Valley construction and associated pitched roofing is used:- to visually enhance an otherwise plain roof structure.
- where the roof plan turns through an angle (usually 90°)to
follow the building layout or a later extension. - at the intersection of main and projecting roofs above a bay
window or a dormer window.
Construction may be by forming a framework of cut rafters
trimmed to valley rafters as shown in the roof plan on page 421.
Alternatively, and as favoured with building extensions, by locating
a valley or lay board over the main rafters to provide a fixing for
each of the jack rafters.valley or
lay board
jack rafter
common or
main rafters
wallplate
ceiling
joist
ridge
board
Valley Construction