Any advice on this will be greatly appreciated.
My house is late Nineteenth Century and has a central hall and living room off to the right both of which have suspended floors. On the left is a dining room and kitchen with concrete floors, and I need to replace the floor in the dining room which has been patched several times and is now cracking again. It's also uneven with signs of heave in the centre.
My guess is there is currently very little infill and only an inch or two of concrete floor. The concrete is probably original, or possibly a replacement for earlier flagstones, and I'm sure it won't have a DPM.
I understand a new floor should have infill, a sand blind, DPM, 50mm polystyrene insulation, 4" of concrete slab, and a 2" screed. However there isn't going to be room for all that without excavating deeper - and major expense! I view this as a repair so I don't see the need for the insulation or anything that's unnecessary.
The builder who is going to do the work proposes to remove the old concrete, lower the infill as necessary, add a sand blind and DPM, and then 3" of concrete with no screed.
My questions are:
a) The room is about 12' 6" square, so is 3" enough? What would be a sensible minimum?
b) Should he be able to level this OK without a screed?
Also I am concerned that a DPM may give me problems elsewhere by pushing moisure into the walls. Two walls are exterior and at least 24" wide made of stone and cob, and if there ever was a DPM in them it will probably have degraded long ago.
Both the other walls are stud walls but are structural. The one between the kitchen probably just sits on the concrete. But the one between the hall sits on the hall joists which are supported by a (new) DPC and wooden wallplate. So any moisure that can't rise through the floor is going to find its way up into these wooden structures.
Any thoughts on whether a DPM is a good idea?
Grateful for any advice.
Harry
My house is late Nineteenth Century and has a central hall and living room off to the right both of which have suspended floors. On the left is a dining room and kitchen with concrete floors, and I need to replace the floor in the dining room which has been patched several times and is now cracking again. It's also uneven with signs of heave in the centre.
My guess is there is currently very little infill and only an inch or two of concrete floor. The concrete is probably original, or possibly a replacement for earlier flagstones, and I'm sure it won't have a DPM.
I understand a new floor should have infill, a sand blind, DPM, 50mm polystyrene insulation, 4" of concrete slab, and a 2" screed. However there isn't going to be room for all that without excavating deeper - and major expense! I view this as a repair so I don't see the need for the insulation or anything that's unnecessary.
The builder who is going to do the work proposes to remove the old concrete, lower the infill as necessary, add a sand blind and DPM, and then 3" of concrete with no screed.
My questions are:
a) The room is about 12' 6" square, so is 3" enough? What would be a sensible minimum?
b) Should he be able to level this OK without a screed?
Also I am concerned that a DPM may give me problems elsewhere by pushing moisure into the walls. Two walls are exterior and at least 24" wide made of stone and cob, and if there ever was a DPM in them it will probably have degraded long ago.
Both the other walls are stud walls but are structural. The one between the kitchen probably just sits on the concrete. But the one between the hall sits on the hall joists which are supported by a (new) DPC and wooden wallplate. So any moisure that can't rise through the floor is going to find its way up into these wooden structures.
Any thoughts on whether a DPM is a good idea?
Grateful for any advice.
Harry
