Natural stone tiles — whether marble, travertine, slate, limestone, or granite — are beautiful but surprisingly easy to damage with the wrong cleaning products or technique. The golden rule is simple: always use a pH-neutral cleaner and avoid anything acidic, abrasive, or bleach-based. Follow the guidance below to keep your stone looking its best for years to come.
Why Natural Stone Needs Special Care
Unlike ceramic or porcelain tiles, natural stone is a porous material that can absorb liquids, stains, and cleaning chemicals. Many stones — especially marble, limestone, and travertine — are calcium-based, which means they react badly to acids. Even everyday household items like lemon juice, vinegar, and some bathroom cleaners can etch the surface, leaving dull marks that are difficult or impossible to remove without professional re-polishing.
Granite and slate are harder and less reactive, but they can still be damaged by harsh chemicals or abrasive scrubbing pads that scratch the surface or strip sealant.
What to Avoid
Before reaching for a cleaner, check the label. Never use the following on natural stone:
- Vinegar or citrus-based cleaners — highly acidic, will etch marble and limestone
- Bleach or ammonia-based products — can discolour stone and break down sealant
- Grout cleaners with acid — commonly sold for ceramic tiles but damaging to stone
- Abrasive scrubbing pads or steel wool — scratch polished surfaces
- Steam cleaners — high heat and moisture can penetrate porous stone and loosen sealant over time (check manufacturer guidance for your specific stone)
- Generic multi-surface sprays — many contain acids or solvents not suitable for stone
Choosing the Right Cleaner
Look for a cleaner specifically labelled as safe for natural stone, with a neutral pH (around 7). In New Zealand, products from Ardex and Mapei include stone-safe cleaning and maintenance ranges. Your local tile supplier or stone specialist will also stock dedicated stone cleaners — always read the product data sheet and confirm it suits your specific stone type.
For routine cleaning, warm water and a few drops of a pH-neutral dish soap (used sparingly) can work well on sealed stone. Rinse thoroughly so no soapy residue builds up.
Step-by-Step: Routine Cleaning
- Sweep or vacuum first — remove loose grit and dirt that could scratch the surface when mopping.
- Mix your cleaner — use a pH-neutral stone cleaner diluted as directed, or a small amount of mild dish soap in warm water.
- Damp mop, don't soak — use a microfibre mop or soft cloth. Excess water sitting on porous stone can cause staining or moisture ingress, particularly important in NZ's wetter climates.
- Work in sections — clean and rinse a section at a time.
- Rinse with clean water — remove all cleaner residue.
- Dry thoroughly — buff dry with a clean microfibre cloth to prevent water spots, especially on polished marble.
Dealing with Spills and Stains
Act fast — the longer a spill sits, the deeper it can penetrate. Blot (don't wipe) spills immediately with a clean cloth. Wiping spreads the liquid further into the stone.
For stubborn stains, a poultice (a paste of an absorbent material mixed with a cleaning agent) can draw stains out of porous stone. The type of poultice depends on the stain — oil-based stains need a different treatment to organic stains like coffee or wine. Your tile supplier or a professional stone restorer can advise on the right approach for your situation.
The Importance of Sealing
Most natural stone tiles should be sealed after installation and re-sealed periodically — typically every one to three years depending on the stone type, traffic, and the sealer used. A good quality impregnating sealer penetrates the stone and helps repel liquids, making cleaning much easier and reducing staining risk.
Check whether your stone is still sealed by dropping a few drops of water on the surface. If the water beads up, the seal is intact. If it soaks in and darkens the stone, it's time to re-seal. Always clean the stone thoroughly before applying a new coat of sealer, and follow the manufacturer's instructions carefully.
Cleaning Different Stone Types
| Stone Type | Sensitivity | Key Watch-Out |
|---|---|---|
| Marble | High | Etches easily with acids; avoid vinegar |
| Travertine | High | Porous and acid-sensitive; seal regularly |
| Limestone | High | Similar to marble; very reactive to acids |
| Granite | Medium | Durable but still needs pH-neutral cleaners |
| Slate | Medium | Can flake if over-saturated; dry promptly |
| Sandstone | High | Very porous; seal well and use minimal water |
Grout Lines on Stone Tiles
Grout between natural stone tiles also needs careful treatment. Avoid acid-based grout cleaners. Use a soft brush with a pH-neutral cleaner, and re-seal grout lines periodically. Mapei and Ardex both offer grout sealers suitable for use alongside natural stone.
When to Call a Professional
If your stone tiles have been etched, scratched, or stained beyond what routine cleaning can fix, it's time to call in a professional stone restorer or experienced tiler. Re-polishing, honing, or deep cleaning of natural stone is specialist work that requires the right equipment and products — attempting it yourself with the wrong approach can make damage worse.
For advice on installation, re-sealing, or restoration, you can find qualified local tilers and stone specialists on tradedirectory.co.nz.
For broader guidance on tile installation standards and waterproofing in wet areas (relevant to NZ Building Code clauses E3 and G12), BRANZ is an excellent NZ-specific resource.
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