Folks, I have a white substance showing on my painted walls (drywall painted in dark color with Benjamin Moore paint). The walls were painted several years ago and the problem seems to have gotten worse over that time. The walls are really starting to look patchy and I finally want to do something. I have tried cleaning with water, but white stuff still there are wall dries. I had a cleaning company come look at it and they didn't have any idea. The white stuff doesn't wipe off when you run your hand over it. Really, it looks like the walls are dusty but it isn't dust. I tried to attach photo but hard to capture with my iPad camera. please help. I am happy to post more information if you can tell me what you need.

My basement storage/laundry room has a mosaic floor, which is old and very unattractive. I am seriously considering painting the floor. The plan would be : a) an extremely good cleaning -- TSP, sanding, more cleaning, deglosser, etc b) two coats of oil- or shellac-based primer c) two coats of either poly-fortified gloss oil paint (e.g BM alkyd floor and patio paint) or epoxy-fortified satin acrylic paint (e.g. BM acrylic floor and patio paint) d) If using acrylic floor paint, two coats of water-based clear poly. Some questions 1) Is this process OK? 2) To save time, I was thinking shellac based primer (dries faster) instead of oil-based primer. Would that be OK? Would BIN do the trick on a floor? 3) Is the oil-based paint necessary? Or an epoxy-fortified Acrylic paint made specifically for floors be good enough? 4) If poly-fortified alkyd is used, would water-based clear poly for added protection be overkill? 5) Is it a good idea to do all this? Thanks