Flat Roof Insulation Requirements Uk

With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same.

Flat roof insulation requirements uk.

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. Our guides to building regulations in england adl1a 2013 building regulations. Depending on where you live in the uk snowfall must also sometimes be considered in determining the gradient of the fall. 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.

Ventilation is required for these roofs. The waterproof layer is above the insulation and a vapour control layer is placed below the insulation. 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. Summary of flat roof building regulations.

The saint gobain insulation uk product portfolio has a solution to help meet the requirements of the scheme. A flat roof should preferably be insulated from above. Room in the roof insulation. A cold roof has the insulation placed below the structural deck which thus remains cold.

A warm roof has the insulation above the structural deck which is thus kept warm. 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. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.

Find out more. The typical u value of an existing uninsulated flat roof is 1 5w m2k. England new dwellings. 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.

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. There are two basic categories of roof design. This means that your approach to insulation will differ from a standard pitched roof. This is best done when the roof covering needs replacing anyway.

The target should be to achieve a u value of 0 25w m2k or better.