Have tile on mud room over ground, no cellar, unheated.?

White spots appear on grout. Could this be from frost or dampness? Nothing gets rid of it. Any suggestions to get rid of and avoid this?

Anonymous2013-04-12T22:55:09Z

Favorite Answer

Sounds to be hygroscopic salts coming out of the ground.The only way to get rid of it is to lay a membrane under the tiles