The longevity of a building depends on the condition of the foundation, the health of which is determined by reliable and efficient drainage surface waters from home at any time. This task is performed by the blind area, which primarily has protective function. One of the most common and accessible is the technology of arranging a concrete blind area around a building. Its correct design, created with your own hands, will effectively perform its functions for many years.
What does it represent?
The blind area is an external waterproof basement concrete structure in the form of a continuous path along the perimeter of the building, sloping from the wall towards the surrounding terrain adjoining plot. Its arrangement involves a tight but movable connection to the base of the house.
The structure is a layered “pie” consisting of materials that together keep the foundation dry. The basis of such protection is in proportion: a compacted, even underlying layer of sand (crushed stone, clay), waterproofing and a coating - concrete, which ensures the waterproofness of the structure.
Functions performed
A properly equipped blind area ensures the longevity of the structure, preventing the destruction of the foundation and structures of the house by moisture from precipitation, melt water. A blind area without concrete, created with your own hands, is a temporary measure that does not solve the entire complex of problems of such a design.
Main function correct blind area- divert and transport water a sufficient distance from the foundation towards the lowest place on the site or into a storm drain.
In addition to the function of a horizontal hydrobarrier, the blind area (especially insulated) reduces the freezing of the soil around the house, which reduces the likelihood of it swelling (rising), and also reduces the thermal conductivity of the building. A blind area without concrete does not prevent periodic moistening of the soil close to the foundation and, as a result, harmful effects which can be caused by hard plant roots. Safety device also gives the building an aesthetically finished look and can be used as pedestrian path.
Requirements for the blind area and design rules
Diagram of a structure using reinforced concrete. The encircling protective structure must have the same width, the value of which is 20–30 cm greater than the overhang of the roof eaves beyond the wall of the building. It is generally accepted that it is about 1 m (or more on subsiding soils). The blind area is buried to no more than half the depth of soil freezing in the area. The thickness of the concrete coating is selected within the range of 7 - 10 cm (up to 15 cm if used as a path).
The recommended slope of the coating is 92 - 94 degrees relative to the wall of the building (or 10 - 100 mm per 1 meter of blind area width). The height of the base above the blind area at the junction of the structure is set to 50 cm. Its outer lower edge should be raised approximately 50 mm above ground level, which prevents the accumulation of water at the edge. The technology for creating a structure assumes the possibility of its integral movement following soil deformations relative to the foundation, which ensures near-wall.
How to make a blind area?
Markings are made on the area, the fertile layer of soil is removed. The underlying (clay) is laid. Geotextiles (for example, roofing felt) are laid. The formwork is formed taking into account expansion joints. The area is reinforced. Concrete for the blind area is prepared in the correct proportion and poured into the formwork. The coating surface is drawn out with the selected slope along the edge of the formwork and leveled. The concrete is given time to dry.
Preparation of tools and materials
The marking quality is checked building level. For earthworks You will need shovels, a pick, twine, a tape measure, a tamper, and pegs. The required volume of geotextile (waterproof film) for the water seal should be calculated. Required in the right quantity and proportions of components for mixing concrete (washed sand, water, gravel, crushed stone of fractions 5 - 10 mm, cement) or (for example, grade M400 and higher). Tools also include a mixer (container) for forming the solution, buckets, carts (stretchers), and a measuring bucket. The laying of the underlying layer must be provided with sufficient sand (clay).
The formwork is formed from boards, but a hacksaw, level, nails, and hammer are also useful. (steel wire), which should be delivered. Will be needed welding machine, a tool for cutting pieces of reinforcement. A long rule, trowel, and spatulas will help in laying and leveling concrete. The construction of seams will require polyurethane sealant.
A trench is marked around the house with pegs and string. The level at which the blind area adjoins the plinth is marked with beacons in 1.5 m increments. A layer of fertile soil is removed around the building, taking into account the layout of the surrounding surface. The bottom of the trench is compacted and leveled with the already formed slope (herbicides can be added). The depth of the passage can be 500 mm (on heaving soils).
Creation and compaction of a sand cushion
The bottom of the trench is lined with sand, the surface of which is also profiled with a slope. The material is abundantly moistened and compacted. The operation should be repeated at least twice. The thickness of the layer can be up to 20 cm. Its surface is carefully leveled.
The use of rolled waterproofing materials for blind areas. Its device involves laying two layers of waterproofing (for example, roofing felt) on a sand substrate, which are slightly wrapped onto the wall to create expansion joint. At the joints the material is overlapped. Next, the geotextile is covered more thin layer sand, and then gravel (about 10 cm thick) with a slope of the top layer and compacted. It is advisable to place a drainage system close to such a water seal.
Creating formwork
Removable wooden mold protects the place where concrete is poured. It is reinforced with strong pegs with outside. The form provides for transverse expansion joints (every 2 - 2.5 m), which are installed, including diagonally, at the corners of the formwork. Their tightness is formed by placing them on edge wooden blocks(butyl rubber belts), impregnated with waste oil and coated with bitumen.
The edges of the mold must be straight for the rule to apply. The difference in its height must correspond to the slope of the blind area. The height of the formwork corresponds to the thickness of the concrete. The expansion joint near the wall (10 - 20 mm wide) is filled with roofing material (hydro-swelling cord).
Reinforcement and filling
The process of pouring the blind area of a house with concrete. A metal mesh of 50x50 (100x100) mm is used, which can be tied to pieces of reinforcement driven into the base in increments of 0.75 m. The mesh is raised above the level of crushed stone by 30 mm. Concrete is mixed and poured with your own hands in portions into the formwork sections to the level of its upper edge.
There should be no air pockets in the concrete. Correct proportions concrete mixture for blind areas they must correspond to frost resistance. The composition of concrete for the blind area is traditional (corresponding grade from M400 and above). Components that increase strength and durability can be added to the solution in proportion.
After the foundation has been erected and the main construction has been completed, an important stage remains in finishing the base of the house - installation of the blind area. As a rule, this stage is not delayed for months or years, since the absence of such an important element can lead to the gradual destruction of the foundation. In this article we will figure out how to properly make a blind area around a house to protect its foundation from destruction.
The foundation blind area is a strip of concrete or other material located around the perimeter of the house with a slight slope from the base. The main purpose of this structure is to drain rain and melt water from the foundation, insulate and strengthen it, as well as partially compensate for ground movements. The structure of the blind area also includes drainage.
As a rule, ordinary concrete is used for its construction, but a blind area lined with paving slabs or porcelain stoneware will give the area around the house an aesthetically complete look.
Most often under country houses poured – reinforced tape made of concrete on which the load-bearing and interior walls. Since concrete is a porous material, it actively absorbs water. This is fraught with unpleasant consequences - the appearance of fungus on the base and loss of frost resistance of the foundation due to constant cycles of freezing and defrosting.
If during the construction of the foundation were not carried out or the materials have worn out over time, the base is waterproofed before installing the blind area. Sometimes this requires digging it out to its full height: a shallow foundation - within half a meter, a buried foundation - below the soil freezing line (at middle lane more than one and a half meters).
If the basement of the building is in use, in addition to waterproofing it is desirable . At high level groundwater Foundation drainage is required. To do this, perforated pipes are laid in a ditch prepared for waterproofing the base and making a blind area with a slope towards the sewer collector.
Before moving on to considering the types of blind areas, let's talk about the basic rules for installing such structures. The width of the blind area recommended by building regulations is at least 20 centimeters from the projection of the eaves overhang to the ground. On average, the width is selected within 1 meter. The slope of the blind area from the base is up to 10 degrees, this is quite enough to drain water from the foundation and for ease of walking.
The method of constructing a strip depends on the terrain, climatic conditions, soil specifics, type of foundation, stylistic design of the house and landscape design. There are about 20 varieties in total. Let's consider the main types of blind areas.
Blind area made of crushed stone or gravel
Such a blind area has an advantage in price and ease of construction, but loses in operational characteristics and service life. This option is designed for an average of 7 years of operation. A blind area made of crushed stone is not capable of providing a sufficient level of foundation insulation and acceptable drainage. In addition, such a surface is inconvenient to move on. The only advantages of a blind area made of crushed stone are ease of installation and low cost.
Below is the procedure for constructing a gravel blind area:
Concrete blind area
A concrete blind area is more complex than a gravel or crushed stone base, but it is the most durable and performs its functions better. The concrete base completely removes all water from the base part of the foundation, but has the only drawback that with strong mechanical influences concrete can chip and wear away.
The procedure for pouring a concrete blind area is described below:
From the given instructions it is clear that the concrete blind area consists of general case from layer sand cushion, a layer of insulation and a layer of reinforced concrete. The thickness of such a blind area is at least 25-30 centimeters. This is enough to prevent the foundation from freezing.
The process of installing a concrete blind area is clearly shown in the video:
Blind area made of paving slabs
Despite the fact that a blind area made of concrete will cost less than installation of tiles, paving slabs are much more attractive appearance, while maintaining high wear resistance.
When building such a blind area, there are two options. In the first case, a concrete strip is installed as a cushion for laying the tiles. The sequence of actions is the same as when installing a conventional concrete blind area. At the final stage, the tiles are laid as a finishing coating. This method is excellent in all respects, except labor intensity and price.
In the second case, a sand and gravel cushion is used as a base for such a blind area. We will analyze this method further.
After installing the blind area from paving slabs All that remains is to fill the seam between the tiles. To do this, you can use regular sand, or fill the seams with cement mortar.
After laying for several days, it is undesirable to apply heavy loads to the blind area. This is necessary for the final uniform shrinkage of all layers of the blind area and giving it strength.
For a better understanding, we offer you a video with step by step installation paving slabs around the house
Strips made from materials such as crushed stone, stone, paving slabs are perfect for columnar foundations, for example for . Such a blind area will remove most of the moisture from the piles and will not require a large construction budget.
No building can do without a reliable foundation to support its weight and ensure the integrity of the entire structure, but it also needs additional protection. If necessary, each person can make a concrete blind area around the house with their own hands, without using the services of professional builders. This process is not very complicated, but it requires careful fulfillment of a number of requirements.
Requirements for the blind area, arrangement rules
This design serves as additional protection for the foundation of the building, preventing the destructive influence of groundwater and environment. In addition to protection, it also performs an aesthetic function - a building with a blind area acquires a complete appearance. Before concreting a blind area with your own hands, you need to familiarize yourself with a number of requirements:
To successfully create a blind area, you should draw up a drawing. You can compile it yourself, based on standard projects, or contact specialists. If necessary, it can be limited using. Being decorative element, it also increases the integrity of the structure and protects against penetration of tree or shrub roots.
Borders are mandatory if you create a blind area around the house from screenings or crushed stone, and if poplar, plane tree, raspberries and blackberries grow nearby.
Materials for creating a concrete blind area around the house with your own hands
Before you start work, you need to prepare all the necessary materials and a diagram. The foundation should be strengthened sequentially, but the entire process should take a minimum of time. In most cases, when drawing up a project, you can use typical units blind areas made of concrete, making adjustments to the design in accordance with the characteristics of your region. You will need the following materials:
- Concrete. The resulting mixture must correspond to class characteristics from B3.5 to B8. When creating it, the best cement will be grade M 400.
- Sand. You can use river or quarry sand as a pillow. The material used when mixing the mixture must be soft; the presence of large impurities is not allowed.
- Crushed stone or gravel. The fraction of crushed stone for the blind area of a house is 10-20. Used as a filler for concrete mix, or as a base material.
- Clay or geotextile. This material is used when arranging a concrete blind area with your own hands for additional protection from moisture, which is important for regions with high humidity.
It is determined by the brand of cement used and its specific gravity as a percentage of the elements of the solution. Good decision The material will be M400 Portland cement. The cement used must be fresh. If the powder forms lumps when squeezed in your hand, it will soon become unusable. The grade of cement selected depends on the planned thickness of the concrete blind area. Recommended proportions for mixing 1 m 3 solution:
- water – 190 l;
- filler (screenings or crushed stone) – 0.8 m3;
- sand – 0.5 m 3
- plasticizers (liquid glass and the like) – 2.4 l;
- cement – 320 kg.
When calculating the size of the blind area around the house, you should prepare the required amount of building materials in advance. It is also important to follow the order in which the materials are presented, which is necessary to ensure the required consistency. Compliance with technology will allow you to achieve the required result and create reliable design. If all the requirements are met, you can effectively build a concrete blind area around the house with your own hands.
The amount of water supplied is great value. Excess will reduce the strength of the resulting concrete. Not enough water will prevent it from hardening properly.
How to make a blind area for a foundation with your own hands - step-by-step instructions
The required amount of cement is poured into a concrete mixer or other mixing container, and then it is filled with water. When mixed, a “cement laitance” is formed into which other components are added. Next, sand is added in small portions, while the mixture must be constantly stirred. Next, filler is poured (crushed stone or screenings). If you find out in advance which crushed stone is best for the blind area and select the material of the correct fraction, mixing will not be difficult.
To ensure more efficient mixing, wait 5 minutes after adding each ingredient.
Once the materials are prepared, you can begin to work. The installation of a blind area around the house includes the following steps:
Also, before pouring, an expansion joint is installed between the blind area and the plinth using boards or sheets of plywood - this measure will protect the concrete from destruction when the temperature changes.
Installation of a blind area made of crushed stone
More economical option will be the use of crushed stone as the main filling material. Its arrangement is subject to the same requirements as for a concrete blind area, however, reinforcement and the creation of an expansion joint are not required. An additional layer of waterproofing (geotextile) is installed between the crushed stone and the sand “cushion”. This will prevent mixing of crushed stone and sand, and will not allow plants to grow from seeds that may have remained in the “cushion”.
You can make a blind area from crushed stone with your own hands without much effort. Large grade material can be used to fill the lower part of the trench. On top, to give decorative effect, fine crushed stone is used. Such a blind area also successfully protects the foundation from the destructive effects of groundwater and the environment. At the right approach you can give it a neat and attractive appearance.
Concrete blind area from A to Z with your own hands - video
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 Source udachnyi.ru
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 width and slope angle, interaction with other elements for draining atmospheric water 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, allowing 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 Source stroitambov.ru
Requirement for the blind area
None regulatory document There are no requirements 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 standards provide only two minimum size width. 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 diagram manual operational control construction for supervision 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 the minimum angle is 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 variety. 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 plinth to compensate for the thermal expansion of the monolithic coating.
Concrete blind area with an expansion gap at the base filled with sealant Source stroyobzor.info
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 Source manesu.com
Soft covering. The classic option is to arrange 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, but with a top layer of 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 Source s-stroit.ru
Now gaining popularity new look 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 Source pinterest.com
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 Source stroimdom.com.ua
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. Bottom irregularities 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 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 must 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. 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 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. Particularly carefully compact the area near the foundation with backfill, 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 Source stroidom-shop.ru
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. Lay on top of the sand waterproofing film. 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”. To do this, use a geomembrane or plastic film 200 microns thick.
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. Usually for concrete coverings expansion joints are combined with technological joints (one portion of fill 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.
DIY installation of a blind area around a concrete house Source fondeco.ru
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 bitumen mastic with the addition of 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 Source vest-beton.ru
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 (proportions of cement and water 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 drainage, when water is collected in special receivers and carried away through pipes away from the foundation.
Storm drainage system Source bloknot-voronezh.ru
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.
Any building, regardless of its functional purpose, needs a blind area. It gives it completeness and makes it invulnerable to weather conditions. The laying technology requires the implementation of a number of rules. But even non-professionals can follow them. All work can be done with your own hands, without outside help.
What is it for?
A blind area can often resemble a path around a house, but it has much more functions.
A blind area is a waterproof covering, soft or hard, up to 1.2 m wide, laid around the perimeter of the building.
The blind area performs a number of important functions:
- Protects the foundation from external waters. Rain or melted snow can seep underneath and into best case scenario fall into the basement, and in the worst case, destroy cement mortar and provoke subsidence of the structure, reducing its service life.
- Minimizes the risk of soil heaving, as a result of which the foundation may be subject to additional loads due to soil shifts. This can lead not only to cracks or flooding, but also to damage to the integrity of the building.
- Protects against freezing of the soil under and around the building. In other words, she does thermal insulation properties, thanks to which you can save on heating.
- Protects the foundation from tree roots or burrowing animals through which water leaks.
- Gives the building a beautiful, finished appearance.
- Provides access to any point along its perimeter, regardless of weather conditions, as it can be used as a path.
The main thing is that it should be laid immediately after the completion of the basic work on the construction of the house, but before the onset of cold weather. In addition, it is important to ensure that at least a year passes between the construction of the foundation and its installation.
The blind area is a complete advantage. The only disadvantage is the type of material used to cover it.
Species
A soft blind area will add a little warmth to the design than cold and austere stone or tiles
Based on the type of surface, a distinction is made between hard and soft blind areas. The first is made of concrete, sandstone, asphalt concrete and other materials that ensure the strength of the coating. The second is made from mulched soil or soil with lawn grass, crushed stone or paving slabs.
Pros and cons of a hard blind area
The advantages of a solid blind area are its strength, maintainability and durability. And the disadvantages are that, when laid directly on the ground, it is subject to negative impact at the moment of freezing and thawing of water in it. This gradually leads to the destruction of the foundation and moisture entering the house.
You can avoid exposure to moisture by regularly cleaning renovation work and sealing cracks.
Advantages and disadvantages of soft
Soft blind areas are increasingly used in construction, as they have several advantages over hard ones:
- It is not afraid of seasonal vertical shifts of the soil caused by the freezing and thawing of water at its base. There are no cracks in it through which moisture can enter the foundation, destroying it. It does not need to be constantly repaired, wasting effort, time and money on it.
- The technology for laying it is simplified, since you don’t have to adhere to the slope from the walls of the building.
- It is distinguished by its practicality and aesthetics. Good choice external covering – gravel, crushed stone, flowers, climbing bushes or lawn plantings - makes a building with such a blind area spectacular and original.
You can achieve greater efficiency during installation by using penoplex as insulation. It will help reduce the depth of seasonal freezing of the soil around it. Thanks to this, even if there is clay soil, installation will occur with less depth of the building’s foundation.
The only drawback of a soft blind area is the need for constant care. Lawn grass it will be necessary to trim, weeds that have grown through the rubble will need to be removed, and the decorative backfill will need to be cleared of debris.
Concrete blind area is ideal for our climate
Classification by material type
- Concrete - its installation does not require special skills or additional funds. Its advantage is practicality, comparative cheapness and functionality. It is ideal for our climate and has only one drawback - the need for regular (once every 1 - 2 years) repair of cracks that appear.
- Cobblestone or rubble - it is laid out from paving stones, stone or paving slabs and serves not only as a protective layer for the foundation, but also as a decorative element. Such a blind area is inferior to concrete in terms of functionality and installation, since it is more difficult to lay.
- From sand - when using it, the sand must be wetted with a warm solution liquid glass, and treat the top with a hardener, thanks to which it will turn into sandstone. In this case, he will not be afraid of either weather conditions or excess moisture.
- From clay - such a blind area was made back in Rus'. Its main advantages are low cost and practicality, and main drawback– the ability to quickly wash out. That is why the clay is covered with crushed stone or other materials on top.
If desired, you can arrange a brick, asphalt or soil blind area, as well as a blind area made of concrete slabs.
An effective blind area is a covering, when laying which not only the top layer, but also the bottom layer - the base - was correctly selected
Each type of blind area deserves attention, but has both advantages and disadvantages. Therefore, builders recommend making your choice taking into account the type of soil - on heaving soils it is better to use soft soil, on less watered soils it is better to use hard soil. The ground floor also matters. If it is available, it is necessary to equip an insulated blind area to reduce heat loss.
Regardless of the choice of materials and method of installation, it is important to follow the technology. An effective blind area is a covering, when laying which not only the top layer, but also the bottom layer - the base - was carefully selected.
Under the concrete blind area you need to make a sand cushion, onto which gravel is poured and the solution is poured. In the case of cobblestones, gravel and sand change places. In this case, the layer of sand cushion should then reach 50 cm, since the cobblestones themselves are pressed into it. Additionally, it is better to lay crumpled clay at the bottom of the trench.
Required Tools
The choice of tools is based on the type of coating. But most often it is:
- roulette;
- level;
- manual rammer;
- buckets;
- hose with sprayer;
- shovel;
- Bulgarian;
- trowel;
- container for preparing mixtures;
- rope or thick nylon thread for marking;
- pegs made of wood or metal.
Calculation
The calculation of the material is carried out individually, taking into account the width of the blind area and the type of coating. Builders often use certain formulas to calculate the required volume of materials.
You can determine the volume of sand for a sand cushion or the blind area itself by multiplying the length along the perimeter by the height of the sand layer and the width of the blind area. In the same way, the consumption of crushed stone or other soft coating is calculated.
When determining the required volume of reinforcement, the length of the blind area is multiplied by its width.
In the case of tiles, the volume is calculated in a similar way, but builders advise purchasing this material with a reserve.
Preparation
The laying of the blind area is preceded by painstaking preparation, which conventionally consists of several stages.
Determining the size and thickness of the fill
The width of the blind area is calculated based on the type of soil and the length of the roof eaves, but the wider it is, the better it will perform its functions.
The width of the blind area is calculated based on the type of soil and the length of the roof eaves. There is an opinion that the wider it is, the better it will perform the functions assigned to it.
According to GOST, the width of the blind area should be 0.8 - 2 m, depending on the subsidence of the soil on which the building stands, and at the same time it must exceed the size of the cornice overhang by 20 - 30 cm.
The thickness of the fill layers is also regulated by building codes. According to them, the base for a blind area made of clay, crushed stone or sand must have a height of at least 15 cm. The thickness of the fill must be at least 5 cm.
If the blind area serves as a pedestrian path, according to the plan, increased requirements are placed on it. In this case, not only its width should increase, but also the thickness of the layers.
When arranging the blind area, we must not forget about the slope. Its absence will lead to rapid destruction of the surface under the influence of accumulated water. And excessive steepness will provoke acceleration of water flows, as a result of which the edge of the blind area at the border with the ground will gradually erode.
The slope is calculated based on the width of the coating. For 1 m of width make 2 - 10 cm of slope. The ideal option is a slope of 2 - 3 cm per 1 m. Thus, the slope will be 3 - 10 degrees.
Preparing the bed
The process of preparing the bed for the blind area is always the most important
The process of preparing a bed for a blind area must be approached responsibly. The old coating must be carefully removed, while also cleaning the part of the foundation that is adjacent to it.
If necessary, at this stage a recess is made under the storm sewer system. You need to dig it on the side opposite to the foundation, and then lay pipes into it.
When calculating the width of the bed, you need to take into account the curbs. If you plan to lay paving slabs, it is reasonable to make the width a multiple of its dimensions. Thus, you can get rid of the need to trim it, thereby saving time.
The depth calculation is calculated based on the number of layers of the blind area and their height. According to building regulations, it should be at least 15 cm. But, as practice shows, it is best to go deeper by 25 - 40 cm.
When installing the blind area on clay soil, you can remove only 30 cm of soil, since in this case there is no need to build a clay castle.
After removing the soil, the bottom must be compacted. The quality of compaction is checked by blows of the tool and confirmed by the absence of soil movement with each effort. After compacting, it is better to treat the surface with herbicides to prevent the growth of weeds and minimize the time for caring for the blind area in the future.
Marking
The quality of markings is checked by the building level
To mark the corners of the bed, pegs are driven in, between which a thick thread or rope is stretched. This stage should not be neglected, since the markings serve as a guide during work.
After its installation, the level checks the quality of work. According to building codes, the curvature of the outer edge of the surface should not exceed 1 cm.
Base structure
The blind area is a layer cake
The blind area is a layer cake with different layer thicknesses. The standard technology for its creation consists of several stages:
1. Arrangement of a hydraulic lock - it drains water. To do this, clay 5–10 cm thick is poured onto the bottom. This layer can be made with a slope, then maintaining it at each stage. An alternative to clay is concrete with a layer of 10 - 15 cm. Ruberoid, geotextile or non-tensioned material is laid on top of the concrete or clay. PVC film. In the latter case, it is better to make a fold near the foundation, thanks to which it can move under the influence of temperature fluctuations of the earth and not tear. If necessary, pipes are laid on top of the film. storm system, which are covered with crushed stone on top to prevent clogging.
In order to minimize the load on the foundation, you need to take care of the gap between it and the blind area. It can be filled with sand, several layers of roofing material or polystyrene foam, thereby providing additional insulation.
2. Laying a sand cushion with a layer of 5 cm to protect the waterproofing from damage by crushed stone. The sand needs to be leveled, watered and compacted. At this stage, you will need a hose with a sprayer, thanks to which uniform watering is carried out. The sand is compacted after drying. If laying of communication pipes is planned, it is carried out at this stage.
3. Installation of the curb. It is carried out according to the finished markings and leveled. Each border is secured with pegs with inside and cement on the outside to prevent the top layer from spreading.
4. Laying crushed stone 5–10 cm thick. The final value is calculated based on the level of precipitation in the region. After backfilling is completed, the pegs to support the curb are removed, and the curb itself is leveled, compacted and covered with sand.
If you have a basement, you can additionally insulate the blind area. To do this, sand is covered in a layer of at least 5 cm, compacted, and sheets of foam plastic are laid on top of it. Sand will help avoid point loads, which this material is afraid of.
Preparation of the solution
Traditionally concrete mortar prepared from cement, sand, crushed stone and water
To prepare the solution you will need:
- Portland cement brand M400 is an ideal option, but not the only one;
- clean sifted sand;
- crushed stone with a fraction of 5 – 10 mm;
- water, preferably at room temperature;
- liquid glass or other additives that will make it frost-resistant.
Proportions are determined in each case separately and depend on the brand of concrete. IN classic version they look like this:
- 1 part cement;
- 3 parts sand;
- 4 parts crushed stone;
- 0.5 parts water.
Water is added to cement to prepare cement laitance. Then sand and crushed stone are mixed into it. After each component, you need to thoroughly stir the resulting mixture (at least 5 minutes) in order to achieve uniformity and the absence of lumps.
Nuances before pouring
- Slope - we must not forget about it, as it fulfills the most important function- drains water. Just 5 degrees is enough. Stretched threads will help simplify the process of arranging it. After pouring the concrete, it is also leveled.
- Waterproofing. Due to the fact that increased demands are placed on it, since it is designed to protect the foundation, waterproofing material must be overlapped.
- Insulation. As such, it is best to use polystyrene foam. It does not rot or accumulate moisture, but has excellent thermal insulation properties.
- Polyethylene or burlap - they must first be prepared in order to cover the filling with them. This will minimize the risk of concrete cracking and extend its service life.
Pouring technology
Formwork is a structure consisting of wooden planks 2 cm thick, laid around the perimeter
Due to the fact that concrete blind area is an ideal option for use in our climate; it is performed most often.
Its installation is carried out in the following sequence:
To ensure the strength and durability of the structure, it is necessary to make seams across it, every 2 - 3 m. They will prevent the destruction of the blind area during frosts. They are made using wooden slats, treated with bitumen mastic to prevent rotting and installed so that their upper parts are flush with the border concrete pouring. Also, such seams are extremely necessary in the corners of the structure.
- Pouring concrete with mandatory leveling and compaction. At this stage you need to remember about the slopes. Pre-installed wooden slats in places expansion joints will serve as excellent beacons.
It is advisable to cover the poured concrete with polyethylene or burlap. The latter must be regularly moistened with water. This will prevent the concrete from drying out and cracking. Its drying time is 1 month. During this time, it becomes durable and invulnerable to adverse weather conditions.
DIY installation video instructions
Thermal insulation and painting
Insulation of the blind area must be carried out during its installation. For this purpose, sheets of foam plastic or penoplex are suitable, which are laid on top of the sand cushion and under the reinforcing mesh.
Paint allows you to refresh the design of the yard and prevents premature destruction of the blind area
Upon completion of the construction of the blind area, it is painted. Paint helps prevent the destruction of the structure and eliminates the need frequent repairs. In addition, it makes the blind area spectacular, and the building itself original.
Best suited for coloring polymer paints– acrylic, water-based, polyurethane enamel or primer-enamel. Their main advantage is that there is no need to prime the surface. In addition, many of them are resistant to chemicals, ultraviolet light and moisture. They are applied in 1 - 2 layers to a cleaned surface and dry quickly.
Installation of a blind area is one of the most important stages of construction, carried out strictly in accordance with technology. Despite the huge number of rules, nuances and subtleties of this work, doing it yourself is not so difficult. The main thing is to get necessary materials and tools and be patient. Moreover, in the end it is rewarded not only with an attractive appearance, but also with comfort, practicality, and also savings on heating the house.
