Flat Roof Insulation Requirements Uk

Pipes water tank and loft hatch.

Flat roof insulation requirements uk.

In this case ventilation is required and the roof can still become wet with condensation which may cause materials to decay. England new dwellings. Flat roof insulation always requires professional insulation and damp roofs require professional assessment before work can be carried out. Find out more.

Flat roof insulation thickness. 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. Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam. 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.

It should be of the maximum available thickness. Insulating a flat roof is relatively simple in terms of what materials you need and the steps taken to complete the job. 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. The chosen insulation laid on top of this should be able to take the weight of anything put above it on the roof without compression or protected from compression by further sheeting.

Cold roofs and warm roofs. Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof. Lay 12mm of plywood or osb board across the timber joists as a base for the flat roof build up. This means that your approach to insulation will differ from a standard pitched 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. U value of a flat roof.

Insulating between the joists of your loft will keep your house warmer but make the roof space above colder. 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. Insulation can also help to limit condensation and contribute to acoustic insulation depending on the type of insulation used. Ventilation is required for these roofs.

There are two types of flat roof. Room in the roof insulation. Install a vapour control layer to reduce the risk of condensation and moisture compromising the flat roof structure.