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Friday, September 19, 2014

Question

We have been trying to remove some serious lime build up from of a quarry tile floor. Nothing we have tried is working.


Answer

The traditional lime remover for masonry is hydrochloric (muriatic) acid. It is readily available at builder’s supply houses and dilution instructions are on the container. Be sure to utilized proper safety equipment (PPE) and it would be a good idea to test the product and process in a small area (3 to 4 inches) to see that you are getting the desired results before widespread use. Follow the directions on the container closely to avoid problems or possible damage to the tile or grout. Use it only with good ventilation as the dissolving lime gives off strong fumes. Don't get the acid solution on any metal surfaces it will cause them to rust and or discolor.
There are other commerical lime scale removers available that may be safer to use. If you have tried this sort of product and it has not worked, consider that the floor may have been sealed with a topical coating that is now preventing the acid from coming in contact with the lime. If so, the surface coating will have to be removed/stripped to expose the lime before it can be treated. If the white discoloration is efflorescence caused by moisture and salts coming up through the concrete slab and or grout, the cause of the moisture will have to be eliminated to prevent the problem on a permanent basis.
Lynn E. Krafft, ICAN/ATEX Associate Editor
lekrafft@juno.com