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.

Flat roof insulation requirements uk. 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 saint gobain insulation uk product portfolio has a solution to help meet the requirements of the scheme. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. In most cases there will not be a loft in a building that features flat roofing.

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

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. Ventilation is required for these roofs. Summary of flat roof building regulations. Find out more.

The typical u value of an existing uninsulated flat roof is 1 5w m2k. Flat roof insulation always requires professional insulation and damp roofs require professional assessment before work can be carried out. 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. The target should be to achieve a u value of 0 25w m2k or better.

A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. Room in the roof 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. 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.

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