Closing the insulation gap - suggestions?

darrenheaphy

Hello. Every winter I tell myself I'll do this but never get 'round to it. This time, says I, Things Will Be Different. Basically I have two loft rooms around which is sporadically placed fibre glass. The rooms themselves are bloody cold though this time of year. I assume it's because the heat escapes through the dry wall bits upon which there's no insulation.

For those gaps, do I just get bog standard rockwool from Woodies and roll it between the joists? Any suggestions or help is really appreciated!

Penn

Yes, you're best off using a similar type and thickness of insulation as the existing, as otherwise you create weak points and are more likely to get condensation/mould at these points.

Why was that gap left? There appears to be a sheet of perspex or something installed in that gap.

darrenheaphy

Thanks @Penn 👍 that’s just the foil covering of the plasterboard wall. So I’ll just get big standard loft insulation from Woddies

One more question, if I may, at parts of the wall are cupboards cut into the plasterboard. I presumable I should insulate those too by wrapping insulation too around them?

Penn

Ha, sorry yes, the foil is obvious now.

Yes, you should try to wrap insulation around anything like that. The insulation should be as even and continuous throughout as possible to prevent weak points. Just try to ensure you don't compress the rockwool insulation too much, as it becomes less thermally efficient when compressed.

MicktheMan

"The rooms themselves are bloody cold though this time of year. I assume it's because the heat escapes through the dry wall bits upon which there's no insulation."

I wouldn't be assuming this at all. By all means rectify the missing insulation but those rooms are likely cold due primarily to air leakage (convection losses) rather than conductive losses which insulation addresses. This air leakage is likely affecting the rest of the house too.