Converting a garage

Zulu

Hello, I'm planning to convert an outside, brick built garage into a room/office.

My plan is to run a layer of plastic over the walls, securing with with studs. Then to anchor insulated backed plasterboard to the studs to finish off the wall.

For the Garage door, I was going to leave it in place but create a "fake wall" - place studs over the entrance. between the studs and the garage door, plastic sheeting. Between the studs, pin insulation, and on the inside clad with old pallet boards (instead of insulated plaster board as this will be revisited in 5-10 years when I've money to take out the door and put in a window or something).

Finally for the floor, again, layer of plastic, then studs, insulation, and chip boards? Which will be finished in laminate I guess.

So I'd greatly appreciate anyone pointing out rookie mistakes in the above!

Also, if anyone can direct to decent youtube/websites for research I'd be grateful. Finally, comments, suggestions, observations very welcome!
Thanks.

Calahonda52

https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx

what about the roof/ceiling?

Wall makeup is wrong as the plastic is on the cold side of the insulation so you will get condensation

What finish is currently on inside of walls

can't follow door idea.
the isulation needs to be protected from air passing through it, but not plastic on cold side

Zulu

Calahonda52 wrote: »

https://www.nsai.ie/S-R-54-2014-Code-of-Practice.aspx

Thanks for that.

what about the roof/ceiling?

There's a plaster ceiling the builder put in. Not sure what if any insulation there is between it and the roof. There'll be an air gap anyway as the roof is pitched, where the ceiling is flat.

Wall makeup is wrong as the plastic is on the cold side of the insulation so you will get condensation

Ok thanks. my thinking was to keep any condensation away from the insulation. Should the plastic go between the stud and the insulation?

What finish is currently on inside of walls

Concrete brick.

can't follow door idea.

It's just to close over the garage door. There's another door I'll be leaving "as-is".

the isulation needs to be protected from air passing through it, but not plastic on cold side

ok thanks where does the plastic go so?

Zulu

Hang about, am I over complicating this altogether? Just looking at the Kingspan website and it looks like I can fix their insulated plaster board directly to the walls with adhesive. No need for moisture barrier. Is that right?
Similarly, I can get insulated flooring that I suspend between joists and fire down chip board on top. No need for moisture barrier either.

Seems very simple. Is this right?

MicktheMan

Zulu wrote: »

Seems very simple. Is this right?

If you're looking for an insulated draughty office, then yes.

Zulu

Well ok then, I'm not looking for draughty.

So the moisture barrier is for draught proofing as well?

cletus

MicktheMan wrote: »

If you're looking for an insulated draughty office, then yes.

What sort of a response is that. The OP is obviously looking for advice, you've obviously notes some issue with his plans, so why not just point it out and explain how best to remedy.

If he knew it was going to create draughts I'm pretty sure he wouldn't be suggesting it