Timber Flat Roof Construction Details

It must provide adequate protection against the elements keeping the buildings structure and interior dry.

Timber flat roof construction details.

The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. A flat roof must be strong durable and stable throughout its lifetime. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading.

A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. For additional stability you can also use steel joists that are built into one or both of the walls. Others would treat even steeper pitches as flat roofs. If your flat roof is beginning to resemble a patchwork quilt then it s time to consider a more extensive treatment with your timber flat roof construction details.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. A popular method involves a cold application bitumen emulsion which is applied onto the surface. On a basic level flat roof construction comes in the form of roofing timbers or joists as they are more commonly known or steels that are laid across two uprights walls in most cases. The construction of the flat roof is similar to that of the timber upper floor.

Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.