Pitched roof insulated under tiles, is this causing condensation/damp?

[Lighthouse_Lad]

There seems to be damp in upstairs ceilings... Previous owner has insulated the entire underside of roof could this be a problem? Does it cause condensation? Am I OK to just rip it off? It's like an oven up there at the minute.

 

[Why Not Indeed]

I can't see that porous insulation like that would lead to moisture buildup, BICBW. It will certainly reduce airflow, which is what cold roofs need.
[EDIT - these two sentences are a bit contradictory really].


Is it damp now, or only in winter, or only when it rains?

 

[Lighthouse_Lad]

I only moved in in Feb, I now notice the top part of most rooms upstairs are freshly painted (probably to hide any issues) It only seems to be showing up in the two places in the pictures. And doesn't seem to be getting worse now we're into summer.

 

[Why Not Indeed]

Check the loft-side of those two ceiling pictures, that might offer some clues. Presumably if there was any plumbing up there you would have noticed.

If moisture can get into the roof space from the habitable space, and the airflow has been reduced by stuffing all the gaps with insulation, then the moisture is going to take some time to escape, right? Seems unlikely that would be enough to cause visible staining on the ceilings, though.

My roof has quite a bit of condensation on the underside in winter. It does drip down sometimes, but we're talking about a small volume of water over a large area, so it would never be noticeable on the ceilings.