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Building regs, loft conversion roof insulation.

Converting loft, existing rafters are 100mm. Will extend rafters by 25mm and insert 70mm kingspan between to allow 50mm air gap above. My question is how to achieve 0.18 value required by building regs ? Could I put multi foil over the top and then board with foil backed plasterboard? If so what thickness multi foil would be required?

1 Answer from a MyBuilder Insulation Installer

Best Answer

It is better to ask the technical helplines of the insulation manufacturers such as Kingspan / Celotex. They will give you the correct insulation, the correct thickness and a calculation which proves the materials being used which Building Control would require.


Answered 23rd Mar 2016

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