Components of Grout Haze

• The grout haze on your porcelain tiles will often not even appear until a day or two after you apply the material. The haze is a result of efflorescence, a naturally occurring byproduct of a chemical reaction between the wet grout and the moisture in the air. If you have ever seen a powdery white substance on exterior brick or concrete walls, this is efflorescence, and it's the same material causing the haze on your tile. The haze is actually a fine white powder that is a result of the concrete components of grout reacting with the moisture of your bathroom.
  
  

When to Clean

• Removing the grout haze will not be effective until after the grout has cured completely. As long as the grout is wet, you run the risk of wiping grout out of the joints. Similarly, the wet grout can always produce more efflorescence, meaning that you will just have to clean the tiles again. Therefore, wait until the grout has dried and cured completely before cleaning away the haze. This generally takes about three full days; it may take longer if your home is particularly humid or hot. Consult your grout product's instructions for specific information regarding curing time.
  
  

Sulfamic Acid

• Sulfamic acid is the ideal product to remove grout haze, as it is strong enough to dissolve the cement-based efflorescence but will not damage porcelain tile. You will be able to find this cleaner in powder form at many hardware and home improvement stores. You may also see liquid cleaners that advertise sulfamic acid; these may also be called grout haze removers. Sulfamic acid doesn't produce strong fumes, but you may want to ventilate the area in which you are working to get rid of the general cleaning smell.
  
  

Cleaning Procedure

• Always wear protective gloves and safety goggles whenever you work with any acid product. Dilute the powder as a 6-percent solution in water; don't use a stronger solution than that or you can damage the porcelain. Rub the cleaning solution onto your tiles with a damp sponge and allow it to work for a few minutes. Simply wipe the haze and cleaner away with the sponge. Be sure to rinse the area with clean water afterward to remove residual acid on the surface.