Short answer: limescale on marble must be removed acid-free only – for example with stone clear UR 27 Marble Bathroom Cleaner: spray on, leave briefly (do not let it dry), wash off with a wet sponge. Vinegar, citric acid and ordinary bathroom descalers etch marble and leave dull marks. If such marks are already there, only re-polishing helps, e.g. with KP 30 Crystallisation Powder.
Why marble reacts so badly to limescale removers
Marble, limestone, travertine, Jura limestone and cement tiles consist largely of calcium carbonate – chemically exactly the same substance as limescale. An acidic descaler cannot tell the difference between a limescale mark and the stone: it dissolves both. The result is dull, rough patches (“etch marks”) that cannot be wiped away.
How to tell whether your stone is acid-sensitive
- Acid-sensitive: marble, limestone, travertine, Jura stone, Solnhofen slabs, cement tiles, many engineered stones and terrazzo.
- Usually acid-resistant: granite, gneiss, quartzite, porcelain stoneware, ceramics.
Not sure? Treat the stone like marble – i.e. acid-free. That way you can never go wrong.
Guide: removing limescale from marble
- Test: try UR 27 in an inconspicuous spot first.
- Spray on: spray UR 27 undiluted directly onto the limescale mark.
- Leave briefly: the product must not dry on.
- Wash off: wash off with a wet sponge. On walls, always work from bottom to top to avoid run marks.
- Dry off: dry with a soft microfibre cloth, e.g. RG 960. That way new water marks don't form in the first place.
Coverage: 500 ml UR 27 is enough for approx. 3–6 m². With regular use, less limescale forms.
Which product for which stone?
| Material | Against limescale |
|---|---|
| Marble, limestone, travertine, cement tiles, engineered stone | UR 27 Acid-Free Marble Bathroom Cleaner |
| Granite and acid-resistant natural stone (worktops) | UR 26 Limescale Remover for Granite Worktops |
| Ceramic tiles, taps, washbasin, WC | BR 90 Bathroom and Sanitary Cleaner – not for natural stone |
Dull spots already? How to restore marble's shine
Dull marks are not dirt but a damaged surface. Cleaning no longer helps – the surface has to be re-compacted and polished. For calcareous floors this is done by crystallisation with KP 30 and a single-disc machine with a white pad. This requires experience – we are happy to do it for you as a service. For slightly worn floors, the self-shining UR 11 Floor Care can already make a big difference.
Preventing limescale
- After showering, remove water with a squeegee or cloth.
- Clean regularly with UR 27 rather than rarely and intensively.
- Seal absorbent stone with SI 88 Stain Stop Aqua – water and dirt penetrate less.
Frequently asked questions
Can I use vinegar or citric acid on marble?
No. Both are acids and etch marble, limestone and travertine. Dull spots appear that can only be removed by re-polishing.
How do I remove limescale from travertine in the shower?
As with marble: acid-free with UR 27. Spray on, leave briefly, wash off with a wet sponge, dry off.
Can I remove limescale from cement tiles?
Yes, also acid-free only with UR 27. Cement tiles are just as acid-sensitive as marble. For care, UR 19 Cement Tile Care is suitable.
What helps against limescale on granite?
Granite is acid-resistant. Here the stronger UR 26 Limescale Remover works faster. Knock off thick crusts with a blade scraper first.
Advice from the Swiss stone care specialist
Not sure what stone is installed in your home? Send us a photo or call us: +41 41 790 38 05. Go to the contact form.
