How to pour a strip foundation

Strip foundation is most often used in a private building in the construction of cottages, garages, bathhouses.It is cheaper to design a solid foundation, with more functional than a foundation pile type, and is ideal for buildings with a basement used.

Materials

Filler strip foundations made of concrete grade 200. It can be ordered or cook yourself.Note that this is a very time-consuming work, and the foundation, filled with small portions, will be uneven.Composition for casting concrete foundation cement, coarse sand and gravel in a ratio of 1: 2: 2.5.

Besides the concrete for the foundation needed:

• planed board 20 mm thick shuttering;
• steel rod of 8-12 mm and a wire for reinforcement of the foundation;
• River sand for sand cushion.

Preparations

before properly pour a strip foundation, must be ordered in engineering and construction firm geodetic survey plot to determine the type of soil and the depth of its freezing in the winter months, as well as the depth of the groundwater.After examining the company will calculate and execute the foundation device project.For the construction of the cottage to perform these works alone is not recommended, foundation settlement under the small house, a bath or a garage can be carried out independently taking into account the recommendations of SNiP II-B.1-62 or use a table.

Layout area

markup - the most important stage of the foundation unit.Before you start marking area must be cleaned of debris and foreign objects, as well as to cut the soil to a depth of 15 cm, to avoid biological decomposition processes in the building basement.

marking technology:

1. Determine the axis of the building and the location of the first corner.Install a peg, using a plumb line.As the peg can be used cutting rebar.
2. pulls the string on the first peg, forming a perpendicular, and mark out the distance on the project of the second and the third angle, set pegs.
3. From the second and third angle pull the string toward the fourth, put on a square corner, put a peg.
4. have obtained the rectangle outlining the outer contour of the building, check the diagonal.If all built right angles, diagonals should be equal.
5. a similar way mark out the inner contour of the foundation, as well as the contours of the foundation for some of its elements: bearing walls, porch, terrace, under the column support.
6. To align horizontal layout set at the correct height wooden slats, through which the twine is pulled.

Earthworks

To fill the basement must be prepared trench with the depth specified in the project.To begin you need to dig a trench from the lowest angle to the excavation depth was not less than the calculated.The walls of the trench should be possible to carry out the vertical, if the ground is crumbling - you can set temporary backup.The bottom of the trench must be aligned and periodically check the level of the lack of bias.

The finished trench is poured a layer of river sand, forming a cushion of at least 15 cm. It is necessary for load transfer to the foundation, especially in heaving soils.Sand sleep in layers, each layer shed water and tamped.

Installing formwork

Formwork operate on a path marked up with twine.

1. Install corner posts of the bar is 50 mm.Once again, check the diagonal foundation.
2. From edged boards collect formwork planks are fastened to each other by bars or metal brackets and screws.Caps screws must remain inside the formwork, and bars and corners - from the outside.
3. From the outside the backup set, to avoid deformation of the formwork when the concrete is poured.
4. formwork height above the ground shall be such as to ensure that the height of the foundation at least 30 cm.
5. Inside the basement indicate the level at which produce concrete pouring.

fittings Laying

as reinforcement using metal rods with a diameter of 8-12 mm, cut to length and laid the foundation length and breadth of the axis, and at a depth of over foundation0.4 meters - even vertical.Valves attached to the walls of the formwork and bonded together by a steel wire.Welding is not recommended because of the reduction in metal corrosion resistance and field welding reducing its flexural strength.

Pouring the foundation

pouring concrete produced simultaneously in the case of an order or ready-mixed concrete in layers, if the concrete is prepared independently.

1. Preparation concrete cement mixed with sieved river sand in the ratio 1: 2 - 1: 2.5, and diluted with water to a consistency of liquid cream, and then pour them prepared gravel.Rubble take as much sand.Stir so that all the rubble proved moistened with a solution.
2. Pour concrete into prepared formwork.For better filling pierce the concrete in several places with a metal bar and sealed with a wooden block, removing the remains of the air voids.It can be used for this purpose punch with a special nozzle or mixer construction.
3. filled with concrete up to the level indicated on the formwork.This rattle shuttering on the outside for better concrete slump.
4. upper layer align rule or trowel.
5. mirror Dust sifted dry cement concrete, you can make it through a sieve.This technique will allow faster to grab the top layer of concrete, prevent its erosion or cracking.
6. Cover the concrete with burlap or cover material and left to mature for 3-4 weeks.In dry weather, you need to sprinkle the top layer of concrete to prevent it from drying out.

To begin the construction of the walls can be only after the concrete maturation.After removal of the formwork must perform the waterproofing of the foundation to increase its service life and heat and damp-proofing characteristics.

Also be sure to read about: a pier foundation raft, and you will be the next step waistrail frame house.