Known for their versatility, numerous styles and durability, ceramic tiles are used on household floors, walls, backsplashes and countertops. Ceramic tiles are installed with grout, which fills the joints between individual tiles and bonds the tiles to the underlying surface. Grout inevitably transfers onto ceramic tiles during installation, leaving a cloudy haze on their surfaces. Acid-washing ceramic tiles dissolves the cement in grout to restore the tiles' original look. Allow new grout to thoroughly cure for a minimum of two weeks before the acid wash.
Fill an acid pail with 1 gallon of cool water. Pour 3/4 cup of sulphamic acid crystals into the cool water. Mix the sulphamic acid crystals into the water with a stirring tool until they dissolve.
Saturate the ceramic tiles with clean water to protect the grout from acid-related burns and prevent the ceramic tiles from absorbing the sulphamic acid too quickly.
Drench a nylon scouring pad in the sulphamic acid solution. Scrub the diluted sulphamic acid liberally onto a 2-by-2-foot section of the grout-stained ceramic tiles for five minutes. Do not let the sulphamic acid solution dry on the ceramic tile surfaces.
Rinse the 2-by-2-foot section of ceramic tiles immediately with excessive amounts of fresh water.
Scrub the sulphamic acid solution onto the remaining 2-by-2-foot sections of ceramic tiles until all grout haze is thoroughly removed. Thoroughly rinse each 2-by-2-foot section immediately after acid-washing.
Mix a commercial alkaline cleaner with water in an ordinary plastic pail. Follow the specific cleaner manufacturer's directions.
Mop the alkaline cleaner onto the ceramic tiles to neutralise the remaining sulphamic acid solution. Let the alkaline cleaner sit on the ceramic tiles for 10 minutes.
Rinse the ceramic tiles thoroughly with clean water. Let them air-dry completely.
Scrape heavy grout build-up off the ceramic tiles with a plastic scraper. Wear long clothing, protective eyewear and heavy-duty gloves when working with the alkaline cleaner.
Never wash ceramic tiles with muriatic acid; the tiles may become permanently damaged. Spot-test the sulphamic acid solution on a ceramic tile to prevent discolouration. Never scrub the ceramic tiles with wire brushes or steel wool. Never use sulphamic acid as a regular cleaner on ceramic tiles.