by BRE (11-Jul-2002)
Pitched roofs can be constructed in several different ways. They can be built in situ with each piece cut and fitted individually, they can use prefabricated or site-made trusses to support in situ fitted purlins and rafters, or they can be built with prefabricated trussed rafters forming the complete roof structure. Prefabricated roofs have become the most common form of construction in recent years but there are situations where a purpose designed and site-built roof (often referred to as a "cut" roof) may be preferred.
In Part 1, this guide explains the principles of this type of construction and describes patterns of roof structure and design considerations. Part 2 describes a method of fabricating and constructing a typical domestic site-built roof.