Bathroom ceiling insulation

[Ian Callaghan]

Hi folks. Just joined to tap into the collective genius thta I am sure is out there. I have mould on the ceiling in bathroom. It is only present on the angle part of the ceiling that is near the external wall under the roof line. The void directly above in the loft space between the roof and the plasterboard has no insulation and in turn is cold. So when warm moist air occurs during showers it condenses on the cold ceiling surface . The area where the joists are is free from mould. My thoughts are the solid timber is insulating to a degree. Since i can't stuff insulation into the void in the loft space directly above the shower area could i attach batons to the ceiling using joists as fixing points - fit rigid insulation to ceiling surface then fit drywall over this. In effect making a very thick but insulated ceiling. Any advice welcome.

Thank you.
Ian.

 

[^woody^]

Go with your plan, using something like minimum 35mm celotex/kingspan foil backed insulation.

Or you can get insulation already glued to plasterboard - look for styrofoam or jablite (blue, yellow or pink) and not the white polystyrene. This is less efficient than the foil-backed type.

The key thing is to have no air gaps and no battens. The insulation goes tight against the plasterboard slope, and then screw through the new plasterboard into the rafters.

Fit a suitable fan too, if you don't already have one

 

[endecotp]

what sort of fan do you have currently?

 

[Ian Callaghan]

thanks woody - i'm gonna go with that - endecopt, I have just installed a new fan with a high rate of air flow - I can actually see the steam wafting towards the fan so I am optimistic the fan and insulation will resolve the mould growth.

Thanks for taking the time to reply guys