The blind area plays an important role in the design of any building. This element prevents water seepage to the foundation, makes the exterior of the house complete, and often also plays the role of a sidewalk. The tape can be made from different materials. At the same time, there are certain standards that regulate parameters such as the width of the blind area around the house, its height and angle of inclination.
From what materials can blind area be made
Most often this important element of the house is made from:
- concrete;
- paving slabs;
- gravel.
It is necessary to make a blind area around the entire building. Some builders believe that when arranging a drain in a house, you can do without it. However, this opinion is certainly erroneous. According to the regulations, even in this case, the blind area is considered a mandatory element.
General requirements of SNiP
The blind area of what width should be arranged around the house, we will find out a little lower. Now let's deal with the general requirements of SNiP regarding this important structural element of any building. Atthe manufacture of the blind area should be guided primarily by the following building codes:
- the structure must necessarily be tilted in the direction from the basement of the house outward;
- between the blind area and the aboveground part of the foundation of the house should leave a gap of about 20 mm;
- Girdle around the house tape should be continuous.
It is imperative to follow these requirements. Otherwise, the blind area will not fulfill its function of diverting water from the foundation. The gap is left so that in frosts the 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:
- base, which can be made of sand, crushed stone or gravel;
- main cover, the main task of which is to prevent the penetration of water to the underground part of the foundation of the house.
Width of blind area at home
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.
- for the length of the overhangs of the eaves;
- soil structure.
On the territory of our country, the soil in almost all areas has a good bearingability. However, sometimes it still happens that in a given particular area it is highly susceptible to deformation. In such areas around the house, a very wide blind area (from 2 m) is usually equipped. If the soil has a good bearing capacity, you can save a little and build a narrower structure.
In any case, when choosing such a parameter 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 eaves. 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 by regulations. According to SNiP, the slope of the blind area made of cobblestone or gravel should be equal to 5-10% of its width. That is, for a structure, for example, at 100 cm, this figure will be about 5-10 cm. For a blind area made of concrete or asph alt, the angle, according to the standards, should be equal to 3-5% of the width indicator. In any case, it is not worth doing too flat blind area. The greater the angle of its inclination, the better water will be drained from the basement and 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 ground.. Sometimes the blind area above the ground is sodo not lift high. Thus, you can save a little on materials. However, it is still better to equip a higher tape near the house. In this case, it will more effectively drain water, and also last longer.
How thick should it be
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 earthworks. The sand cushion under the tape is laid exclusively on a hard clay or lime layer.
When erecting a blind area, expansion joints are required to be equipped. Otherwise, due to temperature changes, the tape will collapse very quickly. According to the norms of SNiP, expansion joints should be equipped with a step of at least 1.7-2 m. It is necessary to make them at the corners of the blind area.
Production technology
Before proceeding with the construction of the blind area, you should complete all work that could damage the tape. That is, the roof, cornice overhangs and visors should already be mounted.
The actual procedure for making a blind area usually includes several steps:
- indicative pegs are installed along the outer edge of the tape;
- dig a foundation pit and compact its bottom;
- crushed stone is scattered in the resulting "trough" (at the base its layer should be 15 cm, at the edge - 10 cm).
In the future, the technology of work depends on whichit is the material chosen for the manufacture of the blind area. The pit is either poured with a cement mixture, or, after laying a 3 cm thick footing, it is laid with paving slabs.
The width of the blind area according to SNiP should be large enough. The thickness of this structure is relatively small. Therefore, under strong mechanical or shock loads, the concrete tape can easily collapse. To prevent this from happening, 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 overlapped rod.
Expansion joints are usually made from 10-20 mm tarred board. At the final stage, the concrete blind area should be ironed out. To do this, 1-2 hours after pouring, its surface must be sprinkled with a layer of cement 3-7 mm.
How to arrange drainage
Most effectively, water from the foundation will be drained only if the blind area of the house is at least 3 m wide.
Most often, the owners of houses and cottages simply use additional protection in the form of stormwater and drainage. In most cases, to drain water, it is enough to dig a not too deep groove parallel to the outer edge of the blind area. To avoid shedding the edges in the future, it should be laid with a plastic pipe cut along the length.
Regulations regarding heightplinth
Choose the material for the manufacture of the blind area should be at the design stage of the house. The fact is that such an indicator as the height of the base depends on what exactly this structural element will be made of. If it is planned to use hard material for the manufacture of the blind area, the project should provide for the above-ground part of the foundation with a height of at least 50 cm. In this case, it is undesirable to make a basement below. Above the blind area of crushed stone or, for example, clay, the height of the above-ground part of the foundation may be less. In this case, it will be enough to fill the base with 30 cm.
Cracks in the blind area
If the technology of pouring a concrete tape is violated, subsequently cracks will form on it. It is impossible to leave such defects on the blind area. Small cracks can be filled with a liquid concrete mixture prepared in a 1x1 ratio. Wide ones are cut down to the full depth, cleaned and filled with mastic made from bitumen (70%), slag (10%) and asbestos (15%). Very large destruction of the tape is eliminated by pouring concrete mix.
Conclusion
Thus, we have found out how wide the blind area of the house should be and what height and slope it should have. In any case, it is imperative to comply with the SNiP standards when erecting a blind area. The same applies to the very technology of manufacturing this structural element of the building. Otherwise, the blind area will not perform the function of draining water from the foundation effectively. And this, in turn, iswill affect the life of the building foundation.
