Timber Flat Roof Construction Details

The joists are attached to load bearing walls by two common methods.

Timber flat roof construction details.

Flat roofs aren t actually flat but must slope to drain water. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. Boardsmust have a nominal thickness of min. Timber flat roof carports timber flat roof construction timber flat roof construction details timber flat roof deck timber flat roof detail timber flat.

3 05 timber frame pitched roof. A roof which is approximately flat is called as a flat roof. 24 mm 20 and should have. Timber framed and historic buildings may be framed with principal rafters or timber roof trusses.

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. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. For additional stability you can also use steel joists that are built into one or both of the walls. A flat roof must be strong durable and stable throughout its lifetime.

The roofs have a timber frame as the supporting structure. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. A timber decking is then constructed and its weight supported by the joists. Flat roof joists spanning the shorter length of the roof form the load bearing members of the structure.

A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. It must provide adequate protection against the elements keeping the buildings structure and interior dry. The construction of the flat roof is similar to that of the timber upper floor. Normally a slope of inch per foot is used.

Usually a flat roof is built with a slight slope to provide some drainage. Ventilated batten void warm roof gable 3 06 timber frame timber flat roof 3 07 timber frame timber flat roof with parapet 3 08 timber frame lintel at window head 3 09 timber frame windows and doors jambs and cills specification within an example should 3 10 timber frame ground.