Cold Flat Roof Construction Detail

Cold bridging through the system is easier to eliminate or control as ordinarily there are no breaches from the structural supports as there is in a cold roof construction.

Cold flat roof construction detail.

Trada and approved document part a give guidance on sizes of joists for flat roofs relating to spans and loading. Flat roof design guide. Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof. Warm roof build ups can be installed on most modern construction material types such as concrete timber and timber based sheets.

It must provide adequate protection against the elements keeping the buildings structure and interior dry. In the case of a flat roof insulation is usually in the form of either a rigid board above the deck or a fibrous quilt immediately above the ceiling depending on the type of roof construction. Hot tar and gravel. Flat roof types.

In case of warm roofs they have an insulation above the roof deck in this way it keeps the deck warm. It is usually the most acceptable type of construction for domestic possessions and belongings as it avoids the need for aeration of the roof construction. The membrane is then attached to the insulation. The 3 most common materials used for flat roof construction.

A flat roof must be strong durable and stable throughout its lifetime. There are three recognised designs of flat roof construction. Joists are placed on edge spaced at 400 600mm centres supported by external and internal load bearing walls. The construction of the flat roof is similar to that of the timber upper floor.

A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. There are several methods and materials for the design of the exterior surface of a warm or cold flat roof. In the case of cold. There must be an adequate void minimum 50mm between the deck and the insulation traditionally mineral wool to allow free movement of air and to prevent moisture vapour being transmitted from the building outwards where it could condensate in the roof.

A warm deck roof is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation. Warm cold and inverted.