Manufacturing of building structures from concrete, and in particular overlapping, requires careful compliance with the technology at all stages. On this depends the quality and strength of the finished result. The construction of ceilings during the construction of the house begins with the removal of the dimensions and preparation of the drawing. It is important to take into account enough holes for stairs, communication pipes, etc. The first stage of the work is the installation of formwork. If you mount it with distortions or other violation of technology, the resulting plate will be uneven.
Materials
Strong materials are required for the manufacture of formwork. Concrete exerts great pressure on the structure, and insufficiently thick walls and bottoms are blown or cracked. It will take:
- boards for the bottom of 2 cm thick waterproof plywood reinforced with cross bars, or 4-5 cm thick wooden planks,
- cross-beams 5-7 cm thick of sufficient length to connect opposite walls,
- 3 cm side wall boardsor plywood,
- old linoleum or roofing felt for lining the formwork or film for waterproofing,
- beams with a board or telescopic supports for support,
- joinery tool, level, fasteners( corners, bolts, screws and nails).
If possible, the formwork can be made of laminated plywood 2 cm thick, padded with blocks 1 * 1 cm. After hardening of the concrete, it is very easy to separate from it. It is easy to use and easy to remove formwork from the OSB.The surface of all sawnwood should be smooth and smooth, so that the plate turned out the same, and the cost of finishing was minimal.
The easiest way to work with telescopic supports in the role of supports, but they are more expensive. Some construction companies rent this equipment. It is worth using such proposals, since one rack can be used to support 2 tons of weight. Unlike wood, cracks they will not let or bend.
Construction
In fact, the formwork for the slab is a form, preferably sealed from the bottom and from the sides, supported by the posts. In the future, the frame is made of reinforcing bars( better than composite), concrete is poured. After the concrete has dried, the slab formwork is disassembled. The floor or the ground under the future slab should be solid, so that due to its subsidence the geometry of the slab is not violated.
First, under the future overlap, the supports are placed. Do this in steps of 1-1.5 m across the entire area. They are laid crossbeams, leveled by the level with the help of pads and screwed to the walls. They can not be laid on walls, since after hardening of concrete to remove such a construction will be problematic. Over the beams fix the floorboards or plywood, which should be located 5 cm below the wall beams. If the cover is not solid, with slots, then a layer of material that will hold the concrete is lined.
After the horizontal base is ready, mount the vertical flanges. Their height should be several centimeters above the assumed layer of concrete. Check the verticality of the walls. Particular attention is paid to fastening the corners, it is better to hold it with metal corners.
When the formwork is ready, it is worthwhile once again to check its horizontality, and it is possible to install reinforcement and pour concrete.
