Horsham Stone Roofs : Guidance Note

Horsham stone is a group of sandstone beds in the Weald Clay of south-east England, centred around Horsham, West Sussex. Difficulties in obtaining slates for roof repairs resulted in a change of detailing, to make the slates go further. The traditional double-lap was changed to a single-lap system and this resulted in confusion between the two systems. This document describes the current state of affairs and offers guidance in conserving, specifying and constructing these important and often complex roofs.