Having your own home is always great. And when it is made with your own hands, what is not a reason for pride? But not everything is 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 of how to build a foundation.
Foundation and its choice
Before you begin to practice, you need to understand the theory. First, let's find out what a foundation is.
This is a solid foundation that bears the brunt of the building. The future of the house depends on the correctness of its choice and installation.
Laying the foundation can only be started when each type of foundation has been studied in detail, all the features have been compared with the design of the house, the geological and climatic characteristics of the area.
What you should pay special attention to when choosing a foundation:
- architectural building project;
- possible load on the soil;
- building weight;
- ground type;
- availabilitycellars;
- groundwater depth;
- material and total building area.
It will be difficult for an ordinary person to understand the intricacies of geological data. Therefore, it is recommended to involve a specialist who will help in this matter.
Main types of foundation
The classification of bases depends on many factors, but most often when choosing, they are guided by the characteristics of the soil.
Main types of foundation:
- columnar;
- ribbon;
- pile;
- slab.
Let's look at each in more detail.
Pillar Foundation
The most common and cheapest type of foundation is columnar. It is used for the construction of light buildings - gazebos, terraces, bathhouses, small wooden houses, low-rise buildings without basements.
Such a base is suitable for soil with a large freezing depth, as well as for sloping terrain. But it can be dangerous on weakly bearing and horizontal soils.
The design of the column base is a pillar or pedestal, located from each other in a certain step and immersed in the ground to the estimated depth. From above, the pillars are combined with randbeams.
There are two types of column base:
- Monolithic. Reinforced concrete is poured into the foundation formwork.
- Team. Installation consists in the installation of ready-made parts made of stone, brick, block, asbestos pipes.
According to the design differences, the columnar foundation can bedivided into two groups - columnar and columnar with a grillage - a reinforced concrete frame under the bearing walls of the building.
Material for poles can be:
- brick;
- tree;
- natural stone;
- asbestos pipes;
- blocks.
Strip foundation
Another foundation for the house, which is used most often, is tape. Such a base is being built for the construction of heavy buildings with basements, but is also applicable for light structures.
A tape of a certain material is laid around the entire perimeter of the future building. It should be everywhere with the same cross-sectional shape.
According to the type of construction, strip bases are divided into:
- Monolithic. Such a foundation is erected directly on the spot. The bottom line is that the reinforcement frame is poured with concrete.
- Teams. Such a base is made of reinforced concrete blocks. And for installation, specialized equipment is required.
Depending on the materials used, the strip foundation is divided into:
- Rubble. Pretty labor intensive foundation. For its construction, flat stones are used, which are stacked on top of each other and fastened with cement mortar. The thickness of such 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.
- Bubble concrete. For its construction, a solution with a certain filling is used, which is chosen depending onfrom soil and moisture. It can be gravel, crushed stone, broken brick, small rubble stone. The mortar is used either cement or cement-lime.
- Filler (concrete). Homogeneous narrow (up to 35 cm) foundation. Most often used for light buildings. It consists only of pure concrete mortar, which is tightly rammed. To make it last longer, it should be strengthened with special reinforcement for the foundation.
- Pile-tape. The bottom line is piles clogged at the corners of the trench. The pile driving depth is about half a meter.
- Brick. Suitable for areas with dry soils. The tape is being built from brickwork 38-64 cm thick, which is poured with a mortar of cement and sand.
The characteristics, the severity of installation and the cost-effectiveness of the strip foundation depends entirely on the design and choice of materials.
Pile Foundation
The pile foundation is similar to the column foundation. Differs in profitability and small volume of necessary material. Used to build private houses and light buildings from various components (from wood to concrete).
Pile foundation is being erected in areas with unstable and weak soils, as well as 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, which are interconnected by grillages. Piles are supports sunk deep into the ground and transferring the load to the soil. Grills, in turn, are necessary to transfer the weight of the building to the piles.
The most commonly used materials are:
- Wood - mainly pine, which has undergone special processing. Used for small private houses.
- Reinforced concrete. Designed for the construction of buildings with great weight.
- Metal (steel). They are used when it is not possible to use concrete piles.
- Combination of metal and concrete. Best option when building on difficult terrain, such as swampy soils.
By design, piles are divided into:
- Printed. To drive into the ground, an impact force or an indentation method is applied.
- Screw. The principle of operation is that the piles are screwed into the soil.
- Aspic. 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 in terms of the price of materials, but also in terms of the cost of installation work. Nevertheless, it is advisable to use it in areas with uneven soil, if groundwater lies close to the surface, etc. Such a foundation is most often required 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 such a structure can be 0.3 … 1.0 m, which is determined by certain calculations. Reinforced strength gives foundation reinforcement with a diameter of 12-25 mm.
This foundation has maximum reliability and durability. In addition, it is highly resistant to both vertical and horizontal loads.
How much does the foundation cost
Price depends on:
- Designs. The number of floors and the necessary materials are taken into account. That is, the heavier the building, the stronger the foundation must be. Therefore, before starting work, it is imperative to calculate how much the foundation costs.
- Foundation type. The presence of basements, plinths, supports is taken into account. The risk of groundwater penetration requires the use of special hydrotechnical concrete.
- Used materials for waterproofing.
- Additional resources for reinforcement and formwork for the foundation.
It is inappropriate to describe the prices in this case, since the cost of each individual item may differ in different regions.
Formwork
Formwork is a temporary or permanent (removable and non-removable) structure, which is necessary for shaping concrete and reinforced concrete structures. Most often, wooden boards are used for the construction of formwork, sometimes plywood or metal sheets.
For the construction of a strip base, temporary formwork is usually used, but a permanent formwork is used to build a foundation from pillars (piles). Although the second type of formwork has begun to gain popularity, because polystyrene foam is used for its construction, which improves the thermal insulation of the base.
Stages of formwork installation:
- Remove and level the area.
- Prepare the boards. Shields on the side where the concrete will be poured should be as clean and smooth as possible. After the mortar has hardened, all irregularities will be visible.
- Think about fixing the formwork. It should be such that no deformation occurs during solidification.
- Boards fit tightly together 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 strip foundation formwork:
- Guide 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 stops should be installed. You can also wear metal clamps.
- Now you need to install the shields, the plane of which should coincide with the edge of the board. Be sure to fasten. The shields installed against each other are fixed with the help of spacers and wire twists. The spacer is a wooden beam with a section of 50 × 50 mm. The most convenient shield length is 2-3 m.
- Formwork from boards is knocked down with nails. When hammering, their hats should be inside the formwork, and the ends of the nails that protrude from the outside need to be bent.
- You can start pouring.
Rebar
Reinforcement for the foundation belongs to the class of rolled metal. The main function is to strengthen the structure, give it shape, resist soil defects.
Most often made of steel, but the development of modern technologyled to the emergence of fiberglass structures - composite. Such reinforcement, according to manufacturers, is several times stronger than steel.
Rebar has its own marking and classification. But for reinforced concrete structures, only three types are used (according to the standards):
- corrugated (or smooth) hot-rolled with a section of 6-40 mm;
- corrugated with increased strength due to the use of thermomechanical method, with a section of 6-40 mm;
- cold-formed 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 (assembly) fittings. Features smooth surface and round cross section. Suitable for those parts of the base where the load is small.
- Class A-III. Working armature. Features a ribbed surface that provides increased strength and the ability to withstand heavy loads.
Strip foundation
If the choice fell on a strip 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.
Steps on how to pour the foundation:
- Clear the site for future construction.
- With special care, mark the internal and external boundaries of the foundation of the building. For this, improvised means are useful - ropes (fishing lines) and pegs (pieces of reinforcement). First you need to define the axisfuture building. Using a plumb line, we outline the first corner of the building. Further perpendicular to it, two more. The fourth angle is calculated using a triangle. We check the angles by drawing diagonals. Now we drive in the pegs and pull the rope. We make the internal markup according to the same principle, departing 40 cm from the external one.
- When the markup is ready, we start digging a pit. To do this, select the lowest point of the perimeter. It is important to consider that the depth should be below the freezing of the soil. It is also necessary that the bottom be optimally flat and the walls vertical.
- Now you need to build a sand cushion. It is needed to reduce pressure on the soil. The sand must be slightly moistened beforehand. The thickness of the pillow is usually no more than 15 cm. A fishing line is used to control the height. Sand is rammed with an electric tamper or a wooden beam. To make the foundation stronger, a layer of rubble is poured on top and waterproofing is installed.
- Next, the formwork for the foundation is being built and reinforcement is laid.
- Now we proceed directly to the question of pouring the foundation. It is important to remember that the cement must be strong and fresh. Concrete should be poured in layers of no more than 20 cm. This is done continuously, the formwork walls must be tapped (to avoid voids).
A few tips:
- start pouring the foundation immediately after the trench has been dug;
- wet the sand before making an air cushion;
- the thickness of the concrete between the reinforcement and the sand cushion must be at least 7 cm;
- Waterproofing can be done 3-5 days after pouring the foundation.
In closing
In the article we figured out what a foundation is and what it is 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 has been studied, you can begin to practice, boldly moving towards the construction of your dream home.
