Setting-Out: Stage 4
Attach a ranging line between the nails in the top of pegs ‘C’ and ‘D’ to establish the last wall line. Finally check all the dimensions and then check for square i. e. that all the corners are 90 degrees, by measuring the diagonals, ‘X’ and ‘’Y’. If both diagonal measurements are equal then the setting-out is correct. If they differ to any extent, the following sequence should be followed.
1. Re-check all wall dimensions and correct any small errors by repositioning the pegs. Assuming that the original base line has been set-out correctly 1m away from the existing building, note that pegs ‘A’ and ‘B’ must only be adjusted along the base line and must not be moved off it. Pegs ‘C’ and ‘D’ can be repositioned in any direction.
2. If any errors have been corrected in the first step, re-check the diagonals.
3. If the diagonals are still not equal, pegs ‘C’ and ‘D’ can be moved the same amount in one direction or the other, ensuring that ranging line ‘C’-‘D’ remains parallel with line ‘A’-‘B’ at all times. If ‘Y’ is the shortest diagonal, move pegs ‘C’ and ‘D’ forward towards the front of the site until the diagonal dimensions are equal. If ‘Y’ is the longest diagonal, move pegs ‘C’ and ‘D’ backward towards the rear of the site.