white film/powder

[renogaw]

we had a tarp on top of our concrete garage floor for a while, when we removed the tarp, the concrete was covered by a thin, powdery white substance, that smelled somewhat like mold. it sorta smelled like mold, but after bleaching it twice so far, the white powder is still there, and it still smells. so it got me thinking, would the tarp on the concrete pull lime out of the concrete, and what would that smell like?

 

[spanko]

Sounds like Concrete Efflorescence, minerals that have been pulled out of the concrete, but you usually see that in humid areas, which I guess is entirely possible if you had the tarp trapping the moisture in. A good power washing with bleach will usually clean this up.

 

[dragonzim]

Quote:
Originally Posted by spanko http:///forum/thread/379990/white-film-powder#post_3305219
Sounds like Concrete Efflorescence, minerals that have been pulled out of the concrete, but you usually see that in humid areas, which I guess is entirely possible if you had the tarp trapping the moisture in. A good power washing with bleach will usually clean this up.

 

[renogaw]

yea, we've had a really humid summer, plus the tarp on top. thanks