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Flat roof construction
Anonymous user 09/03/2024 - 3.21 PM
Hi, I've constructed a flat roof which is attached to the house from 2 sides. It consists of a timber roof frame, osb3 boards on top of it and EPDM roof sheet. My query is, i would like to insulate the the gap between the osb board and the underside which is gonna be plasterboard. Does this void need to have an air gap at all or could I completely pack out the gap between the joists with suitable insulation like celotex. Would be grateful if someone could guide me as I don't want build up of condensation. Thanks
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2 Answers
Af building services
Rating: 5 out of 5
Always leave a 50mm air gap and preferably with a pre- vented soffit.
Answered25 March 2021
9
fife roofing and repointing
Rating: 4.9 out of 5
You can install the insulation boards tight with no gaps atall aslong as you put a damp proof membrane underneath fixed to joists. Also use foil back plaster board.
It’s similar to a warm roof installation.
Answered1 April 2021
0