How do I clean white grout stained by ammonia?

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Q: I have a ceramic tile floor that has self-sealing white grout. I spilled ammonia on it, and it stained the grout. How do I fix this?

A: The ammonia has reacted chemically with the grout. There is no cleaner that will get rid of the stain. Your only option is to scrape out the top layer of the stained grout (at least 1/8") and then re-grout with the same color.

Ammonia is acidic, and grout is alkaline; the two don't mix. The only harsh cleaning agent I would recommend for grout is bleach.  Since you have white grout, then chlorine bleach is the best option. I use the gel-type toilet bowl cleaners with bleach. Squeeze the cleaner out along the grout lines; let it sit for 15 minutes and then wash it off.

Re-grouting is not a difficult job particularly for a small area. You can get a small grout saw to scrape out the stained grout. Then just mix a small batch of grout to the consistency of mayonnaise, spread it into the gaps (you can use your finger), let it set for 10 minutes and then wash off the excess with a clean sponge.

-- Answer from Rick S., plumbing and home improvement specialist on JustAnswer.

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