Timber Flat Roof Construction Details

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.

Timber flat roof construction details.

Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. Others would treat even steeper pitches as flat roofs. The construction of the flat roof is similar to that of the timber upper floor.

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. For additional stability you can also use steel joists that are built into one or both of the walls. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. It must provide adequate protection against the elements keeping the buildings structure and interior dry.

Applying a liquid waterproofing agent will often add a few more years to the roof. A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. A popular method involves a cold application bitumen emulsion which is applied onto the surface. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.

A flat roof must be strong durable and stable throughout its lifetime.