Marble showers accumulate moisture, dirt, oil, mould, mildew, rust stains, scratches and all sorts of insults. From the marble's point of view, the shower is probably the most hostile environment in the home. Proper cleaning can prolong the appearance of fine marble.
Start with clean marble. Deeply dirty marble is probably damaged, and will require professional restoration.
The best results can be obtained by using the right materials before soil accumulates. The best cleaner is a pH neutral cleaner formulated for cleaning natural stone. These cleaners contain minerals that can replace minerals stripped by pollution. Stone cleaners are available from many stone retailers. They are highly concentrated, and are actually economical to use.
Use only tools with plastic and soft fiber parts. Squeegees and wet vacuums should not have any metal parts; these can scratch marble.
Dilute 1 or 2 ounces of the stone cleaner in a 3 to 5 gallon bucket of clean, warm water. Fill another bucket with more clean, warm water. Vigorously apply the cleaner with a sponge or soft, natural brush, and then rinse the marble with a sponge of clean water from a bucket of rinse water. Vacuum the marble or dry with s soft cloth. (
Do use white scrubbing pads; they usually do not harm the marble. Do not use abrasive cleaners; they will scratch the stone. Do not use thick, creamy cleaners; they will stick in the natural pours of the stone. Soft squeegees, soft sponges and soft, natural cloths are ok.
A stronger solution of stone cleaners can loosen small areas of stubborn dirt. Apply with a sponge and allow the cleaner to penetrate the soil. Wipe up thoroughly and rinse well.
Removing stains is not guaranteed. First determine whether the stain is water based or oil based (candles, cosmetics, etc.). Some stone retailers sell poultices that can usually absorb the stain, until it is virtually undetectable. Follow the directions exactly. Usually the poultice is slightly moistened with a suitable liquid, and then spread over the stain. The poultice is usually covered with plastic wrap so that it remains moist. After the specified time has past, remove the plastic cover and wipe up the poultice. Clean with stone cleaner. If two applications of the poultice do not lighten the stain, it has penetrated the stone too deeply. Consult with a professional; resurfacing the stone can remove some stubborn but shallow stains.
Rust stains and water spots should be referred to a professional. Rust stains will require resurfacing the marble to remove the stained surface. Water spots are chemically similar to the marble itself; anything that would remove the spot would remove the marble with it.
Some of the mildew and mould can be removed with aggressive cleaning with stone cleaner. The best treatment of mould and mildew is a professional sealer with anti-mildew additives. Replacing cement grout with epoxy grout usually reduces the reoccurrences of mould and mildew in the grout. [
A small squeegee used to wipe the marble after each shower, will reduce the accumulation of soap scum, etc. between thorough cleanings.