Own home is always beautiful. And when it is done with your own hands, then what is not a reason for pride? But not so simple. Before proceeding with the construction of the building itself, you need to prepare the foundation. What it is, what it happens, how much it costs - this article will tell. Also in this material we will consider in detail the question regarding how to build a foundation.
Foundation and its choice
Before you begin to practice, you need to understand the theory. First, find out what a foundation is.
This is a solid foundation that bears the whole burden of construction. The future of the home depends on the correctness of its selection and installation.
The foundation laying can be started only when each type of foundation is studied in detail, all the features will be compared with the design of the house, geological and climatic characteristics of the area.
What you should pay special attention to when choosing a foundation:
- architectural design of the building;
- possible load on the soil;
- construction weight;
- soil type;
- the presence of basements;
- groundwater depth;
- material and total area of construction.
It will be difficult for an ordinary person to understand the intricacies of geological data. Therefore, it is recommended to attract a specialist who will help in this matter.
The main types of foundation
The classification of the bases depends on many factors, but most often, when choosing, they are guided by the characteristics of the soil.
The main types of foundation:
- columnar;
- tape;
- pile;
- plate.
Let's consider each in more detail.
Column foundation
The most common and cheapest type of foundation is columnar. It is used for the construction of light buildings - gazebos, terraces, baths, small wooden houses, low-rise buildings without basements.
Such a base is suitable for soils with a large freezing depth, as well as for terrain with a slope. But it can be dangerous on weakly bearing and horizontal soils.
The design of the columnar base is a pillar or pedestal, located from each other at a certain step and immersed in the ground at a calculated depth. On top of the posts are combined using random beams.
The columnar base is of two types:
- Monolithic. Reinforced concrete is poured into the formwork for the foundation.
- National team. Installation consists in installing finished parts from stone, brick, block, asbestos pipes.
According to structural differences, the columnar foundation can be divided into two groups - supporting columnar and columnar with grillage - reinforced concrete frame under the supporting walls of the building.
The material for the posts can be:
- brick;
- tree;
- natural stone;
- asbestos pipes;
- blocks.
Strip foundation
Another foundation for the home, which is used most often, is tape. Such a base is being erected for the construction of heavy buildings with the presence of basements, but is also applicable for light structures.
Around the perimeter of the future building is laid a tape of a certain material. It should be everywhere with the same cross-sectional shape.
By type of construction, the tape bases are divided into:
- Monolithic. Such a foundation is being erected on the spot. The bottom line is that the frame of the reinforcement is poured with concrete.
- National teams. Such a base is made of reinforced concrete blocks. And for installation you need specialized equipment.
Depending on the materials that are used, the strip foundation is divided into:
- Butovy. Quite a laborious foundation. For its construction, flat-grained stones are used, which are stacked on top of each other and fastened with cement mortar. The thickness of such a masonry can reach 70 cm. If there are a lot of such stones at the construction site (in nature), then this will be an excellent budget solution.
- Concrete. For its construction, a solution with a certain content is used, which is selected depending on the soil and moisture. It can be gravel, crushed stone, broken brick, a small rubble stone. The solution is used either cement or cement-lime.
- Jellied (concrete). Homogeneous narrow (up to 35 cm) foundation. Most often used for light buildings. Its composition includes only clean concrete mortar, which is densely compacted. That he served longer, it should be strengthened with special reinforcement for the foundation.
- Pile and tape. The bottom line is the piles hammered in the corners of the trench. The pile driving depth is about half a meter.
- Brick. Suitable for terrain with dry soils. The tape is built from brickwork 38-64 cm thick, which is poured with a solution of cement and sand.
The characteristics, severity of installation and the efficiency of the strip foundation completely depend on the design and choice of materials.
Pile foundation
The pile foundation is similar to the column foundation. Differs in profitability and a small amount of necessary material. Used for the construction of private houses and light buildings from various components (from wood to concrete).
A pile foundation is being erected in an area with unstable and weak soils, and also when the building site has significant height differences - from half a meter or more.
The design principle is the presence of a certain number of piles that are interconnected by grillages. Piles are piers that are sunk deep in the earth and transmit the load to the soil. Grillages, in turn, are necessary to transfer the weight of the structure to the piles.
The most commonly used materials are:
- A tree is basically a pine tree that has undergone special processing. Use for small private houses.
- Reinforced concrete. Designed for the construction of buildings with high weight.
- Metal (steel). Applied in the case when it is not possible to use concrete piles.
- Combination of metal and concrete. The best option when building on complex soil, for example, on marshy soils.
By design, piles are divided into:
- Stuffed. To drive into the ground, an impact force or an indentation method is used.
- Screw. The principle of operation is that the piles are screwed into the soil.
- Jellied. The bottom line is to pour the concrete foundation into the installed frame.
Slab foundation
A slab base is a rather expensive foundation not only at the price of materials, but also at the cost of installation work. Nevertheless, it is advisable to use it on terrain with uneven soil, if groundwater lies close to the surface, etc. Such a foundation is most often in demand in the construction of heavy buildings.
The slab foundation for the house is a monolithic reinforced concrete slab of the required height, which is made directly at the construction site. The thickness of this design can be 0.3 ... 1.0 m, which is determined by certain calculations. Reinforced strength gives reinforcement for the foundation with a diameter of 12-25 mm.
Such a foundation has maximum reliability and durability. In addition, it is highly resistant to both vertical and horizontal loads.
How much is the foundation
The price depends on:
- Constructions. The number of floors and the necessary materials are taken into account. That is, the heavier the building, the more solid the foundation should be. Therefore, before starting work, it is imperative to calculate how much the foundation costs.
- Type of foundation. The presence of basements, socles, supports is taken into account. The risk of groundwater penetration requires the use of special hydraulic concrete.
- The materials used for waterproofing.
- Additional resources for reinforcement and formwork for the foundation.
In this case, the prices are impractical to describe, since the cost of each individual item may differ in different regions.
Formwork
Formwork is a temporary or permanent (removable and non-removable) building, which is necessary for shaping concrete and reinforced concrete structures. Most often, for the construction of formwork, wooden boards, sometimes plywood or sheets of metal, are used.
For the construction of the tape base, temporary formwork is usually used, but the permanent one is used to build the foundation from pillars (piles). Although the second type of formwork began to gain popularity, because polystyrene foam is used for its construction, which improves the thermal insulation of the base.
Stages of mounting formwork :
- Remove and level the area.
- Prepare boards. The boards on the side where the concrete will be poured should be as clean and smooth as possible. After the solution solidifies, all irregularities will be visible.
- Consider fixing the formwork. It must be such that no deformation occurs during solidification.
- The boards fit tightly to each other and knock down. The maximum allowable gap is up to 3 mm. If the cracks are large, they are covered with tow or clogged with slats.
Installation of formwork for strip foundations:
- Guiding boards are mounted. So that the shields do not disperse under the pressure of the concrete mass, they are fixed outside with pegs. If the foundation is more than 20 cm, then the stops should be installed. You can also wear metal clamps.
- Now you need to install the boards, the plane of which should coincide with the edge of the board. Be sure to fix it. Fixation of shields installed against each other is carried out using struts and twists of wire. A spacer is a wooden beam with a section of 50 × 50 mm. The most convenient length of shields is 2-3 m.
- The formwork of the boards is knocked down by nails. When driving, their hats should be inside the formwork, and the ends of the nails that protrude from the outside must be bent.
- You can start pouring.
Fittings
Armature for the foundation belongs to the class of metal. The main function is to strengthen the structure, shape it, and resist soil defects.
Most often made of steel, but the development of modern technology has led to the emergence of fiberglass structures - composite. Such reinforcement, as the manufacturers say, is several times stronger than steel.
The fittings have their own marking and classification. But for reinforced concrete structures, only three types are used (according to the norms):
- corrugated (or smooth) hot-rolled with a section of 6-40 mm;
- corrugated with increased strength due to the use of the thermomechanical method, with a cross section of 6-40 mm;
- cold-deformed corrugated with a diameter of 3-12 mm.
How to build a foundation? For the construction of the foundation, the following classes of reinforcement are used:
- Class A-I. Distribution (mounting) fittings. It features a smooth surface and a round cross section. Applicable for those parts of the base where the load is small.
- Class A-III. Working fittings. It has a corrugated surface, which provides increased strength and the ability to withstand heavy loads.
Strip foundation
If the choice fell on a tape base, then it is important to know how to fill the foundation. And this must be done so that the base lasts a long time and is safe.
Stages of how to fill the foundation:
- Clear the plot for future construction.
- With particular care, mark the internal and external borders of the foundation of the building. For this, improvised means are useful - ropes (fishing lines) and pegs (pieces of reinforcement). First you need to determine the axis of the future building. Using a plumb line, we outline the first corner of the building. Further perpendicular to him, two more. The fourth angle is calculated using a triangle. Check the angles by drawing diagonals. Now drive in the pegs and pull the rope. We do the internal marking according to the same principle, departing 40 cm from the external.
- When the markup is ready, proceed to digging the pit. To do this, select the lowest point of the perimeter. It is important to consider that the depth should be below freezing. It is also necessary that the bottom is optimally flat and the walls are vertical.
- Now you need to build a sand cushion. It is needed to reduce pressure on the soil. Sand should be slightly moistened beforehand. The thickness of the pillow is usually not more than 15 cm. To control the height, use a fishing line. The sand is rammed with an electric rammer or wooden beam. To make the foundation more durable, a layer of crushed stone is poured on top and waterproofing is installed.
- Next, the formwork for the foundation is built and the fittings are laid.
- Now we proceed directly to the issue of pouring the foundation. It is important to remember that cement must be strong and fresh. Concrete should be poured in layers of not more than 20 cm. This is done continuously, the formwork walls are tapped (to avoid the appearance of voids).
A few tips:
- to start pouring the foundation is immediately after the trench was dug;
- moisten the sand before making an air cushion;
- the thickness of concrete between the reinforcement and the sand cushion should be at least 7 cm;
- waterproofing can be done 3-5 days after pouring the foundation.
Finally
In the article, we figured out what a foundation is and what it is needed for. We also examined in detail its types and found out what affects the cost of the foundation. We learned how to build a foundation in stages. And now, when the theory is studied, you can begin to practice, boldly moving towards the construction of your dream home.