sounds like iron. Is your tapwater pretty laden with minerals? Is there anything iron like imbedded mesh behind the tiles? When you regrout, use distilled water to mix it. Like Steve, find this somewhat puzzling. Luck, Kizmet
Topic History:
Topic Follow-ups:
About | Press Room | FAQ | Contact | Sitemap | Privacy Policy | Terms of Use | Help
© 2009 BobVila.com