Where to position insulation

[JustinH]

I want to put plasterboard walls in my attic but they will be about 40 cm in from the external walls. Should I put the glass wool insulation against the wall and have a gap between the insulation and the plasterboard or should the insulation be against the plasterboard and have a gap between the insulation and the external wall?

 

[MarineBob]

I wouldn't leave any gaps and I believe its important to have a vapor barrier on the warm side of the wall, like under the dry wall so moisture does not get into the insulation.

 

[JustinH]

Thanks. Should the vapour barrier go between the inside of the external wall and the insulation or between the insulation and the plasterboard?

 

[MarineBob]

The idea is to keep the warm, moist inside air from letting moisture into the insulation from inside. I am talking in cold areas.. If its Florida, different situation. Insulation then vapor barrier under sheet rock

 

[AC Power]

And remember to insulate the water pipes. In other words, DO NOT put insulation on top of the pipes so as to expose the pipes to migrating temperatures from the exterior.....ALWAYS insulate beneath pipes.....NEVER on top of them. Typically, all water, gas & elec services are insulated .....however, water is the important one.

 

[MarineBob]

I wouldn't leave any gaps and I believe its important to have a vapor barrier on the warm side of the wall, like under the dry wall so moisture does not get into the insulation.

I hope my above post is not mixed up. I did not mean to refer to Floirda etc approach to insulating. My cooments were for cold areas, hot humid is a different approach. The Florida comment was meant to say ... a different approach.

 

[JustinH]

I hope my above post is not mixed up. I did not mean to refer to Floirda etc approach to insulating. My cooments were for cold areas, hot humid is a different approach. The Florida comment was meant to say ... a different approach.

Hi
Thanks very much for your help. I wasn't confused by the Florida reference, especially as I live in France.