Timber Flat Roof Construction Details

150mm insulation 0 044w mk between rafters.

Timber flat roof construction details.

The abutment detail of a flat roof is vital in order to prevent moisture penetration. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. A flat roof must be strong durable and stable throughout its lifetime. Having a manual for warm flat roof construction with details and a summary of rules to follow helps.

The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. 215mm aircrete solid wall λ 0 15 w mk render insulation λ 0 022 w mk pitched roof gable. The size of your joists and noggins and preliminary timber layer will be determined by the weight of your flat roof. Flat roofs on houses must be designed and built to be strong durable and wind resistant.

When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. In this type of construction the insulation is placed below the waterproof covering and on top of the roof deck and vapour barrier. The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal however some in the industry would consider up to 15 o as their definition of a flat roof.

3 05 timber frame pitched roof. A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. Load bearing or primary structure usually constructed in timber in a residential construction. Solid external masonry wall.

The flat roof shown above shows warm deck roof construction. It must provide adequate protection against the elements keeping the buildings structure and interior dry. 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 carports timber flat roof construction timber flat roof construction details timber flat roof deck timber flat roof detail timber flat.

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