Insulated plasterboard ceiling?

[JP_]

We are getting a bit of mould on the edge of two opposite rooms, which I assume is due to poor insulation on the eaves part of the loft. Ceilings are high, artex and painted brown.

I was thinking, rather than shoving more insulation in the loft (there is a lot over most of it, all updated a few years ago) maybe better to fix insulated plasterboard, skim and paint. Costlier, but finish will be nicer and insulation probably better too.

The ceiling as a light and extractor fan, but both could do with replacing anyway.

 

[Doggit]

Although you say you have an extractor, mould suggests lack of ventilation, and the moist air is condensing on the cold parts. Post a picture, and we can discuss this further.

 

[motorbiking]

If there is plenty of insulation above, I'd be looking at possible leaky roof of pipes dripping on your ceiling. Or if its right at the edge next to the wall, then possibly damp coming from the walls. Either way celotexing (PIR) out the ceiling wont fix. Also, adding mineral roll to the loft is better from a fire protection point of view.

PIR is good in situations where you have limited space.

 

[noseall]

We are getting a bit of mould on the edge of two opposite rooms

Not unusual especially at the external wall perimeter where the roof tiles are nearest to the ceiling.
Improving the insulation will help a lot as it will also address the cold bridging through the joists.

Although you say you have an extractor, mould suggests lack of ventilation, and the moist air is condensing on the cold parts.

You are unlikely to rid a bathroom of all condensation even with the best of fans. An insulated under-draw will benefit greatly.

 

[JP_]

OK, maybe i will try to get more insulation up there... we have extractor fans, leave window a little open during the day, and have an electric fan heater than is used when showering, but damp still gets up there. Sure it is condensation as it is right along the edge on both sides of the roof (kitchen on left, bathroom on right) and no other signs of damp, e.g. nothing behind tiles, roof looks good (bungalow) etc. But, maybe it is something else.

Will leave it for now. Bleach and sponge cleaned it all off last night. Will have to do that whenever it comes back until I fix it in the summer!

 

[noseall]

OK, maybe i will try to get more insulation up there...

As in fit insulated plasterboard, yes,
This is what I meant when I wrote this.....

Improving the insulation will help a lot as it will also address the cold bridging through the joists.............
An insulated under-draw will benefit greatly.

 

[JP_]

ah, good, so my idea wasn't dafter afterall! Makes sense, cold bridges on joists.

 

[JP_]

Pics of the ceiling, But after I cleaned the mould off. Came off with a bleached sponge, so seems surface only, not rotten through or anything.