March 27/April 3, 2017: Volume 31, Issue 21
By Donato Pompo
Here at Ceramic Tile & Stone Consultants (CTaSC) we field a lot of questions from retailers and consumers alike about restoring the surface of porcelain tile products, which are growing in popularity. Following is a customer’s recent inquiry about how to remove common grout haze from unfinished porcelain tile:
The grout haze and residue was allowed to cure and dry on the porcelain tile for 11 days before any attempt for removal of this product. After three days of cleaning the floor, I still have a dull residue and dripping spots on a large portion of the tile. (Do you think the grout haze and residue remained on the porcelain tile too long to affect the cleaning process? If so, what would be considered an adequate time frame to start removing the grout haze and residue from the tile?)
All materials were installed on a concrete slab—1,030 square feet tiled, three bedrooms with closets and a living room. The tile—Crossville Moonstruck Series Luna and Juno 12 x 24 unpolished with cross-sheen product—is a rectified tile and porcelain installed over Laticrete Fracture Ban 40 mil membrane with the recommended floor primer. The mortar used for the installation of the tile was Mapei Ultraflex 1.
The grout width is 1⁄8 inch thick and the brand used is a Bostik TruColor rapid cure grout. The grouting process was completed on Feb. 17, 2017, by the installers.
On Feb. 28, I first attempted to remove the haze and residue with Bostik Blaze. But there is still a dull residue and shiny dripping spots on the tile.
I would appreciate your advice on fixing this issue.
Dear homeowner:
It’s important to note there is always a grout haze after grouting a tile. For cementitious grouts, the haze should be polished off with a dry clean cheese cloth soon after the tile surface dries. If you wait too long the haze can be very difficult to remove.
Sometimes the haze could be a latex residue from the polymers in the grout or thin-set mortar. There are special removers of latex haze that can be bought from the various tile and stone cleaning and sealing manufacturers. Check the CTaSC Resource Directory at ctasc.com.
However, it isn’t clear what the drip marks are. If you used a very corrosive acid to try to clean the tile it could possibly etch the surface. If it is etched the only thing you can do is get a professional stone restoration company to hone the surface.
If it is a cementitious haze, you can use some diluted vinegar or diluted phosphoric acid and scrub it with a 3M pad to remove the haze. In situations where the haze is more difficult to remove, use a scrubber with water and detergent with silica sand. Note: This can only work if the product is an unglazed or unpolished porcelain tile. You can never perform these steps on a polished tile, so it’s important to know what you’re working with. Always test the scrubbing method in an out-of-the- way spot before you apply it to the floor.
There is a condition called optical haze that can occur on some polished tiles that gives it a sort of cloudy appearance when the light shines on it at a certain angle. But that isn’t known to happen on an unpolished tile.
If all else fails, there are stone restoration companies that can deep clean and refinish stone and some tile floors. Make sure they are credible and qualified with a lot of experience.
Donato Pompo, CTC CMR CSI CDT MBA, is the founder of CTaSC and a leading stone forensic expert and consultant in North America.