Warm Deck Flat Roof Construction Detail

The sandwich warm deck roof is the most common type of flat roof.

Warm deck flat roof construction detail.

This is placed over the roof joists and a. 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. Warm deck flat roofs can be constructed on most modern construction material types such as concrete timber and timber based sheets. 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. 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. The insulation is immediately below the waterproofing layer. The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.

Constructing a flat roof using epdm. 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. Throughout the course of the year the roof deck and all below it is kept at a temperature close to that of the inside of the building therefore the roof structure is protected from extremes of hot and cold lessening the potential for damage caused by thermal movement. The vapour control layer is above the decking but below the insulation.

Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. The construction of the flat roof is similar to that of the timber upper floor. 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. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls.