Concrete pavement device. Step-by-step instructions for laying the blind area with your own hands. Blind area of ceramic tiles
The quality of the various constituent elements of the house largely depends on the structures that are directly adjacent to them and perform a number of inconspicuous, but very important functions.
The blind area is a strip of various materials, located around the entire perimeter of the building and adjacent at a certain angle to its walls. The service life of the foundation and the general microclimate in the basement and basement floors depend on the quality of the erected blind area.
In this article, we will try to consider the general arrangement of the blind area and step by step process her arrangement.
Why is the essence of construction needed
Blind area - device and construction technology
The blind area, as mentioned above, is important and performs a number of functions:
- protection of the foundation from moisture, rainfall and groundwater;
- affects the microclimate in the basement and basement;
- does not give a subsidence of the foundation along the perimeter of the building;
- decorative element;
- in some cases serves as a house sidewalk.
As a rule, the arrangement begins after or in the process of facing the walls and the basement of the supporting base. This process should not be postponed for some time, because after a few years, especially in areas with a high degree of precipitation, flooding of the foundation can significantly reduce its strength.
In the absence of a blind area, in winter and during the cold season, due to freezing of the soil, the soil swells and presses on concrete base and walls. Subsequently, this leads to the appearance of cracks or the destruction of the supporting structure.
General design and components
The device of any foundation blind area is a “construction cake”, consisting of at least two layers: the underlying layer and the outer coating.
- The base or underlying layer is a compacted material laid out on the ground or waterproofing. For the base, both ordinary sand or gravel, and clay, which will serve as additional insulation, can be used. As a rule, the thickness of the underlying layer does not exceed 30-40 cm. The material is taken depending on the coating used.
- The outer coating is a material that prevents the penetration of moisture into the blind area and prevents it from being washed away. For this, a concrete-cement screed with the addition of gravel, asphalt or paving slabs is usually used. The thickness of this layer should be at least 10 cm.
Required width and slope of the structure
Diagram of the device with the required width and slope of the surface
The width of the blind area, first of all, depends on the distance to which the edge of the roof of the building protrudes. The minimum required width is in the range from 60 to 80 cm and depends on the type of soil on which the structure will be built.
For stable soil types, the width should not extend beyond the edge of the roof extension by more than 20-30 cm. If the soil layer is unstable, then the width can be increased to 90-120 cm. Further increase practically does not play any role.
General scheme of arrangement
If the blind area also serves as a footpath, then its width may well be 1.5-2m. The main thing is to monitor the overall composition of the building so that the dimensions of the structure are in harmony with other elements of the building.
The slope depends on the coating that is used for the outer layer. For most concrete structures, a slope of 4-5% is sufficient. For a blind area of crushed stone or gravel, it is recommended to make a slope of at least 5-7%.
Device and technology of work
The general blind area can be reduced to the following main steps:
- At the first stage, it is necessary to excavate the soil to the width and depth of the future blind area. The dug trench is recommended to be processed by special means to remove plant roots.
- Along the perimeter of the trench, formwork from a wide board is installed. As formwork, you can use small concrete blocks or curb stone.
- A layer of underlying material is laid at the bottom of the trench and carefully compacted. It is desirable to lay the material so that part of the sheet slightly extends onto the wall of the basement. This is necessary to create an expansion joint between the blind area and the wall.
- A coating of various materials is laid on top of the inner layer in several layers.
This completes the general device, but for each type of material used to create the outer layer, there is its own installation technology:
Prepared sand base and exposed formwork on the outside
Seams are placed perpendicular to the walls of the building with a step of 2-2.5 meters. Reiki can be used as guide beacons for the distribution of concrete over the surface of the blind area.
After laying the concrete, the wet surface of the foundation blind area must be additionally sprinkled with cement and smoothed out with a trowel. This process called ironing and is necessary to increase the moisture resistance of concrete. After the finished structure is covered with a fabric material and periodically moistened with water until the concrete has completely set.
For concrete structures located on unstable and heaving soils, it is recommended to carry out reinforcement. This is done to increase the service life by laying a metal mesh with cells of 10 by 10 centimeters before pouring concrete.
The technology is quite simple and does not require the involvement of specialists. The main thing is to carry out the work in stages and adhere to the basic installation rules.
Construction sealing
Sealed expansion joint
Sometimes, in houses located on heaving soils, a crack may appear between the base and the surface of the structure. To prevent this, it is recommended to carry out sealing work.
This can be done both at the stage of the device and subsequently in operation. In the first case, the following options are possible:
- the structure must be made on a draining base in the form of sand, gravel and clay;
- the lower part of the blind area should be above the soil around the building;
- the expansion joint must be made so that the tightness between the blind area and the basement wall is maintained.
If these conditions are not met, as mentioned above, a crack may form or the structure may move away from the building. If this happens, then special sealants based on polyurethane are used. The resulting crack is filled with sealant using a mounting gun.
To protect against mold and fungus, the sealed seam is treated with a water repellent.
Construction insulation
Foam insulation and mesh reinforcement
Warming should be carried out when erecting a structure on unstable types of soil. Insulation will help prevent freezing of the soil, thereby preventing soil heaving.
For this, heat-insulating materials are used, which are laid on top of the underlying layer. It is desirable that the outer covering be made of concrete or paving slabs, as this will help to avoid additional load on thermal insulation material.
For the usual and simplest thermal insulation, we recommend using extruded polystyrene foam or polystyrene foam.
Structure repair
In case of obvious damage to the outer layer of the blind area, it should be repaired as soon as possible in order to avoid further destruction. To do this, the damage boundary is determined so that the main cracks or potholes are combined into a common plane that can be removed.
Proceed to repair work better in cool weather, when the main damage is most exposed under the influence of absorbed moisture.
If the asphalt coating is damaged, it is necessary to remove a layer of material in the desired area to the full depth. The pits, after removing the damage, are recommended to be cleaned of dirt and smeared with bitumen.
Only then can the asphalt concrete be re-laid and compacted. It is desirable that the new asphalt cover the layer of the old pavement. This will give better adhesion to the old material.
Use bituminous mastic and cement-sand mortar. Cracks are cleaned of dirt and filled with mastic. Minor damage can be repaired cement mortar mixed in proportions 1/1.
The blind area of \u200b\u200bthe house, compared with its foundation, has an incomparably lower cost. Making a good blind area is much easier than building a foundation. But all of the above does not mean at all that attention to this important detail should also be much less, which, alas, often happens. The blind area, in comparison with the entire structure of the house, may seem like a small cog, but the “health” and long life of the entire structure greatly depend on it.
In the article, we are going to consider in detail how to make a blind area around the house, and how to do it correctly, and also consider different variants and indicate in which cases it is advisable to use them. Recommended Construction Materials, which should be used to create a good blind area at home.
What is a blind area and why is it needed?
A blind area is usually called a strip of waterproof coating that encircles the entire house around the perimeter. Most often, we are used to observing blind areas made of concrete or asphalt, however, everything is not limited to these two materials. The main task of the classical blind area is to prevent atmospheric water from entering the foundation structure and into the soils located near it. Why is this being done?
- Firstly, water that has got to the structure of the base of the foundation can soak the soil near it, and if it is shallow, this can lead to freezing and the appearance of heaving forces. Particularly dangerous are the so-called heaving soils, which include clay and loamy soils. The forces of frost heaving are simply enormous, they are trying to squeeze the house out of the ground. If they are distributed unevenly over the foundation, this can lead to cracks and even destruction of the house.
- Secondly, the forces of frost heaving act not only on the sole, but also on the side structures of the foundation. In building science, such forces are called tangential heaving. According to experts, 1 m² of wall can have a load of 5-7 tons. Not every design will be able to withstand this. The blind area is designed to minimize the ingress of water from above.
- Thirdly, waterlogged soil with poor waterproofing of the foundation can cause water to enter the premises. ground floor. Even good waterproofing does not always save you from leaks or high humidity. After all, the proverb is well known to everyone: "Water will always find a hole." And here the blind area also plays a role, reducing the humidity of the soil adjacent to the foundation.
- And, finally, a poorly made blind area will provoke its own destruction, which will have a bad effect on its protective and decorative qualities.
The creation of a high-quality blind area at home is included in the set of measures for waterproofing the foundation and its drainage - wall or ring. By itself, she is “not a warrior in the field” and will be able to fulfill her main protective purpose only together with other elements. Why do you need a blind area at home?
- As noted earlier, the blind area prevents the penetration of atmospheric water to the foundation of the building. Water that has fallen on the blind area must drain from it and enter the system surface drainage.
- The blind area, provided it is insulated, prevents the soil from freezing under it and therefore reduces or eliminates the occurrence of frost heaving forces. Best of all, this function works in conjunction with the insulation of the foundation. In the countries of northern Europe, insulation of foundations and a blind area have long been mandatory measures in the construction of houses.
- The blind area can serve as a sidewalk along which people move.
- The blind area performs a decorative function. thanks to her, any house in combination with the decoration of the walls and the plinth has a harmonious and complete look. We can say that the blind area is one of important elements landscape design.
Almost all houses and buildings need a blind area. For a strip, slab, monolithic-strip foundation, it is simply necessary. If the house is built on a pile or, then the blind area will only perform a decorative function.
What are the blind areas
Consider what types of blind areas exist so that there is an “opportunity” to try on one or another option to your conditions and choose the most suitable one.
Clay blind areas
This type of blind area is rooted in the distant past. It was this material that our distant ancestors used to protect the foundation of their house from moisture. And, despite the fact that this method of creating a blind area may seem archaic, which is long overdue to be sent "to the dustbin of history", it may well be used on modern buildings. Everyone knows the properties of clay - its plasticity, fire resistance and the main quality - water resistance. This material is the best natural waterproofing. Almost all underground sources of artesian water are enclosed precisely between clay layers. Another useful property clay - it is impossible to grow any plants on it. Of course, if the clay has a certain degree of its purity.
Such a blind area is made very easily. The fertile soil layer is removed to a given width and depth, and then clay is poured and compacted. It is better to use clean quarry clay. The profile of the blind area is given a slope in the direction from the wall to its edge, and then the clay is reinforced with gravel or crushed stone, which must be imprinted into its layer. An interesting composite coating is formed. Clay provides reliable waterproofing and plasticity, and crushed stone or gravel provide the necessary rigidity of the blind area and prevent water erosion. The clay pavement, together with crushed stone or gravel, looks good and can even become an element of home decor, especially wood. The clay blind area will never crack, it is easy to repair. She can serve for decades. Surely many have met unpaved roads on clay soils ah, which are fortified with stones. They've been around for a long time and will last a long time. Even trucks in rainy weather do not “tread” a rut on such roads.
A significant limitation of the wide distribution of clay blind areas is their main drawback - with direct, prolonged and strong exposure to water, the clay will still be gradually washed out. Therefore, in most cases, more modern materials are used.
sand prices
Concrete blind areas
This type of blind area is the most common. And this is absolutely not in vain. one of the most common materials and blind areas from it have a set of advantages:
- Properly prepared and laid concrete has high mechanical strength.
- Concrete is not afraid of water and practically does not let it through, and treated with various hydrophobic coatings, it becomes an ideal waterproofing barrier.
- Concrete blind areas have a long service life - at least 25 years, subject to compliance with the technology.
- It is quite possible to make concrete blind areas on your own, for this you do not need the services of special construction equipment.
- Concrete blind areas can be decorated with pebbles, gravel, various natural stones.
Concrete blind areas, however, are not without drawbacks:
- Along with high mechanical strength, concrete blind areas are fragile. If heaving forces of different magnitude occur in different parts of the blind area, cracks may appear. This problem is solved by reinforcement, which makes the blind area significantly more expensive.
- Bare concrete has an unpresentable appearance, beautiful house on a harmonious natural landscape, a concrete blind area will only spoil.
- The concrete blind area is very difficult to dismantle, it is difficult to locally repair, the need for which arises sooner or later.
The thickness of the concrete blind area in its thinnest part should be at least 5 cm, but given that it is constantly under the influence of natural forces, it is better to make it at least 7 cm. Naturally, the concrete blind area is given a slope of 3-10 ° in the direction from walls to its edge. The width must be at least 20-30 cm greater than the overhang of the roof eaves, but in no case less than 60 cm.
cement prices
The blind area should encircle the entire house along the perimeter and not have a rigid connection with the walls. The fact is that with seasonal soil movements, the structures of the house and the blind area will behave differently and the presence of a rigid connection will lead to the appearance of cracks. In addition, different materials have different coefficients of thermal expansion. Therefore, they do what is called expansion or expansion joint , which, on the one hand, provides the necessary seal to prevent water penetration, and on the other hand, allows mutual movement of the house and the blind area. Expansion joints have long been made from tarred boards, but now various synthetic materials. Very often, expansion joints are made of roofing material folded in half or foamed polyethylene. There are also special damper tapes for screeds or underfloor heating, which can also be used for an expansion joint between the blind area and the basement of the house.
In a concrete tape, blind areas also necessarily arrange expansion joints. They are made in the corners, and then every 1.5-2.5 meters. Oiled or tarred edged boards 20 mm thick, strips of laminated plywood or OSB are used as seams. When pouring the blind area, they serve as beacons for leveling it and in the future, after setting, they can be removed and filled with polyurethane-based sealants or left in place.
Asphalt and asphalt concrete pavements
Such blind areas are also quite widespread, but mostly not in residential construction, but in industrial or commercial facilities. Asphalt is more plastic than concrete, the probability of cracking is negligible. Asphalt pavements are less material-intensive, since 3-4 cm is enough to create a durable and water-resistant coating. They are strong enough and can last for decades.
However, asphalt blind areas were widely used only in the construction of non-residential stock. When heated by sunlight, the asphalt can soften and hydrocarbons, which are part of bitumen, which is a binder for this type of coating, begin to evaporate from it. In addition, asphalt laying requires the use of special road equipment.
Paving stones or paving slabs
This type of blind area will be most preferable if the house is planned to fit harmoniously into the surrounding landscape. cozy and beautiful garden with paths made of paving stones, finished with natural stone or its imitation, the plinth will be in perfect harmony with the blind areas made of paving stones or paving slabs. Natural stone can also be included in the same category, since there are no big differences in terms of technology for preparing the base and laying. Natural stone, however, requires a highly skilled craftsman.
What are the advantages of a blind area made of paving stones or paving slabs?
- As noted earlier, this is an attractive appearance.
- Properly laid high-quality paving stones or paving slabs have a long service life. According to manufacturers - at least 20 years.
- High-quality stone blocks have good frost resistance.
- Coatings made of paving stones or paving slabs made by vibrocompression (namely, these are recommended for blind areas or paths) in wet weather or in the cold season are not as slippery as concrete, asphalt or made from vibroline tiles.
Vibropressed paving stones - an excellent material for the blind area - Each paving stone is laid separately on the base, so cracking is not characteristic of such a coating.
- Coatings made of paving stones or paving slabs are distinguished by their environmental friendliness.
- The paving stone pavement can also serve as a path for people to walk on.
- High strength and wear resistance.
- Pavement pavements can be repaired locally, no complete dismantling is required.
- or paving slabs can be laid independently. This does not require the use of special construction equipment.
The main disadvantage of the pavement pavement is its relatively high cost compared to the concrete "classics". There is a good way out of this situation - if they only walk along the blind area, then it can be paved with paving slabs, which are both thinner and cheaper than paving stones. Platforms and paths that will be subjected to increased loads can already be paved with paving stones in harmony with the blind area. Most manufacturers of vibropressed paving slabs or paving stones offer products of different thicknesses. After laying, it is no longer possible to distinguish where the stones are thicker and where thinner. The device of the blind area from paving stones or paving slabs is shown in the figure.
Prices for paving stones
paving stones
Paving stones or paving slabs still have one important feature, which can appear as looking good, and vice versa. Such coatings are laid on a sandy base and have gaps between adjacent elements. When water gets on the pavement from paving stones most of will be received by storm water inlets, taking into account the obligatory slope, to flow down the gutters and the surface into the water intake trays of the surface drainage system. But some part will still be able to seep between the paving elements into the underlying layers. Now consider how this feature can manifest itself in good and bad form.
- First about the good. If water seeps through the seams, then such a coating will be dry, puddles will not stagnate on it. Of course, this is very useful for paths where the surface is horizontal, but the blind areas have a slope and most of it will still drain into the water intake trays. But, all the same, a part will fall into the underlying preparation.
- Now about not very good possible manifestations. Let's say the house is built on heavy clay soils and the pavement of paving stones or paving slabs is done correctly. Beneath it is both gravel and sand layers, which can take a certain amount of water. When the snow melts, a situation may arise when the water will completely saturate both the sand and the rubble and there will simply be nowhere for it to go, since on the one hand there is a foundation wall with good waterproofing, and on the bottom and side there are heavy clay soils. If the thaw is replaced by severe frosts, which often happens in the climatic zones of Russia, then the water in the gravel and sand layer will freeze and expand accordingly. The blind area can collapse in such conditions very quickly. Even after one season of operation.
At the thematic forums devoted to construction, a lot of questions are raised about paving stones and paving slabs in general and blind areas from them in particular. Developers are sometimes simply at a loss because a good and flawlessly laid paving stone pavement begins to swell after the first winter experienced. And this most often happens due to the fact that gravel and sand, when snow melts, are saturated with water, which simply has nowhere to go because of the clay soils around. This problem is solved very simply, but not free:
- The first solution to the problem is drainage. In the case of blind areas, this is a high-quality near-wall deep drainage, as well as surface point and linear. You can read more about drainage in our portal. Preference should be given to drainage with a wall relief geomembrane. Then the water, having got into the gravel and sand, will not linger in them, but will flow down, where it will be “caught up” and removed by the drainage system.
- The second solution to the problem is the insulation of the foundation. This measure will avoid freezing of the soil in the area of \u200b\u200bthe foundation and the blind area. Materials and technology are described in our portal.
The blind area around the house, in addition to vibrocompressed concrete pavers, can also be made from more expensive natural materials.
- It may be a natural "wild" stone, which owes its name to its irregular shape.
- As the upper layer of the blind area, natural chipped, chipped-sawn or full-sawn granite paving stones are also used. This is a very worthy option, but at a cost it is very immodest.
- The blind area of clinker pavers in combination with the plinth finish with clinker tiles not only looks rich, but also has a very long service life. This option is no less modest than the blind area of granite paving stones.
We will consider in detail how to make a blind area from paving stones or paving slabs in one of the following sections of our article.
Soft blind areas
It may seem that some kind of catch is hidden in the name itself. We are subconsciously accustomed to perceiving blind areas as a rigid and reliable structure, and the word “soft” seems out of place. However, this is far from being the case. Such blind areas have been used for a very long time and successfully. For many decades, soft blind areas have been serving without repair, and in such climatic zones, where they are affected in different seasons by water, snow, severe frosts, and heat.
Some varieties of soft blind areas are also called Finnish, thanks to the country where they are widespread. It is difficult to catch the inhabitants of Finland in stupidity and impracticality, they live in harsher climatic conditions than most regions of Russia, they build a lot of good and comfortable houses. No wonder Finnish builders are considered among the best in the world. It is possible that it also makes sense for us to learn from the Finns some experience.
As noted earlier, the blind area should solve two main problems. The first is to prevent water from entering the foundation structure and the soil near it, and the second is to preserve the integrity of the blind area itself in order to preserve its presentable appearance and solve the first problem. That is, the integrity of the blind area is one of the main tasks and a person is forced to constantly fight for this by reinforcing, creating expansion joints, drainage and other measures. The wise Finns decided to stop the fight and make the blind area soft. One of the options for implementing this approach is shown in the figure.
The main thing in the construction of soft blind areas is a very interesting approach - you don’t have to worry too much about the integrity, solidity and water resistance of the design of the upper decorative layer, but it’s better to focus on how to remove water that has already penetrated through it. That is, “the most interesting”, those elements that carry exactly protective function, in these types, the blind area is out of sight. If water penetrates through the upper layer, then it is better not to interfere with it - let it seep to your health and the sooner the better. But then the drainage pipe is already “waiting” for water, which also “with pleasure” accepts it and carries it away from the foundation into the wells.
The permeable layer on which the blind area and the drainage pipe are located are reliably cut off from other soils by some waterproofing material. Roofing material or other materials, for example, PVC films for pools, can act as it.
The best results for waterproofing are the so-called PVP membranes (profiled waterproof polyethylene). They are made of high density polyethylene (HPDE), absolutely inert to all substances that can be found in the soil. According to official documents - test reports, the service life of the PVP membrane declared by the manufacturers is at least 60 years, and in reality it will be even longer if the installation is done correctly. This means that you will not have to do waterproofing again for all your long and happy life. In principle, the life of a membrane is approximately equal to the average life of a house.
PVP-membranes have on their surface irregularities in the form of truncated cones, 8 mm high. Thanks to these protrusions, water easily collects on the surface and flows down under the influence of gravity. Therefore, the membrane in the soft blind area is always laid at a slope in the direction drainage pipe. For laying in the ground, it is better to use a composite geomembrane consisting of two bonded layers. The first layer is the PVP membrane itself, and the second is a geotextile fabric that freely passes water and does not allow the surrounding soil to fill the entire space between the relief ledges.
For waterproofing the blind area, a profiled geomembrane bonded with geotextiles is best suited In soft blind areas, there may be different finishing layers, that is, those that are visible from the outside.
- The blind area can be covered with rubble or gravel, which will give it a natural look. Such blind areas will always be in harmony with the surrounding landscape.
- Colored decorative or gravel is currently widely used. With their help, you can realize the most daring design ideas. Such and blind areas, and other elements of the landscape, look very good.
- outer layer soft blind area can generally be made from fertile soil on which to plant a lawn. It will give the impression that there is no blind area, although we already know that the main thing is underground. Houses made of logs or standing in the middle of emerald green lawns look simply amazing.
Soft blind areas are more and more used in individual housing construction in Russia. And this is quite justified, because their advantages are obvious:
- The soft blind area is not afraid of seasonal ground movements, which have always been, are and will be in any, even an impeccable design. After freezing and thawing, and, accordingly, movements, the blind area returns to its place. Accordingly, there is no need to equip expansion joints.
- It is not necessary to make a soft blind area under a slope, since water is drained under it. This allows them to be used as a pedestrian zone. Even the blind area with top layer from a lawn can be a pedestrian area if it is well drained and reinforced, for example, with geogrids.
Lawn reinforced with geogrid - The soft blind area is easy to repair in case of local damage, and also easy to completely dismantle.
- Soft blind area has an attractive appearance, in harmony with nature. The use of colored decorative crushed stone or gravel allows you to create unique compositions. And also on such a blind area you can plant various plants: lawn grass or various flowers and small shrubs. For this, however, special measures will have to be taken.
- Soft blind area is cheaper than concrete or paving, the process of its creation is less laborious.
The disadvantages of soft blind areas include:
- When constructing a soft blind area Special attention should be given to the preparation of the base, waterproofing the foundation and drainage system. If the concrete blind area is guaranteed to “throw” water from the foundation to its width even with a poor drainage system, then soft under the same conditions may not be able to cope with the incoming water.
- The crushed stone or gravel covering of the soft blind area is more difficult to clean from dust and debris than concrete or paving stones.
- Various weeds can grow through the gravel, which will require periodic removal.
- The blind area from the lawn also requires constant care.
In some sources, blind areas made of paving stones or paving slabs are classified as soft, arguing that such structures do not have a rigid base. We intentionally do not do this for two reasons:
- A blind area made of or paving slabs, even by tactile sensations, can hardly be called soft.
- Very often, in order to increase the reliability of the pavement from pavers or paving slabs, it is made on a concrete base, on which a thin (5-7 cm) layer of cement-sand mixture is poured. Clinker tiles or paving stones are laid only on a concrete base using special adhesive mixtures. Such blind areas are simply impossible to call soft.
In order to avoid unnecessary disputes about the belonging of one or another type of construction to soft or hard, we consider in the article blind areas made of paving stones or paving slabs in a separate category. That will be much easier.
Is it necessary to insulate the blind area?
In the recent past, some 20-30 years ago, when building houses in our country, such questions did not arise at all. The foundation could be insulated with expanded clay poured into the sinuses, and the blind area was not separately insulated at all. The foundation was always laid below the freezing level of the soil. And this was one of the few measures to protect the foundation from seasonal soil movements on heaving soils. However, building science and technology did not stand still, new materials appeared along with them. As a result, in the global practice of construction, they came to one conclusion in order to reduce the negative impact of frost heaving forces on the foundation, especially on heaving soils - it must be insulated. In addition, this allows you to reduce the depth of the foundation sole in the ground, which significantly reduces the cost of it. And if the foundation itself is insulated, then the blind area is mandatory too. Only this way and not otherwise! Here are the main reasons why it is necessary to insulate the foundation and the blind area.
- If the house has a heated basement floor, then the insulation of the foundation and the blind area is mandatory. This, firstly, will reduce heat loss, and secondly, it will prevent soil freezing, which will reduce heaving forces. In a properly calculated foundation and its insulation, soil freezing can be avoided.
- If the house has a shallow foundation, then insulation of both the foundation and the blind area is mandatory. The shallow-depth slab foundations of the USHP type (insulated Swedish slab), which are now gaining popularity, are necessarily insulated from all sides, including from below.
- Insulation of the blind area still makes sense so that the melt water that has fallen into the crushed stone and sand layers of the substrate does not freeze when the temperature drops, but calmly goes into the drainage pipes.
Insulation of the blind area does not need to be done only in two cases:
- When a house is built on a pile foundation. But then, in principle, no blind area is needed.
- When the house has a deep, non-insulated foundation and does not have a basement. In this case, the insulation of the blind area is just a senseless burying of insulation in the ground.
Completely different materials are offered as insulation, but in order to save readers from the torment of choice, we offer only the best in terms of price and quality. This is extruded (extrusion) expanded polystyrene - EPS. Why is this material recommended?
- Firstly, EPPS has a low thermal conductivity (0.029-0.032 W / (m * K °), which, in principle, explains its use as a heater.
- Secondly, XPS has high mechanical strength. The compressive strength with a deformation of not more than 10% of it is not less than 0.25-0.5 N / mm². That's enough. On this insulation, the foundations of houses are erected.
- Thirdly, XPS has a low density. One cubic meter of this material has a mass of 38 to 45 kg.
- Fourthly, EPPS has extremely low water absorption (no more than 0.2-0.4%) and vapor permeability (0.013 Mg / (m * h * Pa)), which is very useful when located in the ground.
- Fifth, XPS is very easy to process and install. Required minimum set tools.
- Sixth, XPS is durable. Its service life in the ground is at least 30-50 years.
- Seventh, XPS under normal operating conditions does not emit any harmful substances, does not harm either living beings or nature.
- And finally, XPS has a reasonable cost. Availability on the market a large number this insulation from different manufacturers is in the hands of us - consumers.
The world's most popular insulation material is extruded polystyrene foam. The thickness of the blind area insulation is calculated, but in no case should it be less than 5 cm.
As an example, let's take a closer look at the processes of creating three types of blind area: reinforced concrete, pavers and soft.
Do-it-yourself concrete pavement
Consider the process of creating a concrete insulated blind area around the house. At the end of this section, a calculator will be offered that, based on the perimeter of the house, its configuration and the size of the blind area, will help calculate the amount of concrete required for laying.
Let's say right away that the number of options for implementing a concrete blind area using various materials and technologies is endless. It is simply impossible to describe them all, not only within the framework of one article, but even in a multi-volume edition. We will describe one of many, but one that has been implemented on a large number of objects and has been successfully operated for quite a long time to say that such a design justifies itself. For ease of perception, we present the main stages of the process of creating a concrete blind area in the form of a table.
| Image | Process description |
|---|---|
 | Work should be carried out only in the warm season. First, the marking of the blind area is done. It should be no less than 20-30 cm wide than the overhang of the roof eaves. The smallest height is 7 cm, the slope is 3-10 °. Initially, it is indicated with a cord stretched along the level between the stakes driven into the ground, the outer edge of the blind area. If a curb stone is to be installed and drainage trays surface drainage systems, their width is also taken into account, since the soil must also be developed for them. The horizontality of the cord is checked with a spirit level or a laser level. |
 | On the wall of the basement, the upper level of the junction of the blind area is marked. To do this, marks are made in one place at a convenient height (1-1.5 m), and then they are transferred to other places using a laser level or spirit level. Further, with a plumb line and a tape measure, the horizontal is transferred down. The junction line can be drawn with a pencil or marker, but it is most convenient to “beat off” it with a masking cord. |
 | On the marked base, the soil is removed to a depth of at least 30 cm. The main thing is to remove the entire fertile layer and “get” to a solid, reliable base on which the blind area will lie. If necessary, the soil is removed to a greater depth. Be sure to get rid of the roots of all plants and to prevent their growth in the future, you can treat the soil with herbicides. The profile of the bottom of the trench is given a slope towards the outer edge of the blind area. |
 | At the bottom of the trench, an underlying layer of quarry "fat" clay can be poured, which is then rammed. This layer is also given a slope. If the site has clay or loamy soils, then only tamping the bottom of the trench is enough. |
 | A formwork of edged boards is installed on the outer edge of the future blind area, which are fixed with wooden pegs or pieces of reinforcement driven into the ground. The upper edge of the formwork is set along the previously stretched cord and checked with a level. |
 | A non-woven geotextile thermally bonded fabric with a density of at least 150 g / m² is lined at the bottom of the trench, which should completely cover the bottom and have entries on the basement wall and the edge of the trench by at least 30 cm. Geotextiles are needed to separate heterogeneous soils. |
 | Layers of coarse building sand with a thickness of at least 20 cm are poured onto the geotextile layer. The sand is leveled with a rake, spilled with water and rammed for the first time. It is most preferable to use a mechanized ramming method using a vibrating plate. |
 | AT hard-to-reach places where the vibrating plate cannot pass, use a manual rammer. After the first ramming, sand is poured in the right places and rammed again. The process of pouring water and ramming is continued until there is an even and dense base of sand, on which there are practically no traces when walking. |
 | If elements of the surface drainage system are installed - storm water inlets and sewer outlet pipes from them, then holes and trenches are dug out for them in the already compacted sand. In this case, it is necessary to take into account the level of the future blind area - the storm water inlet must be installed at its level, taking into account the slope. Its installation must be carried out on a concrete solution with a layer of at least 5 cm. Sewer pipes must also be laid with a slope of at least 2 cm per 1 running meter pipes. |
 | Trenches with pipes and installation pits of storm water inlets are sprinkled with sand, which is then rammed. In places where sewer pipes pass and near storm water inlets, this can only be done carefully and manually. |
 | A 5 cm thick EPPS insulation is laid on a layer of compacted sand. If the upper part of the basement was not insulated, then this can be done simultaneously with the blind area. Insulation plates are laid on a compacted sand base. If necessary, they are easily cut with a construction knife. The plates must lie firmly on the base. If necessary, when laying them in the right places, sand is poured. |
 | After laying, the seams between the plates are filled with mounting foam. |
 | An expansion joint is formed at the junction of the blind area to the base. This can be done by double-coordinated and glued to the wall roofing felt, foamed polyethylene, a special self-adhesive tape for underfloor heating seams. The seam should protrude beyond the upper edge of the future blind area by 5-10 cm. additional materials no. |
 | A metal reinforcing mesh made of wire with a diameter of 4 mm with a cell size of 100 * 100 mm is laid on the insulation layer. In the right places, the mesh is cut. The edge of the mesh should be 5 cm from the end of the blind area. If more than one mesh is required, then an overlap is made by one cell, and then the meshes are fastened with knitting wire. |
 | The reinforcing mesh should be in the concrete layer in its lower part at a distance of 3-4 cm from the insulation. To install the mesh at the desired height, it is best to use special reinforcement clamps, which have different heights and are designed for different surfaces. To install the reinforcing mesh, it is better to use clamps for loose surfaces. Before laying concrete, all parts of the surface drainage system are covered with plastic wrap. |
 | Beacons are made from edged boards 20 mm thick, strips of OSB boards or thin laminated plywood, which will simultaneously serve as expansion (compensation) seams in the blind area. Segments of the required size are cut from them, which are attached to the base at the previously indicated level at one end, and to the formwork at the other. The upper edge of the beacons should coincide with the surface of the future blind area, and the lower one is tightly pressed against the insulation boards. Lighthouses are set in the corners, as well as every 1.5-2.5 m along the entire length of the blind area. The optimal distance is 2 m. |
 | To fill the blind area, concrete grade M250-M300 is used, but not lower. You can read more about the recipe and preparation of concrete of the desired brand in the right quantity on our portal. The volume required for the blind area can be calculated in the calculator at the end of this chapter. |
 | To improve the properties of concrete during its preparation, it is recommended to use plasticizers, as well as add polypropylene or basalt fiber. |
 | It is better to knead concrete with a concrete mixer or mixer - such mixtures are of better quality than hand-kneaded ones. |
 | Concrete is laid gradually, in sections between the lighthouses. Concrete is first laid on the surface, then spread with a trowel or shovel, and then leveled with an aluminum rule along the beacons. After laying in one section between the beacons, they move on to another. |
 | 1-2 hours after laying, it is necessary to iron the blind area. To do this, a thin layer of dry cement is poured through a sieve onto the upper surface of the concrete - approximately 2 mm. Then, with a manual polyurethane grater, dry cement is rubbed into the surface of the blind area. Walking on the blind area is possible only after 48 hours. |
 | For high-quality maturation of concrete, it is necessary to moisten its surface daily with water, and then cover it with plastic wrap or a damp dense cloth. This operation should be done within 10-14 days. |
 | After the concrete has completely hardened - after 28 days, the formwork is dismantled. The blind area is ready. |
In the future, the blind area can be equipped with a curbstone, a storm sewer can be made along the edges - drainage trays and sand traps can be installed. How to do this is described in detail in an article on this topic on our portal.
Video: Concrete pavement device
Calculator for calculating the required volume of concrete for the blind area
We provide readers of our portal with the opportunity to independently calculate the volume of concrete required for the blind area. The initial data for the calculation are the geometric dimensions of the blind area: its height at the wall, height at the end, width. And also for calculations, you need to know the perimeter of the house: the sum of the lengths of all its sides. This calculator calculates the volume only for houses that have a rectangular configuration, if there are any rounding of the foundation, then this calculator cannot be applied or it will be possible to calculate the volume only on straight sections.
The calculations also take into account the configuration of the house, namely how many external or internal corners. If you need to calculate the volume of concrete for any straight section, then you must specify that the number of external and internal corners is zero.
Master of Architecture, graduated from the Samara State University of Architecture and Civil Engineering. 11 years of experience in design and construction.
The blind area device is an extremely important event. These works are carried out after the construction of the house is completed, therefore sometimes they are not given enough attention, one hundred is unacceptable, since the design of the blind area performs the extremely important task of protecting the foundation from atmospheric moisture. The following describes how a do-it-yourself blind area should be done, step-by-step instructions for each type of protective strip, and recommendations for choosing materials.
Concrete pavement
To date, this is the most popular way to protect the foundation, but it has enough a large number of shortcomings, therefore, if there is financial opportunity to choose a more expensive and reliable option, it is better to resort to it. Most often, this type of blind area is typical for mass urban construction.
The disadvantages include:
The production of a concrete element is carried out in the following order:
- Calculation of the thickness of the entire structure, in which it is required to take into account all layers. This value is needed in order to determine the depth of the trench along the perimeter of the foundation.
- Determination of geometric dimensions. On average, the width should be taken within 90-100 cm. The slope for concrete is 3-5% (for piece materials - 5%, therefore, in order not to get confused in the values, it is recommended to remember the total - 5%).
- Take out markings on the ground. For this, the limits of the future structure along the perimeter of the foundation are indicated by pegs with a cord stretched over them.
- Next, open the trench. The dimensions in the plan are already limited by markings, it remains only to dig the soil to the depth calculated in the first paragraph.
- The base soil is carefully compacted. If possible, a castle is made of clay, which will provide additional protection against moisture.
- The next layer is a sand cushion. Sand performs three functions: replacing heaving soil, which is widespread throughout the country, with conditionally non-heaving soil, leveling the base, and arranging a drainage layer. The sand cushion is made only from coarse or medium sand. If a do-it-yourself blind area is erected using a fine fraction, then large shrinkage, cracks and a violation of waterproofing are possible. The thickness of the layer is selected depending on the characteristics of the soil. It is important to consider strength and water saturation. If the soils on the site are strong, it will be enough to lay about 200 mm of sand. For unstable bases, 500 mm of sand bedding may be required.
- The crushed stone bedding performs approximately the same functions as the sandy one. Here you can use not only crushed stone, but also gravel or a sand-gravel mixture. The blind area device on such a basis increases the strength of the soil and increases the reliability of the entire structure. At this stage, preparatory work. Up to this point, the fundamental differences in how to properly make a blind area for the foundation from different materials, No.
- The next step is setting up the formwork. The formwork is needed so that the liquid concrete mixture does not flow beyond the markup. For manufacturing, you can buy boards with a thickness of 22-25mm. You can use old materials to save money. Walls are knocked together from the boards, which are installed around the perimeter of the foundation. At the same time, it is important to install the board directly to the wall of the building, the thickness of the formwork element will provide the necessary expansion joint, the thickness of which is in the range of 20-40 mm. The seam is needed to prevent cracking and deformation of the structure with different shrinkage of the foundation and blind area.
- After the formwork is installed, reinforcing mesh is laid. They will increase the flexural strength of concrete. The diameter of the reinforcement in the grids is recommended to be approximately 10 mm. This technology of the blind area device will ensure its strength and reliability.
- Further, the blind area device requires installation cross boards around the perimeter of the foundation. The boards will provide expansion joints that cut the strip into separate sections. The step of the boards is assigned 2 meters.
- The next step is pouring concrete. For this, a concrete mixture of classes B20 - B22.5 (grade M300) is made. It is this solution that is able to provide the durability of the structure and the necessary strength. It is possible to use concrete of smaller classes, B15 and B17.5 are suitable, but it is worth remembering that the service life will decrease. When using a mixture of B22.5 normative term service will be approximately 25 years. Filling in each compartment between the boards of expansion joints is performed in one go. After that, compaction is required. There are several ways, but the most common is vibrators. In the absence of the necessary equipment, you can use the bayonet.
- After the solution is poured, the surface is ironed, this is done to increase the strength characteristics.
- The penultimate stage in the manufacture of a concrete blind area of \u200b\u200bthe foundation is the strength gain of the structure and its maintenance. At a temperature of +20 degrees Celsius and normal humidity, it takes 4 weeks to cure. If the temperature is lower, the process slows down significantly. It is necessary to wait for at least 70% of the graded strength of concrete. A week or two after pouring, the surface is moistened every 2-3 hours (and at night 2-3 times a night). This is necessary to prevent cracking.
- When the concrete has gained 70% strength, you can remove the formwork. After that, the blind area device is completed.
Paving slab foundation
The blind area around the house with your own hands in this case has only one drawback - the cost. But in terms of appearance, maintainability and ease of use, it surpasses the previous type.
The preparatory stage of work is carried out according to paragraphs 1-7 for the manufacture of a concrete pavement of the foundation.
Paving slab construction scheme - An additional layer of sand 70-100 mm is laid on the crushed stone, while providing the necessary slope.
- The next step is the installation of tiles.
- The joints of the piece elements are sealed with a cement-sand mortar.
More details about this type of construction can be found in the article "Blind area from paving slabs." Using the same technology, a cobblestone or ceramic brick structure is mounted.
clay pavement
Arrangement of this type to protect the foundation requires the following steps:
Clay construction device - Preparation according to points 1-7 for a concrete blind area.
- Laying a layer of clay 100-150 mm thick and compacting it. For manufacturing, you can use clay, which remained after excavating the foundation pit, but only if it is of good quality and high strength.
- The arrangement ends with the creation of a decorative layer. To do this, stones are sunk into the clay layer or pebbles are laid on top. This will create a comfortable footpath and strengthen the structure.
Clay blind area is an inexpensive and not laborious option for creating a drainage system around the perimeter of the foundation.
membranes
Construction diagram with profiled PVP membrane Before making a blind area around the house, it is recommended to consider the option of PVP membranes.
This material provides the highest degree of protection of supporting structures from atmospheric moisture.
The technology differs from the usual types of protective blind areas:
- Perform steps 1-5 for a concrete blind area.
- A layer of sand is laid, and a membrane is in it.
- Cover it all with a layer of rubble.
- Perform backfilling.
- Planting grass.
The blind area from the membrane does not come to the surface and cannot be used as a sidewalk. Its only function is reliable waterproofing. ATThe choice of material depends on the possibilities and wishes of the future owner of the house.
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 factors. environment. 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 collect 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 rubble in this case at the 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 a cement mixture or 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 buildings will have to be repaired or even refurbished altogether.
Insulated option
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 for erecting a blind area when using different materials is used almost the same. 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, climb 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. Using this procedure, the risk of cracking the tape in the future 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, you should also put a 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. On the next step 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.
The blind area around the house is a wide "tape" with a hard or bulk coating. But that's just the visible part complex design. Many perceive the blind area of \u200b\u200bthe house as a kind 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 from paving slabs
Why do you need a blind area
Among the regulatory documents, there is no separate standard, SNiP or a set of rules on how to make a blind area around the house correctly. There are several documents that define its purpose, requirements for the width and angle of inclination, interaction with other elements of the branch atmospheric waters from the site on which the building stands.
According to the regulations, there must be a waterproof pavement around the building, which is created as part of the mandatory water protection measures against local soaking of the soil in the area of \u200b\u200bthe foundation of the house.
That is, we are talking about protecting the soil, not the foundation. To protect the materials of the foundation itself, the foundation is waterproofed, because in addition to atmospheric waters, there are also groundwaters that rise high during the rainy season and during snowmelt (the so-called perch).
And the earth must be protected from getting wet, because under the influence of moisture, many types of soils (clay, loam) lose some of their bearing properties and simply cannot withstand the design load from the building. To prevent soil erosion, they arrange a blind area, which, however, also protects the foundation in parallel, 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 few ready design solutions, allowing you to mask the blind area, and when using a hard coating, use it as a track.
Beautiful blind area, turning into a path, as part of landscape design
blind area requirement
None normative document there are no requirements that would link the dimensions of the blind area with the roof overhang. Moreover, there are no requirements for exceeding the width of the blind area by 20-30 cm in relation to the projection of the removal of the cornice. When building a blind area around a concrete house with your own hands, you do not need to focus on these numbers.
The regulations provide only two minimum widths. And they depend on the soil:
on sandy - from 70 cm;
on clay - from 100 cm.
This is exactly what is stated in the manual on construction control schemes for supervisory services.
With unorganized drainage, the side roof overhangs of houses up to two floors should be less than 60 cm. If the house is on sandy soil, then the difference in the width of the blind area and the size of the roof overhang can be 10 cm, and not contradict the requirements of the regulations.
That is, it turns out that the parameter 20-30 cm is just a statement of the real ratio of two sizes for most cases. But not for everyone.
Video description
Clearly about the requirements for the blind area at home on the video:
If the soils are subsiding, depending on their type, the standards impose other requirements on the width:
I type - more than 1.5 m;
II type - more than 2 m.
And in any case, the blind area should be 40 cm wider than the sinus of the pit.
The slope angle can be in the range of 1-10%, but in the case of subsiding soils minimum angle is 3°, which is 5.2% in recalculation.
The elevation of the outer edge of the blind area above the site should be more than 5 cm.
Types of blind area
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 the device of the top coating:
Hard cover. Represents a monolithic tape from concrete or asphalt concrete. In the first case, creating a blind area with their own hands, they carry out mandatory reinforcement, in the second it is not required, due to the resistance of asphalt concrete to bending loads.
The arrangement of the base and the filling of the blind area around the house is carried out according to the same technology as for the tracks, but taking into account the obligatory requirement for the slope from the basement.
Protection against water occurs due to the water resistance of both types of concrete. Therefore, it is important that there are no cracks or breaks in the coating on the surface. The second feature is that a gap is needed between the blind area and the base, which compensates for the thermal expansion of the monolithic coating.
Concrete blind area with an expansion gap at the base filled with sealant
Semi-hard coating. They are made from paving slabs, clinker bricks or paving stones. The device and method of laying is 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 laying on a dry sand-cement mixture;
concrete monolithic base.
Semi-rigid clinker brick pavement
Soft coverage. Classic variant- arrangement of the upper layer from a compacted layer of dense (waterproof) clay. Many people know how to make a blind area of this type: they used to do it around village houses, and even now such a solution is periodically used as an “economy option” around small country houses, but with a top layer of decorative (colored) gravel. To improve the waterproofing between clay and gravel, you can lay a waterproof film. You need to understand that the blind area is not just a decor, you should not save much on it.
Crushed stone coating as an economical option
Now a new type of soft blind area around the house based on a profiled membrane is gaining popularity. The general workflow here is as follows:
The membrane is laid in a trench with a depth of 25-30 cm.
The bottom of the trench is rammed with a slope from the foundation.
On top of the membrane, a layer of filtering geotextile is rolled out to the wall of the base of the house.
Then a drainage layer of crushed stone and sand is poured, and on top of it - fertile soil, which is sown lawn grass or plant ornamental plants.
This blind area is also called hidden. This is a beautiful solution, but with a significant drawback - it is not recommended to walk on a soft surface. However, you can always additionally arrange a path.
Hidden blind area with ornamental plants
Common mistakes when creating a blind area
Mistakes can occur 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 backfilling of soil leads to "unplanned" shrinkage and destruction of the integrity of the waterproofing layer or hard surface. The same consequences occur if, due to the negligence of workers, construction debris got into the backfill.
Transverse crack in the blind area, as a result of an error
At the stage of compaction of the bottom of the “trough”, it is necessary to observe the level of the bottom of the pit and its slope. This is one of the important conditions for how to properly make a blind area around the house. Irregularities in the bottom lead to an uneven thickness of the crushed stone layer, a difference in its bearing properties in different areas, which can cause cracks in the concrete. And if the slope of the trench profile is incorrect during the rainy season or snowmelt, the top water will literally drain to the foundation from moisture-saturated soil.
Another mistake is the lack of an expansion joint between concrete blind area and plinth. At high air temperatures, internal stress forces arise in the concrete near the wall, which lead to the appearance of cracks. The same happens if transverse expansion joints are not laid or cut in the reinforced concrete blind area.
When preparing a concrete solution, it is unacceptable to use sand containing clay and dirty water. This will degrade the quality of the concrete, and reduce the 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 outside the blind area in case of leakage of shut-off valves or leaky hose connection.
Video description
Another mistake when installing the blind area on the video:
The maximum slope angle of the blind area is 10%. And with an organized drainage of water from the roof, trays should be laid under downpipes with a slope of more than 15%. This requirement of the regulations is sometimes ignored.
Determining the thickness of the blind area
On the site of a private house, concrete, prefabricated semi-rigid or soft coating is used. The thickness of the semi-rigid coating is set by the material for the blind area around the house: clinker bricks, tiles or paving stones. But the size of the concrete pavement must be calculated. At least in order to calculate the volume of the solution and the depth of the trench for all layers.
Knowing the standard width of the blind area and the minimum level of elevation of the outer edge above the site, it is possible to calculate the only parameter that is not regulated by the standards - the thickness of the hard coating, taking into account its slope.
The minimum thickness of reinforced concrete is about 70 mm - the thickness of two bars 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 on the video:
This size must be multiplied by the slope, once again multiplied by the width of the tape, divided by 100. This will be the height difference between the outer edge and the base. And now the height difference must be added 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 coating at the base is 120 mm.
Technology for the manufacture of concrete pavement
Step-by-step instruction on the topic of how to make a blind area around the house, it looks like this:
Preparation of a trench ("trough") under the blind area. The fertile layer is removed over the entire width (from 20 to 30 cm). Compact the bottom of the trench and form a slope. The area near the foundation with backfilling is especially carefully rammed, 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 coating, the thickness of the pillow (minimum 10 cm, recommended 15 cm) and insulation for the blind area around the house on heaving soils. If the trench after excavation of the fertile soil turned 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 under the blind area with a slope from the foundation
Pillow. For weak soils, the creation of a crushed stone base is recommended as the bottom layer. First, they fall asleep, level and ram the crushed stone of the middle fraction (40-70 mm). Then - small gravel (5-10 mm) to fill the voids of the previous layer. When crushed stone is compacted, it is watered. Sand is next poured, which is also leveled, watered and rammed. It is the sand according to the standards that serves as the basis for the blind area. The level of crushed stone preparation should have a maximum deviation of 15 mm per 2 m, sand - 10 mm per 3 m.
Waterproofing. A waterproofing film is laid on top of the sand. It does not serve to protect the soil, but protects the concrete from moisture loss during the period of its maturation. In the regulations, this layer is called "separating". For this, a geomembrane or polyethylene film 200 µm thick is used.
Video description
You can also use welded waterproofing - an example in the video:
Warming. 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 shift relative to the bottom seams.
Formwork. It is made from edged board and bar. At the same time, rails for transverse expansion joints are laid. Usually, these rails are mounted at the design level of the blind area with a given slope angle, and concrete is poured along them, like beacons. The width of the rail 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 the factor 25 by the thickness of the concrete at the base. Usually for concrete pavement temperature seams are combined with technological ones (one portion of filling between the rails). The expansion joint at the base is formed from folded strips of roofing material with a total thickness of about 5 mm.
Do-it-yourself installation of a blind area around a concrete house
Reinforcement. The easiest way is to lay a road mesh with a cell of 100x100 mm and a bar diameter of 4 mm. Neighboring cards (strips) are overlapped by one cell (or more) and tied with wire. The distance from the waterproofing or insulation is at least 30 mm. This size must be maintained in relation to all surfaces - the front, along the ends of the edge and relative to the base.
Concreting. Use concrete M200. After pouring, within four hours, the concrete must be covered. And for 14 days - moisturize.
Protection against destruction. To improve wear resistance and surface strength, ironing is carried out. There are two types: dry - after pouring, wet - simultaneously with filling expansion joints with sealant. After removing the rails (14 days after pouring concrete), the seams are filled with bituminous mastic with the addition of mineral filler.
Note. As a reinforcement of the surface and giving an attractive decorative look, you can use the technology of stamped concrete.
Stamped concrete from the blind area to the walkway
If the blind area needs repair
If the concrete began to collapse, then, depending on the degree of damage, the recovery technology has the following form:
with a local character (up to 30% of the surface) and narrow cracks - they are poured with cement paste (the proportions of cement and water are 1: 1);
at local repair and wide cracks - they are embroidered, visible reinforcement is treated with an anti-corrosion compound, sealed with a repair polymer mortar;
when crumbling and delamination - weak areas are cleaned and a screed layer 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, treated with a deep penetration primer.
As a summary. It is important to remember that the blind area is only part of the water protection measures. The most effective blind area in conjunction with storm sewer when water is collected in special receivers and piped away from the foundation.
Storm sewer system
As a result, the foundation will receive reliable protection not only from rain or melted snow, but also from groundwater.
And we hope you got answers to your main questions - how to make a blind area around the house and to whom to entrust it.