Air gap in masonry without insulation. Air gap in masonry wall

Most of the private houses are made according to the technology, where the wall is built of cinder block (shell rock, lampach, etc.) and then lined with bricks. An air gap of 3 to 10 cm remains between the cinder block (shell rock, light bulb, etc.) and the facing brick. heat. In an empty air gap, the air warmed up from the inside of the wall rises and takes out about 80% of the heat that is lost through the walls and leaves room for cold air, which breaks 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 leave through the attic, comes into contact with the cold bricks of the outer walls, gives them its heat 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 through the walls. Therefore, when the walls are insulated from the outside, the air circulation in empty air gaps slows down slightly and the heat continues to escape.
What is better to choose?
1. Bulk materials
After insulation, the appearance of the house does not change, which is especially important for new buildings made of expensive, beautiful bricks.

Stop editing by moderator: 9 Feb 2015
Most of the private houses are made according to the technology, where the wall is built of cinder block (shell rock, lampach, etc.) and then lined with bricks. An air gap of 3 to 10 cm remains between the cinder block (shell rock, light bulb, etc.) and the facing brick. heat. In an empty air gap, the air warmed up from the inside of the wall rises and takes out about 80% of the heat that is lost through the walls and leaves room for cold air, which breaks through various cracks from below. The intensity of this process only slightly depends on the thickness of the gap in the wall. The warm air that did not have time to leave through the attic comes into contact with the cold bricks of the outer walls, gives them its heat and, becoming colder, descends until it again receives heat from the inside of the wall. Such a convection circle causes about 20% of heat loss through the walls. Therefore, when the walls are insulated from the outside, the air circulation in empty air gaps slows down slightly and the heat continues to escape.
Which insulation option to choose?
1. Leave empty air gaps in the walls and insulate them from the inside?
When the walls are insulated from the inside, heat does not enter the walls, therefore, cold gets into the deep layers of the load-bearing walls and also transfers the dew point there (the temperature at which moisture begins to condense from the air just like dew on grass in the evening), therefore, not only the external part of the wall, but also its deep layers. In winter, when it gets colder, not only the outer, but also the inner part of the bearing wall is destroyed. In addition, damp walls in cooler summers, most often they do not even have time to dry, and excessive moisture remains in them, to which the negative consequences of the next year are added. Thus, the strength and thermal insulation properties of insulated walls deteriorate 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 the warmed air rises through the inside of the wall and “carries out” the heat through small cracks in the attic. 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. Outside, walls should be insulated in which there are no air gaps. 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 the appropriate material.
How to fill the air gaps in the walls?
Walls will never be warm if there are empty air gaps in them. Such voids "pull" heat out of the premises, like a pipe.
Materials provided for filling air gaps must meet the following requirements:
1) 100% fill the air gaps in the walls and completely stop the air circulation in them, since only "still" air is the best thermal insulator;
2) they should not increase in volume so as not to destroy the wall structure;
3) they must let steam through, i.e. must allow the walls to "breathe";
4) they should not absorb water and let moisture 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 facade finish.
It is clear that not all materials available on the market for filling air gaps meet these requirements, so you need to be very careful when making your choice.
Especially because some of the materials in the walls can do more harm than good.
What 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. The air, albeit more slowly, will circulate between the pellets and the filler boards, thereby removing most of the heat (eg polystyrene or expanded clay pellets).
Most bulk materials are blown into the walls with air through large-diameter hoses, so in the facades you have to do big holes to select bricks from the wall. It ruins the look of the walls.
In addition, the smaller the air gaps in the wall, the less likely it is to fully fill them with bulk materials.
2. Filling the air gaps in the walls with Fomrock insulation is a new, but progressive type of insulation that allows you to avoid the disadvantages that are characteristic of bulk materials. It is absolutely non-flammable, environmentally friendly (does not contain any harmful substances), vapor-permeable, durable.
After insulation, the appearance of the house does not change, which is especially important for new buildings made of expensive, beautiful bricks.
To press, to flare up ...

I hope you forgot about perlite?
I know about perlite. It refers to bulk materials (it is written about them). It is difficult to control the filling of voids with bulk material, especially in narrow vertical gaps. I can hardly imagine the technology of filling gaps with it. If you fall asleep from the very top, then where is the guarantee that everything will be filled, and if through the holes, then what size they should be.
I know about perlite. It refers to bulk materials (it is written about them). It is difficult to control the filling of voids with bulk material, especially in narrow vertical gaps. I can hardly imagine the technology of filling gaps with it. If you fall asleep from the very top, then where is the guarantee that everything will be filled, and if through the holes, then what size they should be.
To press, to flare up ...

dry miraculously open open up to 1 cm when the beast whistles
I don’t want to impose my material and filling technology on you, but I have very big doubts that everything can be filled from above. The experience of insulating such gaps and "well" masonry is about 8 years. It is often found that in some places the gap is filled with mortar (features of "hacky" masonry, probably), therefore, when insulating, we drill the house about every meter (horizontally and vertically), this gives us the ability to control occupancy. And how to control the filling of perlite?
Well, let's have a look at the prices on youtube. You can tell me in private, but I myself think about blowing out the walls in autumn.
wall insulation. 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.), departure to the regions is discussed individually. If interested, call, I threw off my phone in a personal.

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When finishing or reconstructing the 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 of insulation - vapor permeability. This is fraught big problems: wetting, freezing and premature destruction of the bearing wall.

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

The principle of condensation formation explains how it happens: at the point of contact of different temperatures (cold and heat), moisture accumulates on solid surfaces. Often this 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 on the top and bottom of the cladding.

In this regard, when building facades in a “wet” way (applying mortar finishing layers), vapor-permeable compositions 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 workflow. If the lining is done by professional masons, then this process will not take much time, but if you want to do everything yourself, then you need to consider a few important points:

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

If an air gap is provided in the walls of your house, then there must be ventilation boxes!

The main advantages of ventilation boxes:

Ventilate the air space
Protect the wall from rodents and other pests
Protect from precipitation (especially with intense side rain)
Remove condensate to the 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 applied in ventilation system facade. They are of two types: and a ventilation and drainage element for a 10 mm seam

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

Before starting inZvedenand I the first row of masonry, it is necessary to lay a waterproofing (apron made of bituminous mass), along which the 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 height of the wall is more than six meters, another row of ventilation holes is additionally placed 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 hole located at a distance of 1 meter from each other (through 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 is a guarantee of their efficient use, which means long-term preservation of reliability, durability and ideal appearance your facade.

Location of ventilation boxes

Advantages of ventilation boxes:

The inner surface of the facade is dried, which ensures its durability.
Salt stains do not protrude on the ventilated facade, mold does not form.
The heater dries up. Only dry insulation meets all the requirements of thermal insulation.
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 air gap.

Distribution of ventilation boxes:

Ventilation boxes are installed in vertical seams of facing masonry with a frequency of: 1 ventilation box - 2-3 bricks
In buildings up to two floors - 2 rows of ventilation boxes (below - 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, only one row of boxes - in the first row.
In multi-storey buildings - an 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 with the walls, not only horizontal, but also vertical waterproofing to a height of at least 150 mm. (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 face masonry made of bricks and in no way disrupts the continuity of thermal insulation (the face masonry in multilayer walls freezes through and does not perform a heat-insulating function). As a rule, in three-layer or two-layer walls, where the facade is faced with front or clinker brick cold bridges are galvanized anchors or masonry mesh acting as horizontal links.

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) the ventilation gap is obligatory element facade ventilation.

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

Why do we really need these air gaps between the brick and bearing wall?

To begin with, it is necessary to emphasize that the facade of the house can be either ventilated or not ventilated. Now let's take a look at the picture, and then I'll explain everything what's what:

Now let's move on to the explanation. The ventilation facade is a wall structure in which it is possible to freely circulate air flows between the front part of the wall and the carrier, from the base, which stands on the foundation and ends with an unimpeded exit to the atmosphere, as shown by the arrows in the figure.

Since we are considering a wall with a brick cladding, in our case, for normal air circulation, it is necessary to leave unfilled seams in the first row, as shown in the figure above. This helps fresh air to enter the wall. The distance between each hollow joint should be equal to 1 meter. It turns out the following sequence: having penetrated through the cracks of the first row of brickwork, the air blows out moist or heated air in the air gap through the top to the roof and then to the street. Their list includes wood, foam blocks, gas-concrete blocks, mineral wool, fibrous and other material

Let's notice one big mistake of all builders. The air layer should not overlap, that is, nothing should interfere with its free circulation of air, up to the very top row of bricks of the building under construction. And all the air must be free to go outside. Some, approaching the end of construction, make a tasty screed, blocking the air gap. It is not right!

In the cold season, in any heated room there is an increased concentration of moisture that goes outside through the walls of the house and, accordingly, through the insulation, which leads to the formation of condensate on their surfaces. It leads to destruction building material. Plus, when wet, the wall material retains heat worse, which leads to excess heat leakage. In this case, the air layer plays the role of a temperature and moisture concentration regulator. It turns out that the load-bearing wall with insulation evaporates water and nothing prevents it, moisture enters the air gap and escapes into the atmosphere through the upper slot. It turns out that our wall remains dry and unharmed, and this prevents the rapid decay and decomposition of the building material.

But every reasonable person will say that it is extra loss heat in winter period! What to do?
You know. On many forums they write that the external facade masonry still does nothing in the role of heat conservation. It makes me want to scream in their faces. This is not true. Many people write this out of ignorance. I'll ask you a counter question. What do you say about brick walls in residential buildings? Do they keep warm too? Tomorrow I will start dismantling my house and dig myself a dugout. Of course, I am exaggerating this, but brick walls are excellent heat-saving structures. Judging by the school rating scale, a wall of 50 cm saves heat for a grade of 5+, 25 cm for a grade of 4, and a wall of 12 cm will pull a C with a minus. But again, we came to the conclusion that it still keeps warm. And this does not give us any right to say that having faced the wall with brick, it will not keep heat.

So here are my recommendations. If you are building a house in which the load-bearing wall will be made of wood or of a material that does not hold heat well when wet or begins to lose its strength and fall apart, such as wood, gas blocks and mineral wool, then definitely make an air gap between the cladding and bearing wall, and also do not forget to leave empty seams in the first row for admission fresh air. But then, in this case, it will be necessary to make the main wall wider or better insulate, so as not to think about the fact that you will have to burn excess fuel for heating, because heat will also be vented from the air gap with moisture.

If you are building a house from a material that is not affected by moisture in any way, then you should not even bother with ventilated facades. Do it without air gaps! And if you do, you can not leave any empty seams in the first row, so you better keep warm.

In addition, I want to highlight a few features and useful points:

1. The size of the air gap between the bearing wall and the facade structure according to SNIPs and GOSTs should be 1.5-2 cm. I think that they took into account a perfectly flat wall without possible deviations, which is clearly designed for brick layout or Wall panels and the material they had was just the most perfect. But this is nonsense, I want to tell you comrades! In practice, it is very difficult to calculate everything and the air gap is usually left, depending on the situation, about 3-5 cm.

2. In construction, the air gap helps to hide all sorts of flaws in the wall. A wall that is surrounded by brick does not require any intervention. That is, all defects and irregularities that are present will remain in this air gap. They will not need to be leveled, cut down, cleaned off, and if needed, then only the slightest intervention. I don't think this is such a small plus.

3. The following dignity is associated with weather phenomena. In summer, in the heat, the brick in the sun heats up to enormous temperatures (it can reach up to 90 degrees Celsius), at this time the air gap acts as a temperature regulator, because the heated front brick shares its heat not with the load-bearing wall, which transfers all the heat inside residential premises, but with an air gap, which subsequently takes away the entire hot air in atmosphere. This helps to keep the house cozy and cool in the summer and you will not need extra costs for air conditioners and fans. And this means that the material that, when heated, emits gases and is able to collapse will be protected. An example is concrete blocks and tree.

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

What are gaps and why are they needed?

Under the gaps, we mean the distances between the walls, which contribute to ventilation and prevent the accumulation of condensate inside the structure. In such gaps, heat-insulating material can be placed for insulation. With this method of brickwork outer wall The house is made up of three layers:

Basic structure.
Insulation.
Facing.

It is used to increase the thermal insulation of the house and to save energy. Thermal insulation material protects inside the structure bearing wall from freezing. In addition, he himself is reliably protected from damage. And the existing air gap between the insulation layer and the facing masonry contributes to 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 the supporting structure. Then lay out the wall of facing brick, leaving a gap between them for air circulation and, if necessary, for insulation. The size of the distance should be 1.5-2 cm or within 5-15 cm in 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 of the vapor barrier indicator.

The vapor permeability of all layers must be combined. This will help prevent moisture from accumulating on inner sides brick structures, which will prevent the formation of mold and fungus, 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 of the cornices and at the bottom of the plinths of the building. The number of such holes depends on the size of the walls, and their width is 2-4 cm.

Insulation gaps in masonry

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

You can insulate the wall with polystyrene foam.

mineral wool;
expanded polystyrene;
bulk heaters.

When using insulation in the form of plates, all structural elements are fastened together using flexible ties, which are installed on a load-bearing wall. After spread facing masonry to their level and put heat-insulating material on them. 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 deforming. The width of the air cushion varies between 4-6 cm. Bulk heaters they simply fill the void formed between the walls without creating air gaps, after the height of the walls being erected reaches a meter.