Flat Warm Roof Construction Detail

In the case of a flat roof insulation is usually either a rigid board above the deck or a mineral glass wool quilt immediately above the underdrawn ceiling depending on the type of roof design and construction.

Flat warm roof construction detail.

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. Put simply a warm flat roof has insulation of some kind packed into every available void and a cold flat roof allows air to circulate between the joists. The insulation is immediately below the waterproofing layer. For additional stability you can also use steel joists that are built into one or both of the walls.

Having a manual for warm flat roof construction with details and a summary of rules to follow helps. The sandwich warm deck roof is the most common type of flat roof. In terms of rules on ventilation bs 5250. A warm flat roof is formed by placing a layer of insulation over the top of the roof structure.

A roof is considered to be flat when it is of a slope of 1 5 o to the horizontal. This air is vented at either end of the roof to allow a continuous air flow. Waterproof membrane to prevent water penetrating the structure and interior of the building. A flat roof usually consists of the following.

Flat roof construction for residential. The insulation is placed below the waterproof covering and is either mechanically fixed or bitumen bonded on to the top of the deck. Pitched or sloping roof a pitched or slanted roof has a terrain of at least 15 but it is often much more. This is placed over the.

2011 control of condensation in buildings is the document to view. Steve from london flat roofing explains how warm flat roof construction works in this excellent short video. Due to the insulation being over the top of the roof the timber structure beneath is warm which is why the term warm roof is formed. So what is warm flat roof construction.

In terms of the thermal design of a flat roof what are the options and the best practices of flat roof build ups. The recognised flat roof build ups for best design practices are. Flat roof u value 0 18 w m2k 2 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. Flat roofs are usually made of variations of bitumen felt and function as durable long lasting roofs that are perfect for water run off in wet weather and protect wood and cement from potential build ups of damp and dry rot.

Although flat roofs are cheaper to build than pitched roofs they have a shorter life span.