Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof.
Flat roof insulation requirements uk.
Pipes water tank and loft hatch.
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.
Insulation can also help to limit condensation and contribute to acoustic insulation depending on the type of insulation used.
There are two types of flat roof.
Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling.
Flat roof insulation thickness.
Our guides to building regulations in england adl1a 2013 building regulations.
Ventilation is required for these roofs.
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.
England new dwellings.
Room in the roof insulation.
The typical u value of an existing uninsulated flat roof is 1 5w m2k.
Insulating between the joists of your loft will keep your house warmer but make the roof space above colder.
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.
Cold roofs and warm roofs.
In this case ventilation is required and the roof can still become wet with condensation which may cause materials to decay.
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.
Lay 12mm of plywood or osb board across the timber joists as a base for the flat roof build up.
It should be of the maximum available thickness.
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.
Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam.
This means that your approach to insulation will differ from a standard pitched roof.
Insulating a flat roof is relatively simple in terms of what materials you need and the steps taken to complete the job.
Find out more.
Install a vapour control layer to reduce the risk of condensation and moisture compromising the flat roof structure.