The blind area plays an important role in the design of any building. This element prevents the seepage of water to the foundation, makes the exterior of the house complete, and often also plays the role of the sidewalk. The tape can be made of different materials. At the same time, there are certain standards that regulate such parameters as the width of the blind area around the house, its height and angle of inclination.
What materials can be made blind area
Most often, this important element of the house is made from:
- concrete;
- paving slabs;
- gravel.
Blind laid around the entire building. Some builders believe that when arranging a drain in a house, you can do without it. However, such an opinion is, of course, erroneous. According to the regulations, even in this case, the blind area is considered an obligatory element.
General requirements of SNiP
The blind area of what width should be arranged around the house, we find out a little lower. Now let's look at the general requirements of SNiP regarding this important structural element of any building. In the manufacture of blind areas should be guided primarily by such building codes:
- the design must be tilted in the direction from the base of the house to the outside;
- between the blind area and the aboveground part of the foundation of the house should leave a gap of about 20 mm;
- The tape should surround the house continuously.
These requirements must be followed. Otherwise, the blind area will not fulfill its function of diverting water from the foundation. The gap is left so that in cold weather a concrete or tile tape does not press on the base and, as a result, does not destroy it. The expansion joint is usually filled with sand or sealant.
Structurally, any blind area consists of two main elements:
- bases, which can be made of sand, gravel or gravel;
- the main coating, the main task of which is to prevent the penetration of water to the underground part of the foundation of the house.
The width of the blind area of the house
Of course, you need to make the tape correctly. First of all, you should decide on its width. It is believed that the larger this parameter, the better.
According to the regulations, the width of the blind area should not be less than 70 cm. But it is better if this parameter is equal to 1 or 1.5 m. When choosing a specific indicator of the blind area, you should be guided:
- the length of the overhangs of the eaves;
- soil structure.
In our country, the soil in almost all areas has a good bearing capacity. However, sometimes it still happens that in this particular area it is very prone to deformation. In such areas around the house they usually equip a very wide blind area (from 2 m). If the soil has a good bearing capacity, you can save a little and build a narrower structure.
In any case, when choosing a parameter such as the width of the blind area, do not forget that the tape should protrude beyond the plane of the walls of the house at least 20 cm further than the curtain rod. Otherwise, water flowing from the roof will seep under it.
Tilt angle
After the width of the blind area is selected, you can determine the angle of its inclination. This parameter is also regulated. According to SNiP, the inclination of the blind area of cobblestone or gravel should be 5-10% of its width. That is, for a structure, for example, per 100 cm, this figure will be about 5-10 cm. For the blind area of concrete or asphalt, the angle, according to the standards, should be 3-5% of the width. In any case, it is not worth doing a too shallow blind area. The greater the angle of its inclination, the better the water will be diverted from the base and the foundation, and therefore, the longer the building itself will last.
Blind Height
Whatever the width of the blind area of the building, it should protrude at least 5 cm along the outer edge above the surface of the earth. From the base, this figure will be increased by a few centimeters (depending on the chosen angle of inclination). Sometimes the blind area above the surface of the earth is not raised so high. Thus, you can save a little on materials. However, it is better to equip a tape higher near the house. In this case, it will drain water more efficiently, and also last longer.
What should be the thickness
According to the standards, the pit under the blind area should be dug at least 40 cm deep. In any case, the soil vegetation layer must be removed during earthwork. The sand cushion under the tape is laid exclusively on a hard clay or lime layer.
When constructing the blind areas, expansion joints are mandatory. Otherwise, due to temperature changes, the tape will collapse very quickly. According to the norms of SNiP, expansion joints should be equipped with a pitch of at least 1.7-2 m. At the corners of the blind areas, they must be made.
Manufacturing technology
Before proceeding with the construction of the blind area, all work should be completed, the implementation of which can lead to damage to the tape. That is, the roof, overhangs and peaks should already be installed.
The actual procedure for making the blind area usually involves several stages:
- on the outer edge of the tape set pegs;
- dig a foundation pit for the foundation device and compact its bottom;
- crushed stone is crushed in the resulting “trough” (at the base, its layer should be 15 cm, at the edge - 10 cm).
In the future, the technology of the work depends on which material is chosen for the manufacture of the blind area. The foundation pit is either poured with cement mixture, or, having arranged a 3 cm thick concrete pavement, they are laid with paving slabs.
The width of the blind area according to SNiP should be quite large. The thickness of this design is relatively small. Therefore, under strong mechanical or shock loads, a concrete strip can easily collapse. To avoid this, such a blind area must be reinforced. To strengthen the tape before pouring the cement mortar into the pit, you need to install a grid with cells of 100x100 mm. You can also use a lap rod.
Expansion joints are usually made from tarred boards 10-20 mm. At the final stage, the concrete blind area should be ironed. To do this, 1-2 hours after pouring, its surface must be sprinkled with a layer of cement 3-7 mm.
How to arrange a drainage
As much as possible, water from the foundation will be diverted only if the width of the blind area of the house is at least 3 m. Of course, such constructions are extremely rarely built near suburban private buildings.
Most often, owners of houses and cottages simply use additional protection in the form of stormwater and drainage. In most cases, to drain the water, it is enough to dig a not too deep groove parallel to the outer edge of the blind area. To avoid shedding of edges in the future, it should be laid with a plastic pipe cut along the length.
Standards for base height
Choose material for the manufacture of blind areas should be at the design stage of the house. The fact is that such an indicator as the height of the socle depends on what exactly this structural element will be made of. If hard material is supposed to be used for the blind area, the project should include an aerial part of the foundation with a height of at least 50 cm. In this case, making a base below is undesirable. Above the blind area of rubble or, for example, clay, the height of the aerial part of the foundation can be less. In this case, it will be quite enough to fill the base with 30 cm.
Cracks on the blind area
If the technology for pouring concrete tape is disrupted, then cracks will necessarily form on it. It is impossible to leave such defects on the blind area. Small cracks can be poured with a liquid concrete mixture prepared in a 1x1 ratio. Wide are cut down to the full depth, cleaned and filled with mastic made from bitumen (70%), slag (10%) and asbestos (15%). Very large damage to the tape is eliminated by pouring concrete mixture.
Conclusion
Thus, we have figured out how wide the blind area should be at home and what it should have height and slope. In any case, compliance with SNiP standards when constructing the blind area should be mandatory. The same applies to the actual technology of manufacturing this structural element of the building. Otherwise, the blind area will not perform the function of diverting water from the foundation effectively. And this, in turn, will certainly affect the life of the base of the building.