Building a shallow basement foundation with your own hands - instruction

In the construction of light and oversized buildings, such as bathhouses, garages, cottages, on non-heaped soils, the finest stranded foundation is the most optimal. It is more economical and easier to erect, although it is as strong as the foundation of deep occurrence.

Features

Finely buried foundations are most suitable for non-freezing soils, since they are located at a depth of about 50-60 cm, a minimum of 45 cm. For clay soils with a high degree of heaving the depth should be even more - 80-90 cm. The width of the foundation is sufficient forlight house or other structure - 30 cm, total height - 70-80 cm

Construction stages

As with laying of any strip foundation, the whole process can be divided into the following stages:

1. site preparation,
2. basement marking( described in detailhere),
3. trenching and draining,
4. formwork construction,
5. reinforcement,
6. mortar preparation and foundation pouring,
7. waterproofing and insulation.

Preparatory work for

The site is prepared in the usual way: the vegetation is removed, the fertile soil layer is removed, and the soil is ground. Marking is done using pegs and fishing line or fine twine, as when erecting any ribbon foundation.

Excavation

Trenches under a shallow foundation foundation are excavated with a depth of 75-80 cm and a width of 40 cm. At this stage, the entrances and conclusions of engineering communications are laid in the construction. If the site has a slope, or close to the surface of the ground water, it is necessary to drain( read about it here).

At the bottom of a dug trench, sand is poured and ground. The thickness of the sand cushion should not be less than 10 cm, this will compensate for soil whipping during its freezing. The sand layer is leveled by the water level.

Formwork and reinforcement

Formwork can be assembled in several ways:

1. of boards measuring 150 * 25 cm, connected by screws. Spacers are installed every 90-100 cm.
2. is made from OSB, sawn to workpieces measuring 220 * 80 cm. This is a faster but more expensive way.
3. from expanded polystyrene elements.

Prefabricated, non-removable formwork is especially suitable for a shallow foundation, since it will still need to be insulated and the consumption of the elements is not high.

Reinforcement

Reinforcement of a shallow foundation is carried out with a 16 mm diameter reinforcing bar as per standard scheme. For this type of foundation, two reinforcing belts are sufficient: the upper of the two rods, the lower of the three. They should be located not less than 5 cm from the surface of the foundation. First, frames are welded from the lengths of the rod, then the rods of the upper and lower belts are attached to them. At the same stage, you need not forget to lay pieces of polypropylene pipe across the foundation for its ventilation.

Pouring concrete

For the foundation, it is advisable not to use concrete grade lower than the M350.When constructing a lightweight residential building, for example, a frame house, it is desirable to use factory-made concrete, and to expel the air bubbles with a vibratory platform. With small amounts of construction( garage, bath), you can prepare the solution yourself and dispense with a bayonet. And in either case, concrete must be poured at a time. More details about pouring the foundation we wrote in this article.

The concrete poured into the formwork is carefully leveled and covered with a film. To prevent cracks on the surface, it must be kept moist for a week. This can be achieved by watering the foundation once a day with water, sprinkling with damp scribes or covering with a wet cloth. After 2-3 weeks, after complete drying, the formwork is removed. From the inner part remove the soil and lay a layer of waterproofing, a layer of sand 10-15 cm thick is covered.

The shallow foundation requires thermal insulation, which is carried out with the use of expanded polystyrene, and drainage. The blind area will also increase the service life of such a foundation. Another feature - such a foundation easily freezes, so it can not be left uncovered for the winter. Ideally - if the walls are already erected to frost, if not, you will have to take care of its shelter.