In individual housing construction, the most common are band-shaped foundations, since they ideally perform their functions on almost all types of soil, are not too difficult for self-pouring, and are also relatively inexpensive. Another common type is pile foundations used on mobile soils. The very first stage of arrangement of such foundations will be the exact calculation of the required number of building materials, their purchase and delivery to the construction site. At the same time, it will be prudent to immediately purchase the entire volume of construction materials in order not to be distracted by additional purchases during the works and have time to complete all the works for one warm season.
Filled foundation
Directly on the construction site, for starters, it is worth to mark out the territory, i.e.designate the boundaries of the future foundation. Make markup should take into account all factors: the occupied area of the future house, its mass, the relief of the ground area of groundwater level, etc. To do this, along the perimeter of the building and along the borders of the inner digging pegs, between which the parallel lines stretch twine. Check the accuracy of observing the mutual perpendicularity of all marking bands by comparing diagonals between the corners of the trench. If they are equal, then all angles are straight.
We make the marking of the future foundation
Digging a trench for foundation pouring
The second stage will be excavating a trench for a basement or drilling wells for a pile. In the trench in the future, the strip foundation will be flooded, and piles are installed in the wells, so care must be taken to ensure the accuracy of these operations. In particular, the walls of the trench must be reinforced with boards forming the foundation of the foundation. Instead of boards it is quite possible to use any other suitable material, however wooden boards are advantageous for their strength, low cost and ease of work with them. The bottom of the trench should be below the depth of freezing of the ground. The minimum difference between these levels is 20-30 cm. The depth of the wells depends on the density of the soil and is usually about two meters.
When pouring a strip foundation it will also be necessary to create a sand cushion on the bottom of the trench. This is done by pouring a layer of sand and then pouring water and tamping it. The thickness of the sand cushion depends on the characteristics of the soil, such as punching. On top of the sand must be laid a layer of tape waterproofing material.
The figure shows a dug trench for the foundation
Reinforcement.
Since the building creates a significant load on the strip foundation, the simple pouring into the trench of the cement mixture is not capable of providing a concrete base with the required strength. To ensure that the foundation is not destroyed by the forces of compression, reinforcing materials should be included in its construction.
Reinforcement of the pile foundation consists in the management of several bars of metal reinforcement before pouring concrete. A more complex spatial construction, consisting of vertical and metal bars placed in the trench, will be required for the tape base. The distance between adjacent( parallel) rods should not exceed 40 cm. To reinforce the rods have not changed the orientation in space, they should be tied with steel wire or seized with electric welding.
Pouring concrete.
Concrete mortar must be made immediately before casting. If it was decided to purchase a ready-made mortar, then in this case it will be delivered to the concrete mixer already ready for use. For a self-made solution it is worthwhile to think about the advance purchase or lease of a mobile compact concrete mixer in order to be able to prepare concrete directly on the construction site. The standard proportions of a concrete slurry are those when about one part of the cement is taken about three pieces of debris-free sand and five pieces of medium-sized rubble.
The figure shows the process of pouring concrete into the formwork
The filling should occur evenly along the entire perimeter of the basement or the circumference around the pile in the well. It should be ensured that there is no void formation in the well or trench. In addition, after completion of pouring, the concrete solution must be additionally compacted by means of a plate compactor or other similar device.
After pouring the foundation concrete will take some time to recruit strength, so immediately proceed to erect the walls of the house is completely unacceptable. The waiting period largely depends on the ambient temperature, but in summer the concrete collects vintage strength in about four weeks.
