Timber Flat Roof Construction Details

For additional stability you can also use steel joists that are built into one or both of the walls.

Timber flat roof construction details.

It must provide adequate protection against the elements keeping the buildings structure and interior dry. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. 3 05 timber frame pitched roof. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading.

Flat roofs aren t actually flat but must slope to drain water. Usually a flat roof is built with a slight slope to provide some drainage. The roofs have a timber frame as the supporting structure. 24 mm 20 and should have.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. Flat roof joists spanning the shorter length of the roof form the load bearing members of the structure. The joists are attached to load bearing walls by two common methods. A roof which is approximately flat is called as a flat roof.

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. A flat roof must be strong durable and stable throughout its lifetime. Modern timber roofs are mostly framed with pairs of common rafters or prefabricated wooden trusses fastened together with truss connector plates. A timber decking is then constructed and its weight supported by the joists.

The construction of the flat roof is similar to that of the timber upper floor. Timber in the form of rough sawn or planedboards or planks can be used as the loadbearing deck to a flat roof fig. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. 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.

Boardsmust have a nominal thickness of min. Timber framed and historic buildings may be framed with principal rafters or timber roof trusses.