I have read the standard replies on floor screeds at the top of this forum but unfortunately they don't cover what I need to know.
My concrete garage floor was obviously badly laid with a weak mix. Parts of it eventually became dusty. No amount of sealing with either dilute PVA or flooring undercoat helped. Nor did floor paint, which adhered firmly to only about 80% of the surface - the rest was just too crumbly.
There is no damp-proof membrane but it has a clear channel all round to avoid breaching the house DPC, and the slab (laid on a dry sandy soil) does not appear to have a particular damp problem. So which of the various screed options would be preferable? I even wondered about painting with bitumen, dusting with sharp sand to give a grip, and then laying 1cm or so on top using a stronger mix of cement and sharp sand. Stripping the painted part is not an option but I'm not averse to raising the entire level if necessary, but I'd prefer not to; what is most likely to work over the whole area?
My concrete garage floor was obviously badly laid with a weak mix. Parts of it eventually became dusty. No amount of sealing with either dilute PVA or flooring undercoat helped. Nor did floor paint, which adhered firmly to only about 80% of the surface - the rest was just too crumbly.
There is no damp-proof membrane but it has a clear channel all round to avoid breaching the house DPC, and the slab (laid on a dry sandy soil) does not appear to have a particular damp problem. So which of the various screed options would be preferable? I even wondered about painting with bitumen, dusting with sharp sand to give a grip, and then laying 1cm or so on top using a stronger mix of cement and sharp sand. Stripping the painted part is not an option but I'm not averse to raising the entire level if necessary, but I'd prefer not to; what is most likely to work over the whole area?
