Flexible blind area around the house with your own hands. Types and purpose of the blind area around the house. The blind area is two structural layers
At the completion of construction activities for the construction of the building, it seems that the building is completely ready. The desire to do internal improvement and move in faster makes the developer miss some of the nuances. One of these moments is the blind area around the house, which significantly extends the life of the building, protecting the base of the building from moisture.
There is an erroneous opinion that the blind area of a private house is not a necessary element of the structure. However, do not put off its construction until "tomorrow". After all, it is gradually decreasing load bearing capacity at an unprotected foundation, which is deformed as a result of intensive absorption of moisture.
The blind area of the house is one of the important aspects in creating a long and comfortable operation of the house itself.
Used in construction various options edging, performed around the perimeter of the building. To ensure a long service life of the building, reliable protection foundations, it is important, observing the technology, to properly make a blind area around the house. Let us dwell in detail on its purpose, parameters and varieties. We will select the materials and tools necessary for the work. Let us examine in detail how, according to construction technology, a blind area is made around the foundation of the building.
Why do you need to make a blind area
The blind area of a private house represents structural element around the building, made with a slope along the perimeter of the foundation. It performs serious functions, the main of which are:
- reliable protection of the base of the building from the effects of precipitation;
- water drainage along the perimeter of the foundation of the building in storm sewer;
- reducing the depth of soil freezing around the building, which reduces heat loss;
- prevention of swelling of the soil at a negative temperature;
- prevention of damage to the foundation surface by plant roots;
- ensuring the finished look of the building by creating a transition between the plinth and the ground.
Having finished construction works, it is necessary to complete the edging along the contour of the building before the onset of cold weather, so that the moisture-saturated soil layer does not violate the integrity of the base when freezing.
After heavy rains or snowfalls, or snowmelt, water may accumulate near the building
Design parameters
- The width of the edging, which is more than 60 cm. To ensure ease of movement, it is necessary to expand the track to 100 cm.
- The excess of the width above the roof contour is more than 20 cm. This contributes to the ingress of precipitation to the surface.
- A closed path configuration that completely encircles the building. The foundation around the perimeter must be protected.
- The slope of the surface towards the soil is in the range of 1–10%, which corresponds to a slope of 1 to 10 cm per meter of width. With an increased angle, the probability of slipping during glaciation is high.
- The thickness of the surface layer of concrete pouring around the building, which is 7–10 cm. The parameter depends on the depth of soil freezing, increases to 14 cm at increased loads.
- The device of the border, which makes it difficult to damage the base by the root system of plants.
- Elevation of the edging above the zero mark at the level of 50 mm. This makes it difficult for precipitation to flood along the outer edge.
Compliance with the requirements of regulatory documents will ensure comfortable operating conditions and durability of the structure.
When creating a drain, creating a blind area is a must
The blind area around the house - the necessary materials and coatings
A blind area is made around the building using various materials:
- concrete pavers. In specialized stores, material of various colors, original configurations is offered. The presence of rounding significantly reduces the likelihood of chipping off the edges. The dimensions of the paving stones allow to perceive the loads associated with the movement. Edging elements improve aesthetic perception. The material is resistant to deep freezing, temperature changes and allows you to quickly complete the masonry with filling the gaps between the elements with sand;
- natural stone. Stone paving stones are made from natural granite of various shades. The material is supplied in the form of chipped or sawn blanks. Products are offered in a standard cubic shape or in the form of a parallelepiped. Laying is carried out similarly to paving stones, cast from concrete, on a previously prepared base up to 50 mm thick from fine gravel or sand. After sealing the seams, the formed stone mass is compacted;
- concrete. Usage concrete mortar is an inexpensive solution that provides water tightness and high strength. For pouring, the soil is prepared and the wooden formwork for concreting is installed. Expansion joints are also made along the contour of the building. A concrete surface is well perceived, decorated with multi-colored pebbles 1–5 cm in size;
To create a strong durable blind area, you will need to correctly select high quality materials and strictly observe the technological aspects of construction
- paving slabs. The ease of use of the plates lies in the possibility of simple replacement of damaged elements. Tiles are being made square shape with a side up to 0.5 m and rectangular products up to 1 m long. Along with the standard in gray products, you can purchase multi-colored material that has a smooth or decorative texture. With a multiple of the dimensions of the edging to the width of the plates, trimming can be avoided and work can be done quickly;
- rubble. An easy-to-manufacture option used when groundwater is located close to each other and the drainage system is carried out around the building. Along with crushed stone, expanded clay and ordinary gravel are used. For ease of movement, the layer of material should be carefully compacted with preliminary installation of geotextiles. It hinders the growth of weeds, protects the material from mixing with the soil.
Concreting is widely used. Get your tools ready for the job necessary materials:
- A shovel, a wheelbarrow and buckets, necessary when extracting a layer of soil and transporting materials.
- A device for manual tamping, which allows compaction of the array.
- Building level for level control.
- Materials for waterproofing protection.
- Wood for the manufacture of formwork.
- Steel reinforcement or finished mesh with a square cell side of 10 cm.
- Screened sand.
The blind area should be formed with a slope. So the water will drain from the walls of the building
- Crushed medium size.
- Portland cement brand M300.
- clay.
- Extruded polystyrene foam for insulation.
- Construction cord and pegs for marking.
The blind area of a private house - features and types of structures
Regardless of the type of construction and manufacturing technology, the blind area is a path along the perimeter of the building. Consists of the following layers:
- underlying. The basis is fine gravel, clay or sand. The damping layer forms a compacted base for the outer cover;
- finishing. Represents top coat that protect the foundation from moisture penetration. Provides aesthetic perception.
There are various options for how to make a blind area around the house. The blind areas are divided into the following groups:
How to make a blind area around the house - stages of work
The blind area is called the design, the main purpose of which is to protect the foundation of the house from the effects of adverse environmental factors. With its presence, water cannot seep to the base of the building and destroy it. In addition, the blind area often performs a purely decorative function. A variety of materials can be used for mounting such a design.Depending on this, the
What to consider when drafting a project
The requirements for structures of this type are mainly as follows:
The blind area must be waterproof. Otherwise, it will not fulfill its main function - to protect the underground part of the foundation of the house from destruction.
The blind area should be equipped with materials that are resistant to cracking during strong temperature changes. The climate in most of the territory of Russia, as you know, is sharply continental. And the temperature range on the street, even within the same season, can vary quite a lot.
Next, we will consider different technologies for the blind area device. SNiP - rules that, however, must be followed exactly when erecting a protective tape of any kind. The design of the blind area should be drawn up taking into account the fact that:
ribbonmust have a slope of at least 2 degrees in the direction from the wall of the house;
Should be in the range from 70 cm to 2 m;
between the blind area and the foundation, a small temperature gap of 1-2 cm should be left.
The slope of the blind area in the process of its arrangement can be performed both at the stage of backfilling and tamping of the substrate, and when laying the base material. The width of the tape itself is chosen taking into account, among other things, the fact that it should protrude 20-30 cm beyond the roof overhang. Otherwise, the water flowing from the roof will seep under the blind area and spoil the foundation.
What materials can be used
The procedure is relatively simple -blind area at home. DIYsuch a design can be done without much difficulty.Most often, blind areas around buildings are poured, of course, fromcement-sandmixtures. The latter, according to technology, is supposed to be cooked in a ratio of 1x3. The substrate is made using crushed stone and sand. Also, paving stones can be used to equip the blind area. Sometimes it just falls off with rubble. In this case, tightness is ensured by arranging a clay substrate.
The choice of a particular material depends primarily, of course, on the financial capabilities of the owner of the house. The cheapest option for the blind area is crushed stone. Pouring concrete tape is a little more expensive. When using, you can assemble not only a reliable, but also a very beautiful blind area. However, this option will cost the owners of the house, of course, quite expensive.
In addition to the cost, when choosing a material for the blind area, the owners of the house should also take into account design features the building itself. So, for example, for wooden house perhaps a clay blind area is more suitable. The top layer of crushed stone in this case on final stage can be covered with earth. As a result, the space around the house will look as natural as possible. For a concrete building with plastered walls, most likely, a cement blind area is best suited. Around a large brick cottage, of course, it is worth equipping a protective strip from this. This will give the exterior of the building a finished look.
When choosing a material for the blind area, it is worth considering another rather important factor. It is believed that with a basement height of 50 cm around the house, it is more expedient to equip a concrete structure or a tiled one. If the above-ground part of the foundation protrudes above the surface to a height of 30 cm, you can also use crushed stone dump tape for protection.
The main technologies of the blind area
So, the blind area around the house can be built by pouring cement mixture either laying tiles or clay. But there are others, more original ways installation of such structures. For example, when arranging a blind area, geotextiles, multi-colored pebbles and even glass bottles can be used. In any case, when building a blind area, the chosen technology should be followed exactly. Otherwise, after some time, this structural element of the building will have to be repaired or even completely re-equipped.
Insulated version
Most often, homeowners in Russia equip ordinary blind areas around them, consisting of two layers: the substrate and the main upper part. But sometimes insulated versions of a similar design are also constructed around the perimeter of the building. Such blind areas, of course, are more expensive than usual ones. However, in some cases, their arrangement is a matter of necessity. Without fail, for example, insulated blind areas are erected around buildings built on heaving soils. It is also customary to equip such structures to protect columnarand shallow strip foundations. Further in the article, we will consider, among other things,and technology of the device of the warmed blind area.
The main stages of installation
Actually the technology of erecting a blind area when using different materials applied almost identically. This element is usually arranged in several steps:
markup is performed;
a “trough” is dug under the blind area;
formwork is installed;
a substrate is laid at the bottom of the "trough";
the laying or pouring of the main material is carried out.
Below we will considerpaving slab technologyand crushed stone, as well as pouring it from concrete.
How to markup correctly
When performing this procedure, be sure to use a plumb line. With its help, at the first stage, the projection point of the roof is found. To do this, they climb the ladder to the level of the roof, apply a plumb line to its edge and make a mark on the ground. Then they retreat in the direction from the building by 30 cm and drive a peg into this place. Having thus determined the required width of the blind area, establish landmarks around the entire perimeter of the building in increments of 1 m, making the necessary indent from the wall. After all the pegs are driven into the ground, they are connected with a cord.
Foundation preparation
This procedure, like marking, is performed almost the same for all types of blind areas. Preparation is made as follows:
Soil is removed inside the markup. This procedure should be performed using a bayonet sharp shovel. With this tool, you first need to cut the ground along the cord. Then the middle part of the "trough" is selected.
The bottom of the "trough" is compacted. The most convenient way to do this operation is with a shovel.
The total depth of the "trough" under the blind area should be at least 25 cm.
Substrate for cement structures
Concrete pavement deviceinvolves the use of formwork. It is easiest to make this design from boards 1.5-2 cm thick. Such lumber simply needs to be installed on the edge along the perimeter of the “trough” and fixed in this position with support posts.
After the formwork is assembled, you can proceed to the actual arrangement of the blind area itself. This procedure is performed as follows:
Roofing material is laid at the bottom of the trench in two layers.
The sandy "cushion" falls off. This element of the "pie" blind area is considered mandatory. Without a "cushion" in the future, the concrete part of the blind area will certainly begin to crack. The thickness of the sand layer in the substrate should be 5-10 cm.
The sand is carefully compacted by moistening with water from a hose with a shower head.
A layer of rubble is poured over the sand. Its thickness should be 5 cm.
Crushed stone is leveled and compacted with a shovel.
expansion joints
Blind area device technology around the houseinvolves the use of these additional elements in its design.One of the properties of concrete is the ability to expand with increasing temperature. Because of this, cracking of the cement blind area may occur. To avoid this,in the formwork around the entire perimeter of the house, not too thick bars should be installed across, in increments of about two meters (per edge). It is impossible to pour a concrete blind area with a continuous tape.
You should also make an expansion joint along the wall of the house. For its arrangement, you can use foamed polyethylene. This material simply needs to be applied to the wall in the area where the blind area adjoins. But it’s easier to make a compensation layer with the help of a roofing material laid on the bottom of the “trough”. This material must be raised to the wall to the height of the future blind area.
Reinforcement
Blind area technologyinvolves, among other things, strengthening through reinforcement. By following this procedure, the risk of later cracking of the tape can be minimized.Reinforcement significantly extends the life of the blind area. To strengthen the tape, a metal mesh with a cell of 5 cm is usually used. This material is cut according to the widthfuture blind areaand laid on top of rubble around the perimeter.
Concrete pavement technology
Cement mortar forI'm pouring into the formwork lIt is best to cook in a concrete mixer. In this case, it will turn out to be of better quality. It is worth pouring the blind area in one step. In this case, it will turn out to be more durable. When pouring, the slope should be constantly monitored. At the end of the procedure, the tape should be allowed to dry for about two hours. Then the blind area should be covered with plastic wrap for about 2 weeks.
Tile Tape
Blind area device technologyin this case will be slightly different from the method presented above.. To the bottom of the trenchfor tiled constructioncrushed stone is poured in a layer of 5-7 cm. Clay is laid on top of it. There will be a lot of seams between the tiles on such a blind area, for obvious reasons. That is, paving stones will not be able to provide at least relative tightness of the tape like concrete. The role of a waterproofing agent in this case will be performed by clay. The thickness of its layer in the substrate should be at least 5-10 cm. The clay must be compacted with a rammer. On top of it is to put also pvc film. This will provide additional insulation.
A layer of sand is poured over the film in the substrate. A cement-sand mixture prepared in a ratio of 4x1 is poured onto it. The thickness of the concrete layer in this case should be equal to 3 cm. The flooded area is leveled with a mop. Paving stones on the blind area should be laid in the direction away from you with dressing of the seams. Leave a gap of 1 cm between individual tiles.
Crushed stone tape
The technology of the blind area from paving slabs, thus relatively uncomplicated. But it is even easier to make a protective tape around the house from clay and rubble. Such a blind area can turn out to be very reliable. But of course, only subject to certain rules of dumping.
Under the rubble structurealso pre-dig a "trough". Further, the bottom of the latter is carefully rammed and leveled with a slope. At the next stage, clay is poured into the “trough” with a layer of 15 cm. This material should also be laid with a slight slope in the direction from the wall of the house. In this case, a roofing material or a thick PVC film is spread over the clay (with a slight overlap on the foundation). You can fix the material on the surface of the base, for example, with slats. The joints of roofing material are easiest to glue with bitumen.
A layer of sand 10-15 cm is poured over the waterproofing. The resulting “pillow” should be tamped with water and leveled with a slope. A layer of geotextile can be laid on top of the sand. This will prevent the germination of weeds on the blind area. Further, the crushed stone itself (with a rammer) is placed in the "trough".
How to make an insulated structure
In this case, the usual tlaying technologyblind areas.Howeveratherarrangementin addition, thermal insulation material is used. As the latter, it is allowed to use both expanded polystyrene and expanded clay.
The first layer of clay is laid on the bottom of the "trough". Next, crushed stone and sand are poured (with a rammer). Then the selected insulation is laid. Expanded clay should be poured in a sufficiently thick layer. stack as closely as possible to each other. Roofing material is laid on top of the insulation. Next, a layer of sand is poured. At the final stage, the concrete mixture is poured or the tiles are laid.
Instead of a conclusion
The technologies for installing a blind area made of paving stones, concrete or clay are thus simple. However, it is imperative to comply with the SNiP standards when erecting such structures. If there is a sand cushion and a waterproofing pad in the “pie”, it will turn out to be as durable as possible. Compliance with the slope during the installation process will ensure the best efficiency of this element of the building structure.
There is nothing secondary in construction. All structural elements of buildings and structures must be approached responsibly.
One of the final types of work at a construction site is a blind area. It is carried out at the end of the construction of the house, in parallel with the construction of an external staircase or entrance to the garage, but after the facade of the building or at least the basement has been finished.
blind area- this is a strip 0.6-1.2 m wide adjacent to the foundation or basement of the building with a slope, "descent" from it. The slope of the blind area must be at least 1% (1 cm per 1 m) and not more than 10% (10 cm per 1 m).
Do you need a blind area?
The main task of the blind area is to drain surface "rain and melt" water from the walls and foundation of the house. The blind area prevents the penetration of surface water to the base of the foundation, and is also a decorative element of external improvement, forming a sidewalk around the house.
In addition, the blind area does not allow the lawn or plants to grow close to the walls of the house, preventing excessive moisture of its structures and damage to the foundation by the roots of trees and shrubs.
blind area design
The traditional blind area consists of two main layers - a decorative coating and an underlying layer.
Underlayment
The underlying layer serves to create a compacted and even base for further laying the blind area. As an underlying layer, it is used: sand, gravel, clay. The choice of material depends on the top cover of the blind area.
decorative coating
The covering of the blind area must be primarily waterproof and difficult to wash out with water.
In the old days, the blind area was made of clay: they dug a shallow trench along the perimeter of the house and filled it with clay, which was compacted with a slope away from the house and moistened, creating a water-resistant layer, over the surface of which rain and melt water flowed.
Today, when constructing a blind area, clay is replaced with concrete - it allows you to get a monolithic surface without cracks, which is especially important when there is no certainty that the foundation is waterproofed. If the foundation is properly insulated, then you can use piece materials- paving slabs (setting stones), crushed stone, slabs.
blind area device
blind area level
The height of the base depends on the type of material from which the blind area is made. If it is gravel or crushed stone, it is enough to raise the base to a height of 30 cm. If it is a hard and flat surface (for example, concrete or paving slabs), the height of the base must be increased to 50 cm.
blind area width
The width of the blind area is set depending on the type of soil and the removal of the cornice overhangs of the roof. On ordinary soils, the width is taken 20 cm wider than the eaves (but not less than 60 cm), so that the water flowing from the roof does not erode the soil and does not stagnate under the house. On subsidence soils 20-30 cm beyond the slopes of trenches or pits, torn off under the foundation, but not less than 90 cm.
blind area slope
For cobblestone and crushed stone blind areas, the transverse slope from the axis of the house is taken within 5-10% (5-10 cm per 1 m of width). For concrete and asphalt 3-5%. At the same time, the steeper the slope, the better the water is drained and the more inconvenient the blind area becomes as a footpath around the house.
Gap between wall and deck
When constructing a blind area, you should remember about the gap between it and the wall. Its purpose is to protect against damage and destruction of the waterproofing of basement walls. If there is no gap, then the blind area made of paving stones or slabs under the influence of frost will put pressure on the wall, and as a result of walking on it, it will settle and damage the insulation on the outer surface of the foundation wall. It may also be affected facing material, for example, crumbling tiles on the plinth.
To prevent this, it is necessary to leave an expansion joint 1-2 cm thick and fill it with sand, extruded polystyrene foam or sealant.
Drainage around the blind area
Only a blind area of 3 or more meters wide can guarantee complete drainage of water from the foundation and its “dry mode”, which of course is not always realistic, so it is worth using additional protection - a stormwater and drainage device.
For hard blind areas such as concrete and slabs, surface linear drainage is suitable - a drainage groove or gutter along the outer line of a blind area made of stone, concrete, plastic or asbestos-cement pipes, sawn in two along the length. And don't forget about their biases!
Good ready-made drainage elements, complete with upper protective gratings (plastic or polymer concrete). Ready-made trays for drainage, having a drain pipe and an upper grate, adapted for installation in the prepared plane of the foundation blind area.
Blind area from paving slabs
(paving stones)
One of the most commonly used paving materials is concrete pavers. It is resistant to frost and temperature extremes. Paving stones are available for sale different colors and shapes: rectangle, square, hexagon, wave, etc. The edges of the pavers can be smooth or chamfered, which significantly reduces the risk of chipping the edges. Paving stones are produced with a thickness of 4-10 cm, a width of 6-20 cm and a length of 10-28 cm. For the blind area, elements 4-6 cm thick are most often used.
stone paving is a natural material and, compared to concrete, does not have such a variety of shapes. Usually it is a cube or parallelepiped made of gray, red or yellow granite, as well as black basalt. Of course, it costs much more than concrete analogues.
Laying the blind area
Prior to the commencement of work on the installation of a blind area around the building, all work must be completed, the execution of which can lead to damage to the blind area, namely:
- the roof, cornice overhangs and canopies over the entrances were arranged;
- metal-covered plums of window openings;
- All fixtures for drainpipes and fire escapes have been installed.
Pegs are hammered in the corners of the building, on which the height of the blind area adjoining the basement is marked, and according to these marks, a cord is fixed around the entire perimeter of the building. A second line of pegs is installed along the outer edge of the blind area. They mark the height of the outer edge of the future concrete pavement of the blind area.
To drain rainwater, the blind area is made with a slope (at the base, the thickness of the coating is 15 cm, and at the opposite edge, 10 cm). The transverse slope from the basement of the building is - 5% (5 cm per 1.0 m of width).
First of all, it is necessary to determine the width of the blind area, which depends not only on the wishes of customers. This parameter is largely determined by the type of soil and the width of the removal of the eaves of the roof overhangs. On ordinary soils, the blind area should be 20 cm wider than the eaves overhang (its minimum width is 60 cm). In the event that the building is built on subsiding soils, the width of the blind area should be at least 90 cm. Sometimes it is made 1.0 m wide or more - in this case, the blind area, as a rule, performs the function of a path around the house.
The construction of the blind area begins with the removal of vegetation around the house and the removal of the vegetation layer to a depth of 15 cm. Carefully remove the remnants of the roots so that in the future the sprouts that break through do not destroy the coating.
Along the stretched twine, which marks the longitudinal line of the edges of the blind area, manually tear off a trench of rectangular section (trough) for the construction of the base under the blind area. The bottom of the trough is compacted.
On the prepared bottom of the trough, crushed stone of the M400 brand is manually scattered with a layer of 15 cm at the base and 10 cm at the opposite edge, leveled with giving the layer a design slope of 5%. The thickness of the crushed stone layer in the loose body must exceed the design one by the loosening factor. A prepared crushed stone surface is considered when the mobility of individual particles is not felt.
On the prepared crushed stone base, a leveling (mounting) layer of a dry sand-cement mixture 3 cm thick is manually arranged. A tight fit of the slabs to the base is achieved by settling them during laying and immersing the slab into the mounting layer of a dry sand-cement mixture for the final landing of the slabs to a predetermined mark.
Laying of paving slabs should be carried out from any conditional line: the edge of the plinth, parallel to which the seams are located, or a verst row laid perpendicular to the plinth, on both sides or one from it. Alignment of the edges of the plates is carried out along a stretched wire or cord located along the stacked row. The slabs are laid in transverse rows from edge to edge towards the slope.
To maintain the slope and evenness of the coating when laying paving slabs in the blind area, it is necessary:
- arrange a verst row along or perpendicular to the base;
- laying of plates to start from the edge of the blind area and lead towards the slope to the base;
- align the laid slabs with a light tapping with a rubber (wooden) hammer on a wooden gasket lying on the tile.
Alignment of the laid plates is carried out by light tapping with wooden rammers. Ledges in the seams of adjacent plates should not exceed 2 mm. The roller formed at the edges of the slabs from the sand-cement mixture is cut off with a manual template.
The width of the seam between the plates should be 3-5 mm. The seams between the plates are filled with a cement-sand mixture in a ratio of 1:3.
Concrete pavement
Concrete pavement is one of the cheapest and simple solutions. It is this material that makes the blind area waterproof.
The blind area should be at least 5 cm thick (recommended 7-10 cm). The concrete used for the blind area must correspond to road concrete in terms of frost resistance and the grade must be at least M200.
blind area from monolithic concrete should be arranged on a sandy base, compacted to a density coefficient of at least 0.98. The minimum preparation thickness in this case is 10 cm.
expansion joints
The concrete blind area must not only be separated from the wall with an expansion joint, but also divided with expansion joints every 6 m of its length. Practice shows that a solid fill cracks in the very first winter. For seams, a tarred or antiseptic-treated board 15-20 mm thick, laid on the edge, is suitable.
Top surface wooden slats is located at the level of the concrete surface, taking into account the slight slope of the blind area from the house. After that, concrete is laid, and the slats serve as so-called beacons, along which the concrete surface is leveled.
Reinforcement of the blind area
To increase the service life of a concrete blind area, especially on heaving soils, it is recommended to reinforce it. This is necessary in order for the blind area to work both in compression and in tension. Concrete works in compression, and reinforcement works in tension.
Reinforcement in progress metal mesh with cells 100x100 mm or iron bars overlapped.
Iron blind area
At the final stage of manufacturing a concrete blind area (approximately 1-2 hours after pouring the next section), in order to further strengthen the surface, it should be ironed. Freshly poured concrete is sprinkled with cement, creating a layer 3-7 mm thick, and rubbed with a trowel. As a result, the material is protected from atmospheric precipitation by a very durable and stable top layer, which has a characteristic dark blue, steel shade.
So that the concrete does not crumble during rapid drying, its surface should be covered (for 2-3 days) with damp burlap or plastic wrap.
After the concrete has hardened, it is necessary to seal the seam between the blind area and the wall of the house, for which bitumen or sealant is suitable.
The blind area works in the most unfavorable conditions for concrete, therefore it is good and correct to use only high-quality cement or concrete, to which it is desirable to add to protect against freezing.
Asphalt pavement
The base for the asphalt concrete pavement should be compacted with crushed stone (15 cm) or gravel with a particle size of 40-60 mm, pressed into the ground with a roller or rammer. Arranged on top asphalt pavement(3 cm).
The device of a blind area made of asphalt concrete is quite difficult and this material cannot be called popular in private construction. In summer, if the asphalt is very hot, it can soften and give off an unpleasant odor.
Blind area from crushed stone
The crushed stone blind area is the cheapest option for coating. This perfect solution when the groundwater level is high and when drainage is performed around the building, since crushed stone contributes to the penetration of surface water. Instead of crushed stone, you can use gravel, pebbles, expanded clay. It is recommended to use a crushed stone fraction of 8-32 mm.
A special geotextile material is laid on the compacted mainland soil, crushed stone is scattered on top of it - without sand backfilling. The geotextile prevents coarse granules from mixing with the soil and weeds from germinating. The thickness of the gravel layer is about 10 cm.
However, with unorganized drainage from the roof (i.e., when water does not flow down the gutters, but directly from the entire slope), the coating will have to be regularly corrected.
It should be noted that it will not be possible to compact the granules of the same size tightly, therefore, it will be uncomfortable to walk on them.
The blind area around the house no longer performs a decorative function, it protects the soil near the foundation from getting wet and uneven softening. The blind area device has its own tricks and technical requirements, which we will share with readers in our today's review.
Timing and soil preparation
Work on the construction of a concrete blind area should be carried out as early as possible. From the moment the foundation has assumed more than a third of the design load, it already needs protection from soaking. Therefore, a house with lined walls is not recommended to be left for the winter without a blind area. Heaving forces are able to do their "dirty" work even in one season. You can schedule work for almost any time of the year, but taking into account weather conditions, observing the technology of working with concrete.
The first stage is digging a trench along the outer perimeter. The bottom should be located 30-35 cm below the final level of coverage, and it, in turn, should be 50-80 mm higher than the adjacent fertile soil.
The width of the blind area cannot be less than the cornice and gable overhang above it and cannot be less than 60 cm. In the general case, it is defined as 50% of the depth of the foundation. For basement buildings on soils of the first type of subsidence, the width of the blind area can reach two meters.
The general scheme of the concrete blind area: 1 - parent soil; 2 - formwork; 3 - concrete blind area; 4 - clay castle; 5 - gravel preparation; 6 - sand preparation; 7 - damper tape; 8 - fittings
When the trench is open, an clay castle is formed at the bottom with greasy clay 10-12 cm thick. Above, make two layers of incompressible and non-porous materials: first crushed stone with a layer of 50-60 mm, then up to 100 mm of sand. Along the outer edge of the trench, be sure to dig the so-called "tooth" - a groove of about 20x20 cm.
The level of the finished sub-base layer should be 45-60 mm below the planned level of coverage. It should be borne in mind that the thickness of the layers of sand and gravel must be constant at each point of the trench, so that the recess under the “tooth” after the backfilling device is preserved.
To prevent mixing of the layers of the underlying layer, separate them from each other with a geotextile sheet, and separate the substrate itself from the compacted soil with a drainage geocomposite. On strongly heaving and, sometimes, medium heaving soils, insulation of the blind area may be required. It can be done with slabs of extruded polystyrene foam, which are laid on top of a thin (10-15 mm) backfill with sand over a layer of crushed stone, and then another layer of 50-60 mm of dry sand is poured.
Formwork, reinforcement
The device of storm sewers is considered correct in order to divert atmospheric precipitation and perched water into the drainage system. Water from the blind area is collected in a tray at the edge, from where it is discharged into a drainage trench. If a system of hidden channels is provided for these purposes, they are arranged at the stage of preparing the underlying layer. During the preparation of the reinforcing layer, all the necessary elements of the drainage system should be prudently laid.
The formwork under the blind area has the simplest device. It is only necessary to knock down a pair of 20x100 mm boards into shields in parallel, connecting them with jumpers after 50-60 cm. The formwork is installed under the side of the trench, the height of the upper edge is adjusted according to the final level of coverage. For ease of alignment, with an interval of 150 cm, wooden stakes are hammered on the outside of the shields, to which the formwork is screwed with self-tapping screws. After that, from the outside, the shields are supported by a dump of soil from the adjacent territory.
The most important point in the device of the blind area is that it should not be monolithically connected with the basement of the building. Best Schema the removal of external water, including those flowing down the wall, is observed when two layers of concrete are separated by a material with sufficiently high ductility, provided that the plinth finish is put on the blind area from above, preventing water from seeping through the separating layer. If the plinth will not be finished with hinged sheathing, its lining should begin with an EPPS damper strip that compensates for the “floating” of the concrete slab.
The easiest way to achieve such a device scheme is to paste over the bottom of the base with a strip of polyurethane foam about 20 mm thick. The separator sits on the adhesive mastic, as it is mounted, the upper edge is aligned with the cord, setting the slope of the coating towards the adjacent soil at least 3:100. However, the separating material can be cut along a common line after the adhesive has dried, but the principle remains the same: the formwork and the separating layer serve as beacons for leveling the concrete mixture.
Reinforcement of the blind area is carried out with a steel mesh with a rod thickness of 8 mm and a cell size of up to 200 mm inclusive. The reinforcement is laid in one row and placed on remote supports that regulate the protective layers of reinforced concrete at least 45 mm above and below and about 60 mm on the sides.
Preparation of concrete mix
The blind area is allowed to be cast with concrete prepared on site, but the requirements for the quality of the mixture are quite high.
The desired concrete strength class is B25 or higher. The feedstock should be measured by volume so as not to take additional corrections for the moisture content of sand or gravel. In total, 20 liters of sand and 35 liters of crushed stone or large granite screenings are added for 10 liters of cement grade 500 for the preparation of concrete.
To ensure the homogeneity of the mixture, cement milk is first prepared in a concrete mixer with the addition of half the calculated amount of water and sand. After 2-3 minutes of kneading, you can add the rest of the filler and sprinkle the mixture with water as needed. The final consistency of the concrete is a loose mix with a low moisture to cement ratio, with all stones being evenly wetted.
The cycle of continuous mixing of one portion should take at least 15 minutes. To entrain air and provide additional plasticity, one tablespoon of liquid is added to the water. detergent on a bucket. As a result, concrete has a frost resistance class of at least F200 and water absorption resistance of at least W6. If necessary, enhance the desired properties with modifier additives.
Optimal concrete consistency for pouring formwork
Filling, leveling, ironing
The blind area should be poured from the most remote part, gradually moving closer to the place of concrete preparation. The formwork is filled with the mixture almost to the top, after which the concrete is bayoneted or vibrated.
The need for transverse separation of the blind area with expansion joints is determined by the operating conditions. For the shaded sides of the building, this is not necessary, but under the open sun, the blind area should be poured, separating the mixture with strips of polystyrene foam every two widths.
When leveling, it is convenient to move straight through the liquid mixture in rubber boots. Armed with a rail-rule, check the degree of filling of the formwork and the depth of immersion of the tray box in concrete. If necessary, upset the formwork with gentle hammer blows, but do not overdo it: it will be much more difficult to raise the edge higher.
When both beacons and the edges of the tray are brought to the same level, add a small amount of the mixture and stretch it with a rail. It is not necessary to smooth the surface, it is enough to ensure its flatness and correct slope, to remove depressions in which water can collect.
After leveling, a board is laid flat on the edge of the formwork and the tray, on which a small oppression is set for 10-12 hours of preliminary setting of the mixture. For the next 7-10 days, the blind area will need to be sprayed once a day with water from a hose and then covered with a film.
Two weeks after pouring, the formwork can be broken up and wet ironed. For him, a mixture of sand and cement is prepared in equal proportions, instead of water, three parts of milk of lime and one part of liquid glass are added to the solution. The finished mixture should have a consistency slightly thicker than cream.
Before ironing, the blind area must be well moistened and wiped with a metal brush, breaking the structure of the crust formed on the surface, then sweep and rinse again. After preliminary drying, the ironing mixture is poured over the surface from the plinth outward, and then leveled with a wide spatula in the longitudinal direction. The iron layer must be at least 1.5-2 mm, the time for the mixture to solidify is at least 3 days with periodic surface moistening.
The foundation of any home is the foundation. The durability of the building depends on its strength, so this structural element needs protection. And it can be threatened by moisture entering the soil along with precipitation and flood waters. They are required to protect the foundation of each house. And the blind area can help with this.
Markup first
Before you make a blind area of concrete, which is the most common building material for these structures, you should mark the area around the house. The minimum width of the blind area is 60 cm. But it is worth remembering that the strip width must be greater than the roof overhang.. The difference in this case should be 20 cm so that falling drops of water do not fall on open ground, and were extinguished by a blind area made of concrete and went further from the foundation.
The width is taken from the corner parts of the foundation and pins are driven in at these places, the role of which can be played by metal fittings or wooden cuttings. As soon as the entire perimeter has been passed, a lace is pulled, marking the place of excavation for the construction of a concrete blind area. And it starts new stage work.
Excavation
Excavation for a blind area from concrete is carried out only manually. You need to dig to the depth of the fertile land. If this layer is small, then at least 40 cm is removed in order to be able to place layers of sand and crushed stone pillows and a concrete strip. The soil should be taken to the side and distributed over the site, as it will no longer be needed.
The base of the future blind area made of concrete should be even. A layer of geotextile should be laid on it so that the roots of plants remaining in the ground cannot germinate and eventually damage the hydraulic structure. The material is distributed over the entire area of the trench with an overlap on the foundation and the opposite side.
Adding sand and gravel
As soon as the trench is fully prepared, it is necessary to backfill and tamp building sand and granite or limestone rubble. It is important to remember that no impurities should be present in the pillows, which can significantly reduce the quality of the work done. The sand is sifted before use, freeing it from any inclusions. But the crushed stone is cleaned under the usual visual control.
The thickness of the backfill ranges from 15 to 20 cm. The materials should be laid in small portions. Wherein each layer must be rammed. For this, an electric professional tool or a simple wooden "churak", that is, a piece of log or timber with a handle.
An alternative option for compacting a sandy base is to use water. Evenly distributing the flow, you need to strongly moisten the pillow. Water will begin to seep into the sand, helping these small particles to fit closer to each other.
Reinforcement and formwork
After the stage where sand and gravel cushions were backfilled, reinforcement is required so that the concrete pavement around the house with your own hands does not become covered with a huge number of cracks after a couple of years. But fastening with reinforcing bars will avoid trouble. In addition, the metal will give the blind area rigidity, which will positively affect the durability of the structure.
To work, you need a metal bar (smooth or notched), with a diameter of 8 to 16 mm. A reinforcing mesh is also used, which is laid in a trench with subsequent pouring. If a bar is used, then it is distributed perpendicular to each other, forming cells ranging in size from 10 to 20 cm. The reinforcement is fastened using a knitting wire, previously cut into equal segments of 30 cm.
As soon as these works are completed around the entire perimeter of the house, you can proceed to the installation of formwork. In order to make the concrete blind area much easier, it is better to use an edged board. The width of the material will depend on the height of the fill, as in some cases it is allowed to raise the level when further work is planned on the landscape of the site. The optimal thickness of the blind area made of concrete is 10-15 centimeters.
Boards are installed with wooden stakes, to which they can be nailed. During the arrangement of the formwork, a building level should be used. It will be required to maintain the horizontal position of the blind area or the slope device for better water drainage. It is equally important to install special inserts to separate the solid concrete strip of the blind area. This is required to eliminate future kinks from temperature differences.
Preparation of concrete mix
After completing all preparatory work you can start preparing the concrete mixture. To do this, it is worth using a mortar mixer with an electric motor so that the process goes faster and the resulting solution is of high quality. The durability and strength that the concrete pavement around the house will have depends on this.
To prepare the concrete mixture, sifted building sand and crushed stone of a fine fraction are taken. It is this that allows you to get a smooth surface on which you can move freely like a track. Portland cement grade 400 or 500 is required as a binder. Particular attention should be paid to the date of manufacture of this building material. The fact is that cement has the ability to reduce its own qualities and characteristics over time. That's why for work, you should choose the material from the date of manufacture, which, more than a month has not passed.
The mixture for the blind area around the concrete house is kneaded in clean water. The temperature of the liquid should correspond to room temperature, that is, not be too warm or cold. First, water is poured into the mixer, then crushed stone is added, and only then cement can be poured. This allows you to get a uniform mixing of the binder, which contributes to the production of better concrete. When the cement is finally distributed throughout the mixture, sand can be added.
The composition of the mixture by different specialists is determined from the following calculation:
Water is added until the desired consistency is obtained, which should resemble sour cream. This is the only way to get a quality mixture that is convenient for leveling and styling. The resulting brand of concrete depends entirely on the cement used. So, to get M250 concrete, you need to use M400 cement. But the binder with the brand M500 allows you to get concrete M350. The proportions of the material should not change.
Concrete laying
The prepared concrete is evenly placed in the prepared blind area. This is done with buckets or directly from the agitator when it is possible to place it right next to the formwork. Each portion of concrete after unloading is subjected to leveling and vibration. This allows all air bubbles to be expelled from the concrete, which will make it much stronger.
An ordinary wooden block can serve as a vibrator, which produces translational movements. Once this is done, you should proceed to the process of leveling the concrete. To do this, you need a metal rule. This tool allows you to get a flat surface with smoothness and uniformity. Thanks to him, the same thickness of the concrete blind area is obtained, which is also important.
If the formwork was done correctly, then there will be no problems with the slope of the structure. But it still needs to be checked. The slope of the blind area should not be more than 15 mm per meter of width. This is the only way to get an additional path around the house, along which water will flow freely into the territory of the site. If you wish to divert the liquid to one place, a gutter is launched along the perimeter of the blind area. During rain, water will drain into it and go into a storm sewer or into a special ditch.
Design of expansion joints
The laid rails at the formwork stage, which are responsible for the formation of expansion joints, should be pulled out after pouring the concrete. This measure avoids the subsequent decay of the tree and the filling of these technological cavities with various debris. But you don't need to leave them empty either. Therefore, the most effective solution would be to fill the joints with a special sealant. It will not prevent the expansion of the concrete surface, and will also make the technological cavities more attractive in appearance.
The distance between expansion joints is also important. It should not be too large, but it is also not recommended to grind. The optimal distance is 2 meters, which eliminates the formation of cracks with subsequent destruction during the expansion and narrowing of the concrete blind area.
Protective Measures After Concrete Placement
When the concrete mixture is finally laid, the blind area should be covered with plywood or chipboard shields. It is allowed to use slate sheets that are leaned against the wall of the house. This measure allows you to protect fresh concrete from the effects of precipitation, such as rain. Also, such protection will not allow moisture to quickly leave the solution, which can lead to the formation of cracks.
Strengthening the surface of the blind area
What is the difference between the correct blind area of concrete? The strength and strength of the upper layer, on which the water collected on the roof of the house falls. To ensure these qualities apply:
- cement milk;
- Liquid glass;
- Primers and enamels;
- Ceramic tiles and natural stone.
The most common method of protection is the ironing of concrete. For this, dry cement or prepared milk based on it is used. After the processing process, the thinnest layer is formed on the surface, capable of withstanding any effect of precipitation and temperature. This makes the blind area hardy and durable.
Coating concrete with a primer or enamel is also aimed at achieving protective properties and improving the performance of the resulting structure. For this, water repellents are used that penetrate deep into the frozen blind area, providing it with water-repellent properties. Compared to ironing, this method is somewhat more expensive, so it is less common among owners. country houses, although quite effective.
An alternative to priming concrete is to coat it with a mixture of water glass and cement. This composition somewhat resembles the usual ironing of the surface, but provides the blind area with higher rates of resistance to water and other precipitation. Liquid glass is responsible for this in the mixture, which increases the water-repellent properties of the surface and makes it more airtight.
Usage ceramic tiles and natural stone for facing the surface of the blind area allows you to perform two tasks at once:
- Improvement of protective properties;
- Decorative design of the area around the house.
When planning for the future landscape design plot, this method can perfectly fit the house located on it. Many designers use this solution to create a smooth transition from structure to ground. The qualities of ceramics or natural stone make it possible to ensure long-term operation of the blind area, even in cases where frequent movement of people living in the house takes place along it.
Laying of all elements is carried out directly after laying and leveling the concrete. The building level will help to check the evenness and horizontalness of the resulting cladding layer. The only unpleasant moment is that due to the dense coating concrete base it will take longer to dry, which will delay the start of its operation. Otherwise, this decision can be considered the best option design of the blind area around any building.
How to make a concrete blind area - the construction process with photos and videos
How to make a blind area of concrete for centuries? The necessary "bag" of knowledge to build a high-quality concrete blind area around the house with your own hands.
