Setting out of a building
A building is set out in order to clearly define the outer line of the excavation and the centre line of the wall. This can done manually or using EDM equipment. When doing it manually the first thing is to identify where the centre line is and plot this on the land. Identify the boundaries on site, and set where the North of the site will be. You should have a clean site and use uniform and suitable materials if doing it by hand, such as equal size picks, chalk and a measuring tape. First locate point A, the corner of the building and set your pick 1m away from point A. You can then measure from point A and get point B. Fix another pick perpendicular from point A, 1m away then set a straight line from this point using Pythagoras and establish the rue length of the site point C. Point D is set using Pythagoras again and that gives you the house perimeter. The foundations can be marked from this point.
I have seen the effects of when setting out goes wrong and not only is this costly to repair but it is also potentially dangerous as the external leaf of the building isn’t supported and eventually, especially when live loads are introduced the walls will begin to crack. When you have cracking on the external leaf of a newly built building it’s a sign that the external wall isn’t withstanding the pressure being put on it. If the wrong calculations have been used or due diligence hasn’t been carried out when setting out the outer leaf can be unsupported which is dangerous and expensive to fix.