Formwork installation for different types of foundations

Formwork installation is a very important and crucial stage in the construction of the foundation. Formwork is a system of vertical slabs assembled from panels.

Formwork panels are made from various types of durable materials. Vertical panel ceilings, combined into a single structure, form an impenetrable form for liquid concrete.

Due to its design features, the formwork can take any geometric shape. This allows you to build a foundation for a wide variety of layouts of the supporting structures of the building.

Formwork installation is carried out using removable panels. In some cases, the installation of formwork from fixed elements is used. Fixed shields play the role of an integral bearing part of the foundation. Plates made of various polymeric materials are used as a material for fixed ones.

The installation of formwork from fixed slabs is often used when laying a slab foundation.

Wooden shuttering boards suitable for private construction

For example, fiberglass and polystyrene boards serve not only as vertical formwork slabs, but also serve as insulation for the foundation. To prepare the foundation formwork, you need to properly assemble the panels, carefully check the connection of the fastenings of the vertical formwork slabs.

Formwork installation technology depends on the material of the vertical slabs. Formwork is of various types:

• Plank formwork;
• Shields made of construction plywood;
• Metal shields;
• Polymer and foam boards.

Formwork made of boards and plywood

Correctly connected into shields should not have gaps between them. For fastening wooden shields, a system of screeds, struts, slopes, clamps and stops is installed.

The installation of the formwork structure must be carried out in such a way that its inner surface does not have any protrusions, but is smooth and even. The developed standard technologies for assembling plank or plywood formwork for foundations recommend using boards and plywood with a thickness of at least 10 mm for shields.

Plywood with a thickness of at least 10 mm is attached to the frame of the timber

If the foundation has a large width, then the lateral pressure of concrete can withstand shields made of boards with a thickness of 30 to 40 mm. The framing of the shields and the stiffening ribs are prepared from a wooden beam with a section of 40X60 mm. The fasteners of the enclosing structures are made from the remains of boards and timber. Other suitable materials are also used.

After installing wooden or plywood panels, carefully check the surface of the formwork for cracks and irregularities. If any are found, they must be eliminated.

First, boards and plywood are cut to the size of the shields. Boards or sheets of plywood are laid out on the unfolded bars. Then nails or screws connect all the elements. The finished planes are framed with a beam and stiffeners are attached to them.

According to the markings made with the help of twine and wooden pegs, trenches are dug. At the bottom of the trenches I arrange an underlying layer of sand, gravel or crushed stone.

For fastening the formwork, it is necessary to choose only high-quality reinforcement

After that, the enlarged elements are set to the design position and proceed to the installation of fasteners. Support boards are laid along the formwork installation line, the pointed lower ends of the support bars rest against the ground, and the upper ends hold the formwork.

Along the entire perimeter of the marking, the walls of the fence are placed, fixing them with evenly distributed fasteners. The shields are interconnected by pieces of timber using nails or self-tapping screws. The opposite walls of the fence are connected with U-shaped clamps. Clamps are made from boards and timber.

Such structures do not allow the walls of the formwork to disperse under the pressure of the poured concrete mixture. From the outside, slopes are installed from a bar, which with a pointed part rests on the ground, and with the other end supports the upper part of the shield.

The removed plank shields can be disassembled into boards and beams, then they are used in other works. The dismantled plywood sheets can be used again for building a foundation at another facility.

Combined formwork

In loose soils, a combined formwork is installed. For the above-ground part of the foundation or from plywood. Underground enclosing structures are made of non-removable polystyrene plates, asbestos-cement sheets and pipes.

Installation of formwork from metal panels

When mounting the formwork, it is necessary to strictly observe the verticality of the structures.

Metal shields are prefabricated designs. The frame and stiffeners are made of a metal profile. Shields on the area do not exceed 3 square meters.

For small foundations, a small-panel one is used. Metal enclosing structures are made of steel sheets with a thickness of 1.5 to 2 mm.

Metal structures of this type are reusable shields. The formwork can be used as an adjustable fence.

Metal planes are bolted together. Where standard railings do not fit into the overall formwork, the dimensions of the panels are corrected by gas cutting and welding. Quick-release connections of fencing elements are made from a rolled profile.

Reusable metal structures require special care. After the next use of the shields, the structures and elements are thoroughly cleaned of concrete using metal brushes and special steel scrapers.

Before each use of inventory fences, all metal surfaces and parts that come into contact with the liquid solution are lubricated with a special agent. The lubrication provides an easy separation of the shields from the hardened concrete, which allows you to keep the surface of the monolith even and free of cracks.

Installation of formwork from other materials

As a formwork for foundations, wood-fiber and particle boards are used. Formwork from these materials is successfully used for the construction of columnar and other types of foundations.

Fences for pouring foundations are made of foam plastic and polymer plates. As a rule, such structures are non-removable. They are left in the ground as part of the foundation of the building.

General requirements for formwork

The entire inner surface (bottom and walls) of the formwork is lined with a waterproofing film. Waterproofing will not allow cement milk to seep into the soil. Subsequently, the film will protect the foundation from the effects of ground moisture.

Properly applied technology of joining the parts of the fence will eliminate the violation of the verticality of the walls of the formwork and ensure the horizontal position of the concrete surface. After the foundation is poured, its upper horizontal surface is covered with a film or other waterproof material. This will protect the monolith from moisture evaporation from its surface until the concrete mortar is completely cured.

During the installation of structures, it is constantly necessary to control their verticality, using a level and a plumb line.

The fencing elements are dismantled after the full set of the bearing capacity of the base monolith. Before removing the shields, they are tapped with a rubber mallet. This allows you to remove the formwork without much effort.

Watch the video on how the formwork is dismantled.

Conclusion

The formwork forms the foundation of such a width that the load-bearing walls and the edges of the floor structures rest on it. Reinforced concrete slabs are used as the floor.

The floor elements can be supported by reinforced concrete crossbars, wooden logs and metal beams. It is important that the foundation surface is strictly horizontal, which will ensure a high-quality fit of the floor structures.

This will ensure the correct distribution of the load on the horizontal surface of the base of the building. A variety of types of enclosing structures allows the developer to choose the best formwork option for the construction of their foundation.