How to make a blind area around the house yourself?

What is the purpose of a blind area?

In general, a blind area is a waterproof covering in the form of a path that is laid around the house and adjoins its walls. When it rains and snow melts, water drips from the roof, runs down the wall, penetrates the soil surface and accumulates directly near the foundation and basement.

The effect of moisture on concrete leads to cracking and gradual destruction of the material. The blind area ensures the removal of precipitation water from the walls of the house to a safe distance, where the water freely flows into the ground without contacting the structural elements of the building. If it is combined with a drainage system, then full protection of the structure is ensured.

In addition to its main purpose, the blind area can perform additional functions:

• provides insulation of the soil adjacent to the house, protecting it from freezing in winter. This helps to reduce the cost of heating the basement;
• acts as a pedestrian path around the entire perimeter of the house, which means there is no need to lay additional sidewalks;
• finally, it also plays a decorative role, giving a finished look to the entire structure.

Requirements and characteristics

Taking into account the tasks to be solved, the following requirements are imposed on the blind area:

• waterproof coating;
• the dimensions and design must ensure the drainage of water to a safe distance;
• the coating must be durable, allowing you to move along it, and resistant to external atmospheric impacts;
• attractive appearance.

When properly arranged, the blind area copes with the tasks set and provides reliable protection for a private house and any auxiliary structure on the site. It is important to follow certain rules when erecting it with your own hands:

1. Width of the blind area. Since it ensures the removal of precipitation to a safe distance, this characteristic is one of the most important parameters. Building regulations require that the width extends beyond the protruding edge of the roof by at least 20 cm. As a rule, the size is counted from the location of the drain. In addition, the correct choice of width depends on the coating material, type of soil, size of the structure, intended use and possible mechanical loads. As a rule, for a private house it is at least 1 meter.
2. Depth. When choosing this parameter, it is important to take into account the properties of the soil. When heaving soils freeze, they create loads that can deform the blind area and cause cracks to appear around the perimeter of the house. On weakly heaving soils, the required strength of the coating is already ensured with a blind area thickness of about 10 cm (including the cushion). With highly heaving soils, it will have to be increased to 20–25 cm.
3. Forming a surface slope. In order for water to quickly flow off the path, the blind area must be made with a slope away from the wall of the house. The optimal value is considered to be 3–4 degrees. Such a slope ensures gravity flow of water and does not hinder a person’s movement along the blind area.
4. Rise above the ground. If the blind area is located at ground level, flooding will occur during heavy precipitation. This can be avoided by changing the heights of the bookmark. The lower edge should rise at least 5 cm above the ground.
5. Expansion gaps. It must be left between the blind area covering and the wall of the house. The gap eliminates the occurrence of loads during thermal expansion of materials. If it is absent, a load may appear in the contact zone that can cause concrete cracking. The width of the gap is usually about 10 mm. This requirement makes it necessary to make a blind area around the house only after finishing the walls. In addition, it should be taken into account that the gap is a channel for water seepage to the foundation, which means it should be covered from above. Usually, a small canopy is provided in the basement finishing for this purpose, stopping water from flowing down the wall surface.

When arranging the structure with your own hands, it is important to remember that the blind area around the house must be protected from the roots of large plants (trees and bushes). They should be uprooted at a distance of at least 1.5 m from the edge of the coating.

The device of the blind area implies the presence of two main elements. The lower part is the substrate. It is the base of the upper coating and is designed to level the surface, eliminate subsidence of the coating and the negative impact of the soil below. A simple version of the substrate is 2 clay layers. Clay is a good waterproofing material that protects against moisture penetration, but its strength characteristics do not allow it to be used under significant loads. Most often, the substrate is made by filling with sand and crushed stone (gravel). A well-compacted base layer can prevent the coating from deforming.

The outer coating is laid on top of the blind area. Depending on its design, the blind area can be divided into the following types:

1. Hard. The coating forms a hard, durable path. Common options are asphalt and concrete blind areas. The main advantages are strength, resistance to atmospheric influences, durability comparable to the durability of the foundation. Disadvantages are increased cost and the need for insulation and additional waterproofing. Hard coating is the most common for private houses.
2. Soft blind area. This is a simple and inexpensive way of arrangement. For this, several layers of bulk materials are laid. The design includes waterproofing made of roofing felt, which must be laid on top of the substrate. Then, a dry mixture of sand and crushed stone is poured in equal proportions. The layer thickness is 10 cm. Fine gravel is poured on top (the size of the elements is no more than 5 mm). Soft blind area has a short service life (up to 7 years) and is usually used as a temporary drainage system. In addition, its appearance does not correspond to designer fantasies.
3. Semi-rigid. They have the most attractive appearance. The coating can be made of paving slabs, paving stones, stone, reinforced concrete slabs. This type of blind area can be made on low-heaving soils and provided that groundwater is deep. The durability of the coating is several decades. The technology is quite labor-intensive, but the owners are attracted by the aesthetics and the possibility of using various design solutions.

In some cases, an insulated blind area is arranged. It is advisable to build it around a residential building with heating for energy saving. In fact, this is a rigid structure in which it is additionally necessary to lay thermal insulation materials under the outer coating. Insulation can be provided by foam plastic or extruded polystyrene foam.

What is the best material to use?

When choosing materials to create a blind area around a house, experts give the following recommendations:

1. Sand. It is necessary for laying the base. Quarry and river varieties are best suited.
2. Crushed stone. You can use different fractions. Fine crushed stone up to 5 mm in size is suitable for backfill. When laying the compacted layer, elements up to 20 mm are recommended. For large-scale construction (large structures), fractions over 40 mm are used. The crushed stone elements themselves can be acute-angled, flat, cuboid or wedge-shaped.
3. Clay. This is an inexpensive material for laying the first layer of waterproofing.
4. Rubber crumb. It produces a high-quality soft coating. This structure is made of two bulk layers, between which a fiberglass mesh should be installed. You can use ready-made roll material 30-60 cm wide.
5. Geomembrane and geotextile. These materials can act as a filter, freely passing water, but preventing sand from migrating from the substrate. You can use geotextile brands such as Tefond, Izostud, TechnoNIKOL.
6. Asphalt. It produces a fairly strong, smooth surface that can be used as pedestrian paths.
7. Concrete. When making concrete for blind areas, it is recommended to use a mixture of cement grade not lower than M200 (most often, M300 is used). Cement-sand mortar is prepared in a ratio of 1:3 or 1:4. If increased strength is required, reinforcement is made with a steel mesh with a wire diameter of 4-6 mm.
8. Expanded clay and ceramic concrete. They will help to create an insulated blind area. In the first case, a soft structure is made. Ceramic concrete, which is a mixture of concrete and expanded clay, allows you to form a hard coating with thermal insulation properties.

To enhance the decorative effect, the coating can be made of ceramic or paving slabs, paving stones. They can be laid on a compacted bulk substrate or on top of a concrete fill.

How to make a blind area with your own hands?

Most often, when building private houses, a hard type of blind area with concrete pouring is arranged. The procedure is described below.

Step-by-step instructions

So, the stages of work:

1. Preparatory activities. At this stage, the blind area scheme, its dimensions and technological methods are selected. The place for its arrangement is cleared of construction waste and leveled. The roots of large plants are uprooted.

2. Marking the blind area. The reference point is set along the most protruding edge of the roof. A perpendicular is lowered from it to the ground surface and about 20 cm is retreated. A simpler method is often used.

Using a tape measure, 1 m is measured from the wall of the house and stakes are driven into its corners. When making a blind area around a large house, markings with stakes are made every 2.5–3 m. A marking cord is stretched between them, indicating the boundaries of the upper covering.

3. Earthworks. To install a blind area around the house manually, using shovels, it is necessary to dig trenches to a depth of 15 to 30 cm along the entire perimeter of the house. The depth must correspond to the project. The trench boundaries are oriented according to the markings. To form a damper gap, a polyurethane foam film is applied to the wall of the building. The bottom of the trench is carefully compacted and a slope away from the wall of the house is formed.

4. Laying the base. It is formed in the form of a complex, layered structure. Geotextile, waterproofing, a 10-15 cm thick layer of sand, a crushed stone layer of the same thickness and a second layer of waterproofing are laid in turn.

Sand is poured with water during laying for good compaction. When creating a crushed stone layer, a certain order is observed: first, large fractions are poured, and crushed stone with elements less than 5 mm is placed on top.

5. Installation of the base of the rigid coating. First, it is necessary to install the formwork, which will help to raise the level of the blind area above the ground. Formwork made of wooden boards is installed along the lower border of the concrete coating. It must be brought into line with the markings.

Thermal insulation is mounted on top of the substrate (if provided for by the project). For this, a tape of extruded polystyrene foam up to 50 mm thick is laid. Next, it is the turn of the reinforcement. Steel rods with a diameter of 6–8 mm are usually used as reinforcement. They are laid in the form of a grid with a cell size of 15×15 cm.

6. Pouring concrete. In order to properly pour a rigid coating, it is necessary to prepare a concrete solution of the optimal consistency. It should not be too liquid and allow the desired slope to be formed using a standard hand tool.

The solution can be mixed manually or in a concrete mixer. It is poured into the formwork with compaction and leveling of the surface. How to fill the blind area is shown in the photo.

After filling is complete, it is necessary to ensure gradual hardening of the concrete. To do this, the blind area is covered with polyethylene film. Periodic moistening of the concrete surface is carried out for 2-3 days. Complete hardening of the material occurs within 3-4 weeks, when the concrete gains maximum strength.

Video

The process of making the blind area around the house can be seen in the video.

The blind area plays an important role in protecting the foundation and basement of the house from sedimentary moisture. The choice of its design depends on the size of the structure, climatic conditions, soil composition, mechanical loads and financial capabilities. You can arrange the blind area yourself, but for this you should comply with existing building codes and regulations.