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.

A popular method involves a cold application bitumen emulsion which is applied onto the surface. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof. 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. Others would treat even steeper pitches as flat roofs. When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off. The construction of the flat roof is similar to that of the timber upper floor.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. A flat roof must be strong durable and stable throughout its lifetime. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. 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.

A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less.