I did block up the openings for a few days. The condensation in the main loft disappeared - but the flat rood void was dripping wet (though of course, I did the blocking up when it was wet). I'm thinking of waiting till everything dries off (I have fan up there now) and retrying the blocking off.
This is a flat roofed 'orangery', i.e. there is a large glass lantern in the middle of the flat roof (which could be affecting air flow?). The orangery is 7.5m long by 3.5m wide and is attached to the bungalow on three sides. The front of the orangery has a continuous ventilation grill into...
Should the roof void of a flat roof extension be sealed off from the loft void in the bungalow, or should the two be continuous to allow free air exchange? I have a situation where the two voids are continuous and am having dreadful condensation problems at the junction between the two.