Warm Flat Roof Insulation Regulations

In a warm deck roof the insulation is positioned above the structural deck and no ventilation is required.

Warm flat roof insulation regulations.

New roofs thermal resistance insulation there are two ways to insulate a roof. This is placed over the roof joists and a board normally external ply is laid on top. If insulation is installed below the flat roof deck this is called a cold roof. In most cases there will not be a loft in a building that features flat roofing.

Laying flat roof insulation. 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. With a warm roof the usual process is to split the insulation into two layers. As a rule any roof with a pitch below 10 is classified as a flat roof.

If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the rafters. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. 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. All warm flat roofs must also have a vcl vapour control layer inserted between the top decking and the first layer of insulation.

From there the flat roof system you choose will determine the materials you apply. This means that your approach to insulation will differ from a standard pitched roof. No ventilation is required for these types of roofs. U value of a flat roof to comply with part l of the building regulations 2010 all roofs to rooms except those in unheated buildings should be thermally insulated to a maximum u value of of 0 18 w m k.

This can be made of polyethylene membrane bitumen sheet polymeric foil or even be a cheap easy to apply self adhesive sheet. There should be no insulation below the deck and no ventilation is required. A note to consider before construction. Consider geography budget and use for the roof to determine the best option.

Warm deck roof with this type of roof the insulation is placed above the roof deck but below the weatherproofing. Warm deck this is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation.