you need
  • - cement;
  • - sand;
  • - fittings;
  • - boards for formwork;
  • - building tools (trowel, shovel, ax, etc.);
  • - cord;
  • - gidrouroven or flexible hose.
Withdrawal foundation "by zero" during its pouring

Put a marker or chalk in a corner of the foundation poured inside the formwork mark the planned surface (zero point).With gidrourovnya define and mark the similar zero points in the other corners of the foundation.
the absence gidrourovnya zero points can be set at the corners with a normal hose.To do this, place the ends of the hose in two corners of the matching tools.Fill it with water, making sure that there was no formatio
n of air pockets.Set the edge of one end of the hose exactly at the level of the original zero point.
raising or lowering the other end until you get to the end of the water in the first set at the level of the edges of the tube (ie at the level of the initial zero).Fix the position in which the water is established in the second end of the hose.This position corresponds to the zero point.Mark it on the formwork.
Make every corner of the basement, two vertical cutting in the formwork so that they are located in the middle of the foundation walls, and their lowest point is flush with zero points.Now, if you pull the cord through the appropriate cuts, it will definitely mark the zero level surface of the foundation.
Pour concrete mix into the mold to a level strung cords.Thus, your foundation will be derived "under a zero."
Withdrawal "under zero" already finished basement

gidrourovnya or hose Check the position of all the corners of the foundation height, taking one for the source.Make all corners of the digital marking, reflecting the position of the angle relative to the original.(For example, "-50" and "30" means that the active corner 50 mm or below 30 mm higher than the initial angle).
Set on top of the foundation formwork consisting of two boards, the lower edge of which cover the foundation with the two sides and the top are connected via a spacer having a length equal to the thickness of the foundation.
Mark in all the corners of the inside of the casing zero points, to which should be poured the foundation, based on the actual position of the corners, as defined in the previous step.Through this operation, keep in mind that the minimum thickness dozalivaemogo fragment of the foundation should be at least 30-40 mm.Too thin layer of concrete to be fragile.Make cuts in the formwork to their lower edges are at zero marks (similar to as was done in step 3).
Set formwork reinforcement.Prepare a mixture of sand and cement with a ratio of 1: 3 or 1: 4.Moisten the surface of the basement with water and place the mixture into the mold.Compliance with the zero level surface, check a piece of rope through the cuts.