Setting-Out for Corners at Foundation Level
Using a spirit level, transfer the wall line vertically down to foundation level from the setting-out string-lines. Marks can be made with a trowel point in a very thin mortar screed
(approximately 3mm thick) spread with the back of the trowel blade on top of the foundation.
Setting-out line for position of wall
Trowel marks plumbed down from setting-out lines to mark position of wa at foundation
Thin mortar screed
Using the spirit level as a straight-edge and with the point of the trowel, join up the four marks to form a complete right-angle in the mortar screed. Check the right-angle for accuracy with a builder’s square.
Any inaccuracy at this point will be as a result of shortcomings in the positioning of the setting-out lines and/ or in the process of plumbing down from them. It will need to be investigated and corrected
before proceeding. Once setting-out at foundation level is complete, the corner can be constructed (see Fig 132).
Fig. 132 The stages of building a corner.