Blind area around the house: types and methods of installation
The blind area around the house is needed in order to provide its foundation with effective protection from moisture, which is the main cause of the destruction of the concrete base. The blind area is usually used in conjunction with other drainage systems - drainage and stormwater. The need to lay deep drainage pipes is due to the requirements to protect the lower part of the foundation from the effects of groundwater.
The rainwater drainage system, consisting of pipes installed around the perimeter of the roof, removes rainwater. For this process to be as effective as possible, you will need a blind area, with the help of which surface water (top water) is removed from foundation at a distance of up to 1 m or more. Water, which is formed as a result of melting snow or precipitation, flows through pipes onto a tape of tiles or concrete, laid with a slope on the ground around the entire perimeter of the structure.
The blind area of the house not only serves as protection for its basement and foundation, but also significantly improves the appearance of the entire building. High-quality tiles or stone from which it is made expressively emphasize the features of design and architectural solutions. And also contribute to a greater decorativeness of the exterior.
Why do you need to make a blind area around the house
It serves as an important additional element to the framework with the following functions:
- protective - prevents the penetration of moisture and dust into the soil next to the foundation;
- insulation - does not allow the soil to freeze and protects from frost heaving;
- regulates the expansion and contraction of air in the soil, affects its composition;
- decorative - it can look like a beautiful finishing element;
- pedestrian - allows you to walk along the blind area around the house without getting your shoes dirty.
Precipitation trapped in the ground during rapid freezing can significantly increase in volume, which will lead to heaving of the soil and distortion of the foundation and initiate the destruction of the house. The blind area will protect the soil from freezing and make the lateral pressure more even.
In order for the blind area to reliably protect the foundation, it must be installed around the entire perimeter.
If moisture seeps through cracks and gaps, the base of the structure will gradually deteriorate. The thickness of the cushion on which the blind area is laid usually corresponds to the depth of soil freezing.
Blind area around the house: main types and features
Blind areas are of the classic type and monolithic. Moreover, monolithic is considered to be of higher quality. To make it, a layer of sand is first poured into the trench and tamped, and then it is filled with concrete, which must be resistant to freezing.Construction requires knowledge of the type of soil layer in order to correctly calculate the required width. To strengthen the monolithic blind area, you will need reinforced rods. The blind areas differ not only in appearance, but also in a number of technological features.
They are classified depending on the properties, purpose and materials used:
- From paving stones. This is a semi-rigid, strong and reliable coating that can protect the base of the foundation from heavy physical exertion and sudden changes in temperature. Most often, paving stones are used with a thickness of about 6 cm.
- Soft blind areas. The main structural element is a waterproofing film that protects the lower layers of the soil from getting wet. On top of the film, paving stones are laid or gravel is poured. The best qualities are possessed by waterproofing materials based on polypropylene. In the case of using roll materials, vertical insulation should also be performed, slightly lifting the edge of the insulation layer. Polyethylene and roofing felt are less reliable and cannot ensure the operation of the structure for a long time.
- Concrete blind areas. Hard cover. To prepare a high-quality concrete mix, you should choose a cement that has good waterproofing properties.
The angle of inclination of the blind area is usually about 3-5 degrees. Its minimum value is 3% (3 cm per 1 m of the structure), it is recommended for asphalt and concrete structures. And the maximum is up to 10% (up to 10 cm per 1 m), for crushed stone and cobblestone.
Blind areas with a steeper slope drain water much better, but it is inconvenient to walk on them. Their width depends on the technical characteristics of the foundation and the characteristics of the soil. Average indicators are from 60 cm to 1 m 20 cm.
It is not difficult to repair a covering consisting of paving slabs. Any damaged item is easy to replace. You can use tiles of any shape, as long as there are no gaps between them. And the variety of their color palette allows you to choose the shade that best suits the overall style of the house and the decoration of the exterior walls.
Design features of the blind area
At the heart of any blind area there are only two layers - decorative and underlying, which is necessary to compact the soil and level it. Most often they use clay, sand, crushed stone. An important property of the decorative layer is moisture resistance, as well as strength, which does not allow water to erode the top layer of the blind area.
In the distant past, the blind area of a house was often made entirely of clay. The construction technology was simple. A trench was dug along the entire perimeter of the house, the depth of which was insignificant. They filled it with clay and, keeping a slight slope away from the walls or foundation, tamped it down, and also moistened it as needed. The clay layer turned out to be quite waterproof, rainwater flowed down it and did not damage the house. Currently, this method is almost never used. It is suitable for temporary structures that have a short lifespan.
Concrete is many times more reliable and stronger than clay. When using it, an integral surface is obtained, which is optimal for a foundation with insufficient waterproofing.
If the foundation was installed in accordance with the technological requirements, in the manufacture of the blind area, it is allowed to use piece materials - stone, paving stones, sidewalk slabs, or crushed stone.
There must be a gap between the blind area and the wall, which is necessary to protect the waterproofing of the walls of the basement and semi-basement rooms. In the absence of gaps, a blind area of slabs or paving stones, during winter cold snaps, will put pressure on the walls. And if you walk on it, the blind area will settle and damage the insulation of the walls of the foundation or cladding. The thickness of the compulsory expansion joint should be from 1 to 2 cm. Sand, extruded polystyrene foam or sealant are suitable for filling it.
Do not forget about the appropriate drainage and stormwater.It is they who ensure the dryness of the foundation. Indeed, in their absence, the width of the blind area should be at least three meters. Rigid blind areas are equipped with a surface drainage system in the form of a drainage groove made of stone or concrete. For the same purpose, plastic or asbestos-cement pipes, sawn to length, are excellent. In order for the water to drain better and not stagnate at the bottom, the pipes must be laid with a slight slope.
How to make a blind area around the house yourself
In order to create reliable protection for the base of the house, the help of experienced specialists is not required, since the design of any blind area is quite simple. In addition to economic benefits, the independent production of this important part of the foundation will allow owners to be confident in the quality of their work.
The blind area made of real stone - basalt or gray, yellow, red granite has high decorative qualities. True, the shape of these products is quite simple - a cube or a parallelepiped. The total cost of such a structure is much higher than the price of a blind area made from other materials. Monolithic blind areas made of concrete or asphalt are reliable. They are also more durable.
Most often, the blind area around the house is made of concrete paving stones. It can also be multi-colored, and besides, even hexagonal, square, rectangular or other shape. Chamfering along the edge of the paving stone improves the appearance and prevents chipping. The thickness of the paving stone is from 4 to 10 cm.
Building a blind area will not require a lot of working time. When making a blind area at home with your own hands, you need to use certain tools and consumable building materials.
You will need:
- concrete mixer - it is convenient to prepare in it a high-quality sand-cement mortar in any quantity, in its absence it is mixed manually in any suitable container;
- a grinder with diamond discs for cutting concrete - it is required in order to fit the paving slabs as accurately as possible in size in some parts of the structure;
- building level - to control the slope of the main canvas and additional layers;
- tape measure and rubber hammer - with their help, paving slabs are installed;
- shovel and bayonet - for digging trenches and filling them;
- bucket and trowel - for working with mortar;
- crushed stone, sand - to create a compacting bed, and sand-cement mortar;
- clay;
- grout for the final design of tile joints;
- pegs and twine - for marking;
- concrete curbs and paving slabs;
- cement for mortar grade M-400 or M-500;
- special material for waterproofing in rolls - glassine, glass insulation and other types.
If the technology is observed, a tiled blind area can be no less reliable than a monolithic one made of concrete.
How to make a blind area correctly
When creating a blind area around the house, do not forget about some conditions that must be met. Although its width is not specified in building codes (SNiP), experienced craftsmen make it more than a meter. Since it is quite difficult for a person of average build to move freely on a blind area less than a meter wide, he will touch the walls. In addition, it is necessary that the water pouring from the storm drainage pipes is not absorbed immediately near the building, so the width should be at least 30 cm more than the protruding eaves of the roof.
The blind area around the house must be monolithic and run along the entire perimeter of the building and protect the basement from heat loss. The liquid falling on the blind area should drain from it by gravity, along the slope.
How to make a blind area around the house
Before starting construction, you need to carry out preparatory work. At a distance of up to two meters from the walls, remove all the grass and remove the top layer of soil approximately at the bayonet of a shovel.And also complete all work, during the performance of which damage to the blind area is possible. Drainpipe fasteners, a fire escape should be installed, a roof and eaves overhangs, a canopy above the entrance should be installed. And then they begin to make a blind area.
Step-by-step instruction:
- The marking of the blind area is made using a tape measure, several reinforcing pegs and twine. Stakes, 30 to 40 cm long, are driven into the ground every 2 m, along the entire perimeter of the house, at a distance equal to the width of the blind area + 10 cm (for the curb). Then a string is pulled between them.
- A pit is being pulled out. Its depth should be approximately 20 cm. Then the foundation and plinth are inspected. If cracks are found, they are sealed with a special cement mortar with the addition of construction glue or a special compound for concrete.
- Equip a compacting cushion consisting of three layers - clay, sand and fine gravel. They should all be the same thickness. Waterproofing is laid between them. This is done as follows: a layer of clay, about 5 or 7 cm, is laid on the bottom of the pit, tamped by hand. From above, roll insulating material, for example, pergamil, is spread in one layer. It is docked with the base, fixed on it with liquid nails, and the resulting seam is sealed with a sealant. Then a layer of rubble or pebbles, 5 cm thick, is placed on the waterproofing layer. It will stiffen the blind area and its surface will not sag, even if strong pressure is applied to it. The last is poured a layer of sand, about 10 cm, which should be poured with water and tamped.
Borders must be installed along the outer edge of the blind area so that the canvas does not move after laying the tiles.
Why are the walls of the trench leveled. The curb stones are placed on a thick sand-cement mortar and during work, they are constantly checked for correct installation using a building level.
How to lay tiles correctly
To install paving slabs, it is necessary to make a thick cement-sand mortar, consisting of 1 part of cement and 4 parts of sand. In this case, alignment and alignment of the tiles can be done quite easily.
Start work from the corner of the house. The solution is evenly distributed over the compacted sand, in a layer of two or three centimeters. Tiles are laid on it, which are leveled and compacted with a rubber hammer. The work should use the building level. Sizing of the tiles is carried out with a grinder with a diamond wheel for work on concrete.
When the paving slabs are laid, you should wait about three days. Walking on the blind area is strictly prohibited. During this time, the solution will completely harden.
To seal the tile joints, you can use a special grout purchased at a hardware store or make it yourself. Mix M-400 cement and sand in a 1: 3 ratio. The resulting composition is distributed along the seams using a wide brush or even a floor brush. After grouting, the blind area must be watered with a hose. Be sure to use a spray bottle as the spray will wash the grout out of the joints. After that, the grout will begin to harden, and the blind area will become completely monolithic. Such a structure will effectively protect the soil near the house from moisture entering it.
Possible mistakes when arranging the blind area
During the construction of the blind area, you need to pay attention to various details and features of the soil. It is worth following all technological requirements and is attentive to the choice of materials.
Even minor mistakes can seriously affect the quality of work:
| Violations | Effects | |
| 1. | Poor compaction of the bottom of the trench-trench dug for the blind area. | The uneven thickness of the crushed stone layer threatens the appearance of cracks in the concrete. |
| 2. | Incorrectly selected trench slope angle. | In the rainy season or during the melting of snow, the top water can drain directly to the foundation, due to the fact that the soil will be excessively saturated with moisture. |
| 3. | There is no expansion joint between the concrete blind area and the bottom of the plinth. | Internal stress can cause cracks in the concrete laid against the wall. |
| 4. | There are no transverse expansion gaps. | The integrity of the surface layer of the blind area may be violated. |
When installing a concrete blind area, it is necessary to control the quality of the water used for mixing the solution. It should be clean, free of multiple inclusions of clay particles and small debris. Otherwise, the quality of concrete will deteriorate and reduce the planned service life of the entire structure.
How to make a blind area in the country with your own hands
Country houses and ordinary residential buildings are often made on stilts. This is very useful for uneven terrain with strong elevation differences. Since labor-intensive excavation work is not required.
It is simply necessary to perform a blind area with a pile foundation. It prevents moistening of the lower part of the house and soil erosion near the piles, protects the subfloor from flooding, neutralizes the processes of soil heaving and their general negative impact on the pile-screw foundation. In addition, the construction of the blind area completes the process of decorative finishing of a summer house or a small country house.
For the construction of a safety belt around the dacha on piles, craftsmen usually use a simplified technology:
- A layer of clay is poured under the piles, leveled and carefully tamped.
- Then covered with a layer of gravel. It is quite simple to do all this, and such a pillow for some time really protects the structure from rains and melting snow. But this is a temporary construction, its use is justified only in certain cases.
All technical characteristics of the blind area for a summer residence on a pile foundation coincide with the general requirements. But there are some nuances. The thickness of the concrete top coat should be approximately 13–15 cm, of stone or paving slabs - from 5 to 6 cm. The asphalt should be laid in a layer that is only 3-4 cm thick.
The blind area made for the pile-screw foundation cannot be connected directly to the basement of the house. Any, even minor, ground movements will destroy all of its finish and the protective belt itself. Therefore, the base is isolated from the blind area. To do this, use penoplex, cement particle boards or boards impregnated with bitumen. The thickness of the insulating layer must not exceed 3 cm.
The drainage system for the blind area can be omitted in arid regions, where groundwater is located especially deep.
For other areas, the arrangement of drainage is necessary:
- To make it, a ditch is dug along the outer edge of the blind area, a layer of sand about 10 cm thick is poured into it, and compacted.
- A layer of geotextile is placed on top, and then a perforated tube with a large number of holes is laid.
- The entire structure is covered with gravel and covered with geotextiles.
- The pipes must be directed towards the collector well.
Additional details
The features of this blind area include the creation of expansion joints (gaps):
- They are made every 200 cm. Planks of a suitable width, up to 3 cm thick, are placed on the edge across the excavation dug for the blind area.
- The same seam should be at the junction of the base and the future blind area. It is made from moisture-resistant cement-bonded particle boards or foam, for which they are placed close to the base.
After the surface concrete layer is poured and frozen from the blind area, the transverse boards are removed, which were necessary for the formation of deformation gaps.
Sand or fine gravel is poured into the voids. And only then they install paving slabs or stone, other materials with pronounced decorative qualities. They not only perform a protective function, but also decorate the exterior of the building, the landscape of the entire site.
Sometimes the blind area is made with insulation. Its construction uses ecowool, polystyrene and other insulating materials that do not accumulate moisture. Also, they should not be suitable for various rodents and have good thermal conductivity. If the pile foundation is high enough, it can be used as a utility room.
For the pile foundation, a blind area is often made of rubble. Its indisputable advantages over other building materials include low cost, ease of use, and high speed of arranging the blind area. If concrete is used in construction, special attention must be paid to expansion joints.
A high decorativeness to the building on a pile foundation is given by a blind area made of concrete paving stones.
It is done as follows:
- A layer of sand is poured at the bottom of the trench, the thickness of which must correspond to the thickness of the selected paving stones.
- It is compacted, slightly moistened and poured with a five-centimeter layer of concrete.
- Then a reinforced mesh is installed on top, which is again covered with concrete.
- When the structure is completely frozen, it is again covered with a mixture of concrete and sand, and paving stones are already installed on top.
- At the end of the construction of the blind area, borders are placed along the edges.
Similarly to work with paving stones, the installation of paving slabs is carried out, which every year become more and more in demand among consumers. The blind area has good operational capabilities and is a real decoration of the exterior of the building.
Don't forget the most important thing!
Unlike other residential buildings, houses on screw piles need high-quality basement ventilation. Small holes are often made 50 cm from the blind area. They are covered with a net. Before the onset of the winter season, they are closed with specially prepared corks, which makes it possible to keep warm.