The construction of any building begins with the construction of a solid concrete foundation. But first you need to build a formwork, with which you can give the foundation the desired shape. The mentioned construction is constructed from various building materials. In order to properly build the formwork according to the foundation, it is necessary to strictly follow the instructions that will be given in this material. You should consider in more detail the design features.
Formwork assembly conditions
Previously, the structure was mounted using wood, but nowadays, polymer high-tech materials are also used. Formwork is being built to perform such tasks:
- creating the desired form in which the concrete mortar will solidify;
- isolation of the building from the soil.
Construction technology begins with soil preparation. The area on which the building will be erected should first be noted with the help of kapron thread and wooden pegs. After this, you need to make sure that the territory is cleared of garbage. Formwork is made of wooden panels or other building materials. The main thing is that the inside of the structure is cleaned from contamination. In addition, the building materials used must be free of defects.
The correct formwork for the foundation is a design in which the individual elements are tightly interconnected, since the reliability and durability of the base depend on this condition. Neglecting this requirement, the concrete will collapse in a short time. Tightness of the structure - this is another technical condition that must be met in order to get a solid foundation.
Formwork: varieties
There are two types of construction: removable and non-removable. Builders recommend exploring the advantages and disadvantages of each option in order to figure out which formwork to build under the foundation. You should study these varieties in more detail.
- Removable formwork is disassembled after completion of the foundation. This is a profitable option: building materials can be used again. In this case, the board for formwork of the foundation is most often used.
- The fixed structure is made of polymeric materials (for example, of wood concrete or polystyrene concrete). Masters advise building a formwork of this type if you want to build a massive structure. In addition, the design, performing a heat-insulating function, will protect the concrete base from the negative effects of low temperatures.
It is recommended to organize a wooden formwork of a fixed shape, if it is necessary to build a narrow and shallow foundation. Sometimes a combined structure is erected, which builders advise to use when building an object on loose soil. Formwork of this kind consists of the outer and inner layers. As a rule, boards are used for the construction of the outer side of the structure, and polystyrene concrete for the inside.
Formwork materials
The size and variety of the base are criteria affecting the type of structure mentioned. To create the formwork, builders use the following materials:
- metal;
- polystyrene foam;
- reinforced concrete;
- tree.
If the building will be built on a strip or monolithic foundation, it is recommended to use metal products for the organization. To obtain a high-strength structure, in this case sometimes steel reinforcement is welded to the formwork iron panels. The foundation of the building will be durable if reinforcement is used for it. Universality is another advantage of metal formwork, since the shape of steel sheets can be changed, but there is also a significant drawback - the high price of metal products.
Expanded polystyrene is a known and expensive material, with the help of which elements of fixed formwork are erected. In addition, the product has high thermal insulation properties, but sometimes there are problems when selecting individual components for the construction of the structure.
Reinforced concrete is rarely used for the construction of private buildings, since in this case it will be necessary to lay out a large sum of money for the work. In addition, constructing reinforced concrete formwork yourself is a laborious task. The construction of the said material is assembled from plates.
Wood formwork: advantages and disadvantages
The construction of the boards is being built most often. This is not surprising, since the process of manufacturing wooden formwork does not take much time. If it is necessary to build an inexpensive structure, then for work it is recommended to purchase sheet plywood, which should be fastened to struts made of boards.
Accessibility and low cost are the advantages of wooden formwork, which is also quite easy to install. In this matter, the main thing is to strictly follow the instructions and purchase the necessary materials, and the simplest tools will be needed: a hammer, tape measure, screwdriver and construction level.
Wooden formwork for the foundation of the house has some disadvantages, since for its manufacture it will be necessary to use additional elements to strengthen the structure. This need arises due to the overall differences of the individual parts, so builders recommend preliminary accurate material calculations.
Improvised formwork
The design can be made of flat slate, doors, old furniture and other materials. Cheapness is a key advantage of such a formwork under the foundation. However, the correct construction of the structure will be very problematic, since you will have to carefully select the required parts.
You should know: this option is prohibited for use in the construction of concrete foundations for residential buildings. In addition, the formwork needs to be constructed in such a way that it is completely tight, and it will be difficult to fulfill this condition from improvised materials. In this case, special supports should be set to obtain a stable and reliable design.
It is recommended to use special studs to tighten the walls of the formwork.
Laminated plywood: material features
The mentioned material is a standard product, which builders recommend using during the creation of formwork forming elements. This is moisture resistant plywood with high technical characteristics. The material will be on the surface of the structure, and its main function is to protect the boards from moisture.
The minimum sheet thickness is 3 mm and the maximum is 40 mm. Due to its low weight, plywood panels will be easy to transfer and connect to the rest of the formwork.
Wooden formwork: necessary materials
Initially, it is necessary to prepare the site on whose territory the building will be built. And then purchase the necessary materials and tools. To build the formwork for the foundation, you will need such building items:
- planed bars 100 x 50 mm;
- edged boards, the width of which should be from 100 to 150 mm, and the thickness - 25-30 mm;
- wooden stakes;
- laminated plywood 125 x 250 x 1.5 cm;
- nails or screws;
- building level;
- wire or kapron thread;
- polyethylene film.
The number of building materials directly depends on the dimensions of the future foundation. The height of the formwork must be performed so that its level is 5 cm above the base.
Quick installation of wooden formwork: step by step instructions
First, you need to make boards of moisture-proof plywood (laminated), since the forming material should not absorb water: this can lead to disruption of the hardening of the concrete solution. The external side must be strengthened with a beam, the dimensions of which are 100 x 50 mm, with the help of nails or screws.
The formwork will be strong if it is fixed with stakes, which must be installed every 70-100 cm. The distance from the base to wooden sticks should be no more than 1 m.
The next step is to place the prepared plywood panels at the edges of the trench, and then connect them using special jumpers with dug stakes. Before the final installation of the formwork for the foundation, the fence should be checked for verticality, and for this it is necessary to use the building level. Next, it will be necessary to fix the formwork to the mowing and cover the inside of the structure with a film.
The final stage of work is the installation of a reinforcing grating and pouring concrete mortar. Masters recommend bending sheets of plywood if it is planned to erect a base with rounded sections.
When to remove the formwork from the foundation?
If a removable structure is organized, then in any case, sooner or later it will have to be dismantled. As a rule, a concrete mortar completely hardens after 28 days, but this indicator depends on temperature and humidity. Experts recommend not rushing to disassemble the structure, since it is necessary to wait until the concrete gains 50-70% strength.
If the question arises as to how long to remove formwork from the foundation, then the following parameters should be considered:
- If the air temperature warms up to 30-35 ° C, then the structure must be dismantled after 2 days.
- The formwork was built at 20-25 ° C - it is necessary to disassemble it after 3-4 days.
- If the temperature reaches an indicator of 10-15 ° C, specialists dismantle the structure for 5-7 days.
- After 10 days, the formwork is removed if the foundation was built at an average daily temperature of 5 ° C.
If the concrete base is built at a low temperature (from 0 to +10 ° C), then the mentioned structure should be dismantled after 15-20 days. This indicator is also affected by air humidity - builders advise carrying out work on pouring the foundation in dry and warm weather.
Strip foundation: formwork construction
To organize this foundation, you first need to dig a trench. The next stage is the purchase of wooden blocks and edged boards. The number of building materials for each individual project will be different. Masters recommend purchasing boards with a certain margin so that they do not have to be additionally purchased already during the construction process.
Before constructing the formwork for the strip foundation with your own hands, you should check the quality of the trench: it must be dry and not loose. Therefore, it is better to carry out the mentioned works when the weather is dry. Formwork must be performed in the form of a box, which will be installed throughout the trench. The main thing is that the design is tight, so it is recommended to sheathe the boards with roofing material. In addition, the formwork must be strong and rigid, since the poured concrete mortar will strongly pressure its walls. Builders recommend fastening the structure with jumpers, which must be installed every 2 meters.
If it is planned to construct a removable formwork, then the design must be performed in such a way that during dismantling it does not damage the lumber.
Concrete base without formwork
If it is planned to build a basement in a building, then such a foundation is not suitable for the construction of an object. In addition, in cold regions, the construction of a base without formwork is a risky and irrational task. However, this design has its advantages, namely:
- reduction in the cost of building a foundation;
- reduction of the construction time of the building;
- reduction of labor costs.
To organize the foundation without formwork, it is required to perform the following works:
- Dig a trench, taking into account the dimensions indicated in the design documentation.
- Cover the outside with plastic wrap.
- Fill the bottom of the trench with a 10-cm sand layer.
- Strengthen the structure from above and below with steel reinforcement.
- Pour concrete mixture.
Cement grade should be M300 or higher. For example, professionals recommend using the M400 to build a solid foundation.
Finally
Performing formwork for the foundation is a simple matter, if you study in detail the information given in the material, and also listen to the recommendations from professional builders. For the construction of small residential buildings, the structure is most often made of wood, which is why the technological process for the manufacture of formwork from boards is discussed in detail in the article.