I have just put in a new staircase and the underside was filled in with wire mesh and then plastered - approx 10 days ago. The plaster has now dried out except for four or five spots which still appear damp and dark in colour. A couple of the spots have sprouted a white furry bloom. There are no pipes nearby and it is some way from an external wall. Does anyone have any thoughts about what it might be? Would apprciate any ideas or suggestions. Thanks.
Hi,
Was the staircase stone that have you plastered. Because i'm assuming that a couple of things, damp spots are still drying out and the plaster has picked up some salts from the stone stairs.
KB
Hi and thanks for replying. No, not stone. The stairs are made from new timber and the underside was covered with wire mesh to allow the plaster to be built up.
I'd give some time to dry out, water content in the mix, warmth of area and depth of application all play a part. I'd brush the white salts away this could be due to the water used.
KB
