide high-quality waterproofing on the ground (film extending onto the walls), things can only get worse. There is a second suitable material with better thermal insulation characteristics and is completely non-hygroscopic - granular foam glass or broken glass. This material appeared relatively recently and few people know about it. For this case - an excellent choice. True, it is more expensive than expanded clay, but it is also many times warmer and safer (expanded clay is often environmentally unsafe).

Ventilation of different rooms of the bath:

Due to differences in the temperature and humidity conditions of each of the bathhouses, ventilation in them is organized differently.

car washes

The washing compartment is the wettest, so it is recommended to equip it with a ventilation riser, which is located in the corner, under the floor. This is an asbestos-cement pipe, which is then brought to the roof and is equipped with a deflector on top. Ventilation in the sink occurs due to the pressure difference between the room and the end of the pipe above the roof; the air tends outward, taking with it excess moisture.

The reason why it is necessary to vent it to the roof is simple: if the humid air is immediately expelled to the street, then the wall where this hole will be located will quickly deteriorate from the outside.

steam rooms

attic

Attic ventilation is a special story. This is done at the stage of roof installation.

1- ceiling 2- soffits 3- roof ridge

Supply openings are made under the roof canopy (between the roof sheathing and the upper part of the wall, where the rafters rest on the power plate), and exhaust openings are made at the ridge. There should be holes on the gables, but they are small and very high.

It is also important to take into account the ratio between the area of the supply and exhaust openings on one side and the total area of the attic. It is optimal that the first ones are 1/500 of the second. The ratio between the area of supply and exhaust is not 50 to 50; exhaust should be 10-15% larger in area than supply .

This system is suitable for those baths whose attic is cold. And there are also bathhouses with attics. There, ventilation is also done at a time when the roof is still open from the attic.

To ventilate the under-roof space (between the roofing material and the membrane), either natural or forced ventilation can be used. But for both to function, aerators and soffits are needed.

Aerators are installed either on the roof slope or on the ridge (these are the most effective). They serve for extraction. And the soffits are responsible for air flow. These are siding panels for covering roof overhangs, some of which must be perforated. The ratio of the area of the ventilation holes to the ventilated area is the same as mentioned above 1/500.

Fans for the under-roof space are used as supply fans. Particular attention is paid to the wiring so that it does not cause a fire.

baths in the basement or ground floor of the house

Some owners of country houses allocate a basement or ground floor for a bathhouse. Such an arrangement of a hot and humid room places special demands on ventilation, on which the durability of the entire house now rests.

Note that the redevelopment of a former residential or utility room also includes the redevelopment of ventilation. In general, this is more expensive than a bath included in the design of a house under construction.

One way or another, you need to remember about the ventilation gap between the walls and the insulation . This will protect against damage to the insulation by condensation. But the moisture in the air corridor must also go somewhere. Therefore, for basement and basement baths, professionally made supply and exhaust ventilation is recommended, and it is better not natural, but forced. Both are accompanied by the installation of a base deflector.

The location of basement ventilation depends on the specifics of the project and will not be given here. It is also possible to install a special dehumidifier.

A good option would be to choose bastu ventilation - it is not so expensive, but very effective. The bastu device was discussed above.

shower

If there is a shower stall or open shower in the bathhouse, it is worth installing forced ventilation nearby, which will speed up the drying process.
If we assume that the air flow is ensured by the existing supply openings located in the washing room and other rooms, then you can install the fan only on the exhaust opening, which is located near the shower. (You can do the same if the bathhouse has a bathroom.)

dressing room

The dressing room suffers from condensation due to the temperature difference between it and the hot rooms of the bathhouse. Therefore, ventilation in it is necessary in the same way as everywhere else in the bathhouse . One vent is located at the bottom, the other at the top. The lower one is responsible for the inflow of air, the upper one is responsible for its outflow. Installation of forced ventilation is not prohibited. In addition, you can ventilate the dressing room using the door and (if there is) a window.

*** As you can see, the importance of ventilation in the bathhouse can hardly be overestimated. This is part of the sauna device, on which both the comfort of vacationers and the durability of the building largely depend. Therefore, it is worth paying attention to the details and reading more detailed materials describing the ventilation system in the bathhouse. We advise you to look at the corresponding section of our website. Tips about a bath hood and how to make ventilation with your own hands may also be useful.

Source

Should you close the vents for the winter or not?

There are two points of view on whether to close the ventilation holes in the underground for the winter or not. If they are left open, moisture will not accumulate. And this is good, but in return we get a cold floor and increased heating costs. The solution is enhanced floor insulation so that ventilation does not affect its temperature and does not require increased heating.

If the vents are closed for the winter, moisture accumulates in the soil. Warm, moist air from the house enters the floor, falling on cold surfaces, and in winter these are the walls of the basement, the moisture condenses and flows into the ground. This means that later, in the summer, it will evaporate from there, increasing the humidity in the basement.

Question answer

What is burst ventilation?

This is when a significant amount of new air enters the room, but for a short time. Can be used between visits to the steam room or in the summer on an ongoing basis - for drying.

What additional steps should I take to speed up drying?

Collect excess water with a rag or sponge, remove wooden flooring and shelves and place them upright (it is better to make them removable from the beginning).

Do I need to close the doors during the final fire to dry out?

If there is good ventilation, be sure to close it. If not, then at first you need to keep the doors closed so that the heat does not escape, and then open them a few centimeters.

Should a forced exhaust fan be powered from a light switch?

Not worth it. It is better to display a separate toggle switch or key - there will be more freedom of action.

Foundation ventilation without vents

This is a complex set of works, which begins with the installation of a drainage system. Water must be diverted from the foundation so that it does not seep into the building due to the hygroscopicity and vapor permeability of concrete. By the way, it can be reduced significantly by using a primer for deep penetration concrete with polymers.

Drainage system

The next stage is waterproofing the foundation and plinth and insulating them. Waterproofing can be coated or built-up. Insulation - for this case, they recommend EPPS - extruded polystyrene foam. It is ideal for these conditions: in addition to excellent thermal insulation characteristics, it is not hygroscopic, does not allow water to pass through in either liquid or gaseous states, insects and animals do not like it, it does not rot, and microorganisms do not multiply in it.

The blind area is insulated with the same material, because without this the soil in the underground may freeze.

Insulation of the basement, blind area

After this, it is necessary to minimize the flow of moisture from the soil - cover it with waterproofing material. You can use any material with suitable characteristics - from polyethylene film (density from 150 microns) to modern diffusion membranes, which will not interfere with steam escaping from the underground, but will not let steam in. The panels are laid with one overlapping the other by at least 15 cm, the knocks are taped with double-sided tape. Also, the waterproofing film is placed on the walls - 20-30 cm, where it is fixed using a pressure strip (fixed with dowels or nails, depending on the material of the base).

Waterproofing membrane

Next, a ventilation system is organized. One or more pipes are led to the roof (depending on the volume of the underground), several supply holes are made in the floor, preferably from non-residential premises. From the side of the house they are closed with ventilation grilles.

Organization of underground ventilation without vents

Ventilation in the bathhouse

Bastu-type ventilation, named after the convection Swedish baths, is becoming increasingly popular in Russian baths. It is simple to do and highly effective.

The air flow under the stove is carried out using a ventilation pipe from the street. In this case, you definitely need a damper to block it.

For air outflow, a box is installed, which starts 20-30 cm from the floor and goes outside. The location of the box is diagonal from the stove. Material: stainless steel is best. The box must also overlap 100%.

So, it works as follows: if a certain volume enters a room, then the corresponding volume will be pushed out of there if there is an exit. A working furnace actively draws in cold air from the supply air duct. Part of it is used in combustion (and leaves through the chimney), and part rises upward, heating up along the way from the stove. Excess volume in parallel begins to escape through the box, which takes air from the floor. Therefore, fresh heated air ends up in the breathing zone, and exhaust air ends up below and leaves.

Video

Watch how Bastu is explained and done in these videos:

Bastu ventilation is “turned on” and “off” by manipulating the valves. At the same time , the furnace must work, because it is the heat pump responsible for air circulation. If the stove goes out, the ventilation in the bathhouse will not work .

Bastu ventilation is ideally used in a sauna, where you need to change the air 6-8 times per hour. But in a Russian bath, the conditions are somewhat different, and although basta can be performed in it, there are restrictions on its use.

Ventilation bastu in a Russian bath

A Russian bath is not too high a temperature and an abundance of steam. In such conditions, the bastu ventilation in a Russian bath should not be “turned on” while steaming .
But you can safely start it at the very beginning, at the stage of warming up the steam room. In this case, the heating time will increase, but it will be uniform. If you leave the valves open, the basta will dry out and overheat the steam room. You can try to “turn on” the basta at the last stage of soaring - the air will be light, hot, you can breathe freely. The perfect end to your vaping experience.

In a Russian bath, basta is also useful for drying after procedures - it copes with this perfectly and there will be no odors or mold during such drying.