Flat Roof Timber Detail

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.

Flat roof timber detail.

Flat roof joist and decking 3 10. From there the flat roof system you choose will determine the materials you apply. Flat roof with no permanent access and altitude not exceeding 100m 0 75 kn m udl 0 9 kn point load most areas exceeding 100m but not exceeding 200m excluding parts of scotland pennines north east england refer to bs 6399 3 1 kn m udl 0 9 kn point load. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Dormer in section 3 11. 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. Dormer in perspective view 3 12.

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. Flat roofs aren t actually flat but must slope to drain water. Roof panels 3 8 1 roof panel connections 3 9. Normally a slope of inch per foot is used.

Parapet detail joists perpendicular 3 13. Rainer barthel 1 loadbearing structure matthias beckh mark. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. The construction of the flat roof is similar to that of the timber upper floor.

Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. Parapet detail joists parallel details in section 4. 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. 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.

Intermediate floor joist parallel 4 3. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing 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.