Timber Cladding Flat Roof Detail

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

Timber cladding flat roof detail.

Flat roof joist and decking 3 10. However the width of cavity is generally decided by the style and width of the cladding board. Assuming that the cladding will always be subject to some penetration of moisture a separate protective membrane will be necessary behind the cladding largely protected from wind rain and daylight by the cladding itself. 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.

When building a flat roof it is vital that a degree of falls is built into the construction to ensure rainwater run off. Others would treat even steeper pitches as flat roofs. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. Timber frame wall detail tile cladding. Separating wall junctions 1 4. Render on timber frame.

Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. Non loadbearing wall junctions 1 5. Guidance on flat roof construction pitched roofs and drainage. 2 50 vat add to basket dwg dxf jpg.

As well as the small selection of timber frame detail drawings shown here many of the building notes have a related construction detail drawing with specific dimensions. Timber boarding on timber frame 1 9. Details on plan 1. Cad details document name pdf dwg download all cad construction details 37 1 mb 3 4 mb mc01 identification of roof areas 694 kb 167 kb mc01a single layer underlayment 678 kb 302 kb mc01b double layer underlayment 711 kb 322 kb mc02 vent pipe flashing 626 kb 349 kb mc03 valley.

For additional stability you can also use steel joists that are built into one or both of the walls. The more open the cladding style the wider the cavity required to protect against moisture penetration. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. It dealt in detail with flat roof constructions and can be regarded as one of the first guidelines for such roofs fig.

Membrane edge fixed timber roof element hose clip pipe collar. Whether a solid masonry or timber frame structure tdca recommends that this cavity shall be a minimum of 21mm wide.