Marking up the battens ready to line out a new natural slate roof in Sheffield. Before any slates go on, the battens are marked so every slate ends up in exactly the right place.

Why we set out a slate roof:

Slates are laid so each vertical joint (the perp) sits over the middle of the slate below, so rain runs off the face of the slate instead of through the joints.
Marking out keeps the perps in a straight line from the eaves to the ridge. Without it, small errors build up course by course and the joints drift.
It lets us plan the verges so the roof finishes neatly, with no thin, weak cut slates at the edges.

It’s the part of the job most people never see, but it’s what makes a slate roof look right and stay watertight for years. Paisley Roofing have been roofing in Sheffield for 28 years, carrying out new roofs, re-roofs, slating, tiling, leadwork, chimney repairs and drone roof inspections.