Do-it-yourself blind area: step-by-step instructions and installation nuances

A blind area must be made to the foundation of any building.
It protects it from dampness, freezing, and cracks in the walls. The better the quality of the pie, the longer the foundation will last, because most often it is destroyed precisely because of moisture, from which the blind area saves.

In this article we will talk about the correct arrangement of the blind area around the house.

Construction of a blind area around the house

The structure of the blind area around the house is quite simple and consists of two main elements: a substrate and a covering. The main role of the substrate is to create a smooth and durable base for laying the protective coating. Typically, the substrate is two layers of clay or sand and crushed stone. The good thing about using clay is that it can perform a waterproofing function and not allow moisture to pass through, but to do this it will need to be laid well and the layer must be uniform. Sand is easier to use, as it can easily smooth out any unevenness in the soil surface.

Simplified design diagram of the blind area

Any suitable materials that have the following properties can be used as a coating:

Have sufficient strength to withstand expected mechanical loads.
They have high-quality waterproofing properties.
Resistant to sudden temperature changes.
Thanks to the smooth surface, they are able to efficiently remove moisture from the foundation.

Therefore, concrete, asphalt, stone or tile coverings are mainly used for blind areas.

Related article:

How to make a blind area around the house with your own hands? We will tell you about competent design and installation in a special publication on our portal.

Consequences of non-compliance with construction rules

The blind area serves as protection for the foundation from snow, moisture and freezing. But this is provided that all the rules are followed and the creation is approached wisely. Otherwise, all this can have dire consequences:

One of the main mistakes is incorrect calculation of the width of the pie. If the path is too narrow, it will cease to fulfill its function and water from the roof will begin to erode the soil. The width should be at least 25 cm greater than the roof overhang.
The second mistake would be creating a slope that is too small, because... it must be done at least 10%. Otherwise, water will accumulate there, and the blind area will not be able to remove excess moisture.
The third mistake is lack of insulation. The foundation may freeze and crack along the entire perimeter.
An extreme mistake is the lack of proper protection from water. It will get inside and also destroy the foundation.

When constructing a structure, you cannot save much, as this can lead to undesirable consequences. It is better to purchase quality materials and hire good craftsmen.

The most important and useful information on the construction of blind areas is collected in this section.

Photo of the blind area around the house: main types of structures

When designing photos, blind areas around houses will greatly simplify their selection. There are these types of structures:

Tough. They are structures based on hard coatings that, under load, retain their shape without deformation. Usually made of concrete or asphalt. Their service life is usually compared with the duration of operation of the building. In terms of installation cost, rigid structures will be more expensive than others, as they require mandatory insulation and waterproofing. Requires medium or high density soil for installation.

Scheme of a rigid blind area

Appearance of rigid structure

Soft. They are distinguished by simple installation technology and minimal operating requirements. In fact, it consists of several layers of bulk materials. Requires minimal cost and physical effort to install. The service life is on average 5-7 years. They can be laid on any type of soil, including loose ones. They are used mainly for temporary purposes, since their appearance is not entirely aesthetic and is unlikely to fit into the design of the building facade.

Scheme of soft blind area

Soft design appearance

Semi-rigid. They represent a compromise between hard and soft structures in terms of financial and physical costs. The outer layer is usually laid with tiles, stone or reinforced concrete slabs. The service life can be up to several decades. They have excellent maintainability, since part of the structure can be replaced or rearranged without any problems. However, they are limited for use in areas with high groundwater, on soils with large freezing depths and on heaving soils. The cost of installation work will be cheaper than hard work, but the highest quality aesthetic appearance will be achieved.

Semi-rigid blind area diagram

Appearance of semi-rigid structure

Practicality

A blind area arranged along the border of a building or house, the drawing of which will show that it can be used as a pedestrian zone. There is a need to cover the blind area with a road surface.

If the owner of the home plans not only active walks on foot, but also possible travel by car along a certain part of the blind area, the layers of the blind area need to be increased with additional coverage that will correspond to the heaviest loads imposed, taking into account the operating conditions of the facility.

Determining the parameters of the blind area

In order to understand how to properly make blind areas around houses, you need to correctly select its technical parameters. One of them is width. It is determined by the current building codes and regulations, which state that it must be 20 cm longer than the most protruding part of the roof slope. Usually this size is measured from the gutters. The width of the blind area around the house is determined based on the selected type of material, the density of the soil on the site and the magnitude of the expected variable and static loads. In most cases, the width of the structure for private houses is made at least 1 m.

Another parameter is the degree to which the structure is buried in the ground. It is mainly influenced by the level of soil freezing. In regions where there is a significant decrease in air temperature, the structure is significantly affected by soil properties such as heaving, which can damage it literally within a year without the possibility of recovery. Therefore, the filling level must provide sufficient strength so that it effectively resists heaving and does not deform. The minimum depth is at least 10 cm, including a layer of sand and crushed stone cushion. If constant loads are expected, it is recommended to increase the thickness to 15-20 cm.

Sketch of the blind area with size designation

Helpful information! Where the porch adjoins the house there is no particular need to lay a blind area, since the main foundation in this case will be protected. However, if a monolithic or brick porch is built, it is recommended to protect it too, since the weight per unit area is quite large and the likelihood of subsidence is high.

For high-quality sediment removal, the surface must have a certain slope. The magnitude of the angle to the horizontal, on the one hand, is influenced by the amount of precipitation in a particular region, and on the other hand, by the ease of using the structure as a pedestrian path or for other purposes. A value of 2-3° is considered optimal.

In order to prevent flooding of the structure, it is recommended to make it 5 cm higher from the ground surface. If there are trees or bushes near the house, you will need to uproot them to a distance of approximately 1.5 m from the house.

Attention! You can protect the structure from destruction by the roots of trees or any plants by installing a border.

Angle of inclination and ironing

Do not forget about the slope of the blind area, which should be uniform and not very noticeable. It is done away from the house. The angle of inclination of the blind area, recommended by experts, should be 25 mm for every 1 m of the structure.

It is necessary to slope the blind area while laying the clay layer. It is then that a uniform slope of the structure will be obtained, which will retain its functions, but will not be visible from the outside.

Be sure to iron it at the last stage, after pouring the structure. The technology is quite simple:

uniform filling of wet concrete with dry cement;
leveling with a spatula over the entire surface;
covering the finished structure with oilcloth to protect it from external influences while the solution completely hardens.

For the structure that should be made of tiles or paving stones, ironing technology is not used.

It is imperative to remember that expansion joints remain between any structure and the foundation of the building. They are sealed with special insulating materials.

Preparatory work

Preparation for installation is carried out in several stages:

Marking the territory.
Carrying out earthworks.
Laying the underlying layer.

We mark out the area for installation of the blind area

Using pegs around the perimeter of the house it is necessary to mark. To do this, use a tape measure to measure a distance of 1 m from the walls and drive wooden pegs into the corners to a depth of 0.5 m so that it is possible to carry out excavation work without moving them from their place. We pull a rope on them.

Helpful information! If the building has a large area, it is recommended to install additional pegs along the walls every 2.5-3 m.

Marking the area for the blind area

Excavation stage

Using a shovel, you need to dig a trench according to the markings. The depth is determined by the type of structure chosen, climatic conditions and soil composition. The layer should be removed evenly with a slope of 2-3° from the building. This is quite easy to do by setting the digging depth along the building and along the marking line.

Digging a trench

Since the main foundation and the structure of the blind area will have different coefficients of thermal expansion, it is recommended to create a thermal gap between them of 1-2 mm. To do this, after stopping digging, you need to lay a damping layer based on polyurethane tape along the wall.

The bottom of the trench should be carefully compacted with a special tool, which is a steel rod with a flat sheet welded on the lower end. If such a device is not at hand, then you can use a regular log.

Laying a pillow under the blind area

It is necessary to lay waterproofing at the bottom of the prepared trench and fill it with a layer of sand 10-20 cm thick, depending on the type of structure and the depth of the trench, with careful compaction and leveling. For ease of work, it is recommended to spill the layer generously with water in order to compact it as much as possible. However, before laying the outer layer, you will need to wait until the pillow dries.

Laying waterproofing followed by backfilling and compacting sand

Important! If construction is carried out in an area with high groundwater, a drainage system will need to be installed. It is a pipe with holes in the upper part, which is located around the perimeter of the building and is connected to the storm sewer system.

It is necessary to pour gravel with a fraction size of up to 5 cm on top of the sand, and level the top layer with crushed stone with a grain size of up to 5 mm. This will save building material on the outer layer due to the absence of the need to fill the pores formed.

A layer of crushed stone is laid

Helpful information! Crushed stone can be replaced by other types of stone or even broken bricks. The most important thing is to use a homogeneous material so that areas with different strength characteristics are not created.

The main mistakes of individual developers

When constructing a buried foundation for a house on a site, a foundation pit is torn off, the cavities of which are later filled with inert materials. To make your own shallow or non-buried foundation on clay soil without violating the joint structure, it is necessary to carry out a set of measures to reduce heaving forces. Therefore, the heaving soils of the base are replaced with an underlying layer of crushed stone or sand.

In any of these options, a technogenic zone is created in which perched water inevitably collects, since the permeability of non-metallic materials in the underlying layer and filled-in sinuses is much higher than that of natural soil. Therefore, any moisture near the base of the dwelling will accumulate underground and destroy concrete structures. The blind area should be wider than the openings of the pit and the roof overhang, and a storm drain (troughs, gutters, point storm drains) should be integrated into its outer edge.

When making a blind area with your own hands, an individual developer often makes mistakes:

clay castle - this material really does not allow water to pass through from the outside, but absorbs it and sharply increases in volume when it freezes, resulting in the destruction of the concrete screed or asphalt;
insufficient width - in the absence of a roof drain, water flows easily erode the soil near the edge of the blind area, penetrate into the ground, and cause damage to the foundation of the house, in the concrete structures of which multiple cracks open;
rigid connection of the blind area with the foundation - residual heaving forces cannot push a heavy floating slab, MZLF tape or grillage pillars to the surface, but easily lift the blind area, which tends to tear the foundation or tilt it;
the lack of insulation is especially important for temporary and seasonal housing, houses with joists, since the soil adjacent to concrete structures freezes and swells.

Be sure to make expansion stitches.

The existing opinion that the blind area should be created at the stage of landscaping or landscaping after the construction of the building frame and roof is completed is erroneous. Even during the construction season, heavy rainfall is possible. With “long-term construction,” the foundation remains unloaded in the winter. These factors negatively affect the service life of the underground structure, so the blind area should be poured immediately after completion of the zero cycle, waterproofing and insulation of the outer edges of the tape, slab or grillage pillars.

A properly manufactured blind area should be adjacent to the foundation through a damper layer. A special elastic tape must be installed between these structures.

How to properly make a blind area around the house?

The installation process depends on the type of structure and the selected material. For example, when installing a soft structure, no additional work will be required, but when installing a hard one, you will need to lay several waterproofing layers. How to carry out installation correctly will be described in the following subsections.

Installation of a rigid blind area

It is recommended to install a rigid structure on a heat- and waterproofing layer, which will significantly extend the life of the structure. For these purposes, it is recommended to use heat-insulating materials that are highly resistant to moisture and have increased strength under significant mechanical loads. An example would be expanded polystyrene or foam boards.

Installation of formwork and waterproofing

Attention! Before laying the insulation, it is necessary to install formwork, for which it is recommended to use boards lined with a waterproofing film from the inside. This solution will prevent the absorption of moisture from the subsequently poured concrete solution and it will be able to gain design strength. Otherwise, the dehydrated parts will become brittle and the service life will be significantly reduced.

To understand the technology of pouring a blind area around a concrete house, how to make formwork and what sequence of actions to follow, you need to read the step-by-step instructions. It looks like this:

We install the first slab from the corner of the building along the wall, checking the correct position using a building level.
We fix the insulation onto a suitable type of fastening, pressing it tightly against the wall.
We install the next one butt to the first plate with a minimum gap.
We secure the slab and carefully seal the joint with construction foam.
Similarly, we lay the entire perimeter of the walls with heat-insulating material.

Attention! If the blind area is installed in the northern regions, then it is recommended to lay two layers of insulation with ligation of the joints of the two layers. This will avoid the formation of cold bridges.

Installation of polystyrene foam boards

Before pouring concrete into the formwork, it is necessary to lay the reinforcing mesh. For these purposes, ready-made meshes with a rod diameter of 8-10 mm and a cell size of 10-15 cm are used. It is important to lay them in such a way that the steel rods are in the concrete layer. To do this, you need to use special plastic supports.

It is recommended to fill the structure with concrete mortar grade M400 or higher, and at one time, so that the structure acquires maximum strength. Therefore, you need to calculate the approximate volume in advance and order the solution in the required quantity at the cement plant.

Pouring concrete

When pouring, it is important to create a uniform layer, for which you carefully smooth the concrete over the surface using a shovel or mop. Additionally, the solution must be stirred to remove air bubbles from the layer. After driving the layer to the level of the edges of the formwork, it is necessary to level the surface as a rule. The side parts of the formwork will serve as guides.

Leveling the blind area

At the final stage, the surface of the blind area must be sprinkled with a thin layer of cement. To ensure ideal conditions for concrete hardening, you will need to cover the entire top part with a layer of polyethylene. Every day it is necessary to moisten the surface with water. The curing time is 28 days depending on the temperature and humidity of the environment.

Installation of the rigid blind area is completed

Installation of a soft blind area

The soft blind area around the houses is laid on a waterproofing layer laid on top of a sand cushion. It is recommended to use rubemast as an insulating material, which has an increased service life. Laying is done overlapping at a distance of 10-15 cm not only along the main surface, but also on the walls of the main building. The connecting seams are sealed with bitumen under the heat of the burner.

The laying of the crushed stone blind area is completed

On top of the waterproofing it is necessary to pour a 10 cm layer of a dry mixture of sand and crushed stone in equal proportions. Then the surface should be thoroughly compacted and leveled. In this case, it is imperative to maintain the angle of inclination. Another layer of crushed stone with a grain size of no more than 5 mm is laid on top of the embankment and also compacted.

DIY semi-rigid blind area: step-by-step instructions

Is it possible to create a semi-rigid structure on your own in the absence of suitable experience? The task is completely solvable and you can create a reliable blind area with your own hands - step-by-step instructions will allow you to go through all the stages without errors. It is installed directly on a prepared sand-crushed stone cushion, on top of which an additional layer of sand 8-10 cm thick is poured. To paving paving slabs, it is necessary to study the layout of the elements in advance, and also choose the direction of laying. In this case, the layout can be absolutely any and not limited by anything. The main requirement is to create joining seams that are minimal in thickness.

The installation technology step by step is as follows:

The first tile is placed on the leveled base.
Using a mallet, its surface is gently tapped to ensure reliable fixation.

Laying tiles with leveling

It is necessary to control the angle of inclination with a level to prevent distortion.
The next tile is placed end-to-end with the previous one.
To level, it is necessary to lay a wooden plank on the surface of the tiles and, by tapping, achieve their correct location.
If there is subsidence in one of the corners of the tile, then you need to add a little sand and repeat the leveling using a mallet.
If you need to cut tiles for laying under the wall of a house or along a border, you need to use a grinder.
We lay paving slabs over the entire area of the blind area.

Laying tiles on the blind area is completed

Kinds

A soft blind area will add a little warmth to the design than cold and austere stone or tiles

Based on the type of surface, a distinction is made between hard and soft blind areas. The first is made of concrete, sandstone, asphalt concrete and other materials that ensure the strength of the coating. The second is made from mulched soil or soil with lawn grass, crushed stone or paving slabs.

Pros and cons of a hard blind area

The advantages of a solid blind area are its strength, maintainability and durability. But the disadvantages are that, being laid directly on the ground, it is exposed to negative effects at the moment of freezing and thawing of the water in it. This gradually leads to the destruction of the foundation and moisture entering the house.

You can avoid exposure to moisture by regularly carrying out repairs and sealing cracks.

Advantages and disadvantages of soft

Soft blind areas are increasingly used in construction, as they have several advantages over hard ones:

It is not afraid of seasonal vertical shifts of the soil caused by the freezing and thawing of water at its base. There are no cracks in it through which moisture can enter the foundation, destroying it. It does not need to be constantly repaired, wasting effort, time and money on it.
The technology for laying it is simplified, since you don’t have to adhere to the slope from the walls of the building.
It is distinguished by its practicality and aesthetics. A successful choice of external covering - gravel, crushed stone, flowers, climbing bushes or lawn plantings - makes a building with such a blind area spectacular and original.

The only drawback of a soft blind area is the need for constant care. Lawn grass will need to be trimmed, weeds that have grown through the rubble will need to be removed, and decorative backfill will need to be cleared of debris.

Concrete blind area is ideal for our climate

How to repair a blind area?

The blind area around the house, if you do not know the nuances of laying technology, how to properly pour concrete or lay tiles, will certainly contain defects that will emerge sooner or later and require repair work. Restoration is carried out depending on the degree of damage:

If there are cracks no larger than 1 mm, repairs are not required, since they are not critical and will in no way worsen the performance characteristics of the structure.
If the crack size is up to 3 mm, then it is recommended to use water-cement mortar in equal proportions. After the solution dries, a durable layer will be created that will provide maximum protection to the building foundation.
For cracks up to 3 cm, it will be necessary to fill them with concrete mortar, having previously cleaned them of dirt and treated them with a deep penetration primer. It is also possible to use waterproof putties or sealants.

Sealing cracks in blind areas up to 3 cm wide

Cracks more than 3 cm - it is necessary to study the strength of the structure and evaluate its maintainability. It may be necessary to remove part of the top layer and level the pillow. After making sure that the structure has sufficient load-bearing capacity, concrete should be poured.
The crumbling of the blind area is eliminated by applying a water-cement composition to the surface in order to strengthen it.

Causes of cracks

Destruction and displacement of the blind area can be observed in old houses and in new buildings.

Main factors:

Ignoring waterproofing. The main destructive factor is moisture from precipitation. If you forget about waterproofing during the construction of the foundation and the construction of the sidewalk surface, the structure will constantly become wet.
Incorrect backfill. The construction of a basement sidewalk begins with the laying of a kind of cushion of sand and gravel. If this layer is poorly compacted, the decorative coating will not adhere firmly.
Weather. It is not advisable to make a blind area in heat, rain and frost, since building materials behave differently in appropriate conditions. This does not affect the strength of the structure for the better.
Violation of technology in preparing the solution and pouring it. Too much cement or not enough cement leads to rapid cracking of the structure. The lack of reinforcement reduces the strength of the structure.
When constructing a blind area, you cannot use material for interior work or fill the structure with already set mortar.
Damper seam. There must be a damper joint between the plinth and the sidewalk, which prevents the structure from being destroyed by soil movements.
Destruction from time. If the paving surface is not new, has served for decades and has gone through many freezing cycles, the appearance of cracks is inevitable. And over time, any crack without proper attention turns into a trench.

The sidewalk can collapse due to uneven shrinkage of the building. Shrinkage is a necessary phenomenon in any new building.

Materials

To make a blind area, you can use a variety of materials, it all depends on their cost. In each specific case, a variety of types of materials are used. Reinforced concrete is most often used.

The cushion, formwork, and reinforcing mesh are filled with concrete. It is very important to correctly position the reinforcement in the concrete foundation. For this purpose, it is raised slightly. For the production of concrete, it is better to use cement grade “M 400” and higher.

Proportions – 1/5/2 crushed stone, cement and sand, respectively.

Sometimes builders use ash, which is formed after the combustion of coal, to build a blind area. The cost of such a product is quite affordable. Ash requires very careful handling, as it is sometimes radioactive, which can pose a threat to human health, especially those living in a private home.

After the concrete solution has completely hardened, waterproofing is applied and a coating for insulation is laid. For coating, you can use FEM or granite paving stones.

FEM is distinguished by its appearance and high quality.

Acid-resistant bricks are considered the highest quality, the cost of which is in the affordable price segment.

Table of characteristics of acid-resistant bricks

This material is able to withstand climate changes and heavy loads.

Conventional FEMs do not have great strength; their soft base reduces their service life. After just a few years they lose their original beauty. Various types of such bricks are designed for 10 years of operation. However, walls made of such bricks provide excellent insulation to the entire building.

Norms

The main task of the drafters of any standard is to propose solutions that will avoid a decline in the load-bearing characteristics of structures. The use of sufficiently elastic insulating materials is mandatory. If a prestressed structure with crack resistance levels 1 and 2 is created, the gap between the expansion joints must be calculated taking into account the calculated crack resistance. SNiP provides for the mandatory use of cement not lower than M400. If seams with an opening of less than 0.5 mm are cemented, then special low-viscosity solutions must be used.

Inspection and acceptance of work areas is carried out strictly before finishing. The compensating layer must be adjacent to the entire wall of the house. By default, fastening is provided along the perimeter of the cross boards. Their thickness should be 2 cm, and the pitch should be from 1.5 to 2.5 m.