The construction of any building begins with the erection 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 structure is constructed from various building materials. In order to properly build the formwork on the foundation, it is necessary to strictly follow the instructions that will be given in this material. The design features should be considered in more detail.
Formwork assembly conditions
Previously, the structure was assembled using wood, but nowadays high-tech polymer materials are also used. Formwork is erected to perform the following tasks:
- creating the required form in which the concrete solution will solidify;
- isolating the building from the soil.
The construction technology of the structure begins with the preparation of the soil. The site on which the building will be erected should first be marked with a nylon thread and wooden pegs. After that, you need to make sure that the area is cleared of debris. The formwork is made of wooden panels orother building materials. The main thing is that the inner side of the structure is free of contaminants. In addition, the building materials used must be free from defects.
The correct formwork for the foundation is a structure in which the individual elements are firmly connected to each other, since the reliability and durability of the foundation depend on this condition. If this requirement is neglected, then the concrete will collapse in a short time. The tightness of the structure is another technical condition that must be met in order to get a reliable foundation.
Formwork: varieties
There are two types of construction: removable and non-removable. Builders recommend studying the advantages and disadvantages of each of the options in order to figure out which formwork to build for the foundation. These varieties should be studied in more detail.
- Removable formwork is dismantled after completion of the construction of the base. This is a profitable option: building materials can be used again. In this case, the foundation formwork board is most often used.
- The fixed structure is made of polymeric materials (for example, wood concrete or polystyrene concrete). Masters advise building this type of formwork 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 non-removable form 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 type consists of outer and inner layers. As a rule, boards are used to build the outside of the structure, and polystyrene concrete is used for the inside.
Formwork materials
The size and type of the base are the criteria that affect the type of construction mentioned. Builders use the following materials to create formwork:
- metal;
- styrofoam;
- reinforced concrete;
- tree.
If the building will be built on a strip or monolithic foundation, it is recommended to use metal products for organization. To obtain a high-strength structure, in this case, sometimes steel reinforcement is welded to the iron formwork panels. The foundation of the building will be durable if reinforcement is used for it. Versatility 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 well-known and expensive material with which elements of fixed formwork are erected. In addition, the product has high thermal insulation properties, but sometimes there are problems in the selection of individual components for the construction of the structure.
Reinforced concrete is rarely used for the construction of private buildings, since in this case you will have to pay a large sum of money forwork. In addition, building a reinforced concrete formwork on your own is a laborious task. The structure of the mentioned material is assembled from slabs.
Wooden formwork: advantages and disadvantages
The structure of the boards is built most often. This is not surprising, since the process of making wooden formwork does not take much time. If you need to build an inexpensive structure, then for the work it is recommended to purchase sheet plywood, which should be fastened to spacers made of boards.
Availability and low cost are the advantages of wooden formwork, which is also quite easy to install. In this case, the main thing is to clearly follow the instructions and purchase the necessary materials, and the tools you will need are the simplest: a hammer, tape measure, screwdriver and building level.
Wooden formwork for the foundation of the house has some disadvantages, because for its manufacture it will be necessary to use additional elements to strengthen the structure. Such a need arises due to the overall differences in individual parts, so builders recommend that you first carry out an accurate calculation of materials.
Handmade formwork
The structure can be made from flat slate, doors, old furniture and other materials. Cheapness is a key advantage of such foundation formwork. However, it will be very problematic to build the structure correctly, since you will have to carefully selectrequired parts.
You should know: this option is not allowed to be used in the construction of a concrete base for residential facilities. In addition, the formwork must be built in such a way that it is completely airtight, and it will be difficult to fulfill this condition from improvised materials. In this case, special supports should be set in order to obtain a stable and reliable structure
It is recommended to use special studs to tighten the formwork walls.
Laminated plywood: material features
The mentioned material is a standard product that builders recommend to use during the creation of forming formwork elements. This is a moisture-resistant plywood with high technical performance. 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 3mm and the maximum thickness is 40mm. Due to their low weight, plywood panels will be easy to move and connect with other formwork elements.
Wooden formwork: materials needed
Initially, it is necessary to prepare a site on the territory of which the building will be erected. And then purchase the necessary materials and tools. To build a formwork for the foundation, you will need the following building items:
- planed bars 100 x 50 mm;
- cut 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 amount of building materials directly depends on the dimensions of the future foundation. The height of the formwork is required to be carried out so that its level is 5 cm above the plinth.
Quick installation of wooden formwork: step by step instructions
First, you need to make shields from moisture-resistant plywood (laminated), since the forming material should not absorb water: this can lead to a violation of the hardening process of the concrete solution. The outer side must be reinforced with timber, the dimensions of which are 100 x 50 mm, using 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 the wooden sticks should be no more than 1 m.
The next step is to place the prepared plywood panels along the edges of the trench, and then connect them with 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 cut and cover the inside of the structure with a film.
The final stage of work is the installation of a reinforcing grid and pouring concrete. Masters recommend bending plywood sheets if you plan to build 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, the concrete mortar completely hardens after 28 days, but this figure depends on temperature and humidity. Experts recommend not to rush to dismantle the structure, since it is necessary to wait until the concrete gains 50-70% strength.
If the question arises of how long to remove the formwork from the foundation, then the following parameters should be taken into account:
- 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 - must be dismantled after 3-4 days.
- If the temperature reaches 10-15 °C, specialists will dismantle the structure for 5-7 days.
- The formwork is removed after 10 days 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 to carry out work on pouring the foundation in dry and warm weather.
Strip foundation: formwork construction
To organize the indicated foundation, first of all, you need to dig a trench. The next step is the purchase of wooden bars and edged boards. The amount of building materials for each individual project will be different. Masters recommend buying boards with some margin so that you don’t have toin addition to acquire them already in the process of construction itself.
Before you build 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, the mentioned work is best done when the weather is dry. The formwork must be made in the form of a box, which will be installed throughout the trench. The main thing is that the design is airtight, therefore it is recommended to sheathe the boards with roofing material. In addition, the formwork must be strong and rigid, since the poured concrete solution will strongly press on its walls. Builders recommend fastening the structure with jumpers, which must be installed every 2 meters.
If it is planned to build a removable formwork, then the design must be done in such a way that the lumber is not damaged during dismantling.
Concrete base without formwork
If it is planned to build a basement in the building, then such a foundation is not suitable for the construction of an object. In addition, in cold regions, building a base without formwork is a risky and irrational exercise. However, this design has its advantages, namely:
- reducing the cost of foundation construction;
- reducing building construction time;
- reducing labor costs.
To organize a foundation without formwork, you need to do the following:
- Dig a trench, taking into account the dimensions indicated in the project documentation.
- Cover the outer sides with polyethylenefilm.
- Fill the bottom of the trench with a 10 cm layer of sand.
- Strengthen the structure from below and above with steel reinforcement.
- Pour concrete mix.
The brand of cement must be M300 or higher. For example, professionals recommend using the M400 to build a solid foundation.
In conclusion
It is not difficult to make formwork for the foundation 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, therefore it is the technological process of manufacturing formwork from boards that is discussed in detail in the article.
