Pile foundation - an inexpensive and not time-consuming solution for the construction of the foundation of the house. It is important to ensure the joint work of individual elements for a reliable foundation for the building. The binding of screw piles is carried out after screwing and cutting to the desired length. An event can be completed in several ways.
Harness selection
Before starting work with your own hands, you need to choose which element will play the role of the foundation grill. There are several options for tying a pile foundation:
- timber;
- metal rolling;
- reinforced concrete.
The choice depends on the design of the building. For a frame or wooden house, a beam is suitable. The bearing capacity of the piles does not allow massive buildings to be supported on them, but if it was decided to build a small one-story house of foam concrete or brick with your own hands, it is better to choose rolled metal or reinforced concrete as a pile grillage.
Timing
It is important to choose the right material for the manufacture of grillage. The following recommendations can be made regarding the choice of wood:
- the minimum cross-sectional size is 150x150, the value is selected depending on the load;
- wood for production must be coniferous species of the first or second grade;
- the material should not be affected by rot, fungus or mold;
- it is best to choose wood felled in the northern regions in late February-early March, this will ensure high quality and durability of the upper layer;
- before purchasing the material, the necessary quantity is calculated, 3-5% is added to the resulting value for unforeseen expenses;
- normalized moisture content of wood - 12%.
Timing is performed in the following order:
- processing purchased wood with antiseptic compounds and flame retardants to increase fire resistance;
- during the drying of the impregnating compositions, the pile heads are checked, which should be at the same level (using a laser or water level);
- roofing material or other rolled waterproofing material is laid on the pile heads (the use of roofing is highly not recommended, since this waterproofing is outdated and cannot provide reliability);
- they connect the corner elements of the timber trim (this can be done by connecting "in the paw" or "into the floor of the tree"), preliminary cuts are made on the wood;
- at the junction of the beam they lay jute;
- lay out linear elements (fastening to the pile is performed in the same way);
- the joining of the beam along the length is performed “into the floor of the tree” or “oblique cut”, while the joints are placed only above the heads, the location of the joints on the spans is unacceptable;
- in wooden beams, holes are drilled that pass through;
- in order to mount, bolts or studs are threaded through the holes in the heads and piping and tightened.
You can strengthen the joints of wood with a corner when connecting at right angles and with trims and brackets when connecting along the length. You can tie the foundation of the house in two rows, while the joints of the lower beam should not coincide with the joints of the upper.
Steel wire harness
There are several rental options that are used as grillages. The binding of screw piles with a channel, an I-beam, a pipe of square or rectangular section can be performed. Between the grillage and the head there is no need to lay waterproofing, since these elements are made of one material - steel. Waterproofing should be provided between the grillage and the wall of the house.
Rosverk from the channel is positioned so that when cut along a vertical plane, it takes the form of the letter P. Connection of structural elements to each other is performed for welding. The I-beam is positioned so that the wall is in an upright position.
When using the channel do not use heads, for the I-beam and pipe they are needed. In the manufacture of channel grillage, the upper part of the pile is poured with concrete, in which the part is laid. To fix to the foundation of the house after hardening concrete, this part is welded to the channel. I-beams and pipes for the foundation are also fixed by welding on the annular seam.
Reinforced concrete grillage
The grillage for a fairly massive house can be made of reinforced concrete. There is also an option for concrete strapping, without reinforcement. Use this design with caution.
Do not lay reinforcement in the grillage only if the following conditions are met:
- the distance between the piles is small;
- the load on the foundation is small;
- the type of grillage is in-depth and not deep (the use of the hanging is unacceptable).
The device of reinforced concrete grillage for the foundation of the house is performed in the following order:
- Put formwork from the boards. For the device, it is enough to buy lumber 22-25 mm thick.
- Lay reinforcement. The rods are welded with piles to ensure the joint work of the elements. Depending on the height of the grillage, the number of rows of reinforcement is selected. With a height of more than 150 mm, at least 2 rows must be provided, for a thickness of 150 mm or less, one is enough. The diameter of the reinforcement depends on the pitch of the piles and the load, on average, a diameter of 14-16 mm is taken. Also affects the location of the element relative to the ground. For structures that rely on the soil throughout the span, reinforcement is required less than for hanging harnesses. Reinforcement class - А400. Three types of rods are used for the frame: workers, transverse clamps, vertical clamps. The diameters of the clamps can be assigned from design considerations of at least 8 mm. It is important to lay the reinforcement also inside the piles for the joint work of the structure.
- Concrete is being poured. It is best to carry it out at a time. The maximum number of steps is -2. In this case, the gap between the layers with different fill times should be horizontal, and not vertical. The class of concrete is largely dependent on the location of the element. When resting the entire span on the ground, a mixture of B20 - B22.5 is sufficient. For hanging, stronger concrete may be needed depending on the load and pitch of the piles.
- Hardening and maintenance of concrete. You can remove the formwork after a set strength of 70% of the brand. The design gains 100% strength at a temperature of + 20 ° C within 28 days. Care consists in moistening the surface and preventing evaporation from it.