Flat Roof Timber Detail

The construction of the flat roof is similar to that of the timber upper floor.

Flat roof timber detail.

Rainer barthel 1 loadbearing structure matthias beckh mark. The evolution of the flat roof christian schittich. Flat roofs aren t actually flat but must slope to drain water. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.

Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board. Intermediate floor joist parallel 4 3. Having a manual for warm flat roof construction with details and a summary of rules to follow helps.

Parapet detail joists parallel details in section 4. Dormer in section 3 11. Parapet detail joists perpendicular 3 13. Where a new flat roof abuts an existing external wall the joists can be hung on metal joist hangers which are fixed to a horizontal timber plate wall bolted to the wall.

Normally a slope of inch per foot is used. For additional stability you can also use steel joists that are built into one or both of the walls. 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. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.

A cavity closer should be provided to the top of the walls to prevent fire spread and to stop damp air entering the roof space. Dormer in perspective view 3 12. A roof which is approximately flat is called as a flat roof. Flat roof joist and decking 3 10.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. Usually a flat roof is built with a slight slope to provide some drainage. Timber flat roof carports timber flat roof construction timber flat roof construction details timber flat roof deck timber flat roof detail timber flat.