What is this frothy substance that comes up between cracks on painted floors, painted on concrete? I have this house. the floors are concrete floors, painted. The house...

I have this house. the floors are concrete floors, painted. The house was moved out empty for a year and a half. (Long story.) When I returned to the house final weekend, one room, the floor was covered with white frothy specks, and a few certainly looked like shaving cream. obviously it isn't. what is it, and what is the best road of eliminating this? I'm afraid it might be mildew, and if i swept it, spores would come flying up into the air.

any tips/advice?

gratitude.
What does it indicate when your wash contrivance...
Answers:    Rod, I think you mean efflorescence.
Yours sounds similar to the non destructive variety, and it's caused by the unbound salt leeching out of cementitious materials, and shouldn't worry you. You can just bathe it off. If you like you can paint the walls near a coat of masonry paint or other waterproofing coating to seal them, but you should be OK just cleaning stale, and over painting with your usual paint, if you want to.

Here's a join describing it, with photos.
http://en.wikipedia.org/wiki/Efflorescen...
Public Adjusters: How do they gross their...
It is caused by hose under the floor. You could check the drainage away from the house and water within the area.
I own a small bathroom, no pane, i...
Effervescence, it is caused by wet infiltration.