Etch Marks on Terrazzo
Etch marks on terrazzo appear as dull spots, lighter patches, or surface roughness caused by chemical exposure. The severity and cause depend on whether the terrazzo is cement-based or epoxy-based.
What’s Happening
Terrazzo is made from decorative stone chips embedded in either a cement binder or an epoxy resin binder.
Cement-based terrazzo contains calcium and reacts chemically to acids — similar to marble. When exposed to acidic substances such as vinegar, citrus, wine, or certain cleaning products, a chemical reaction can dissolve a microscopic layer of the surface and leave a dull area.
Epoxy terrazzo does not chemically “etch” in the same way, but the resin binder can still be damaged by aggressive chemicals. Strong acids, industrial disinfectants, and highly alkaline cleaners can:
- Break down the resin surface
- Cause hazing or dullness
- Create uneven sheen
- Lighten or discolor patches
In commercial environments — such as medical facilities or dialysis centers — repeated exposure to strong chemical agents can chemically alter both cement and epoxy terrazzo over time.
Because terrazzo combines aggregate with binder, damage may appear as dullness in the binder while chips remain glossy.
If the area appears dark rather than dull, review Oil & Grease on Terrazzo to rule out staining.
What To Do
If your terrazzo is cement-based…
Clean the area with a pH-neutral cleaner and allow it to dry completely. If the dull spot remains and feels slightly rough, acid exposure likely etched the cement matrix. Minor etching may require professional honing and polishing to restore uniform sheen. Avoid over-the-counter acidic “cleaners” or DIY polishing powders without confirming compatibility. Spot correction attempts can create uneven gloss if not blended properly.
If your terrazzo is epoxy based…
Clean thoroughly with a neutral cleaner and dry the surface completely. If the dull area remains consistent whether wet or dry, the resin binder may have been chemically altered. Aggressive sanding or grinding can damage the surface further. In some cases, controlled professional refinishing may improve appearance, but deeper chemical alteration may be permanent. Identify and eliminate the chemical source to prevent continued damage.
If you’re not sure which type of terrazzo you have…
Assume it is sensitive. Use only pH-neutral cleaners and avoid acidic or high-alkaline products.
If the surface shows persistent dullness, professional evaluation can determine whether the terrazzo is cement-based or epoxy and recommend appropriate restoration methods.
If discoloration is orange or brown instead of dull, review Iron Staining on Terrazzo once published.
What NOT to Do
- Do not use vinegar or acidic cleaners.
- Do not use heavy-duty disinfectants without confirming compatibility.
- Do not use abrasive pads or sanding tools.
- Do not attempt spot grinding to remove dull patches.
- Do not ignore recurring chemical exposure in commercial settings.
When to Call a Professional
Call a professional if the dull area is expanding, highly visible, or caused by repeated chemical exposure. Terrazzo restoration requires blending the binder and aggregate uniformly. Improper DIY attempts can create uneven sheen or permanent surface damage. Professional evaluation ensures the correct restoration method based on the terrazzo type.
Safety Equipment
- Protective gloves
- Eye protection
- Adequate ventilation when using cleaning products
- Respiratory protection if using refinishing compounds
Prevention
- Use only pH-neutral cleaners approved for terrazzo.
- Avoid acidic or high-alkaline cleaning products.
- Confirm compatibility of disinfectants in medical or commercial settings.
- Clean spills promptly.
- Establish a routine maintenance program appropriate for the terrazzo type.
Disclaimer:
The information provided through Surface IQ is for general informational purposes only and is not a substitute for professional evaluation or service. Surface conditions, materials, finishes, and installation methods vary, and results cannot be guaranteed.
NextGen Surface Care assumes no liability for damage, injury, or loss resulting from the use or misuse of this information. Always test any treatment in an inconspicuous area before full application. Follow all product instructions carefully and use appropriate personal protective equipment (PPE) with proper ventilation.
For delicate, valuable, or antique surfaces—or if you are unsure about the material, finish, or condition—consult a qualified stone care professional before attempting any treatment.