Flat Roof Insulation Requirements Uk

The typical u value of an existing uninsulated flat roof is 1 5w m2k.

Flat roof insulation requirements uk.

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. With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. The two variations of flat roof usually flat roof constructions are defined as either cold or warm depending on how the thermal insulation is positioned in the construction.

The target should be to achieve a u value of 0 25w m2k or better. Our guides to building regulations in england adl1a 2013 building regulations. Find out more. It should be of the maximum available thickness.

If you are replacing more than 25 of the roofing area then you will also need to replace the thermal insulation. The saint gobain insulation uk product portfolio has a solution to help meet the requirements of the scheme. 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. 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.

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. Summary of flat roof building regulations. Depending on where you live in the uk snowfall must also sometimes be considered in determining the gradient of the fall. In most cases there will not be a loft in a building that features flat roofing.

Room in the roof insulation. 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. 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. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity.

This means that your approach to insulation will differ from a standard pitched roof. Flat roof insulation always requires professional insulation and damp roofs require professional assessment before work can be carried out. In bs 6229 a roof is defined as flat if it has an overall pitch of 10 degrees or less.