Flat Roof Insulation Requirements Uk

If you are replacing more than 25 of the roofing area then you will also need to replace the thermal insulation.

Flat roof insulation requirements uk.

A u value of 0 55 w m k is used for cavity insulation and 0 30 w m k for internal or external wall insulation. A layer of rigid insulation board can be added either on top of the roof s weatherproof layer or directly on top of the timber roof surface with a new weatherproof layer on top of the insulation. The target should be to achieve a u value of 0 25w m2k or better. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof.

Find out more. A cold roof has the insulation placed below the structural deck which thus remains cold. Room in the roof insulation. This means that your approach to insulation will differ from a standard pitched roof.

In most cases there will not be a loft in a building that features flat roofing. The typical u value of an existing uninsulated flat roof is 1 5w m2k. Depending on where you live in the uk snowfall must also sometimes be considered in determining the gradient of the fall. The saint gobain insulation uk product portfolio has a solution to help meet the requirements of the scheme.

To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. 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. There are two basic categories of roof design. Cold deck this is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.

A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. The waterproof layer is above the insulation and a vapour control layer is placed below the insulation. With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. A warm roof has the insulation above the structural deck which is thus kept warm.

England new dwellings. Summary of flat roof building regulations. Our guides to building regulations in england adl1a 2013 building regulations. Warm deck the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications.

Ventilation is required for these roofs.