Basement device with strip foundation

It is more rational to design the construction of the strip foundation of the house with the simultaneous arrangement of the basement. The space under the ground floor of a house can serve a wide variety of functions from food storage to a gym. The basement floor can be completely buried in the ground, but more often the foundation tape is arranged only slightly below the depth of soil freezing. Therefore, part of the basement walls constitutes the basement of the building.

Install a basement in a house with strip foundations

The device of a cellar in a house with a strip foundation

The simplest room under the floor is called the cellar and has a number of significant differences from the basement:

The cellar serves only as a storage facility: under the floor, a stable positive low temperature is almost always maintained. This is the best mode for storing food.
The cellar does not necessarily occupy the entire space bounded by the walls of the foundation.
The depth of the cellar may not be enough for free movement, but the volume of the underground space should be sufficient for the storage.
The device of the cellar does not imply large costs for the installation of floors, wall decoration, installation of stairs.
Cellar ventilation is usually provided only by opening the entrance hatch (manhole).
Apart from minimal lighting, no engineering systems are used in the cellar.

Cellars can be arranged in existing and long-operated buildings, and not be designed before the start of construction. Such premises are usually arranged in small country houses, garages and outbuildings.

In this video, we will consider a basement with a strip foundation:

Features of the construction of the strip foundation

The basement strip of the house can be arranged in a trench manner, without the development of a foundation pit under the building. In this case, the foundation performs only the function of the supporting structure.

But the strip foundation, arranged to a depth of freezing, may well be used as the walls of the basement. The additional costs for soil sampling are paid off by creating additional multifunctional space under the floor of the first floor of the house.

Tape base

A solid foundation in the form of a tape around the perimeter of a house under construction is considered the most reliable and affordable for self-construction. From the point of view of cost and construction time, there are cheaper and faster ways to build foundations, but the construction technology according to the tape option allows you to increase the usable area of the house at the expense of the basement floor.

When planning the device of the basement, one should proceed from its functional purpose. The parameters and characteristics of the foundation tape will depend on this:

foundation height;
the presence of technological openings in the tape for engineering networks and communications;
the need for the device in the tape of embedded parts, anchors and fixtures;
foundation wall thickness;
application of additional measures to strengthen waterproofing, insulation, decoration of basement walls.

The first stage in the construction of a house with a basement on a strip base should be considered the development of a pit around the perimeter of the house being built. The generally accepted norm for the height of the ceilings is 2.5-3 m, from this value the basement depth is calculated. It is possible to reduce the depth by creating a plinth of the required height.

The pit is being developed with a margin of 0.5 m in all directions for convenient performance of work on the construction of external surface waterproofing of the foundation.

Further, the bottom of the pit is cleaned from loose soil, then the surface is leveled under a single mark by means of sandy continuous filling 5-15 cm thick. A layer of crushed stone of fine fraction is poured on top of the sand layer with compaction by rammers and by irrigation.

Assembly process

Installation of the strip foundation is carried out:

In a monolithic way. The formwork fence of the tape is prepared on both sides, the space inside the formwork is reinforced and filled with a concrete mixture with compaction.
With the use of foundation reinforced concrete blocks. Typical concrete products for the construction of building foundations are usually marked with the letters FBS with digital indicators of the parameters of length, height, thickness in decimeters, for example: FBS 24-6-3. Blocks are mounted by analogy with brickwork on a cement-sand mortar.
Sometimes the foundation tape is built as a wall of small-piece concrete solid blocks. The typical size of the material is 40x20x20 cm, the thickness of the walls can be any, the masonry is similar to the brick.

The fastest way to build foundations is to use special blocks. But industrial products such as FBS are expensive, lifting mechanisms are needed for installation, and transportation of blocks to the facility is expensive.

Small-piece concrete products are used for small volumes of tape bases. The most affordable way of building with your own hands is the construction of a monolithic foundation tape.

DIY construction of a strip foundation with a basement

For an independent basement device using a strip foundation, the most difficult moment is the installation of formwork panels.

In general, you need to understand that the possession of minimal skills is necessary to perform any job. The construction of the foundation of the house is considered the most crucial stage, therefore, thoroughness and thoroughness are required in the work.

Build a basement with your own hands

Calculation and preparation

You should not independently calculate the load on the foundation without special knowledge. The thickness of the walls should correspond to the design, as well as the height. It is necessary to calculate the number of boards for the formwork device, the need for reinforcement and the required volume of concrete mixture in advance.

The starting point of calculations for independent work should be a sketch of the foundation with the exact dimensions of the tape:

The total area of the enclosing formwork panels is equal to: the outer perimeter of the house X the height of the wall X 2, plus 10% for spacers, stops, screeds.
The need for reinforcement is calculated individually, depending on the expected load on the foundation. The reinforcement frame must be made in the sketch, not forgetting about the different thicknesses of the main rods and connecting elements.
In the section on the sketch of the strip foundation, there must be at least three pairs of reinforcing bars laid along the perimeter of the basement.
The need for concrete mix is equal to the volume of the inner space of the formwork + 5% for losses.

Before construction, it is necessary to plan the correct storage of materials at the construction site, equip the entrance and free access to the pit. Do not make concrete yourself, especially in large quantities.

Concrete mix prepared in artisanal conditions can never be compared in quality with prefabricated concrete. The best solution would be to order concrete from the factory with delivery by a mixer. From the point of view of the quality of the foundation, the entire volume of concrete should be poured at a time.

Layout and earthwork

The foundation is marked at the bottom of the pit according to the rules for constructing rectangles on a plane. Pegs-beacons are hammered in the corners, then a cord is pulled along the outer perimeter.

Parallel and similar to the external one with an inward displacement by the wall thickness, the internal perimeter is indicated. The correctness of the division is determined by the equality of the diagonals of the rectangles.

From the outside, it is necessary to ensure work on the subsequent waterproofing of the monolithic strip foundation, to prevent the soil from falling into the pit.

Formwork and reinforcement cage

Formwork panels are made outside the pit. When manufacturing, special attention should be paid to the absence of gaps between the boards. Usually a board of 20-25 mm is used, a bar for ties and stops 40x40, 50x50 mm.

Work progress:

The outer perimeter shields are lowered into the pit and pre-fixed.
The frame reinforcement is installed and tied with a knitting wire.
The shields of the inner perimeter are lowered.
The formwork is set exactly in size, the inner and outer shields are knocked down from above with crossbeams.
From below, the shields are fixed against spreading by wedges, in height - by stops from the outside, which rest on stakes driven in at a distance.

All ties and stops are rigidly fastened with nails or self-tapping screws. In the fastening, it is better to overdo it and hammer in an extra emphasis than to allow the formwork to disperse while receiving concrete.

Stripping, waterproofing and backfilling

The concrete is poured evenly over the entire belt to the full formwork height. The minimum setting time for the mixture is 7 days. Stripping should be done evenly, removing stops and ties. Do not hit fresh concrete. The shields are carefully removed and removed from the pit.

After the final drying of the concrete from the outside, the surface is coated with a continuous layer of bitumen mastic. The bitumen is glued with an overlapping roofing material or roofing felt with a continuous carpet in one direction. After drying on top of the glued layer, the second is similarly applied, but perpendicular to the first.

After the waterproofing of the foundation tape is completed, the soil is backfilled.

For additional waterproofing, you can use a thick solution of ordinary clay instead of filling the outer sinuses with soil. If you fill the sinuses with such a solution, then a clay lock is formed, ensuring that there is no water in the basement.

Strip foundation for a house with a basement

A foundation concrete strip should be considered as a basement wall. Having ensured the absence of moisture with a waterproofing device, you can finish the walls of the basement in accordance with the purpose of the room. The basement, arranged in a house with a strip foundation, can be adapted for any direction, up to a bomb shelter.