When building your own home, it is important not to miss the smallest details that can affect the safety of operation and the durability of the structure. To an expert, some element may seem insignificant, but with a more careful study of the issue, without it the building will bring many problems during operation. One of these inconspicuous defenders of the structure is the blind area around the house.
What is the blind area
The blind area of the house is a wide strip along its perimeter. The design must be made of durable materials that can withstand the load of a person’s weight and not collapse when exposed to adverse atmospheric conditions. The construction of the blind area is quite simple, its device can be handled independently.
What is the blind area for?
This structural element performs several functions, but was originally intended only for one - the most important one. The blind area around the house is needed in order to solve the following problems:
- Creating the architectural appearance of the building. The design gives the facade completeness, and when using decorative materials, it can become its decoration.
- Installation of a pedestrian zone around a residential or administrative building. The construction is made of durable materials that are resistant to stress and external influences. Walking around the house on the ground can be inconvenient, because in the autumn or spring, the soil is very saturated with water and slush appears. At this time, the blind area is an indispensable element. The track allows you to move around the perimeter of the house without serious inconvenience. It is important to be careful when walking along the blind area in winter, when snow or ice can fall from the roof.
- Waterproofing the foundation. This is the main purpose of the blind area. For structures, building supports provide several degrees of protection against various types of moisture. The foundations are protected from groundwater by vertical waterproofing and a drainage system. To reduce the load on these types of waterproofing, they prevent rain and melt water from entering the ground in the immediate vicinity of the building. The blind area takes on this function.
- Foundation insulation. If the supporting structures of the house are laid above the freezing depth, warming is necessary to prevent frost heaving forces. Warm construction protects the soil from freezing.
Based on the foregoing, to the question why a blind area is needed, one can answer: for waterproofing. But this does not prevent her from performing additional functions. If you can do without a path around the house, and the incompleteness of the facade will not cause destruction, then insufficient waterproofing of the foundation will lead to disastrous consequences, which include:
- flooding of basements, socles and technical undergrounds;
- the formation of mold, fungus and rot, which lead not only to damage to the supporting structures, but can also cause various dangerous diseases in humans (children, the elderly and those who have health problems suffer the worst indoor climate);
- violation of the interior decoration of the premises located in the basement, additional costs for repairs (if the waterproofing problem is not eliminated, the repair will become a systematic measure);
- water leads to the destruction of the supports of the house, their bearing capacity decreases, the likelihood of cracks, shrinkages and deformations increases;
- if groundwater has aggressive substances in its composition, the danger to the foundation increases several times.
From this we can conclude: it is easier to spend small funds during construction than to fix the problem later.
In addition, the installation does not require high labor costs and can be performed independently.
Regulatory requirements
Before the device, it is important to familiarize yourself with the regulatory documentation on the issue. To effectively perform the function, the design must meet two parameters:
- width;
- bias.
The requirements that the blind area around the house should satisfy include:
- They are made from materials that do not allow water to pass through.
- If the soils on the site have good strength characteristics, then the width of the blind area around the building is taken more than the departure of the cornice by 20 cm. This is necessary so that water dripping from the roof falls on the path and is diverted beyond the boundaries of the development spot. The minimum recommended width in this case is 80 cm.
- If unstable soils with high mobility and prone to subsidence occur on the site, the minimum width is 90-100 mm.
- The slope of the blind area is determined depending on the material for its manufacture. The blind area of the foundation, made of piece materials, such as brick, gravel, cobblestone, must have a slope of at least 5%. If the structure is poured from concrete or asphalt concrete, such a solution needs a smaller slope, the optimal value of which is in the range of 3-5%.
- The distance from the blind area to the wall of the house is 20 mm. This is a deformation seam. It is necessary because of the following phenomenon: during operation, foundations sag a little. At the same time, the massive building and its light protruding parts give different shrinkage. The same seam, for example, is needed when building the porch of the house and entrance groups. If it is not foreseen, the part of the blind area, which is located closer to the house, will sag with it, and the remote will settle more slowly. This will lead to a violation of the slope (in fact, the element will cease to fulfill its function) and to the appearance of shrinkage cracks (decrease in waterproofing ability and violation of the first requirement in the list presented).
Percentage slope is the ratio of height to width. For example, a slope of 5% means that for every meter of the width of the structure there must be 5 cm in height. In this case, the slope is provided in the direction from the building, that is, the highest point should be located against the wall of the house, and the lowest, at a distance from it.
If it is planned to erect columnar or pile foundations in the area with strong soils, you can neglect the blind area. It is important to pay attention to the drainage system. There may be two options:
- internal drainage;
- an external organized gutter with drainage pipes that divert water into a rain sewer or behind a house stain;
- outdoor unorganized drainage.
In the latter case, it is necessary to lay a waterproof coating in places where water flows to the ground. In the first two cases, no additional measures are required.
Types of blind areas and construction
The correct construction of the blind area can be made of many materials. When using each type, it is important to follow the layer order and technology.
The main types of blind area:
- clay;
- cobblestone;
- ceramic brick;
- concrete;
- asphalt;
- paving slabs;
- PVP membranes.
Further about each in detail taking into account features and design.
Clay construction
Clay is a proven material that is used by builders not even hundreds, but thousands of years. The term "clay castle" is common among builders. The advantages of this material include:
- low cost - you can not buy materials for the work, but find it yourself (if there is good clay at the construction site, raw materials can be found in the foundation pit, which is torn off during the construction of foundations, this will reduce costs not only for purchase, but also for transportation);
- high degree of protection;
- simplicity of the device.
The construction of the blind area is as follows (all layers are presented from the bottom up):
- compacted base soil;
- drainage and leveling layer (crushed stone, gravel or coarse sand), laid with layer-by-layer compaction, thickness 30-50 cm;
- a clay layer 100-150 mm thick;
- for strengthening in clay they heat stones;
- top decorative layer (pebbles, stones).
Between the blind area and the foundation, a waterproofing layer is required. The top coating of pebbles or stones will give not only a decorative effect, but also will not allow clay to erode during the off-season. This will ensure cleanliness around the house and the possibility of using the blind area as a sidewalk.
Production of piece materials
This category includes brick, paving slabs, cobblestones. The finished design is quite reliable in waterproofing pallets. At the same time, the appearance allows you to decorate the facade of the building and perform rather unusual architectural decisions. It will be convenient to walk along such a path at any time of the year.
To increase reliability, a clay lock is provided on the compacted soil layer, which retains moisture, even if it passes through the material.
Additional advantages of such materials include the fact that if access to storm sewers and drainage is required, the blind area is easily disassembled. After inspection or repair of utilities, the parts are simply installed in their old place.
Concrete and asphalt
Everyone could see such a design. Concrete and asphalt are the most common materials in the construction of apartment buildings, administrative and public buildings. The cost of the element is quite low, even a layman is able to perform the work, having familiarized himself with the technology.
But there are several drawbacks due to which it is better to choose another material for your own home:
- unpresentable appearance and lack of choice in texture or color;
- the likelihood of cracking with time;
- the need to wait for time after pouring concrete to gain strength (under normal conditions, the process will take 4 weeks if the temperature during pour time drops below +20 degrees Celsius; the estimated time increases);
- the need to manufacture the formwork into which the mixture will be poured (additional costs for the purchase of boards and an increase in the complexity due to preparatory work).
But this type of construction is extremely attractive in price, so it does not give up its position in mass construction. Provides the necessary waterproofing while observing the pouring technology.
PVP membranes
Modern type of waterproofing coating. The technology of its laying differs from other options.
If all the previously presented methods, the implementation of the waterproofing strip along the perimeter of the structure was made of durable materials and could serve as a pavement, then PVP membranes are used only to remove moisture.
The material is not laid on the surface, but in a layer of sand on compacted soil. The whole element pie is located underground, and a backfill is made on top and a lawn is planted. This species can be safely called an invisible foundation assistant.
The disadvantages of the method include the lack of sidewalks around the house and the relatively high cost of the material. It is suitable if it is required to provide a high degree of waterproofing, but there is no need to ensure passage along the perimeter of the structure, since the lawn in this case reaches the very walls of the house.