Help please, sorry a bit long but trying to give all the info I know.
Have just "finished" redecorating a small (2 x 3 metre) upstairs bathroom including tiling floor to ceiling around the bath. In doing so I replaced part of the ceiling (about 1 x 1 metre), the bit I took down had bowed from what look like a water leak in the roof - investigation showed, before my occupation, the roof has been repaired (partially replaced) and looks now in generally good nick.
The room is finished all but for final painting the ceiling and untiled walls.
Whilst generally browsing around the web including this site, I note the comments on vapour barriers - just before I felt sick!
Plaster board ceiling, vapour barrier, insulation, replaced a bit - oh b-----!
When taking the old damaged board down I noticed that it was foil backed , but true to form like a good Diyer, I never thought anything of it and but back the normal unbacked stuff along with its (50mm thick)insulation. (mistake number 1!). The roof timbers looked fine including the underside of the top ply although there might have been a little black mold growth (mistake number 2 for not looking more carefully!). As I say it is a flat roof, I now know that it is a cold construction, only roof joist high, fully enclosed I can't get in there to see whats going on!
There is some opportunity for air flow across the underside of the roof through spaces left on the facias.
The bathroom also has three downlighter spot lights fitted to the ceiling - these have rubber washers fitted between the light fitting and ceiling and have glass (screw in) covers over the bulbs (again with rubber washers). They are not above the bath/shower (and not in the bit I replaced). The insulation around these areas is 100mm kingspan which has been cut back well away from the lights (evidence the the ceiling has been partially replaced before?). Having unscrewed one of these it smells a bit damp up there!
Overall I think a vapour barrier is needed - but how to fit one is the problem without fetching the ceiling down! If I under clad the ceiling, (poly sheet then new taped board) I then interfere with the new tiling. I am trying to find another way and am looking for ideas please!
I have thought of painting with Zinsser primer sealer which the manufacturer say forms a vapour barrier, but does it? Oil based paint, undercoat - will it work? What about aluminium foil to the underside of the ceiling - I've tried a bit with PVA and it seems to stick - then coat with metal primer then emulsion. Any thoughts, ideas, or shall I just cut my throat?
Have just "finished" redecorating a small (2 x 3 metre) upstairs bathroom including tiling floor to ceiling around the bath. In doing so I replaced part of the ceiling (about 1 x 1 metre), the bit I took down had bowed from what look like a water leak in the roof - investigation showed, before my occupation, the roof has been repaired (partially replaced) and looks now in generally good nick.
The room is finished all but for final painting the ceiling and untiled walls.
Whilst generally browsing around the web including this site, I note the comments on vapour barriers - just before I felt sick!
Plaster board ceiling, vapour barrier, insulation, replaced a bit - oh b-----!
When taking the old damaged board down I noticed that it was foil backed , but true to form like a good Diyer, I never thought anything of it and but back the normal unbacked stuff along with its (50mm thick)insulation. (mistake number 1!). The roof timbers looked fine including the underside of the top ply although there might have been a little black mold growth (mistake number 2 for not looking more carefully!). As I say it is a flat roof, I now know that it is a cold construction, only roof joist high, fully enclosed I can't get in there to see whats going on!
There is some opportunity for air flow across the underside of the roof through spaces left on the facias.
The bathroom also has three downlighter spot lights fitted to the ceiling - these have rubber washers fitted between the light fitting and ceiling and have glass (screw in) covers over the bulbs (again with rubber washers). They are not above the bath/shower (and not in the bit I replaced). The insulation around these areas is 100mm kingspan which has been cut back well away from the lights (evidence the the ceiling has been partially replaced before?). Having unscrewed one of these it smells a bit damp up there!
Overall I think a vapour barrier is needed - but how to fit one is the problem without fetching the ceiling down! If I under clad the ceiling, (poly sheet then new taped board) I then interfere with the new tiling. I am trying to find another way and am looking for ideas please!
I have thought of painting with Zinsser primer sealer which the manufacturer say forms a vapour barrier, but does it? Oil based paint, undercoat - will it work? What about aluminium foil to the underside of the ceiling - I've tried a bit with PVA and it seems to stick - then coat with metal primer then emulsion. Any thoughts, ideas, or shall I just cut my throat?
