Stains on terrazzo can be unsightly and may lead you to decide you have no choice but to have tile or carpet installed over it, but often stains on terrazzo can be effectively removed. You can attempt to remove the stain yourself or contact a professional stone restoration contractor. Here is what will need to be done.
Are your terrazzo floors waxed or coated?
It is not uncommon for a terrazzo floors to be coated or waxed with a topical finish. The only way to know whether the stain is in the topical finish or in the terrazzo itself is to remove any old finish. If you are certain that your terrazzo has a natural, honed or polished finish then you can skip the stripping process described below and move on to the poultice application.
Also note that most modern terrazzo is made with a resin matrix that will soften if stripped. If you are sure that your terrazzo has an older cementitious matrix, you can safely proceed with stripping. If you have any doubts or know that you have a newer, resin matrix terrazzo floor, do not apply a stripper to your terrazzo. Please contact your stone restoration contractor for guidance.
Stripping Waxes and Coatings
It is very important to note that floor stripper is very caustic and can cause injury or damage. You must wear heavy latex gloves and eye protection and use masking tape and plastic to protect the floor surrounding your work area.
Mix one part water-based floor stripper (the same kind used for vinyl tile or polymer finishes) with six parts water and apply to the stained area. Allow five minutes dwell time. Agitate the solution with a green scrubbing pad. Use an absorbent white cloth or paper towels to soak up the solution. Then, repeat this entire process.
At this point, if the coating was stained and not the terrazzo itself, it is possible that the stain may be gone. If so, use a pH-neutral, stone-safe cleaner to remove any remaining stripper and clean the area. If the stain is still there, that means it is in the terrazzo, and you can try to remove it using a poultice application.
The Poulticing Method of Stain Removal
A poultice is a combination of a dry, absorbent medium and a liquid chemical or cleaning agent. The ingredients for your poultice will depend on what type of stain you are trying to remove.
Restoring Your Terrazzo Finish
Please note: If your terrazzo has a natural, honed or polished finish, there is no need to strip or reapply coatings.
If you stripped the stained area, you removed the topical finish. That means you now have a small area that looks dull compared to the surrounding floor. To resolve this problem, use a paint brush to reapply a water-based finish. It may take up to eight coats to give the work area a nice, even sheen that blends with the surrounding area.
Professional Terrazzo Stain Removal and Refinishing
An experienced natural stone restoration contractor can use a floor machine with an aggressive pad to strip your entire floor, if needed. Depending on the severity of the stain, the technician can either apply a poultice or grind the affected area, removing a very thin upper layer and virtually erasing the stain. Then, the floor can be deep scrubbed and recoated to rejuvenate the existing finish or honed and polished for a beautiful, natural finish that eliminates the need for any future stripping or recoating.