Timber Frame Roof Construction Details

The roof sheathing consisted of inch thick wide pine boards nailed to the purlins and thick enough to resist much sagging.

Timber frame roof construction details.

The construction of the flat roof is similar to that of the timber upper floor. Wood frame or glued laminated arches for roof con struction which spring from the floor line or grade and do not support floor loads shall have members not less than 6 inches nominal in width and 8 inches nominal in depth for the lower half of the height and not less than 6 inches nominal in any dimension for the upper half of the height. Below is a sketch of the original roof wall structural details for this building. Many people still think that the roof structures of timber framed buildings look like the upside down hulls of boats.

Modern timber roofs are mostly framed with pairs of common rafters or prefabricated wooden trusses fastened together with truss connector plates. The original roof was built using purlins beams extending between gable ends. Timber framed and historic buildings may be framed with principal rafters or timber roof trusses. An early form of the stud wall only much heavier.

Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. Shipwrights were the original american timber framers. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading.