Any construction starts with the foundation. The types and sizes of the foundation depend on the building that will be built on it. The higher the weight of the building, the more thorough the foundation. For the construction of a wooden house or a house of foam concrete blocks, a strip foundation is perfect. The main advantage of the strip foundation is that it can be built with your own hands without the use of heavy construction equipment.
Conventionally, the construction of a strip foundation can be divided into several main stages.
Markup.
To simplify the process of marking, the site chosen for the construction of the house should be leveled, cut the shrub and tall grass. Then, at the location of one of the walls of the building, designate the edges of the foundation with hammered pegs, conditionally naming them A and B. The main task of marking is to give the contours of the building the correct shape with right angles. For this, there are special geodetic instruments. But you can do without them. To do this, you have to remember the school course of geometry. A distance equal to the edges of the foundation of the perpendicular wall deviates from point A perpendicular to the straight line AB. We denote this point by the letter B. Now we have a right triangle, legs AB, AB. Knowing the dimensions of the legs, you can calculate the length of the hypotenuse BB and compare with what happened on the ground. If necessary, the peg should be moved to the desired point. Similarly, the location of the fourth corner of the foundation is determined. Laser tape measure is best for distance measurements.
Trench under the foundation.
A trench under the foundation is dug strictly according to the markup. The width of the trench is 40-50 cm, but the depth should be determined by the depth of freezing of the soil. Digging should be 20 cm below the freezing depth. Then, no movement of the soil and its expansion during freezing will be scary for the foundation. Before pouring the foundation, a sand cushion 20 cm high is poured into the bottom of the trench and rammed tightly.
To save, sometimes use the pile-tape method. At the corners of the foundation and around the perimeter, reinforced piles are poured to the freezing depth every half meter. The reinforcement from them should stick out to the height of the strip foundation. This is necessary for a strong bond of the main strip foundation and the piles themselves. In this case, the foundation tape may be shallow.
Formwork.
Before pouring the foundation, it is necessary to erect the formwork, which will give the foundation the necessary shape. Formwork can be made of boards with a thickness of 40-50 mm. Also suitable sheets of chipboard or sheet slate. The upper edges of the entire formwork should be an ideal horizontal surface. If you assemble the formwork from the boards, then its inner edges should be covered with a film to prevent leakage of cement and facilitate its subsequent disassembly. To prevent the formwork from bursting under the weight of the cement, spacers are installed on the outside of the structure. To ventilate the internal volume of the foundation in the formwork, round holes are cut from both sides where plastic pipes are inserted.
Reinforcement.
To give the foundation tensile strength, the internal volume of the formwork is filled with a reinforcement frame of iron reinforcement with a cross section of 8-10 mm. Between themselves, the reinforcement is connected with a special soft metal wire.
Fill.
For pouring use a concrete mortar brand M300. The solution can be bought ready-made, but for this you should accurately calculate the volume of the foundation. With this option, there is one significant minus. The whole solution should be worked out in 1-2 hours, otherwise it will become unusable. You can fill the foundation yourself. To do this, you will need sand, gravel and cement. Mixing proportions are usually indicated on cement bags. A small electric concrete mixer will significantly speed up the process of preparing the mortar. Fill should be exactly along the upper edges of the formwork.
Drying out.
After pouring, the foundation should be covered with a film in rainy weather and left to dry. If the weather is hot, the foundation needs to be watered. After drying, you can remove the formwork and begin building a house.
