Air gap between brick and shell rock. Ventilation of brick walls in a country house. Process technology and gap sizes

Air gap between brick and shell rock. Ventilation of brick walls in a country house. Process technology and gap sizes
Air gap between brick and shell rock. Ventilation of brick walls in a country house. Process technology and gap sizes
18.10.2019

The brick has high level water absorption. Therefore, when facing a house with brickwork, ventilation gaps are made for weathering. excess moisture. Thermal insulation properties brick walls not high enough, and in order to create comfortable conditions for living, insulation is a prerequisite when constructing houses from this building material. When using the method of three-layer masonry of load-bearing structures with internal insulation They also leave gaps for ventilation.

What are clearances and why are they needed?

By gaps we mean the distances between the walls, which promote ventilation and prevent the accumulation of condensation inside the structure. In such gaps you can place thermal insulation material for insulation. With this method brickwork outer wall the house consists of three layers:

  1. Basic structure.
  2. Insulation.
  3. Facing.

It is used to increase the thermal insulation of a home and to save energy resources. Thermal insulation material inside the structure it protects the load-bearing wall from freezing. In addition, it itself is reliably protected from damage. And the existing air gap between the insulation layer and the facing masonry promotes ventilation and evaporation of excess moisture.

Process technology and gap sizes


The width of the hole should not be more than 2 cm.

Masonry begins with the construction of a supporting structure. Then they lay out the wall facing bricks, leaving a gap between them for air circulation and, if necessary, for insulation. The distance should be 1.5-2 cm or within 5-15 cm in the case of thermal insulation and depending on the thickness of the material layer. An air cushion is made in order to exclude deviations from the norm in the vapor barrier indicator.

The vapor permeability of all layers must be combined. This will help prevent moisture from accumulating on the internal sides brick structures, which will prevent the formation of mold and mildew, as well as preserve the heat-shielding properties of the insulating material and extend its service life.

Regardless of the presence of insulation inside the wall, for air circulation between load-bearing structure and make special gaps in the form of embroidered vertical seams in the facing masonry. They are located at the top at the eaves and at the bottom at the plinths of the building. The number of such holes depends on the size of the walls, and their width is 2-4 cm.

Gaps when insulating brickwork

The choice of insulation depends on the material external structure at home, since the vapor permeability coefficient of elements of all layers should be taken into account. As insulation you can choose:


You can insulate the wall using polystyrene foam.
  • mineral wool;
  • expanded polystyrene;
  • bulk insulation.

When using insulation in the form of plates, all structural elements are fastened together using flexible connections, which are installed on a load-bearing wall. Then they lay out the facing masonry to their level and place it on them. heat insulating material. Waterproofing is attached to the insulating layer and a gap is left for ventilation. To create it, use connections that have a plastic washer with a latch. It presses the insulation against the wall and prevents it from slipping and deformation. The width of the air cushion varies between 4-6 cm. Bulk insulation they simply fill the void formed between the walls without creating air gaps, after the height of the walls being built reaches a meter.

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When finishing or reconstructing a facade, as a rule, its insulation is done along the way. In pursuit of the best thermal insulation, the customer often forgets or ignores the most important indicator insulation - vapor permeability. This is fraught big problems: wetness, freezing and premature destruction of the load-bearing wall.

Ventilation holes in the facing masonry are necessary to maintain an optimum temperature and eliminate the “greenhouse effect”, which significantly accelerates the destruction of walls. Therefore, every 3-4th vertical seam in each row facing masonry should not be filled with solution. These will be the ventilation ducts.

The principle of condensation formation explains how this happens: at the point of contact different temperatures(cold and heat) moisture accumulates on hard surfaces. This often causes “ice walls” or damaged interior decoration. The only way out is to provide moisture with the opportunity to freely evaporate into the atmosphere, i.e. outside the building.

It is also necessary to leave air vents at the top and bottom of the cladding.

In this regard, when constructing facades using the “wet” method (applying mortar finishing layers), vapor-permeable compounds are used. In another case, a ventilated facade system is used.

Wall ventilation, which is placed under the brick - this is a very important part of the work process. If the cladding is carried out by professional masons, then this process will not take much time, but if you want to do everything yourself, then you need to take into account several important points:

  1. All rows of stones are laid using mortar, but the 34th row is installed without it, this will help ensure natural ventilation walls. Sometimes this type of masonry is not suitable and can be left air cushion between the roof and the wall;
  2. The ventilation gap should be at least 25 mm, but this is for a wall that is completely flat. When facing wooden house from the timber you need to maintain a gap of 30 mm;
  3. If the gap is under the beam, then it can be closed using a special strip, without laying a row of bricks.

If the walls of your house provide air gap, then there must be ventilation boxes!

The main advantages of ventilation boxes:

  • Ventilate the air gap
  • Protect the wall from rodents and other pests
  • Protects from precipitation (especially during intense side rain)
  • Discharge condensate outside
  • Matched to the color of the masonry, they are almost invisible, which does not spoil the impression of the facade

Ventilation and drainage boxes

Ventilation and drainage boxes used in ventilation system facade. They come in two types: and a ventilation and drainage element for a 10 mm seam

Facade ventilation system it is quite simple to create and consists of only two elements: an air gap 10 cm wide with a distance between the heat-insulating layer and the façade layer of 4 cm and ventilation holes - vertical seams between the bricks that are not filled with mortar, into which the ventilated elements of the facade are mounted.

Before startingsoundedand I the first row of masonry must be laid with waterproofing (an apron made of bitumen mass), along which condensate will flow freely through ventilation holes out. Similarly, waterproofing should be laid over each opening of the building.

Ventilation holes located in the first and last rows of brickwork. If the wall height is more than six meters, another row of ventilation holes is additionally located in the middle of the wall. At the same time, the distance from the corners of walls and openings to the first ventilation hole should not be less than 25 centimeters.

Horizontal holes placed at a distance of 1 meter from each other (every 4 bricks). At the same distance, ventilation holes are located under and above the openings, but at least two holes for each opening. Vertically, the holes are placed directly above each other, and in no case in a checkerboard pattern.

Proper placement and installation of fans guarantees them effective application, which means long-term preservation of the reliability, strength and ideal appearance of your facade.

Location of ventilation boxes

Advantages of ventilation boxes:

  • Drying inner surface facade, which ensures its durability.
  • Salt stains do not appear on the ventilated façade and mold does not form.
  • The insulation is drying out. Only dry insulation meets all thermal insulation requirements.
  • According to studies conducted in Germany, the thermal resistance of a wall with a ventilated air gap is 6% higher than a similar wall without an air gap.

Distribution of ventilation boxes:

  • Ventilation boxes are installed in the vertical joints of the facing masonry with a frequency of: 1 ventilation box - 2-3 bricks
  • In buildings up to two floors - 2 rows of ventilation boxes (at the bottom - in the first row of masonry, and at the top - in the last) If the wall insulation turns into insulation pitched roof- in this case there is only one row of boxes - in the first row.
  • IN multi-storey buildings- additional 1 row of boxes every two floors.
  • Additional ventilation boxes are installed above and below the openings
  • The ventilated air gap should be within 30-50 mm.
  • At the junction of the foundation and the walls, not only horizontal, but also vertical waterproofing to a height of at least 150 mm must be provided. (according to DIN 1053 T1).

Is the ventilation box a cold bridge?

The ventilation box cannot be a cold bridge. The ventilation box is mounted in the body of the facing brickwork and does not in any way disrupt the continuity of thermal insulation (facing brickwork in multilayer walls freezes and does not perform a heat-insulating function). As a rule, in three-layer or two-layer walls, where the façade is faced with facing or clinker bricks The cold bridge is galvanized anchors or masonry mesh, acting as horizontal connections.

Why is a ventilated air gap needed in two-layer or three-layer walls?

For walls made of vapor-permeable materials(such as ordinary brick, aerated concrete, foam block, ceramic block and shell rock) ventilation gap is mandatory element ventilation of facades.

The ventilation gap in the wall performs the following functions: - removes condensation from the thermal insulation (three-layer walls) or load-bearing wall (two-layer walls), thanks to this the materials retain their original thermal insulation properties; - prevents the appearance of efflorescence on the facing brickwork; - creates favorable microclimate indoors.

  1. Most of the private houses are made using a technology where the wall is built from cinder block (shell stone, lampshade, etc.) and then lined with brick. Between the cinder block (shell stone, lampshade, etc.) and the facing brick there remains an air gap of 3 to 10 cm. There are air gaps between the load-bearing and facing wall, look like a “pipe” running around the house and “pulling” it out of the premises a large number of heat. In an empty air gap, the air warmed from the inside of the wall rises up and carries out about 80% of the heat, which is lost through the walls and leaves room for cold air, which makes its way through various cracks from below. Intensity this process only slightly depends on the thickness of the gap in the wall. Warm air, which did not have time to escape through the attic, comes into contact with the cold bricks of the outer walls, gives off its heat to them and, becoming colder, goes down until it again receives heat from the inside of the wall. Such a convection circle causes about 20% of heat loss occurring through walls. Therefore, when insulating walls from the outside, air circulation in empty air gaps slows down slightly and heat still continues to escape.

    Which is better to choose?

    1. Bulk materials

    After insulation appearance the house does not change, which is especially important for new buildings made of expensive, beautiful brick.

    Last edited by moderator: 9 days 2015

  2. Most of the private houses are made using a technology where the wall is built from cinder block (shell stone, lampshade, etc.) and then lined with brick. An air gap of 3 to 10 cm remains between the cinder block (shell stone, lampshade, etc.) and the facing brick. The existing air gaps between the load-bearing and facing walls are similar to a “pipe” running around the house and “pulling” a large amount of heat. In an empty air gap, the air warmed from the inside of the wall rises up and carries out about 80% of the heat, which is lost through the walls and leaves room for cold air, which makes its way through various cracks from below. The intensity of this process only slightly depends on the thickness of the gap in the wall. Warm air, which did not have time to escape through the attic, comes into contact with the cold bricks of the external walls, gives off its heat to them and, becoming colder, sinks down until it again receives heat from the inside of the wall. Such a convection circle causes about 20% of heat loss occurring through walls. Therefore, when insulating walls from the outside, air circulation in empty air gaps slows down slightly and heat still continues to escape.

    Which insulation option should I choose?

    1. Leave empty air gaps in the walls and insulate them from the inside?

    When insulating walls from the inside, heat does not enter the walls, so it does not penetrate into the deep layers. load-bearing walls the cold gets in and also transfers the dew point there (the temperature at which moisture begins to condense from the air, just like dew on the grass in the evening), so in the fall not only the outer part of the wall gets wet, but also its deep layers. In winter, when it gets colder, not only the outer, but also the inner part of the load-bearing wall is destroyed. In addition, damp walls in cooler summers, most often they do not even have time to dry, and they retain excess moisture, to which they also add Negative consequences next year.Thus the strength and thermal insulation properties insulated walls are getting worse every year.

    2.Leave empty air gaps in the walls and insulate them from the outside?

    Insulation from the outside is effective only when there are no empty air gaps in the walls, since inner part walls, the warmed air rises up and through small cracks in the attic “carries out” the heat. Only a small amount of heat escapes through the outer part of the wall. Therefore, if there is an empty air gap, it is irrational to insulate the walls from the outside, since the benefit will be minimal. From the outside, walls that do not have air gaps should be insulated. Therefore, if there are air gaps in the walls and regardless of their thickness It is imperative to stop air convection in them by filling them with appropriate material.

    How to fill air gaps in walls?

    The walls will never be warm if there are empty air gaps in them. Such voids “pull” heat out of the premises, like a chimney.

    Materials provided for filling air gaps must meet the following requirements:

    1) fill the air gaps in the walls 100% and completely stop the air circulation in them, since only “stationary” air is the best thermal insulator;

    2) they should not increase in volume so as not to destroy the wall structure;

    3) they must allow steam to pass through, i.e. should allow the walls to “breathe”;

    4) they should not absorb water and allow moisture to pass through to the inside of the wall;

    5) they must have good thermal insulation characteristics;

    6) they must be stable and durable;

    7) they must create the possibility of 100% filling of air gaps, without leaving noticeable damage to the façade finishing.

    It is clear that not all air gap filling materials available on the market meet these requirements, so you need to be very careful when making your choice.

    Especially because some materials in the walls can do more harm than good.

    Which is better to choose?

    1. Bulk materials

    All bulk materials, by their nature, cannot stop the circulation of air in the air gaps, so the benefit will be minimal. Air, although slower, will circulate between the granules and the filler slabs, thereby removing most of the heat (for example, polystyrene or expanded clay granules).

    Most bulk materials are blown into walls with air through hoses. large diameter, so in the facades you have to do big holes to select bricks from the wall. This spoils the appearance of the walls.

    In addition, the smaller the air gaps in the wall, the less likely it is to completely fill them with bulk materials.

    2. Filling the air gaps in the walls with Fomrok insulation - a new but progressive type of insulation that allows you to avoid the disadvantages characteristic of bulk materials. It is absolutely non-flammable, environmentally friendly (does not contain any harmful substances), vapor permeable, and durable.

    After insulation, the appearance of the house does not change, which is especially important for new buildings made of expensive, beautiful brick.

    Press to burn...

    I hope you suddenly forgot about pearlite?

  3. I know about perlite. It refers to bulk materials (written about them). It is difficult to control the filling of voids bulk material, especially in narrow vertical gaps. It’s hard to imagine the technology for filling gaps with it. If you fill it from the very top, then where is the guarantee that everything will be filled, and if through the holes, what size should they be?

  4. I know about perlite. It refers to bulk materials (written about them). It is difficult to control the filling of voids with bulk material, especially in narrow vertical gaps. It’s hard to imagine the technology for filling gaps with it. If you fill it from the very top, then where is the guarantee that everything will be filled, and if through the holes, what size should they be?

    Press to burn...

    dry miracle seals open up to 1 cm when sleeping with an animal

  5. I don’t want to force my material and filling technology on you, but I have very serious doubts that everything can be filled from above. I have about 8 years of experience in insulating such gaps and “well” masonry. It is often found that in some places the gap is filled with mortar (probably a feature of the “hacky” masonry), therefore, when insulating the house, we drill the house approximately every meter (horizontally and vertically), this gives us the opportunity to control occupancy. How to control the filling of perlite?
  6. Well, let's check the price list and look at it on YouTube. You can tell me in private, because I’m thinking about blowing between the walls in the fall.

  7. insulation of walls. Professional video not yet. Also our other videos




    Not very high quality, but I think the principle of insulation is clear.
    For the price, in Krivoy Rog turnkey work costs 80 UAH (material, work, delivery, etc.), travel to the regions is negotiated individually. If interested, call, I sent you my phone number in a private message.