One of the final stages of the construction of any building is the construction of the blind area. This is not only a way to protect the building from rain moisture, but the foundations from subsidence, but also an important element of landscaping the surrounding area. Usually, the blind areas start the device after finishing the facade or after finishing the basement.
In order for the blind area to justify its main purpose, it must be made of waterproof material in compliance with certain rules. Its proper arrangement provides a reduction in the load on the waterproofing of the underground part of the building and thereby extends its service life, so this business should not be put off the shelf.
Any blind area requires preliminary soil preparation. Regardless of which material it is intended to be coated with, the soil must be cleaned of the plant layer and carefully compacted. This is especially important for a house built on heaving soils.
The device of the blind area of the house includes the device of the underlying layer and cover. The underlying layer (for it you can use sand, clay, sifting, fine gravel) is necessary to create an even compacted base for subsequent laying of the coating. The type of the underlying layer is selected depending on the type of top material. The thickness of the layer is usually chosen 20 cm. Concrete, fine cobblestone, asphalt, paving slabs are used for coating.
The correct arrangement of the blind area around the house
Sand is poured into the trench around the house and carefully rammed or watered with water for compaction. Rubble, gravel or broken bricks are poured over the sand. This pillow is necessary for filtering moisture, which can penetrate through the capillaries of the upper layer and freezing, destroy the blind area. Please note that construction debris for pillows must not be used. With a high location of groundwater between the layer of stone fractions and sand, it is necessary to lay a geotextile, which will protect against siltation.
The next stage is the device of the selected type of coating. The depth of the trench should be calculated in advance so that the top layer is not too thin. A removable formwork is installed along the outer edge of the trench. Instead of formwork, a curb stone can be installed . If it is planned to lay a concrete coating, then first it is necessary to make expansion and temperature joints that will protect the concrete coating from destruction in a frosty winter. Deformation seams are slats placed on an edge across the blind area with a step of no more than 3 m. Reiki is treated with bitumen. Their upper surface should be at the same level with the upper surface of the concrete, taking into account its slope. Then concrete is laid, the slats at the same time serve as beacons, along which it is leveled. Ready wet blind area is sprinkled with cement, and then smoothed with a trowel and covered with a wet cloth. During a week, the concrete is kept in this state, periodically pouring with water so that the fabric is always wet. After a week, the blind area is completely finished.
When constructing the blind area, the following rules should be followed:
1. So that water is diverted from the house, the blind area is laid with a slope from the building. The slope should be at least 2%. And although it is almost invisible, it nevertheless guarantees the removal of water from the base.
2. A gap is left between the blind area and the wall to protect the walls from damage during the settlement of the blind area. The expansion joint is filled with polystyrene foam, sand, polyurethane sealant. Sometimes two layers of roofing material are enough.
3. Along the perimeter of the blind areas, they dig out grooves for drainage or lay special gutters that look much more aesthetically pleasing.
4. The blind area is taken 20 cm wider than the projection of the roof overhang on the ground, but not less than 60 cm.
If the blind area is made in violation of these rules, then, unfortunately, very soon the consequences will be revealed: cracks, chips, destruction of individual sections, which will adversely affect the operating conditions of the building. The very importance of the function that the blind area performs assumes a responsible attitude to its construction.