Extra layer of insulating board?

[damonbotley]

Our house is circa 1900, stone built. Top floor is converted. One bedroom is warm enough because it's a newer dormer, but the hallway and other bedroom are cold. Both mainly have a pitched roof. Both ceilings painted but one appears to be standard plasterboard, one Styrofoam and both are pretty cold to the touch, so I doubt there's much insulation.

So my probably daft question is - can I just stick up (or space out with a thin batten if necessary) an additional layer of insulating board to keep the warmth in.

I should say that I don't get the impression there's much space between the ceiling and the roof itself, and would rather not be pulling down ceilings if I can help it.

Thanks
D

 

[^woody^]

Yes you can. It won't need a gap, just fixed to the ceiling

 

[damonbotley]

Thanks, much appreciated. Was worried about condensation but assume if I use something with a foil backing (foil facing up) that will barrier against any passage of water from inner side to outer side

 

[^woody^]

It won't matter, as the situation will be no different to what it is now in terms of condensation within the roof.