Flat Roof Insulation Requirements Uk

Ventilation is required for these roofs.

Flat roof insulation requirements uk.

Pipes water tank and loft hatch insulating between the joists of your loft will keep your house warmer but make the roof space above colder. 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. Our guides to building regulations in england adl1a 2013 building regulations.

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. Find out more. In bs 6229 a roof is defined as flat if it has an overall pitch of 10 degrees or less. 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 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. Summary of flat roof building regulations. If you are replacing more than 25 of the roofing area then you will also need to replace the thermal insulation. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.

With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. In most cases there will not be a loft in a building that features flat roofing. It should be of the maximum available thickness. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity.

England new dwellings. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. Room in the roof insulation. The saint gobain insulation uk product portfolio has a solution to help meet the requirements of the scheme.

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. The target should be to achieve a u value of 0 25w m2k or better. This means that your approach to insulation will differ from a standard pitched roof.