Pitched roof construction

It is not uncommon for designers of low rise buildings to be instructed by their clients that a requirement for a pitched roof is part of the design brief. This may reflect an aesthetic preference by the client, but is more likely to be due to the opinion that the pitched roof is a traditional and well‐tried construction form. While it is true that pitched roofs do have a generally good record of satisfactory performance, especially when compared with some types of flat roof construction, the structural design of the majority of pitched roofs constructed in the last 25 years is very different from those illustrated in textbooks of ‘traditional’ roof carpentry. In addition to use of trussed rafters, other factors, such as increased insulation or the development of the roof space as habitable accommodation, have similarly changed the way in which the roof performs and the areas of consequent potential risk.