Warm Deck Flat Roof Construction Detail

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

Warm deck flat roof construction detail.

Construction studies drawing detail showing how to draw a flat roof warm deck construction detail to a scale of 1 10 with a short introduction highlighting t. Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. The insulation is placed below the waterproof covering and is either mechanically fixed or bitumen bonded on to the top of the deck. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.

The sandwich warm deck roof is the most common type of flat roof. In a warm flat roof construction the insulation is positioned above the structural deck and no ventilation is required. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. For additional stability you can also use steel joists that are built into one or both of the walls.

Warm deck flat roofs can be constructed on most modern construction material types such as concrete timber and timber based sheets. In a warm roof construction the principal insulation layer is placed above the structural decking resulting in the structural deck and support structure being at a temperature similar to that of the building interior. Inverted warm deck roof the insulation boards in an inverted warm deck are laid over the structural deck and the waterproof covering. Warm deck flat roof the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications.

The vapour control layer is above the decking but below the insulation. The construction of the flat roof is similar to that of the timber upper floor. The insulation is immediately below the waterproofing layer. A warm flat roof or a built up roof bur is one where all the insulation is above the joists deck making them part of the warm fabric of the building.

To use epdm for a warm deck flat roof construction solid closed cell roof insulation such as kingspan or celotex should be placed on top of the roof deck rather than in between the rafters. Having a manual for warm flat roof construction with details and a summary of rules to follow helps. This is placed over the roof joists and a.