Hi,
The plasterboard under our bedroom window has a bit missing and so I am getting a plasterer to sort this out when he skims the whole room and a few people have suggested taking off the old plaster from the stud wall immediately below the bay and then putting Celotex between the vertical joists. I don't do much DIY and not done anything with insulation before, but I was thinking of getting celotex which is not as deep as the void and putting it in so that it is flush with the internal face of the joists, thus leaving a gap between the panels and external face of the bay i.e. so there is ventilation.
My understanding is that celotex is foil backed so that will act as a damp proof membrane (i.e. have the foil facing the plasterboard / room). But I also read threads talking about sticking foil tape to the wooden joists? Would this mean simply putting the tape over the internal face of the joists, which will then be covered with the plasterboard?
Secondly, is this essential or can I just fit the celotex in between the vertical joists then get the plasterer to plasterboard over i.e. does it matter if the front of the joists are in direct contact with the plasterboard? The joists have been there for 80 odd years without any tape etc and from what I can see they look ok (have pulled some of plasterboard off)... or is it the actual fitting of insulation panels that can cause some type of damp problem between the joists and plasterboard?
Any help appreciated.
Thanks.
The plasterboard under our bedroom window has a bit missing and so I am getting a plasterer to sort this out when he skims the whole room and a few people have suggested taking off the old plaster from the stud wall immediately below the bay and then putting Celotex between the vertical joists. I don't do much DIY and not done anything with insulation before, but I was thinking of getting celotex which is not as deep as the void and putting it in so that it is flush with the internal face of the joists, thus leaving a gap between the panels and external face of the bay i.e. so there is ventilation.
My understanding is that celotex is foil backed so that will act as a damp proof membrane (i.e. have the foil facing the plasterboard / room). But I also read threads talking about sticking foil tape to the wooden joists? Would this mean simply putting the tape over the internal face of the joists, which will then be covered with the plasterboard?
Secondly, is this essential or can I just fit the celotex in between the vertical joists then get the plasterer to plasterboard over i.e. does it matter if the front of the joists are in direct contact with the plasterboard? The joists have been there for 80 odd years without any tape etc and from what I can see they look ok (have pulled some of plasterboard off)... or is it the actual fitting of insulation panels that can cause some type of damp problem between the joists and plasterboard?
Any help appreciated.
Thanks.