Flat Roof Insulation Requirements Uk

This means that your approach to insulation will differ from a standard pitched roof.

Flat roof insulation requirements uk.

The waterproof layer is above the insulation and a vapour control layer is placed below the insulation. A warm roof has the insulation above the structural deck which is thus kept warm. 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. Depending on where you live in the uk snowfall must also sometimes be considered in determining the gradient of the fall.

Summary of flat roof building regulations. 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. Room in the roof insulation. A flat roof should preferably be insulated from above.

Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation. Find out more. This is best done when the roof covering needs replacing anyway. 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.

The target should be to achieve a u value of 0 25w m2k or better. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. Our guides to building regulations in england adl1a 2013 building regulations. 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.

In most cases there will not be a loft in a building that features flat roofing. A cold roof has the insulation placed below the structural deck which thus remains cold. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. England new dwellings.

The typical u value of an existing uninsulated flat roof is 1 5w m2k. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. There are two basic categories of roof design. Ventilation is required for these 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.