Happy Valley Posted November 8, 2021 Share Posted November 8, 2021 The design of our warm roof has 100mm insulation between the vapour barrier and the steel coating and an additional 70mm underneath between the wooden spars. There is a suspended ceiling below all of this. Is it better to insulate above the suspended ceiling than to put the 70mm insulation between the spars? The reason to ask is that I am concerned that the heat will just go through the suspended ceiling and into the unused loft space. Link to comment Share on other sites More sharing options...
Iceverge Posted November 8, 2021 Share Posted November 8, 2021 It wouldn't make any difference really if you have a decent thermal envelope. Link to comment Share on other sites More sharing options...
ADLIan Posted November 9, 2021 Share Posted November 9, 2021 A drawing would help. Be aware that having the insulation at rafter level but with a horizontal ceiling has a major negative impact on the calculated U-value. You may think you are getting say 0.18 W/m2K but due to the correction factor it may be nearer perhaps 0.22 W/m2K! Link to comment Share on other sites More sharing options...
joe90 Posted November 9, 2021 Share Posted November 9, 2021 A warm roof is insulated at rafter level (like mine), yes the volume of the house is larger so will affect the overall u value but I wanted a usable loft storage space and find it works fine as long as your insulation is adequate. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now