U value of a flat roof.
Flat roof insulation requirements uk.
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.
The saint gobain insulation uk product portfolio has a solution to help meet the requirements of the scheme.
Ventilation is required for these roofs.
In most cases there will not be a loft in a building that features flat roofing.
The typical u value of an existing uninsulated flat roof is 1 5w m2k.
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.
Our guides to building regulations in england adl1a 2013 building regulations.
In this case ventilation is required and the roof can still become wet with condensation which may cause materials to decay.
Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof.
Insulating a flat roof is relatively simple in terms of what materials you need and the steps taken to complete the job.
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.
Room in the roof insulation.
Pipes water tank and loft hatch.
Flat roof insulation thickness.
It should be of the maximum available thickness.
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.
Flat roof insulation always requires professional insulation and damp roofs require professional assessment before work can be carried out.
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.
Find out more.
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.
Lay 12mm of plywood or osb board across the timber joists as a base for the flat roof build up.
Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling.
England new dwellings.
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.
Insulating between the joists of your loft will keep your house warmer but make the roof space above colder.
This means that your approach to insulation will differ from a standard pitched roof.
