Production of formwork for strip foundation

Recently, many owners of private household plots have decided to independently build cottages or country houses of a large area. In order for the structure to withstand the corresponding load, it is better to make the foundation monolithic.

When preparing a monolithic foundation, it is necessary to apply additional elements so that the flooring is even. These include formwork for a strip foundation, which are forms of a future building made of wood, subsequently filled with concrete and subject to dismantling after it hardens.

Large firms rent such structures or constantly use elements of their own production. For a one-time construction, it makes no sense to buy or rent these wooden molds. They can be made by hand.

Production of formwork for strip foundation

The main task of the structure is to maintain the shape of the poured concrete during curing. Devices can be made from the following materials:

• Planed edged boards with a perfectly flat surface on at least one side. The thickness of the wood must be at least 3 centimeters;
• Sheets of plywood. Easily accessible and inexpensive material that can withstand minor loads. With a thickness of plywood sheets of 1-1.5 centimeters, it is used in the construction of concrete fences or technical buildings.
• Plastic. When using plastic structures, the future wall does not have roughness, but this type does not justify itself in private construction due to the high price;
• Metal. The most costly option for making molds. It is used in large construction.

With individual construction, most often the decision is made in favor of wood cladding. This is due to the fact that wood is the cheapest and most affordable material at hand. Boards can be easily fastened together with screws, nails or corners. It is also easy to dismantle them for further use. All other materials require a large investment for the same efficiency.

Formwork for a strip foundation is easy to do with your own hands, does not require any special skills, but is time-consuming, which is why many companies and owners of private houses prefer to buy ready-made elements or rent them.

Device

Based on the load that the skin must withstand, the very design of the retaining elements is formed. There are three types of formwork installation that you can do yourself:

• Demountable design or, in other words, removable. It consists of separate parts of wood, knocked down into the shape of a shield of a given size, assembled into a single composition before starting work on tamping the mixture and to be dismantled after they are completed;
• Fixed design. It is made of polystyrene foam blocks installed on supports, filled with a mixture and, after hardening, remaining part of the foundation, while performing the role of a heater;
• Combined design. It is an intermediate option, which includes two types of structures, while plates of any insulation are additionally placed in the prepared wooden form on two or one side, and after disassembling the wooden part, they remain fixed.

Currently, the non-removable and combined types are gaining popularity, since in this case the insulation of the living space is provided. The non-removable design is the most waste-free and does not require additional reinforcements.

Installation of the element during construction

The form is mounted around the entire perimeter of the base, including the depth, and is displayed at least 30 centimeters from the ground for the basement of the foundation. Such work is easy to do with your own hands.

In the case when the owner has chosen a removable or combined option, installation work should begin with a complete set of prefabricated panels consisting of plywood or boards.

Raw materials must be taken dry. To ensure a smooth surface, gaps should be avoided. The height of the shields must be calculated at a level of 5-7 centimeters above the planned tape of the building base. The boards are assembled into shields by fastening the bars across the structure, the distance between the fasteners should not exceed 1 meter. Nails, self-tapping screws or plates for fasteners are hammered from the opposite side of the one into which the concrete will be poured. The plywood form device is no different from the installation of boards. The only difference is that the plywood sheets are not attached to each other, but to the frame.

Given the characteristics of the soil on which the strip base is planned, it is possible to mount the structure exclusively above the ground or inside a dug hole. The walls of the pit should be pre-aligned to the maximum. Ready-made blocks of boards or plywood are installed vertically along the edges of the pit and fastened to fix the formwork with braces. Such a device is mounted to ensure a stable structure.

Braces are prepared from the remains of a tree of any condition with their own hands. They are screwed into the ground with pegs at a distance of about one meter from each other. The braces are attached to the finished blocks with self-tapping screws in the place where the bars are connected to the boards. In another version, they are attached to special overlays from the remnants of the board, which are nailed to the bars. The braces are arranged according to the calculated distances of the transverse bars and blocks (no more than 1 meter). To make the device more stable, intermediate jumpers must be installed at a distance of 0.5 meters. The remaining improvised boards are suitable as a material.

The main thing to do during installation and fixing is to ensure that the formwork is strictly vertical and does not have bends along the entire length of the foundation. This process is controlled using a rail, rule or spirit level two meters long. The axis of attachment should not be displaced in relation to the design position of the base of the house. Permissible deviations are no more than 2-3 millimeters.

In order for the installation of the skin to be carried out perfectly, you need to make cuts in them. In this case, the device is controlled by hanging or stretched threads and wires. According to them, you should continue to monitor the height of the tape and the fill level. In some cases, the required height is marked with a marker on the inner surface of the wooden device.

After the fastening is ready, the bottom is covered with a waterproofing material so that the concrete meets the specified strength. Waterproofing is laid with an additional overlap in order to prevent its rupture during the concreting process.

Installation in an unstable location

The most difficult option for installing formwork, but it is also possible to do it yourself. With unstable soil, the formwork is installed starting from the bottom of the trench. Often, underwater groundwater requires that the bottom of the structure also be reinforced with molds. A prerequisite is the laying of waterproofing at the very bottom.

With unstable soil, the formwork for the strip base is formed in a combined way. The underground part, buried in the ground, is made of any insulation that suits you for this type of construction. Keep in mind that it will forever remain part of the house.

Unstable soils can collapse at any time after heavy rain, so the base is made higher and the mount, respectively, is also made of boards over one meter long. In order to properly lay the construction site, they dig a trench with a certain angle of inclination and an acceptable width for convenient installation of blocks. The installation principle for the rest remains almost identical to the previous one.

The essential difference of this method is that a small concrete layer with a reinforced mesh is poured into the base under the formwork. This is done to give strength to the entire building and the impossibility of undermining the base of the house with groundwater. This must be done a few days before installation.

Sometimes during installation with the help of wooden frames, so-called ties are used, which, in fact, are small studs. Initially, it is necessary to drill recesses in the plywood board, and place steel tubes in the formwork itself. The length of the latter is equal to the width of the tape base itself. The distance between such screeds is not more than 50 centimeters. Be sure to follow this rule. When dismantling, the fastening elements are removed, and the remaining recesses are decorated with a cement mortar of any brand.

Combined installation

There are no special differences from the previous methods when installing in a combined way. In addition, in strong stable soils, an additional trench does not dig. The main thing is to achieve the most smooth surface of the dug trench for laying the strip foundation. The upper part is made by the standard method with the fixation of boards or plywood boards with the help of thrust braces, and the lower part goes to the depth of the foundation and is a non-removable sealant. Subsequently, the upper part must be dismantled after the concrete has completely hardened.

Conclusion

Making formwork is a laborious process, but feasible. To make this element of construction is not so difficult. Formwork plays a key role in the formation of a stable and strong foundation for a house, cottage, basement, bathhouse, shed, fence and other technical buildings that need a foundation. Remember that any house, first of all, begins with the foundation. Thus, the statement “My house is my fortress” can be supplemented with the phrase “Formwork is its basis!”.