Manufacturing of a blind area insulated with foam plastic, features of such thermal insulation, preparation of the base of the structure and the procedure for performing work. The content of the article:
- Features of thermal insulation
- Advantages and disadvantages
- Preparatory work
- Insulation technology
Insulation of the blind area is a way to protect the foundation from moisture and freezing. It is laid along the perimeter of the building in the form of a pedestrian path. Read about how to do this job using foam as thermal insulation in this article.
Features of thermal insulation of the blind area with foam
One of the important points in the construction of a building is the device of a blind area, which serves as the main obstacle to the penetration of melt or rain water from the roof to the foundation. In the absence of this element, moisture permeates the concrete of the house's support, and if it freezes, it can cause its destruction with all the ensuing consequences.
If there is a basement in the building, the insulated blind area protects it from destruction and performs the function of energy saving of the walls. With its help, you can significantly extend the life of the house, especially if it is erected on damp or heaving ground. When planning to insulate the blind area with foam for such a soil, you can build a foundation without taking into account the depth of its freezing. This can give up to 30% real cost savings on earth and concrete works due to the shallower foundation depth of the building.
A greater effect for the thermal insulation of a building can be achieved if, in addition to the blind area, the walls of the basement and the basement are insulated. High-quality execution of these works will allow in the future to save 20% of funds for heating payments. Thermal insulation will help maintain a positive temperature within 5-10 degrees, without requiring the use of heating devices in the basement or basement of the house. In case of freezing of the soil, the insulation of the blind area will prevent shifts in the vertical direction of the shallow foundation.
The design of the blind area provides for the presence of several layers that perform the functions of hydro-thermal insulation and drainage. Its outer covering must be impervious to protect the building from erosion of soil underneath and destruction of load-bearing walls. Layer-by-layer blind area includes geotextile, crushed stone, washed sand, insulation and facing material.
Its device must be carried out immediately after the construction of the foundation and external walls. In addition to the technical purpose, the blind area can be considered a decorative part of the building, which favorably emphasizes the finish of its basement. Walking along the blind area, you can easily walk around the whole house without getting your shoes dirty, which is especially important in inclement weather.
Pros and cons of foam insulation
Polyfoam is a fairly common thermal insulation material. First of all, it differs from other heaters in cost. But despite the low price, the foam boards have excellent insulating properties and do not absorb moisture.
Due to its structure, most of which is air, the foam has a very low thermal conductivity and high sound absorption. These qualities are especially indispensable if there is a basement in the house.
In addition, other advantages are inherent in the insulation: low weight, frost resistance, ease of processing and installation.
The disadvantage of foam is its low strength. Therefore, in the blind area, this material must be protected from mechanical damage by external reinforcement.
High-quality insulation of the blind area with foam creates significant savings in many parameters, while the additional costs during installation include only the cost of the insulation. Summarizing all of the above, we emphasize the main benefits of insulating the blind area with foam:
- No need for deep foundation laying;
- Reducing the cost of space heating;
- Improving the durability of the foundation and the building as a whole.
These advantages are a good reason for installing an insulated blind area.
Preparatory work on the insulation of the blind area with foam
It is recommended to insulate the blind area during the warm season of the year. This greatly simplifies the excavation work that precedes the main process.
To prepare the base for the blind area, you first need to use pegs and a cord to break down the perimeter of the site on which the work will be performed. The width of the blind area is taken at least 60 cm. But first of all, this parameter is influenced by the size of the roof overhang. The blind area should be 30 cm or more wider than it.
If the distance from the edge of the roof to the wall is small, the width of the future blind area must be determined by the depth of soil freezing in the construction region. For example, if the amount of freezing is 150 cm, the width of the blind area should be at least one and a half meters. This will provide reliable protection for the foundation.
When calculating the width of the trench, you should also take into account the size of the insulation sheet. This will reduce waste of material. After marking the resulting area, it is necessary to remove the soil to a depth of about 30 cm along with the vegetation layer. The roots should not be left in the ground, since in the future, germinating, they will cause damage to the blind area. After excavation, the bottom of the trench must be leveled.
Knowing its size, it is easy to calculate the required amount of foam for insulation, gravel and sand. The thickness of the sand cushion and the layer of crushed stone should be at least 100 mm, one layer of insulation - 50 mm, respectively two - 100 mm. At the stage of earthworks, it is necessary to provide for the creation of a slope to drain water to the outer edge of the blind area from the wall. The slope can be 3-10 degrees. If winters are especially harsh in the construction region, in addition to the blind area, it is recommended to arrange a drainage system to better drain water from the foundation. To do this, in the process of preparatory work along the outer perimeter of the planned blind area, you need to dig a narrow ditch half a meter deep, lay geotextiles in it, then drain pipes, wrap them with the same material and fill them with rubble. To drain water from the system, you need to equip a separate well.
Technology of insulation of the blind area with foam
Before insulating the blind area with foam, it is necessary to prepare all the materials and the necessary tools. Materials will require foam sheets, sand, water, crushed stone and cement, asbestos-cement pipes, slats, bitumen mastic, plastic wrap, formwork boards, reinforcing mesh or individual metal rods. Tools for work are very simple: a shovel, a plastering trowel or spatula, a sharp knife, a building level and a rammer.
After preparing the trench, a 15 cm thick underlying layer of sand must be laid on its bottom, which must then be moistened with water and carefully compacted. A shovel and rammer will be the best helpers for such work. A similar operation should be carried out with a ten-centimeter layer of crushed stone, which must first be distributed over the sand cushion.
After layer-by-layer backfilling of the trench, lay sheets of foam plastic on an even and dense layer of rubble. The remaining cavities between the elements of the insulating coating and the walls of the house must be filled with waterproof foam. As mentioned above, the foam needs protection from mechanical damage. Therefore, in order to reduce the external load on it in the future, the insulating layer should be covered with a reinforcing mesh. After laying the reinforcement, the blind area will be practically ready for concreting and further finishing. Before pouring a multi-layer structure with concrete, asphalt or other binder, it is necessary to install a plank formwork along the outer edge of the trench. Its height should be 10 cm higher than the ground level.
In the prepared formwork, concrete or other mixture must be laid observing the accepted slope from the walls of the building. In addition, every 2.5 m, the blind area must be separated by expansion joints. For their manufacture, thin slats or a dense film should be laid in fresh concrete, and after the start of hardening, these products must be removed from the blind area. Fill the joints that have formed in this case with liquid glass or molten bitumen.
If, instead of concrete, asphalt is laid in the formwork, expansion joints can be omitted. After the end of the concrete hardening, its surface must be reinforced with iron. This work is done with plastering tools.
Decorate the outer edge of the finished insulated blind area with a drainage system, which is made in two ways. In the first case, gutters made of asbestos-cement pipes sawn along the length of 100 mm should be placed on the underlying layer close to the path. Another option is to make a monolithic concrete gutter. You can use a piece of pipe or a sanded log to shape it into the desired shape.
What is the blind area - look at the video:
That's all. We hope that the presentation of our material will help you to make a high-quality foam-insulated blind area. Good luck with your work!
