Flat Roof Insulation Thickness Building Regulations

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 thickness building regulations.

The thickness of insulation will depend on the type of insulant. All roofs should be insulated. Used within a bauder waterproofing system our products meet current uk building regulations part b for fire protection. The type of insulation required will depend on the immediate environment in your area and specific building regulations.

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. Below that there are more detailed guides to the thermal insulation parts of building regulations standards. 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. Take our online course on the building regulations and standards.

A ventilation gap usually 50mm should be provided between the top of the insulation and underside of the roof covering to allow the air to flow across. Roof insulation thickness for building regulations will vary depending on the type of insulation used. When installing or repairing a flat roof you must adhere to building regulations. Different insulants have different efficiencies and performance levels which affects the thickness required to meet building regulations.

As you can see below there are separate regulations for england wales and scotland. Part h of the building regulations regarding drainage state that water should drain to one or two edges. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. The below drawing shows the u value requirements set out for new properties in the building regulations for each element walls floors and roofs.

For further information contact the building regulations division. Cold deck the thickness of insulation required will vary depending on the material you decide to use and the manufacturer s specification. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines. There must be a slope of 1 80.

U values calculations take into account the thermal resistivity and thickness of the insulation. The actual specification required for a compliant building and necessary building fabric u value targets may vary depending on the actual overall proposed specification and the outcome of the energy. Insulation between flat roof joists 50mm air gap above decking surrey building control guidance note number 13.