I'm building an extension and I'm wondering whether the insulation will work properly for my internal wall. I have a heated room and a garage, but I want the option to convert the garage in the future, so I want it insulated.
I'm using rigid "full fill" insulation, which is 90mm with a 10mm cavity. It's this 10mm cavity that I'm having doubts about. I'm wondering whether the garage will be insulated properly if there is a 10mm gap between the wall and the insulation. This is more of an issue at the end of the wall where it meets the other cavity as there is a gap below the insulation where air/heat could get through.
There are two options I can think of. The first option is to close the cavity with a block and then cavity closer, which should eliminate/reduce the thermal bridging from the side. The other option is using a proper full fill insulation like DriTherm32, but that would result in a much lower U-value (0.22 instead of 0.16).
Does anybody know what is usually done and whether closing the cavity would solve the problem (if it's allowed)?
I'm using rigid "full fill" insulation, which is 90mm with a 10mm cavity. It's this 10mm cavity that I'm having doubts about. I'm wondering whether the garage will be insulated properly if there is a 10mm gap between the wall and the insulation. This is more of an issue at the end of the wall where it meets the other cavity as there is a gap below the insulation where air/heat could get through.
There are two options I can think of. The first option is to close the cavity with a block and then cavity closer, which should eliminate/reduce the thermal bridging from the side. The other option is using a proper full fill insulation like DriTherm32, but that would result in a much lower U-value (0.22 instead of 0.16).
Does anybody know what is usually done and whether closing the cavity would solve the problem (if it's allowed)?