Garage conversions

[Tuerto]

Don’t forget to check finished floor level to u/s of existing joists. You’re going to need insulation on the existing concrete floor, 100mm at least (although some authorities regs are now 150mm, ridiculous depth really), u/f heating snake clipped to the insulation. 50mm sand/cement screed or liquid screed over the lot. That’s at least 150mm higher than your existing slab. I presume you’ve got bare joists at the moment so insulation (100mm at least) should be fitted between them, this would create a ‘cold’ roof. Given that it’s a flat roof and not pitched you can’t get above the joists to insulate over the top so you should really be using an insulated plasterboard on the ceiling to complete uninterrupted ceiling insulation, this would most probably result in your ceiling finish being 50mm below u/s of existing joists. Doing it this way, which is normal practice now, would result in your storey height being 200mm (8 inches)less than it is now.

There are options, the iso insulation that comes in blanket form might be allowed, reducing loss of height, although the floor screed will have to be a minimum of 75 mm up to 100 mm with chicken wire over the insulation. Madness!

[splott parker]

There are options, the iso insulation that comes in blanket form might be allowed, reducing loss of height, although the floor screed will have to be a minimum of 75 mm up to 100 mm with chicken wire over the insulation. Madness!

If it was mine I’d be very much inclined to take the existing slab up, reduce the levels inside the room and put a traditional floor in to nigh on the same height as it is now, membrane, insulation the lot. Regs have changed on inside to be 150mm above outside with disabled access to the fore now so that problem’s solved, Mike said existing drainage was nearby so a run of Aco’s into that may help. Would certainly help with storey heights, bit of heartache at first breaking the slab up but I reckon looking at the finished article you’d think it was well worth it.

[Tuerto]

If it was mine I’d be very much inclined to take the existing slab up, reduce the levels inside the room and put a traditional floor in to nigh on the same height as it is now, membrane, insulation the lot. Regs have changed on inside to be 150mm above outside with disabled access to the fore now so that problem’s solved, Mike said existing drainage was nearby so a run of Aco’s into that may help. Would certainly help with storey heights, bit of heartache at first breaking the slab up but I reckon looking at the finished article you’d think it was well worth it.

Completely agree, new floor is the way to go. Absolute ball ache the other way round.