Due to geological features, the house is exposed to external factors not only from the atmosphere, but also from the soil. Installing a blind area around the house is one of the stages comprehensive protection, allowing to protect the building from manifestations of nature (rain, melt, groundwater). The roof and drainage system protect the walls and the house itself from water, but precipitation flows onto the ground near the building and destroys the foundation. What is a blind area? Why do you need a foundation blind area, what is its purpose and how to do it yourself?
What is a blind area at home
A blind area is a covering around the perimeter of a house, designed to protect the foundation, basement and basement from water. It is made of waterproof material at a slope from the foundation.
Why do you need a blind area around the house (functions):
- hydrobarrier - protecting the foundation of a building from moisture. First of all, rain and melt water are diverted away from the foundation using a blind area. In addition, the presence of a blind area imparts thermal insulation properties to the foundation;
- comfort - the blind area can be used as a path around the house. A wide blind area can become the basis for arranging a recreation area or terrace near the house. With the correct calculation of the load, it is possible to organize the movement of a car or its parking along the blind area;
- aesthetics - design of the site and local area, giving the structure completeness.
- the blind area stabilizes the air-gas regime in the soil surrounding the foundation. The soil invariably contains oxygen, which is necessary for plant growth and vital functions. soil microorganisms. Large pests also create passages for air to enter the soil;
- eliminates the possibility of damage to the foundation due to frost heaving of soil. It occurs due to the fact that water, solidifying in the soil during the cold season, increases its volume. Soil heaving in itself does not pose any threat, but it creates a significant lateral load on the foundation of the house, which can result in a distortion of the foundation of the house, which will ultimately lead to the destruction of the building standing on it. Thus, the blind area allows you to distribute the load more evenly.
Types of blind areas around the house
Taking into account the fact that the period of operation of the blind area should be equal to the period of operation of the structure itself, special attention should be paid to the choice of material for its construction.
In practice, several approaches to making a blind area are used, but in general it is classified as either hard or soft.
Rigid blind area
1. Concrete blind area
The blind area is made of concrete in the vast majority of cases. Concrete is a reliable material, time-tested and proven by more than one generation of users. Almost every man has an idea of how to make a concrete blind area. And knowing the nuances of pouring it, he can do the work with his own hands.
It is mostly used to protect the foundations of multi-story buildings. This is caused by two factors. Firstly, the difficulty of compacting the material (considerable effort is required). Secondly, to keep the asphalt in a condition suitable for pouring, its temperature should be about 120 degrees. Agree, it is difficult to make a blind area from asphalt without special equipment. Thirdly, when heated, asphalt emits harmful impurities, and therefore few users are ready to replace clean air country house, for a typically urban scent.
3. Blind area made of ceramic tiles
It belongs to the category of hard because the tiles are laid on a concrete mortar. Clinker tiles are used as a facing material, as they are more resistant to external influences. This blind area copes well with its functions, but the cost of clinker tiles is high. Therefore, its analogue, concrete paving slabs, has become more widespread.
Soft blind area
4. Blind area made of paving slabs (paving stones)
A relatively new direction in protecting foundations from water. Despite the novelty of the material (or rather, old, since it is a prototype of paving stones - a cheaper analogue), laying paving slabs with your own hands does not cause any particular difficulties.
5. Blind area made of gravel (crushed stone) or natural stone
The gravel blind area (made of cobblestones, rubble stones) has not become popular for several reasons: the difficulty of compaction, the inconvenience of movement, the need to constantly correct the coating (it can be washed away by unorganized drainage), and the possibility of weeds sprouting. Stone blind area - a good option, but more complex installation and high cost compared to tiles.
6. Hidden blind area around the house
In this case, the facing material is soil, on which you can plant lawn grass, flowers, and arrange flower beds. A blind area of a hidden type is made according to general principle: the top layer of soil is removed, a layer of waterproofing, a layer of sand and crushed stone are laid. The difference is that the top of the pie is covered with geotextile or PVP membrane, on top of which soil is poured. It is not advisable to walk on a hidden blind area; there is a risk of damaging the profiled membrane and trampling the grass. But, if done correctly, it will serve faithfully for a long time.
Which blind area is better - made of paving slabs or concrete?
Each of the above types of blind area has its own advantages, disadvantages and construction features. According to statistics and reviews, today the most popular (most often used) blind areas are poured from concrete and laid out from tiles. Therefore, it would be correct within the article to consider what is better, concrete or paving slabs for the blind area?
This question is asked by many craftsmen and users. Practical operating experience indicates the effectiveness of the tiles. The advantages are as follows:
- the ability to create a continuous, strong and stable blind area. At the same time, ensuring the integrity of a concrete blind area is much more difficult than a tiled one;
- maintainability. The tiles can be dismantled completely or partially. Thus, the process of repairing a blind area or laying communications is significantly simplified. In the case of concrete, it is necessary to destroy part of the blind area, dispose of the concrete fractions, and restore it again after laying. Eliminating tile subsidence or replacing a defective element in a tile blind area is not difficult and will not take much time. And most importantly, the tiles can be reused;
- reliability. The tiled blind area drains water well due to the large number of seams. This allows us to assert that it does not deform as a result of soil heaving or water freezing. Water that has frozen on the surface of a concrete blind area can lead to local cracking of the material. At first, these cracks will not pose a threat, but each subsequent flooding will cause the crack to expand and the blind area to collapse.
Another nuance is the location where the blind area adjoins the house. As you know, the blind area should not form single design from the foundations (should not be connected to it). Soil movement and freeze/thaw cycles will inevitably cause this bond to break. When laying tiles it is easier to ensure the required technological gap. In addition, the destruction of concrete most often occurs precisely at the place where it adjoins the foundation or plinth (the blind area comes off);
- foundation insulation. The technology for laying paving slabs involves the arrangement of several layers, incl. the use of clay and the possibility of laying insulation. An insulated foundation blind area is an additional protection for the basement, ground floor, which reduces heat loss and ultimately leads to savings on home heating;
- reduction in plinth height. With a rigid blind area (made of concrete), the minimum height of the plinth should be at least 500 mm. When soft (tiles, paving stones, gravel, a natural stone) a height of 300 mm will be sufficient. This reduces the cost of installing a plinth;
- ease of work, no need for a reinforcing frame, minimum waste, minor dustiness of the work;
- additional waterproofing of the foundation blind area. While a concrete blind area protects the foundation only from the influence of surface water (rain or melt), a clay hydraulic lock, which is made to form a cushion for laying paving slabs, allows you to protect the base of the building from groundwater;
- more aesthetically pleasing compared to concrete blind area, appearance. A variety of installation options, designs, sizes and colors allows you to create a unique blind area.
The main advantage that led to the use of concrete as a material for the blind area is its low cost. Buying paving slabs and materials for laying them will cost more, even if you do the installation yourself.
Cost of blind area of a private house
In order not to be unfounded, we will give a brief comparative description, i.e. We will indicate in the table the prices for blind areas made of concrete and paving slabs. All prices for 2015, approximate, are presented for information purposes as a guideline for drawing up estimates.
The cost of a concrete blind area (width 1 m, thickness 10 cm)
| Material | Material consumption per 1 sq.m. | Price | The cost of a concrete blind area per 1 sq.m. rub. | |
| Concrete M22, class B-15 | 1 | RUB 3,500 | 350 | |
| For self-cooking concrete | ||||
| per 1 cubic meter | For 1 sq.m. | |||
| Cement M 500 | 320 kg | 32 kg | 200 rub/50 kg | 128 |
| Screenings or crushed stone (fraction 5-10 mm) | 0.8 cubic meters | 0.08 cubic meters | 160 | |
| Sand | 0.5 cubic meters | 0.05 cubic meters | 400-600 rub/m3 (the price is also affected by the loading location: quarry or delivery) | 30 |
| Water | 190 l | 19 l | At local rate | |
| Concrete additives* | ||||
| For pillow | ||||
| Geotextile, PVC film) | 1 sq.m. | 110-2500 rub/roll (50 sq.m.) | 100 | |
| Sand | 0.05-0.1 cubic meters Depending on the thickness of the layer and the composition of the finishing base for the tile | 400-600 rub./m3. | 25-50 | |
| 0.1 cubic meters | 1800-2000 cubic meters (the price is also affected by the loading location: quarry or delivery) | 190 | ||
| Reinforcement | ||||
| Fittings, diameter 6 mm. | 12 m.p. | 10 r/m.p. | 120 | |
| Reinforcing mesh 50x50, diameter 3 mm. | 1 sq.m. | 60 rub./piece (1000x2000) | 60 | |
| Reinforcing mesh 150x150, diameter 3 mm. | 1 sq.m. | 33 RUR/piece (500x2000) | 66 | |
| Formwork installation | ||||
| Boards for formwork** | ||||
| Beam 30x30 for spacers** | ||||
| Total: | ~ 800 rub/sq.m. | |||
* we're talking about about additives (plasticizers) that give concrete additional properties (strength, frost resistance). Adding plasticizers to the composition concrete mortar is at the discretion of the master. In the “classic” recipe given, their cost is not taken into account.
** to form the formwork when pouring a blind area, in practice, old boards or used plywood are used. Therefore, their cost is also taken into account.
The cost of a blind area made of paving slabs 1 meter wide
| Material | Material consumption per 1 sq.m. | Price | The cost of a blind area made of paving slabs per 1 sq.m. rub. |
| For pillow | |||
| Clay | Depends on the soil and the desired thickness of the hydraulic lock 0.05-0.1 cubic meters. | 250-400 rub/m3. (depending on the location of the quarry and the fat content of the clay) | 15-30 |
| Geotextiles, PVC film | 1 sq.m. | 110-2500 rub/roll (50 sq.m.) | 100 |
| Sand | 0.15-0.2 cubic meters Depending on the thickness of the layer and the composition of the finishing base for the tile | 400-600 rub/m3 | 75-100 |
| Screenings or crushed stone (fraction 3-10 mm) | 0.1 cubic meters | 1800-2000 cubic meters (the price is also affected by the loading location: quarry or delivery) | 190 |
| For the finishing layer | |||
| Cement M 500 | 10 kg. Depends on the purpose of the formwork | 500 rub/50 kg | 100 |
| Sifted sand | 2.5 - 10 kg. Depends on the purpose of the formwork | 100 rub/50 kg | 10 |
| For the front layer | |||
| Tile | Depends on the size of the tile. 50 pcs. for the “brick” shape | 300-1,500 RUR/pcs. on average 400 rubles. for the “brick” shape | 2000 |
| Border | 2 pcs. | 75-300 rub/piece. depending on thickness | 360 |
| Water for irrigation sands and blind areas | Before puddles form | At local rate | |
| Total: | ~ 3000 rub/sq.m | ||
How long does it take to install a blind area?
An important point, based on the experience of constructing blind areas of various types, we can give the approximate time for the construction of each of them. The calculation was made based on the total time spent by one person on making a blind area of 50 square meters.
- Completion of all work on preparing the base, forming the formwork and pouring the concrete blind area takes approximately 40-50 minutes. per 1 sq.m. (20-25 minutes when using ready-made concrete).
- Filling the pillow and laying tiles 1 sq.m. takes 60-70 minutes. Moreover, a significant amount of time is spent on the process of compacting the base.
It should be noted that with an increase square meters(area) the speed of work increases.
How to make a blind area around the house with your own hands - video
Construction of a blind area for a house - SNiP and GOST
The second aspect that needs to be taken into account before you start building a blind area with your own hands is the provisions and recommendations of regulatory documents. These include:
GOST 9128-97. Mixtures of asphalt concrete road, airfield and asphalt concrete. Contains recommendations on determining the angle of inclination of the blind area.
GOST 7473-94. Concrete mixtures. They contain requirements for the quality of concrete used for arranging the blind area. Required when arranging a blind area that serves as a driveway for a car.
SNiP 2.04.02-84. Water supply. External networks and structures. SNiP regulates the construction of a blind area around a well, contains recommendations for choosing the angle of inclination, as well as for arranging a castle made of clay or rich loam.
SNiP 2.02.01-83 Foundations of buildings and structures. Regulates the main parameters of the blind area device (dimensions):
1. Width of the blind area around the house (foundation)
Determined from the position of soil type. As you know, soil with different compositions subsides differently. For example, clay soil is divided into two types:
- Type 1 soil does not sag under its own weight or its subsidence is no more than 50 mm and can be caused by external factors.
- Type 2 soil can sag under its own weight.
Thus, based on soil data, the composition and thickness of the base layers for laying paving slabs is selected. Based on the provisions of SNiP, craftsmen determine how wide the blind area around the house should be.
It has been verified by practice that for type 1 soil the minimum width of the blind area should be at least 700 mm, for type 2 - at least 1,000 mm.
If there is normal soil on the site, the optimal width of the blind area can be 800-1,000 mm. In this case, the width can be considered sufficient if it is greater than the overhang of the roofing material above load-bearing walls by 200 mm (for normal soil) and 600 mm for clay soil Type 2.
The final decision on how wide the foundation blind area should be depends on the users and the purpose of the blind area. Which may consist of the following: only foundation protection, protection + occasional human movement, protection + heavy pedestrian traffic (for example, a terrace or gazebo) or protection + car traffic.
Such parameters as the length and height (thickness) of the blind area are not regulated by SNiP. Users advise taking them as:
2. Length of the blind area around the house
3. Thickness (height) of the blind area around the house
Minimum thickness of the blind area: no less than 70 mm, optimally 100-150 mm.
Note. The height of the blind area is not determined to zero. It should rise above the soil by at least 50 mm.
For the blind area that serves as a pedestrian zone, the requirements are becoming more stringent. They mainly concern the design of the pillow. For a motor vehicle zone, it is advisable to do as much as possible solid foundation and when choosing paving slabs, give preference not to vibro-cast, but to vibro-pressed ones.
SNiP III-10-75 Landscaping. The standard regulates the installation location of the blind area. It should fit tightly to the base at an angle. At the same time, the slope of the blind area should be within 1-10% in the direction opposite to the load-bearing wall.
4. Slope of the blind area of the house
The angle of inclination of the blind area is measured in percentages and degrees. For 1 m of blind area width, the slope should be 10-100 mm, i.e. 1-10%. In practice, the slope does not exceed 15-20 mm per 1 linear meter. This slope is invisible visually, but does an excellent job of draining water from the foundation and base of the house.
Note. A large slope can lead to the fact that the flow of water will increase speed when moving along the blind area and, gaining strength, quickly destroy its outer edge.
Another document worth considering is the “Schemes for operational quality control of construction, repair and construction and installation work" Based on it you can study permissible deviations from the given standards.
5. Expansion joint in the blind area (deformation, temperature)
To compensate for the movement of the blind area and reduce the pressure on the foundation, an expansion joint is provided - a gap between the wall (basement) and the blind area. A thermal seam is formed by installing a sheet of insulation or several layers of roofing felt to a vertical surface. Sometimes at the junction they install wooden board, which is then removed, and the place where it is installed is sealed (covered) with sand. This is a labor-intensive method, because removing a board from hardened concrete is quite difficult.
Conclusion
The information provided from the theoretical part will become a useful basis for constructing a blind area around the house with your own hands. Knowing how to properly make a blind area, you can be sure that the created structure will last a long time and effectively.
The work is not limited to just the construction of a private house. It will be necessary to make some efforts to arrange the home so that it is as reliable, comfortable and durable as possible. One of the main stages performed after completion of the main construction work, is to create a blind area around the house. This element performs a number of important functions. If you wish, you can make a blind area with your own hands; there is nothing super complicated about it.
Some homeowners ignore the need to build a blind area. And absolutely in vain! This building element helps to increase the service life of the building and generally creates more comfortable living conditions. The blind area protects the foundation and the surrounding land from the harmful effects of various types of water. Atmospheric and melt water, in the absence of obstacles, can erode the soil so much that moisture seeps into the foundation and then into its base. The consequences of such exposure can be very severe, including destruction of the foundation and the house.
Thus, the blind area is very important element, especially if the house is built on a shallow foundation, the base of which is located close to the top layer of soil. When wet, the base of the base will lose its strength and begin to sag, which will lead to a significant decrease in the strength of the concrete structure, up to its destruction.
But even if the house is built on a strong, buried foundation, the need for a blind area cannot be ignored. It must be present in any case, regardless of the type of foundation, soil and level of precipitation characteristic of a particular region, etc.
Preparing to create a blind area around the house
There is nothing complicated about constructing a blind area yourself; you just need to take into account and follow the basic recommendations in order to get the most reliable and durable building. It is first necessary to prepare materials and understand the main stages of the technology.
Selecting the width of the blind area
Choose the appropriate width of the structure. Since the “shoulders” of this structure bear the function of protecting the foundation of the structure, the width of the fill should be quite large. To reduce the risk of foundation destruction under the influence of moisture, it is worth taking care to drain water from the walls of the building to the greatest possible distance. The optimal width of the blind area is at least 80 cm.
Quite often, the blind area is made so wide that it simultaneously serves as a convenient path. This point also needs to be taken into account at the stage of planning the blind area, so that in the future you do not have to move sideways along such a path. Thus, the most convenient width of the blind area, which can provide both reliable protection, and freedom of movement, is 150-250 cm.
The blind area is carried out with a certain slope, which can ensure the drainage of rain and melt water from the house. According to building codes per 100 cm of structure width there should be at least 5-10 cm of slope. Thus, if the blind area is, for example, 100 cm wide, then the edge that joins the wall of the house will rise by 5-10 cm, and opposite side will be flush with the ground.
Such a descent is quite sufficient to effectively drain water from the building. However, it is difficult to move around such a structure. But if you reduce the angle of inclination, the flow of liquid will not be as effective. In view of this, the slope is made at a level of 1.5 cm per 100 cm of the width of the structure. This optimal value, which does not interfere with walking along the path and promotes effective moisture removal.
Materials for the installation of a blind area
The independent construction of the design in question requires the presence of certain devices. The list of materials may vary depending on the selected type of blind area. The most common option is concrete construction.
First you need to clean the area under the blind area, lay reinforcing mesh from rods with a diameter of at least 6 mm, connect the rods with a special binding wire, install the formwork and pour the concrete solution. This is the general scheme. However, each stage has its own characteristics and requires separate consideration.
Set for pouring blind area
- Shovel for digging a trench.
- Level.
- Wheelbarrow.
- Manual tamping.
- Materials for moisture insulation.
- Material for thermal insulation.
- Clay.
- Crushed stone.
- Sand.
- Reinforcing bars or finished structure with cells 100x100 mm.
Remove everything from the walls of the house that could interfere with the work, collect the devices listed above and start marking. For this step you will need some rope and metal pegs. When creating markings, make sure that the structure has the same width in all places.
Guide to pouring a blind area
The blind area makes a big contribution to the durability of the foundation, so its creation must be approached with maximum responsibility.
The structure consists of an underlying and a top layer. The first is responsible for creating an even, compacted base for the next layer. It is created from sand and small gravel. The total thickness of the layer is about 2 cm. You can also use clay. When choosing a specific bedding material, focus on the material of the top layer.
The top layer is designed to create water resistance and increase the resistance of the structure to water. Can be created from small cobblestones, clay, concrete and other materials. The thickness of such a layer is about 10 cm.
The instructions will discuss the procedure for arranging the most popular type of blind area - concrete. Having dealt with its construction, you can make a blind area from any other materials suitable for this purpose without any problems.
How to make a blind area with your own hands. Digging trenches and erecting formwork
The technology for arranging a blind area around the house requires mandatory reinforcement. Thanks to the reinforcing mesh, the rigidity and durability of the concrete structure will be increased. As noted, you can buy a ready-made mesh or assemble it yourself from metal rods. Cells with a side of 10 cm are considered optimal.
Special attention must be paid to the expansion joint. It is created at the junction of the basement of the house with the blind area. Due to such a seam, the said structures will be protected during the process of soil subsidence. That is, the blind area will be able to sink along the seam without causing damage to the base of the house. The standard seam width is 1-1.5 cm. The seam must be filled with roofing felt, sand-gravel mixture or bitumen of your choice.
You can also use a special rope for filling, the manufacture of which uses foamed polyethylene.
It is important that the diameter of this bundle is approximately ¼ greater than the width of the expansion joint and fits into the gap as tightly as possible. For more convenient compaction of the bundle, take plywood or other similar material.
The blind area technology requires that seams be present across the concrete structure, approximately every 200-300 cm. They will protect the blind area from ruptures during frosts. It is most convenient to make transverse seams using wooden slats. It is enough just to install the slats so that their top is located at the same level with the upper border of the concrete pour. Also, expansion joints must be present in the corners of the building. Don't forget to take into account the slope of the blind area.
To protect the slats from rotting, they must be pre-treated bitumen mastic, waste oil or other similar material. Also, expansion joints must be present in the corners of the building.
Concrete for blind area. Preparation and pouring
Concrete is prepared from 1 part cement (it is best to use the M400 grade material or the less expensive M500), two parts sand and four parts crushed stone.
After pouring, the concrete must be compacted and leveled. Wood slats, previously used to create transverse expansion joints, will simultaneously serve as beacons by which you can navigate during the work process.
After pouring is completed, the concrete should be covered with a cloth; burlap is ideal. The cloth should be regularly moistened with water to prevent the concrete from drying out and cracking.
In the end, all that remains is to wait until the concrete gains strength. On average, this takes 1 month. If desired, you can complete the finishing lining of the blind area. Acid-resistant bricks are perfect for this.
Thus, there is nothing complicated about pouring the blind area around the house yourself. Just follow the instructions you received and everything will work out.
Good luck!
Video - DIY blind area around the house
The blind area of a house is one of the important aspects in creating a long and comfortable operation of the house itself. It creates protection for the foundation and soil around the circumference from moisture. After intense rain or snowfall, or melting snow, water may accumulate near the building. It can also drain from the roof. Moisture can have a destructive effect on the top layer of soil and reach the foundation. If this happens, the bearing potential of the foundation will be seriously weakened. As a result, the entire structure may collapse.
When creating a drain, creating a blind area is mandatory. The drain will protect the soil from water coming from the roof, but will not protect it from precipitation.
It is extremely important to properly build a blind area when you have a shallow foundation. Its sole is quite close to the surface, and water can reach its very depth without any problems. Then the strength of the sole will disappear, the sole itself will sag, and the foundation will lose its shape and begin to collapse.
A blind area should also be created with a built-in buried foundation.
To create a strong, durable blind area, you will need to wisely select high-quality materials and strictly adhere to the technological aspects of construction.
Tile blind area.
Determining the width of the blind area
The main task of the blind area is protection. And its width is the parameter that should be the maximum possible. Its recommended minimum value is 80 cm. And the maximum numbers are a purely business matter. There are no standards here. The required width will ensure that moisture is absorbed into the soil far from the house.
When determining the width, it is worth considering one more task of the blind area - path around the perimeter of the building. The blind area should ensure free movement along this path: no walking sideways or close to the wall. Taking this factor into account, the width should be set in the range of 100 – 250 cm.
The blind area should be formed with a slope. This will allow water to drain away from the walls of the building. According to Soviet standards, the slope parameter is as follows: 5 – 10 cm per 100 cm width. That is, the edge of the blind area, whose width is 100 cm, will reach a height of 5–10 cm near the wall of the building. Its other edge will be flush with the ground. This results in a rather steep descent. It is optimal for fast and efficient water drainage. But moving along such a blind area will be problematic. If the angle of inclination is reduced, the flow rate will drop significantly, and water may generally accumulate on the surface. Although movement along the blind area will be comfortable.
Given that ideal surface blind area (evenness, smoothness), an inclination of 1 cm is acceptable. However, it will be difficult to move on such a surface in winter time- very slippery.
If a material with a rough surface is used for the assigned tasks, the minimum tilt value is 1.5 - 2 cm.
When a blind area is created around a non-residential building, for example, the recommended angle at the entrance is: 2 - 3 cm. This way the surface will receive high-quality protection from rainwater. It will quickly drain, without penetrating into it and not freezing in the cold. And your garage will not have puddles and ice.
Selection of materials
This task should be approached extremely seriously. Exist different variants materials for creating a blind area. The most popular is considered reinforced concrete.
When using it, the work is performed according to the following algorithm:
- Clearing the site for future construction.
- Reinforcing bars (minimum diameter - 6 mm) form a mesh. Its cells are as follows: 30 x 30 cm. The cells are connected with knitting wire.
- Installation of formwork. For this, boards are used.
- Pouring formwork.
Before creating the blind area, its base is prepared: along the perimeter of the building along the width of the blind area, the top soil layer is removed - approximately 13 cm. At the walls, the depth should slightly exceed the specified parameter. The poured concrete mixture should flow towards the house, slightly compressing it. Any other fastenings of the blind area to the building are not necessary.
Then they are marked boundaries of the blind area. The pegs come into play. They are driven in. A cord runs between them. The bottom of the trench is covered with a 5 cm layer of sand. Concrete will be placed on it.
If in work area The soil is sandy, the use of sand can be eliminated. Place on this layer formwork, reinforcement cage, concrete pouring follows. Reinforcing elements must be completely concentrated in concrete base. To do this, the base rises a little.
Concrete is created in the following proportions:
- cement M400: 1 share,
- sand: 2 shares,
- crushed stone: 4 or 5 shares.
Concrete blind area.
Radioactive materials
If you intend to build a blind area from ash - the result of coal combustion at a thermal power plant, be vigilant. Ash can be a source of radiation. And this will have a detrimental effect on the health of residents.
As a rule, coal mining is carried out in Russian mines. There is a very high level of radiation there. Radiation checks are not carried out at thermal power plants. An important factor there is the ash content of the coal. Therefore, by purchasing ash and using it in construction activities, you risk seriously deteriorating your health. To reduce the risk, purchase ash with a dosimeter. This device will calculate her radiation level.
Also included in the category of radiation materials is cinder block. It also contains ash. There are known cases of determining very high level radiation in residential premises made from such blocks.
It is extremely rare that increased radiation occurs near foundation blocks and reinforced concrete slabs. In construction, sawdust blocks can be used instead of cinder blocks. This option is completely environmentally friendly.
Metal can also give off radiation. This applies to both black and colored varieties. A dangerous background is most often present in melted metal. The echo of Chernobyl speaks here. A lot of metals were taken out and melted from this zone. And there is some probability that when buying metal product for the blind area, you acquire the “element” of Chernobyl. When purchasing, also use a dosimeter.
Working on the covering for the blind area
After the concrete mixture has completely hardened, a coating can be laid on it. Very often the coating is formed from figured paving elements (FEMs), or from granite paving stones.
The first ones differ in their quality and appearance. Acid-resistant bricks with dimensions of 12 x 25 x 5 cm are considered high-quality options. They cope excellently with loads from frequent movement and walking, as well as natural conditions.
Standard FEMs do not have the required strength. This negatively affects their service life. It hardly reaches 5 years. After this period, their original appearance is completely lost. Such coating should last at least 10 years.
Paving stones – great option for covering. Its strength is high, its service life is decent, and it has a rich color range. It can be used as a mosaic and formed into intricate patterns. Its main drawback is related to its huge price.
Coverage example
The nuances of creating a blind area around the house yourself
In this work it is worth paying attention to the following nuances:
- Don't build a blind area immediately after the construction of the basement. When backfilling is performed, the trench is filled with soil that was previously removed from it. That is, black soil, clay, etc. are used. To a certain extent, there is subsidence of any soil. It takes time for it to completely subside. If you build a blind area right away, without waiting for this subsidence, then if moisture penetrates into the soil, it will begin to sag, changing the shape of the blind area. And cracks form on its surface. To prevent such a situation, make the backfill from sand, which easily allows water to pass through. When you water it properly and level it, the blind area can be created within 24 hours. Although it is better to start this construction after the construction of the building box or 8-12 months after work on the foundation.
- To cover Do not use porcelain tiles. It has a smooth, slippery and traumatic surface. In addition, it has a very modest service life. After all, it is laid directly on a concrete plane, which expands in cold weather. And such a coating will soon burst.
Principles of installation of FEM
To lay this material, use a mixture created from a bucket of cement (grade M400) and 3-4 buckets of sand, as well as 70 grams detergent. The last component protects the created composition from subsidence.
There is a more economical version of installation - on sand. But the service life of the coating in this situation will be short. When moisture penetrates the sand, the material will sag and will need to be re-laid or completely replaced.
Another economical option with similar characteristics is laying on a dry mixture. This way the surface will retain its pleasant appearance a little longer. Therefore, the first proposed option remains the most optimal.
Example
Creating blind area protection
As you know, the main task of the blind area is protective. But it is advisable to protect this structure itself from water coming from the roof. Here it is necessary to arrange a high-quality outlet in the format of gutters. They will be organized along the entire perimeter of the roof. This way, the water will first end up in the gutters and flow through them into the drain pipe. As a result, it will still end up on the blind area, but the height of its flow will be radically reduced. The impact on the surface of the blind area will also be reduced.
According to old standards, diversion technology was used for buildings with more than two floors. Nowadays, allotments are arranged in any private houses.
Examples:
It wouldn’t hurt to insulate the blind area additionally. This way the soil will freeze less in cold weather. For such purposes in concrete composition castling is made: instead of crushed stone - expanded clay.
Another good insulation method is to fill the blind area in two layers, with insulation placed between them, for example.
Final requirements for the blind area:
- Optimal width for efficient drainage and comfortable walking: 1-2 m.
- The optimal slope according to the same criteria: 1.5 cm (per meter of width).
- When creating the foundation, it is necessary to dig a trench with a slight slope towards the residential building. The blind area should be in close contact with the house throughout its entire depth.
- The optimal and safe material is reinforced concrete. It guarantees excellent results in terms of strength and durability.
- The best option for coating is acid-resistant brick - FEM. It is laid on a concrete mixture.
- No matter how many floors there are in a built house, high-quality drainage is necessary. It will seriously increase the service life of the blind area.
An example of a finished blind area with drainage. 
Video instructions
Alexander Kvasha’s video on creating a blind area with your own hands is not only one of the most popular. The authors of the material did not turn off the ability to comment, so viewers were able to actively criticize the presented material and analyze errors in detail.
Saving on construction is a difficult stage, where the quality/cost line is important, so that you don’t go broke on repairs in the future, and at the same time, feel quite comfortable when operating the structure.
The blind area should be built after the foundation, basement, walls, and roof have been completely built. Although, the blind area can be constructed at almost any stage of construction, after the walls have been laid. But the blind area after all stages of construction will be the cheapest and least time-consuming, because in this case you save on calculations and errors, and the formwork can be constructed on only three sides.
How to make a blind area correctly?
A concrete blind area of 70 cm around the entire house will be the most simple option. To build a high-quality blind area, it is necessary to take into account a number of rules:
- The width of the blind area should be greater than the protruding part of the roof, usually by at least 20 cm. This is done so that moisture dripping from the roof does not deform land plot, which actively affects the quality of the foundation.
- The blind area should be continuous, monolithic around the entire house. Only in this case will the foundation be safely protected from moisture, which, however, does not exclude waterproofing in any case.
- A wider blind area is also more functional in terms of protection from moisture.
- The slope of the blind area will optimally provide drainage at 1.5 degrees. You can make the slope larger, but remember that on a steeper slope in winter you can slip. The slope is formed at the stage of the underlying layer, and it is also possible at the stage of laying the covering.
- A blind area made in accordance with all the rules ensures high quality, savings and no repairs, and a long service life for both the blind area and the plinth.
The blind area is two structural layers
- The underlying layer is a smooth, compacted base for the coating. For him, materials such as clay, fine crushed stone, and sand are used. The material of the underlying layer directly depends on the coating material used. Thickness up to 2 cm.
- The coating must be completely waterproof and resistant to the destructive effects of water. They use clay, concrete, asphalt, and small cobblestones. Layer thickness up to 10cm.
These layers are necessary for any blind area.
It is necessary to mark for the future blind area
In our case, the width of the blind area is 100cm. The soil along the entire perimeter of the house must be removed to a depth of 20-25 cm. As a rule, the soil here is removed at the very beginning of building a house. You should dig to the entire width of the blind area of 1 m. The calculation is also based on the material with which the blind area is laid. Regarding a blind area made of concrete, a depth of 20-25 cm is required; relative to other materials, a different depth is needed.
Some developers recommend immediately after digging a trench around the house, leveling the floor and walls, and then immediately covering them with herbicides. So that the plant roots do not grow later and damage the blind area. It's your own choice.
The formwork is made of boards. As a rule, 2cm thick boards are used for this.
A layer of clay of several centimeters should be laid on the soil that we have compacted. Then, it is necessary to level the layer and compact it.
A layer of sand is laid 10cm thick. It is also carefully compacted. To make the compaction process easier, moisten the sand with water. But not abundantly, so that the water does not reach the clay.
Then there is a layer of crushed stone of 5-10 cm.
To strengthen the blind area, reinforce it fiberglass reinforcement with intervals at the joints of 10 cm. Reinforcement makes it possible to achieve concrete resistance not only to compression, but also to tension. Earth displacement occurs frequently, so reinforcement is required in any case.
At the junction of the blind area with the walls of the basement, you need to make a seam. It's called compensatory. Also, this seam is called a deformation or temperature seam. This seam will protect the base and blind area from ground subsidence and further destruction. In this case, the blind area will lower, but the movement will not damage the base, since all the mechanical impact will be on the seam. The width of such a seam is up to 1.5 cm. It should be made from a mixture of fine gravel and sand, bitumen, mastic, or two layers of roofing material. Some even use a tourniquet made of foamed polyethylene. The diameter of such a bundle is a quarter larger than the width of the seam. Thus, the rope fits very tightly into the seam gap.
Features when placing the tourniquet - it should go completely into the gap, and leave a little space on top. Those. There should be a depth at the top free from everything, which is equal to half the width of the seam. A piece of plywood will allow you to this process faster.
In our case, a simple sealant was used.
When filling the blind area, an expansion joint should be made across it every 2 meters. They preserve the blind area from ruptures in the winter. Wooden slats placed on edge are perfect for these purposes. The surface of the slats should be flush with the surface of the blind area. The slope of the blind area should also be taken into account, and therefore, place the slats either on a slope, or make the slats pre-slanted on the edge, to match the slope. To protect wooden inserts from rotting, they should be treated with bitumen mastic.
Expansion joints should also be installed in the corners of the house. Those. at the corners of the blind area.
In addition to pouring the concrete, it should also be compacted and leveled. The slats will help you navigate the height of concrete pouring. Just wait until it hardens completely.
Ironing gives the greatest strength to the formwork. Ironing done using the wet method will help the blind area achieve the greatest water resistance.
The last stage is to cover the concrete surface with fabric material, gradually, as it dries, wetting the fabric with water. This will help keep the concrete from drying out before it finally hardens. If you have to lay a blind area during the rainy season, then you can do without moisture.
In 2 weeks the blind area will be ready.
Repair of concrete blind area
When laying the foundation, plinth and blind area of the house correctly, long years you won't have any problems. But what to do if they appear? For example, is the blind area cracked? Yes, even significantly.
It will be enough to fill small cracks with a portion of the concrete mixture in a 1:1 ratio.
Larger cracks should be cut out to the full depth of their formation, the recess should be cleared of dust, dirt and other debris, and filled with liquid mastic (2/3 bitumen, BND-90/130, 10% crushed slag and 15% asbestos material). Then sprinkle the filled cracks with any sand.
If the destruction of the blind area turns out to be even more significant, then it should be fully restored using a fresh portion of concrete and a couple of simple manipulations. The surface must be cleaned of dirt and primed. For the latter, a cement solution is suitable. Place the fresh mixture and level it. Then, it is necessary to prevent the fresh concrete mixture from drying out until it has completely hardened. Those. Moisten it steadily, at the slightest drying, and cover with polyethylene film.
Repairing the blind area is best done in the spring or autumn. Need cool weather. During the summer period, you should choose the morning as the most favorable time for work. Because due to high temperatures, the concrete will expand and the cracks will decrease. In winter, working with concrete is impossible.
Do not forget that the brand of concrete also affects the level of strength of the blind area. It is easy to find 500 grade cement on sale, which we then divide into the required proportions. With the highest density of 500 grade, the blind area will be very strong, and it will really last for decades. If only because it is the 500 grade of cement that is used for the construction of large bridges and tall buildings over 30 floors.
Video instructions for building a blind area
The blind area around the house is a wide “ribbon” with a hard or loose covering. But this is only the visible part complex design. Many people perceive the blind area of a house as a type of path along the wall, and although such use may be included in the list of functions, the main purpose of the structure is different.
Blind area around the house made of paving slabs
Why do you need a blind area
Among the regulatory documents, there is no separate standard, SNiP or set of rules on how to make a blind area around a house correctly. There are several documents defining its purpose, requirements for the width and angle of slope, interaction with other elements of the outlet atmospheric waters from the site on which the building stands.
According to the standards, there must be a waterproof blind area around the building, which is created as part of mandatory water protection measures aimed at preventing local soaking of the soil in the base area of the house.
That is, we are talking about protecting the soil, not the foundation. To protect the materials of the foundation itself, waterproofing of the foundation is done, because in addition to atmospheric waters, there is also groundwater, which rises high during the rainy season and during snow melting (the so-called high water).
And the ground must be protected from getting wet, because under the influence of moisture, many types of soil (clay, loam) lose some of their load-bearing properties and simply may not withstand the design load from the building. To prevent erosion of the soil, they create a blind area, which, however, also protects the foundation at the same time, removing part of the load from the waterproofing layer, which protects the concrete base of the house from getting wet.
In addition, the blind area around the house is an element of the architectural appearance of the building and part of the landscape of the site. There are quite a lot of ready-made design solutions that allow you to disguise the blind area, and when using a hard surface, use it as a path.
A beautiful blind area that turns into a path as part of the landscape design
Requirement for the blind area
There are no requirements in any regulatory document that would link the size of the blind area with the roof overhang. Moreover, there are no requirements to exceed the width of the blind area by 20-30 cm in relation to the projection of the cornice extension. When building a blind area around a concrete house with your own hands, you do not need to rely on these numbers.
The regulations provide only two minimum width sizes. And they depend on the soil:
on sandy ones - from 70 cm;
on clayey soils – from 100 cm.
This is exactly what is stated in the manual on construction operational control schemes for supervisory services.
With unorganized drainage, the side roof overhangs of houses up to two floors should be less than 60 cm. If the house is on sandy soil, then the difference between the width of the blind area and the amount of roof overhang can be equal to 10 cm, and not contradict the requirements of the regulations.
That is, it turns out that the parameter 20-30 cm is simply a statement of the real ratio of two sizes for most cases. But not for everyone.
Video description
Visually about the requirements for the blind area of a house in the video:
If the soils are subsident, depending on their type, the standards impose other requirements for the width:
Type I – more than 1.5 m;
Type II – more than 2 m.
And in any case, the blind area should be 40 cm wider than the pit bosom.
The slope angle can be in the range of 1-10%, but in the case of subsidence soils minimum angle equal to 3°, which in terms of 5.2%.
The elevation of the outer edge of the blind area above the site should be more than 5 cm.
Types of blind areas
Before you properly make a blind area around the house with your own hands or order its construction, you need to decide on the type. There are three options for top coating:
Hard coating. It is a monolithic tape made of concrete or asphalt concrete. In the first case, when creating a blind area with your own hands, mandatory reinforcement is carried out, in the second it is not required, due to the resistance of asphalt concrete to bending loads.
Arrangement of the base and pouring of the blind area around the house is carried out using the same technology as for paths, but taking into account the implementation mandatory requirement along the slope from the base.
Protection from water occurs due to the water resistance of both types of concrete. Therefore, it is important that there are no cracks or tears in the coating on the surface. The second feature is that a gap is required between the blind area and the base to compensate for the thermal expansion of the monolithic coating.
Concrete blind area with an expansion gap at the base filled with sealant
Semi-rigid coating. They are made from paving slabs, clinker bricks or paving stones. The design and installation method are carried out by analogy with sidewalks and platforms made of these materials with the obligatory creation of a waterproofing layer as part of the blind area:
waterproof geomembrane, when laid on a dry sand-cement mixture;
concrete monolithic base.
Semi-rigid clinker brick covering
Soft covering. Classic version– arrangement of the top layer from a compacted layer of dense (waterproof) clay. Many people know how to make a blind area of this type: it used to be done around village houses, and even now this solution is periodically used as an “economy option” around small country houses, nose top layer from decorative (colored) gravel. To improve waterproofing, a waterproof film can be laid between clay and crushed stone. You need to understand that the blind area is not just decoration; you shouldn’t save much on it.
Crushed stone covering as an economical option
Now gaining popularity the new kind soft blind area around the house based on a profiled membrane. General procedure The works here are as follows:
The membrane is laid in a trench with a depth of 25-30 cm.
The bottom of the trench is compacted with a slope from the foundation.
A layer of filtering geotextile is rolled out over the membrane, extending onto the base wall of the house.
Then they pour drainage layer made of crushed stone and sand, and on top of it - fertile soil, which is sown with lawn grass or planted with ornamental plants.
This blind area is also called hidden. This nice solution, nose significant drawback- It is not recommended to walk on soft surfaces. However, you can always additionally organize a path.
Hidden blind area with ornamental plants
Common mistakes when creating a blind area
Errors can happen at any stage. Therefore, it is very important to know how to properly fill the blind area around the house. But even with technology, you need to be careful.
For example, insufficiently compacted backfill soil leads to “unplanned” shrinkage and destruction of the integrity of the waterproofing layer or rigid covering. The same consequences occur if, due to the negligence of workers, construction waste gets into the backfill.
Transverse crack in the blind area as a result of an error
At the stage of compacting the bottom of the “trough”, it is necessary to maintain the level of the bottom of the pit and its slope. This is one of important conditions how to properly make a blind area around the house. Irregularities in the bottom lead to uneven thickness of the crushed stone layer, a difference in its load-bearing properties on different areas, which may cause cracks in concrete. And if the slope of the trench profile is incorrect, during the rainy season or melting snow, the perched water will literally flow down to the foundation from the moisture-saturated soil.
Another mistake is the lack of an expansion joint between the concrete blind area and the plinth. At high temperature air, internal stress forces arise in the concrete near the wall, which lead to the appearance of cracks. The same thing happens if transverse expansion joints are not laid or cut in the reinforced concrete blind area.
When preparing concrete mortar, it is unacceptable to use sand containing clay and dirty water. This will deteriorate the quality of the concrete and reduce the service life of the blind area.
If a tap for irrigation is provided in the basement of a private house, then a separate gutter must be laid under it. It is needed to drain water beyond the blind area in case of leakage of shut-off valves or a leaky hose connection.
Video description
Another mistake when installing a blind area on a video:
The maximum slope angle of the blind area is 10%. And with organized drainage of water from the roof, trays should be laid under drainpipes with a slope of more than 15%. This regulatory requirement is sometimes ignored.
Determining the thickness of the blind area
On the site of a private house, concrete, prefabricated semi-rigid or soft covering is used. The thickness of the semi-rigid coating is determined by the material itself for the blind area around the house: clinker bricks, tiles or paving stones. But the size of the concrete coating needs to be calculated. At least in order to calculate the volume of the solution and the depth of the trench for all layers.
Knowing the standard width of the blind area and the minimum level of elevation of the outer edge above the site, you can calculate the only parameter that is not regulated by the standards - the thickness of the hard covering, taking into account its slope.
The minimum thickness of reinforced concrete is about 70 mm - the thickness of two rods with wire binding plus the thickness of the concrete layer on all sides is more than 30 mm.
Video description
What are the features of a hard and thick blind area in the video:
This size must be multiplied by the slope, multiplied again by the width of the tape, divided by 100. This will be the height difference between the outer edge and the base. And now you need to add the difference in heights to the thickness of the edge to get the thickness at the base.
If the thickness of the edge is 70 mm, the slope is 5%, the width of the blind area is 1000 mm, then the height of the covering at the base is 120 mm.
Technology for manufacturing concrete blind area
Step-by-step instructions on how to make a blind area around the house look like this:
Preparing a trench (“trough”) for the blind area. The fertile layer is removed over the entire width (from 20 to 30 cm). Compact the bottom of the trench and form a slope. The area near the foundation with backfill is especially carefully compacted, while adding local soil - the thickness of the compacted layer in this place is at least 15 cm. The depth of the trench should be sufficient for the underground part of the hard covering, the thickness of the cushion (minimum 10 cm, recommended 15 cm) and insulation for the blind area around the house on heaving soils. If the trench after excavating fertile soil turns out to be deeper than the calculated one, then the difference is compensated by backfilling with compaction of either local soil or a layer of clay (the second option is preferable).
Trench for a blind area with a slope from the foundation
Pillow. For weak soils, it is recommended to create a crushed stone base as the bottom layer. First, crushed stone of the middle fraction (40-70 mm) is filled, leveled and compacted. Then - fine crushed stone (5-10 mm) to fill the voids of the previous layer. When compacting the crushed stone, it is watered. Sand is poured in next, which is also leveled, watered and compacted. According to the standards, it is sand that serves as the basis for constructing a blind area. The level of crushed stone preparation should have a maximum deviation of 15 mm per 2 m, sand – 10 mm per 3 m.
Waterproofing. A waterproofing film is laid on top of the sand. It does not serve to protect the soil, but protects the concrete from loss of moisture during its maturation. In the regulations, this layer is called “separation layer”. For this, a geomembrane or polyethylene film with a thickness of 200 microns is used.
Video description
You can also use built-up waterproofing - example in the video:
Insulation. When creating a blind area on heaving soils, the structure is insulated with extruded polystyrene foam. If two layers are laid, then the seams top sheets shifted relative to the lower seams.
Formwork. It is made from edged boards and a bar. At the same time, slats for transverse expansion joints. Typically, these slats are mounted at the design level of the surface of the blind area with a given slope angle, and concrete is poured along them, like beacons. The width of the slats is 20 mm, the height in section is more than 25% of the thickness of the blind area. The approximate distance between the seams is calculated by multiplying a factor of 25 by the thickness of the concrete at the base. Typically, for concrete pavements, expansion joints are combined with technological joints (one portion of pouring between the slats). The expansion joint at the base is formed from folded strips of roofing material with a total thickness of about 5 mm.
Do-it-yourself installation of a blind area around a concrete house
Reinforcement. The easiest way is to lay a road mesh with a cell of 100x100 mm and a rod diameter of 4 mm. Adjacent cards (strips) are overlapped by one cell (or more) and tied with wire. The distance from waterproofing or insulation is at least 30 mm. This size must be maintained in relation to all surfaces - the front, at the ends of the edge and in relation to the base.
Concreting. M200 concrete is used. After pouring, within four hours, the concrete must be covered. And for 14 days - moisturize.
Protection from destruction. To improve the wear resistance and strength of the surface, ironing is carried out. There are two types: dry - after pouring, wet - simultaneously with filling expansion joints with sealant. After removing the slats (14 days after pouring the concrete), the seams are filled with bitumen mastic with the addition of a mineral filler.
Note. To enhance the surface and give an attractive decorative look, you can use stamped concrete technology.
Stamped concrete from the blind area to the walkway
If the blind area requires repair
If the concrete begins to deteriorate, then, depending on the degree of damage, the restoration technology takes the following form:
if the cracks are local (up to 30% of the surface) and not wide, they are filled with cement paste (the proportions of cement and water are 1:1);
for local repairs and wide cracks - they are expanded, the visible reinforcement is treated with an anti-corrosion compound, and sealed with a repair polymer cement mortar;
in case of crumbling and delamination - weak areas are cleaned and a layer of screed is poured around the entire perimeter of the house cement-sand mortar(with preliminary installation of a new curb and installation of a reinforcing frame).
When performing each type of repair, the surface of the blind area must be cleaned of dirt and debris and treated with a deep penetration primer.
As a result. It is important to remember that the blind area is only part of the water protection measures. The most effective blind area is in conjunction with storm sewer, when water is collected in special receivers and carried away through pipes away from the foundation.
Storm drainage system
As a result, the foundation will receive reliable protection not only from rain or melted snow, but also from groundwater.
And we hope you received answers to your main questions - how to make a blind area around the house and who to entrust it to.