Foundation of the house largely determines its durability. Therefore, the process of its construction should pay special attention to all stages. Formwork for strip foundation (namely this type of foundation is the most popular) must be built according to certain rules, otherwise it will not sustain heavy loads.

Formwork device for continuous footing

formwork for the construction of strip foundation is removable and non-removable. The latter type can be built from blocks of polystyrene serving for forming the concrete casting and for thermal insulation. They joined "the castle" because of the design of adequate strength, suitable for any type of soil. Also removable type of formwork can be made:

• metal;
• fiberglass;
• plastic;
• reconstituted wood (plywood planks, chipboard).

Collect any of them is not difficult, you will not need to use complex tools and technologies. Formwork for strip foundations removable type has the following advantages:

• assembly is carried out in a short time (this contributes to ease of construction);
• perfectly smooth inner surface of the formwork;
• the waterproofing of the base will be easier to perform due to the good quality of the surface;
• smaller finishing materials costs.

The disadvantage is that it is an expensive formwork for a ribbon foundation, the price is usual several times less.

Production of formwork for ribbon basement from boards

Most often, formwork is collected from boards and bars, less often - from plywood appropriate thickness. The material is fixed with nails, self-drawing, twisted with wire. The main components, of which such a formwork consists of:

• forests - support racks and backups, with which the design acquires rigidity;
• deck - made from boards, sheets of plywood or boardboards panels;
• fasteners - self-tapping screws, nails and wires, with which they connect forests and decks into a single design.

Choosing material for formwork, pay attention to the following.

1. Plywood and boards must be resistant to bending. She will have to withstand the weight of concrete and reinforcement without changes in geometry and form.
2. The most optimal material for formwork is the throat pine boards with a thickness of at least 25 mm (coniferous rocks are stronger hardwood, with the exception of oak), and better - 40-50 mm. It is preferable to use edged boards: their ends are tightly adjacent to each other, which prevents the formation of slots and, as a result, the flow of concrete.
3. The width of the adhesive material is selected up to 150 mm. Dry boards do not suit: they pull moisture from concrete and thereby violates the natural process of frosting, which leads to a decrease in strength. The humidity of the board should be about 22%.

How to install formwork

1. Installing the formwork for a ribbon foundation should not only be durable. The quality of the formed surfaces should be such that their finishing costs are as low as possible. Work is performed in several stages.
2. The plot settled for development must be aligned.
3. Using wooden pegs, roulette, the rope is marked by the future base. The correctness of marking is checked not only on the sides, but also diagonally.
4. With the help of technology or manually, the trench of the required depth and width rotates. The bottom of the trench is taught, the sandy subference is satisfied with a thickness of at least 100 mm. In the event that the soil crepts, the width of the trench should be such that the formwork can be constructed, ranging from the bottom of the trench. If the soil is dense - it is allowed to use the edges of the trench (they should be additionally aligned) as the formwork walls.
5. The assembly of the ribbon foundation is made in such a way that there are no more than 3 mm between the boards (through which concrete can flow): wood, absorbing moisture from concrete, will expand and block small gaps.
6. Wide slots eliminate with the help of rails or score their pacles.
7. Boards of low formwork (less than 200 mm) can be secured by wooden pegs. If the base is higher - formwork is fixed with additional backups (inclined pins) and metal clamps.
8. Boards to spicks are nailed. At the same time try to eliminate the gaps.
9. The shields collected from plywood and boards located on the opposite sides of the trench are fixed with a wooden strut or twisted with wire. The distance between the struts is in the range of 0.5-1.0 m.
10. Final Stage - Sealing: Formwork walls are lined with rubberoid or other waterproofing material. This will allow concrete to gain strength in optimal conditions.

Useful Tips: This is important for the proper formwork device.

1. On the fixation of the formwork, it is impossible to save: the destruction of the shields under the pressure of concrete will lead to loss of material, and the deflection of the boards - to the formation of the surface of the base of poor quality.
2. In order for the formwork to dismiss it easier, the inner surface of the shields should be covered with any hydrophobic composition.
3. To make sure that the geometric parameters of the formwork are correct, it is necessary to use various tools: plumb, level, roulette, ruler, ugle. The permissible deviation vertically is 5 mm / 1 m of height. The formwork axes cannot be shifted by more than 10 mm.
4. When pouring concrete, a vibrator is used to seal it. It helps to eliminate the formation of air bags.
5. The mortgage reinforcement should not touch the walls of the formwork (this will lead to corrosion of the metal). The minimum distance is 30 mm.
6. The waterproofing pill is placed so that the adjacent layers are located with the nasha: in this case, they will not be moved due to the mass of concrete. The upper part of the waterproofing is fixed to the boards with a stapler.

Preparations for pouring the foundation - a very important stage of construction. How about to formwork for strip foundation: a video demonstrating the process to your attention (in two parts).