Timber Flat Roof Detail

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 detail.

Roof panels 3 8 1 roof panel connections 3 9. Normally a slope of inch per foot is used. 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. Parapet detail joists perpendicular 3 13.

Today flat roofs are used by architects for the same reasons that they became a cornerstone of modernist architecture. Similar to the abutment of a lean to roof lead flashing is chased into the external block allowing it to overlap the lead upstand coming from the tiles. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. The abutment detail of a flat roof is vital in order to prevent moisture penetration.

Dormer in perspective view 3 12. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. 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. A roof which is approximately flat is called as a flat roof. Parapet detail joists parallel details in section 4. 2 ply rigid plastic foam board vapour barrier separating membrane.

From there the flat roof system you choose will determine the materials you apply. Flat roof joist and decking 3 10. It dealt in detail with flat roof constructions and can be regarded as one of the first guidelines for such roofs fig. Flat roofs aren t actually flat but must slope to drain water.

Dormer in section 3 11. For additional stability you can also use steel joists that are built into one or both of the walls. Contemporary designers frequently aim to produce the same clear and simplified forms that appeared at the beginning of the 20th century but are now free to use a wide range of new materials and construction techniques that reflect present day technology. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.