The blind area is called the construction whose main purpose is to protect the foundation of the house from the effects of adverse environmental factors. With its presence, water cannot seep to the base of the building and destroy it. In addition, the blind area often performs a purely decorative function. A variety of materials can be used for mounting such a design. Depending on this, the technology of the blind area is also selected .
What to consider when designing a project
The requirements for constructions of this type are presented mainly as follows:
The blind area should be waterproof. Otherwise, it will not fulfill its main function - to protect the underground part of the foundation of the house from destruction.
The blind area should be equipped with materials that are resistant to cracking under strong temperature extremes. The climate in most of Russia is, as you know, sharply continental. And the temperature range on the street, even within the same season, can vary quite strongly.
Next, we will consider various technologies of the blind area. SNiP - rules that, however, must be strictly observed when erecting a protective tape of any kind. The project of the blind areas should be made taking into account the fact that:
the tape should have a slope of at least 2 degrees in the direction from the wall of the house;
the width of the blind area should be in the range from 70 cm to 2 m;
Between the blind area and the foundation, a small temperature gap of 1-2 cm should be left.
The slope of the blind area in the process of its arrangement can be performed both at the stage of backfilling and tamping the substrate, and when laying the main material. The width of the tape itself is chosen taking into account, among other things, that it should protrude 20-30 cm beyond the roof overhang. Otherwise, water flowing from the roof will seep under the blind area and spoil the foundation.
What materials can be used
The procedure is relatively simple - the device blinds at home. With your own hands, this design can be done without much difficulty. Most often, the blind areas around the buildings are poured, of course, from a cement-sand mixture. The latter, according to technology, is supposed to be cooked in a proportion of 1x3. The substrate is made using crushed stone and sand. Also, paving stones can be used to equip the blind area. Sometimes this element of the building’s construction is simply covered with rubble. In this case, the tightness is ensured by arranging the clay substrate.
The choice of a specific material primarily depends, of course, on the financial capabilities of the owner of the house. The cheapest option for the blind area is gravel. Filling a concrete strip is a bit more expensive. When using paving slabs it is possible to collect not only reliable, but also very beautiful blind area. However, this option will cost the owners of the house, of course, quite expensive.
In addition to cost, when choosing a material for the blind area, the owners of the house should take into account the design features of the building itself. So, for example, for a wooden house, an clay blind area may be more suitable. In this case, the upper layer of crushed stone can be covered with earth at the final stage. As a result, the space around the house will look as natural as possible. For a concrete building with plastered walls, cement blind area is most likely suitable. Around the brick large cottage is, of course, to equip a protective strip of paving slabs. This will give the exterior of the building a finished look.
When choosing a material for the blind area, it is worth considering one more rather important factor. It is believed that with a basement height of 50 cm around the house, it is more expedient to equip a concrete structure or a tiled structure. If the aboveground part of the foundation protrudes above the surface to a height of 30 cm, you can also use crushed stone gravel for protection.
Basic technology of the blind area
So, the blind area around the house can be built by pouring a cement mixture or laying tiles or clay. But there are other, more original ways of installing such structures. For example, when arranging the blind area, geotextiles, multi-colored pebbles and even glass bottles can be used. In any case, when building the blind area of the selected technology, it is worth following exactly. Otherwise, after some time, this structural element of the building will have to be repaired or even completely equipped again.
The warmed option
Most often, the owners of houses in Russia equip ordinary blind areas around them, consisting of two layers: the substrate and the main upper part. But sometimes, insulated versions of a similar design are constructed along the perimeter of the building. Such blind areas are, of course, more expensive than ordinary ones. However, in some cases their arrangement is necessary. Without fail, for example, insulated blind areas are erected around buildings built on heaving soils. It is also customary to equip such structures to protect columnar and shallowly indented footing foundations. Further in the article, we will consider including the technology of the device of the insulated blind area.
The main stages of installation
Actually, the technology of erecting the blind area when using different materials uses almost the same. This element is usually arranged in several steps:
markup is in progress;
digging a "trough" under the blind area;
formwork is installed;
a substrate is laid at the bottom of the “trough”;
laying or pouring of the main material.
Below we will consider the technology of building the pavement of paving slabs and gravel, as well as pouring it from concrete.
How to make markup correctly
When performing this procedure, be sure to use a plumb line. With its help, at the first stage, the projection point of the roof is found. To do this, climb the ladder to the roof level, put a plumb line to its edge and make a mark on the ground. Then they retreat 30 cm from the building and drive a peg into this place. Having thus determined the necessary width of the blind area, they establish landmarks around the entire perimeter of the building with a step of 1 m, making the necessary indentation from the wall. After all the pegs are driven into the ground, they are connected with a cord.
Foundation preparation
This procedure, like marking, is performed almost identically for all types of blind areas. The preparation is as follows:
Inside the marking, soil is taken out. Perform this procedure using a bayonet sharp shovel. With this tool, you first need to trim the soil along the cord. Then the middle part of the “trough” is selected.
The bottom of the “trough” is compacted. It is most convenient to carry out this operation with a shovel.
The total depth of the "trough" under the blind area should be at least 25 cm.
Substrate for cement structures
The construction of a concrete blind area involves the use of formwork . It is easiest to make this design from boards with a thickness of 1.5-2 cm. Such lumber just needs to be installed on the edge along the perimeter of the “trough” and fixed in this position by supporting posts.
After the formwork is assembled, you can proceed with the arrangement of the blind area itself. This procedure is performed as follows:
At the bottom of the trench is laid roofing material in two layers.
Sandy "pillow" is being poured. This element of the "cake" blind area is considered mandatory. Without a “pillow” in the subsequent concrete part of the blind area will necessarily begin to crack. The thickness of the sand layer in the substrate should be 5-10 cm.
The sand is carefully compacted by moistening with water from a hose with a shower head.
A layer of rubble is poured over the sand. Its thickness should be 5 cm.
Crushed stone is leveled and rammed with a shovel.
Expansion joints
The technology of the blind area around the house involves the use of these additional elements in its design. One of the properties of concrete is its ability to expand with increasing temperature. Because of this, cracking of the cement blind area may occur. To avoid this, in the formwork around the entire perimeter of the house, not too thick bars should be installed across, in increments of about two meters (per edge). It is impossible to fill the concrete blind area with a continuous tape.
You should also make a compensatory seam along the wall of the house. For its arrangement, you can use foamed polyethylene. This material just needs to be applied to the wall in the area of the adjoining blind area. But it’s easier to make the compensation layer with the help of roofing material laid on the bottom of the “trough”. This material must be raised to the wall to the height of the future blind area.
Reinforcement
The technology of constructing a concrete blind area involves, among other things, reinforcement through reinforcement. Using this procedure, the risk of tape cracking in the future can be minimized. Reinforcement significantly extends the life of the blind area. To strengthen the tape, a metal mesh with a cell of 5 cm is usually used. This material is cut in accordance with the width of the future blind area and laid on top of the gravel around the perimeter.
Concrete Blind Device Technology
The cement mortar for pouring into the formwork is best prepared in a concrete mixer. In this case, it will turn out better. Fill the blind area is in one step. In this case, it will turn out to be more durable. When pouring, the slope should be constantly monitored. At the end of the procedure, the tape should be allowed to dry for about two hours. Then the blind area should be covered with plastic wrap for about 2 weeks.
Tile tape
The technology of the blind area device in this case will be slightly different from the above methodology . At the bottom of the trench for the tiled structure, crushed stone is poured with a layer of 5-7 cm. Clay is laid on top of it. For obvious reasons, there will be many seams between the tiles on such a blind area. That is, to ensure at least the relative tightness of the tape like concrete paving stones can not. In this case, clay will play the role of a waterproofing agent. The thickness of its layer in the substrate should be at least 5-10 cm. The clay must be compacted using rammers. On top of it is also worth putting a PVC film. This will provide additional insulation.
A layer of sand is poured over the film in the substrate. A cement-sand mixture prepared in a 4x1 ratio is poured onto it. The thickness of the concrete layer in this case should be equal to 3 cm. The flooded area is leveled with a mop. Paving stones on the blind area should be laid in the direction from themselves with dressing of the seams. A gap of 1 cm should be left between the individual tiles.
Ballast tape
The device technology of the paving of paving slabs is thus relatively uncomplicated. But it’s even easier to make a protective tape around the house from clay and gravel. Such a blind area can turn out to be very reliable. But of course, only subject to certain rules of dumping.
Under the gravel construction, a “trough” is also pre-excavated. Further, the bottom of the latter is carefully tamped and leveled with a slope. At the next stage, clay is poured into the “trough” with a layer of 15 cm. This material should also be laid with a slight slope in the direction from the wall of the house. In this case, roofing material or a thick PVC film (with a slight overlap on the foundation) spreads over the clay in this case. You can fix the material on the surface of the base, for example, with slats. Joints of roofing material are most easily glued with bitumen.
A layer of sand 10-15 cm is poured over the waterproofing. The resulting "pillow" should be tamped with water and leveled with a slope. A layer of geotextile can be laid on top of the sand. This will prevent weed germination on the blind area. Further, crushed stone itself (with tamping) is laid in the “trough” itself.
How to make an insulated design
In this case, the usual technology of laying the blind area is used. However, when arranging it , heat-insulating material is additionally used. As the latter, it is allowed to use both expanded polystyrene and expanded clay.
The first layer of clay is laid on the bottom of the “trough”. Then crushed stone and sand are poured (with tamping). Then the selected insulation is laid. Expanded clay should be poured with a sufficiently thick layer. Expanded polystyrene plates are laid as tightly as possible to each other. Roofing material is laid on top of the insulation. Then a layer of sand is poured. At the final stage, concrete mixture is poured or tile is laid.
Instead of a conclusion
The technology of the blind area made of pavers, concrete or clay is thus simple. However, it is necessary to comply with SNiP standards when constructing such structures. If there is a blind area of the sand cushion and waterproofing in the "pie", it will turn out to be as durable as possible. Compliance with the installation of the slope will ensure the best efficiency of this element of the building structure.