Raining indoors!

[Penk]

We like to get out even in the depths of winter and, by and large, feel pretty snug. I’ve always made up extra insulation for roof lights using the sort of silver stuff you put behind radiators, with no ill effects. But tonight I went to get into bed and realised it was wet. When I looked up, it was ‘raining’ down condensation from the roof light. When I pulled the blind aside and removed my insulation there was a positive downpour. I found the same with all the roof lights. I’ve now dried them, put the insulation back and pulled the blinds across again. Is it the insulation that’s causing this? Or the pretty exceptional cold? Do I need to expose and wipe them down daily (we’ve been here 2 nights)? Any tips gratefully received - or we’ll have to sleep under an umbrella

 

[Kannon Fodda]

Any gap between insulation and a colder surface will be at risk of condensation if warmer air can migrate into it.

Any insulation material placed into a rooflight is not going to be totally sealed around perimeter. So condensation can form above. Same issue as those who use internal screen covers to windscreens. This very cold spell will risk exacerbation of the effect you won't see in cold but less extreme conditions.

 

[Minxy]

Do I need to expose and wipe them down daily (we’ve been here 2 nights)?

Yes, I always remove ours in a morning and wipe the condensation off then leave them off until bed time to let the residue dry off. If you don't the condensation will build up as you've found.