DIY Doctor UK DIY Forums

Hi

I hope you can help please.

I have a long, 'tandem' garage attached to my house. The wall to the left is my house wall so is a cavity wall. The wall to the right is a single skin brick wall (100mm wide). I shall be dividing the garage in half with a stud wall and plan to put insulation between the roof joists (flat roof) with a plasterboard ceiling.

I wish to use the garage as a gym / 'chill out' room so would like to make it a bit warmer. I should add there will be a spa in there also, so a bit of moisture generated from that.

I've tried to find information on the internet and it all seems to contradict itself, so I thought I'd asks the experts on this forum!

Various websites say that I have to put a damp proof membrane against the wall before I attach the insulation, but others say that I do not need this and the insulation board can fix directly to the wall with no damp proof membrane. Some suggest forming a small cavity using battens.

etc, etc ...

Any advice would be greatly appreciated please.

Thanks.

Rob :)

there are various ways to insulate

you can batten out the walls and fit drytherm insulation,vapour barrier,plasterboard,then plaster.
Use insulated plasterboard and fix using drylining adhesive,then plaster.

But you mentioned a spa,the plasterboard would not last so you are best using tounge and groove timber for that.
so you would need to batten out the walls,insulate,then fix the T&G to the battens

Thanks for you reply Welsh Brickie.

That make sense - I don't want it all falling off the wall and ceiling in a soggy heap! I assume the timber will need to be treated (tanalised ?) to combat the moisture.

Your advice is much appreciated.

Rob :)

yes its best to be treated you can stain it but no varnish as the wood needs to breathe.

Thanks again for your help.

It's always appreciated when somebody who knows what they are doing is willing to offer advice.

Rob