Hi,
I'm itching to get cracking on converting my garage into a semi habitable room but have a few queries. I have tried searching for answers but can't find anything definitive on all the queries, at least not that my brain can fathom...
Two walls are existing insulated cavity walls, roof is flat and currently uninsulated.
The floor is concrete and has no DPM, and one wall is single skin joined to neighbours garage.
Question 1: I plan to insulate between roof joists, I will leave 50mm gap above insulation but do I need to leave an air gap at each end for ventilation as the joists run 90 degrees to garage door opening?
Question 2: There is visible efflorescence on the floor and also some damp patches on the floor. I had a piece of plastic on the floor to keep the bottom of a cupboard dry and when I pulled that up it was very damp underneath. I want to put a membrane down on top of the concrete slab and make a floating floor with PIR and OSB but do I then risk the concrete getting damp and water sitting under the membrane and causing problems? Do need to seal the concrete somehow before doing this?
Question 3: Similar to the floor, our neighbour's garage floor is 2ft higher than ours and the section of wall on my side that is below their garage has efflorescence coming through and anything that goes near the wall gets mouldy. Can I fix timber battens to the wall with DPM strips under them and then fix PIR to the battens to create a cavity or again do I need to seal the problem wall with something first?
And finally question 4, once floor is sorted how do I finish the DPM off? Bring it up the wall a bit behind the PIR, behind the battens or just cut it off at finished floor level before skirting?
Any advice very much appreciated, I'm still learning and this is my first major project I've decided to try and DIY.
Cheers
I'm itching to get cracking on converting my garage into a semi habitable room but have a few queries. I have tried searching for answers but can't find anything definitive on all the queries, at least not that my brain can fathom...
Two walls are existing insulated cavity walls, roof is flat and currently uninsulated.
The floor is concrete and has no DPM, and one wall is single skin joined to neighbours garage.
Question 1: I plan to insulate between roof joists, I will leave 50mm gap above insulation but do I need to leave an air gap at each end for ventilation as the joists run 90 degrees to garage door opening?
Question 2: There is visible efflorescence on the floor and also some damp patches on the floor. I had a piece of plastic on the floor to keep the bottom of a cupboard dry and when I pulled that up it was very damp underneath. I want to put a membrane down on top of the concrete slab and make a floating floor with PIR and OSB but do I then risk the concrete getting damp and water sitting under the membrane and causing problems? Do need to seal the concrete somehow before doing this?
Question 3: Similar to the floor, our neighbour's garage floor is 2ft higher than ours and the section of wall on my side that is below their garage has efflorescence coming through and anything that goes near the wall gets mouldy. Can I fix timber battens to the wall with DPM strips under them and then fix PIR to the battens to create a cavity or again do I need to seal the problem wall with something first?
And finally question 4, once floor is sorted how do I finish the DPM off? Bring it up the wall a bit behind the PIR, behind the battens or just cut it off at finished floor level before skirting?
Any advice very much appreciated, I'm still learning and this is my first major project I've decided to try and DIY.
Cheers
