Water poses a threat to construction sites, eroding nearby soil and adversely affecting the structure of their materials. So that the most open house structures are not exposed to such influences, it is necessary to provide special engineering structures. A blind area around the house and drainage on a sand and gravel basis can be a comprehensive solution for protecting this kind.
What is the blind area?
This is a technological coating, which is usually arranged after the completion of basic construction activities. It is recommended to build a blind area together with adjacent structures (garage, building facade) or landscape structures - it acts as a kind of floor framing of an architectural object, providing a stable drainage system. Its main function is to protect the soil near the walls, basement and foundation. But if in the old days this coating performed exclusively the task of external waterproofing in a certain area of soil, today it is also a full-fledged floor base for movements. For example, a car may well ride along a concrete blind area near a garage. However, not every solid site can be considered as a blind area. Its principal difference, from the point of view of the structural device, is the insulating function. To provide it, the coating is based on a substrate with a monolithic structure that impedes or reduces the possibility of water passing into the soil.
Materials for the blind area
The following materials may be used in the device of this coating:
- Concrete tile. It is used most often as a durable and multiformat material in texture and size. The blind area can be laid out from rectangular, square and round elements with a thickness of 5-10 cm and a length of 10-30 cm. Tiles made of concrete are resistant to frost, physical stress and organically combined with sand embedment in the joints.
- Stone tiles. Derivatives made of stone have much more design advantages, since in any performance this material will win with a natural noble texture. Especially good in this regard is granite paving for the blind area, but it is produced only in the form of a cube or parallelepiped. As for wear resistance, this is the most durable solution.
- Paving slabs. In this segment, there are practically no restrictions on the design, texture and form of release. Moreover, you can find material for a soft blind area around a polymer-based house with rubber crumb. It is from the point of view of waterproofing the soil - this is the best solution.
- Rubble. Option to combine the principles of blind area and drainage. Around the target object is filled with crushed stone on the geotextile layer. Also, pebbles, gravel or expanded clay fractions from 8 to 30 mm can be used in this capacity.
Drainage system design
In the classical view, drainage is a network of pipelines designed to collect and discharge drains. Today, this principle of protection against rainwater is combined with local means of filtration through a sand-drainage pad. The main components of such systems include water collection points, channels of its movement and places of accumulation. Both the blind area around the house and the drainage provide the function of providing insulation, but the second option not only embodies a kind of barrier, but also carries out targeted drainage to a specific area or collection point. This is made possible by pipelines. Another thing is that such systems are much more complicated in the technical structure and, in principle, can only be organized on a site with a flat topography.
Drainage materials
The main structural element of the drainage system are pipes. They can be made of metal or ceramic, but the most practical will be the use of polypropylene or polyvinyl chloride (PVC) products. Moreover, the pipes must be perforated to infiltrate water without particles of earth and debris. The best solution would be to purchase plastic perforated pipes with corrugation, which also includes a geotextile sheath or a coconut filter. It is also recommended to use plastic in the form of geofibre as an insulating substrate. Any solid-state bulk material in combination with sand is used as dusting. According to engineers, proper drainage around the house is carried out by sprinkling pipes with layers of gravel in a fraction of 5-30 mm. Layers of soil are further laid on this surface and compacted.
Applied Equipment
Power units and, in principle, machinery with mechanisms are not recommended as part of gutter systems. It is desirable that the channels operate in full autonomy, stably diverting the accumulating water. But if we are talking about areas with complex terrain, where it is impossible to organize natural drainage, then you will have to use special pumps. These are drainage pumping units located directly in the places of collection of effluents. It is necessary to think over in advance the place where the water will be directed both from the blind area around the house and from the drainage on the site. On a large site, there may be several such collection points. Wells are arranged in them, into which the pump is immersed. Pipes departing from equipment nozzles forwarding water already under pressure.
Preparation of soil for the blind area
A durable coating for a floor drain is possible only on a rigid, reliable base. That is, on dense soil, which is rammed around the entire perimeter of the walls. The humus layer is completely removed by 10-15 cm. It is impossible to leave it both due to the depreciation of the blind area and due to the ability of the root system to retain moisture. A layer of the same rubble or expanded clay can be laid out on the cleared area. But how to make a blind area with your own hands around the house so that it matches the planning level in height? At each stage of the device during ramming, the height will change, but maintaining a small margin of 2-3 cm will be a win-win option. If necessary, it can always be leveled by more intensive compaction. On average, the calculation is made from the fact that the layer of the removed vegetation will be approximately 15 cm, the coating itself will take 6 cm, and the preparatory base with sand will be about 4-5 cm. The remaining supply can be allocated for the installation of the drainage layer.
Blind device instructions
When the plant layer is removed, and the soil under it is compacted, you can begin work on the device for covering the blind area:
- The marking of the target site is carried out, followed by delimitation by borders - the opposite side relative to the walls.
- An initial backfill is made with gravel or gravel 5-6 cm thick. This layer must also be compacted.
- If you plan to create a soft blind area around the house, then under it it is advisable to organize an armature frame to give rigidity to the supporting base.
- An insulator is laid - geotextile with sanding. However, it is not worth it to be monolithic. It is recommended to leave the temperature seams after 2-2.5 m.
- A slope of 1.5-2% is necessarily maintained, that is, for every 50 cm, a bevel is made in the direction of the curb by about 1 cm.
- The coating material in the form of tiles or pavers is laid out on a sandy base.
- The resulting gaps are wiped with special moisture-resistant solutions for tile joints.
Step-by-step instructions for installing drainage around the house
The configurations and organization options for this drainage system may vary, but in the standard version it is implemented as follows:
- A circular trench with a depth of about 40-50 cm digs around the perimeter of the house. Contours with a direction to one point of collection or redistribution of effluents also depart from it.
- Plots of the potentially largest accumulation of water are noted, after which deeper holes are organized in them - up to 100 cm, depending on the volume of estimated runoff.
- At the bottom of the trench, a sand and gravel pillow up to 20 cm high is laid along all the lines. Again, expanded clay, crushed stone, and broken brick with pebbles can be used to fill it. The main thing is that the fraction is not less than 4 mm and not more than 30 mm.
- A waterproofing material is laid on the surface of the made filter base.
- Pipes with perforation are laid. Installation is carried out by segments going straight without refraction. Joints are made using fittings at the turning points.
- Again, dusting is carried out using sand and gravel 5-10 cm thick.
- The trenches are covered with seized soil, which is compacted.
Organization of a drain for drains
Even at the stage of designing and drawing up a drainage scheme, one should consider the place of final collection of wastewater. It is on him that the drainage network will be guided by the slope and direction of pumping from the pumping equipment. Both the blind area and the drainage around the house can act as sources for one drive, and the correct organization of wells for local collection of sewage will allow a natural drainage. The simplest solution is to discharge water into a nearby body of water. One pipe is brought to it, with which channels from different water collection points on the site are connected at the receiving point. If this is not possible, then you can install a septic tank with biological treatment. It will provide a thorough filtration of the accumulated water, which can then be used for irrigation in the same area.
Conclusion
It is possible to solve the problem of erosion of the soil under the building without special equipment and structures. It is enough to use simple plumbing fixtures and bulk building materials. A typical concrete blind area is completely performed as a conventional screed with the inclusion of a waterproofing. However, in order to increase the efficiency of the drain on the site, it is still recommended to organize a comprehensive drainage system that eliminates the likelihood of flooding of the homeownership during heavy rains. Moreover, as an example of using a septic tank shows, precipitation can be collected not just to protect the foundations, but for subsequent use in irrigation activities without harm to plants.