Cleaning marble?

muffler

Right, I have a mate who is a window cleaner but also does a bit of wall cleaning also (power hosing etc) and he has to clean the external walls of a local shop. The walls are cladded in what appears to be polished marble/artificial marble and he's having difficulty in removing stains.

Its a job with a bucket and sponge apparently and the stains are from water run off from the roof. Anyone any suggestions as to what product could be used to help remove the stains?

Many thanks

red sean

I'm not an expert, but would say it's most likely polished granite rather than marble.
Try http://www.hgcleaningproducts.com/. They're available in most hardware/builders suppliers.

Apelles

I've always found cellulose thinners or acetone to be brilliant all-round stain removers & cleaners for removal of imbedded grime on tough surfaces (be cautious when using on some plastics).

Get him to try one of the more obscured stains with a little of his mis·sis's nailpolish remover (which has very similar properties) as a test area, if that works then he could invest in a gallon of some cellulose thinners for about €15 in most hardware or motorshops.

Spread

Try ammonia:water. 1:40 and wash off thoroughly. Citric and vinegar mixes will etch.
If all is good afterwards coat it with a penetrating sealer.

Google should turn up some ideas, or marble manufacturers.