|For the best results, clean Limestone with stone cleaner and rinse well with clean water. Ease cleaning and limit staining with a professionally applied sealer.
Because the chemical composition of limestone is similar to marble, routine cleaning of limestone floors is similar to cleaning marble floors. Limestone is often softer than the crystallized marble and it usually has a more textured surface. Three things the homeowner can adapt from cleaning marble: Prevention, Cleaning Without Damage, and Stain Removal.
There are two classes of prevention 1. The daily things that the homeowner can do, and 2. Professional services that provide future protection.
The homeowner should prevent damaging grit tracked in by foot. Large mats placed at each outside door will collect outside grit and soil. These mats should be shaken or vacuumed frequently. The floor should be vacuumed frequently. Be sure that the vacuum lifts the grit and soil and does not push it around.
Prevent contact between staining materials and the floor. Put plastic castors under wood and metal furniture feet. Metals will oxidize (rust) and wood will leach tannins. Put plastic trays under potted plants. The pot itself can stain the floor and dark stains are leached from the plant soil. Do not use rubber pads under rugs; the rubber contains sulfur. Also do not use rough fiber pads; they can scratch limestone.
Wipe up spills promptly. Moisture will pull stains into the limestone. Acids will dissolve the calcium carbonate in the limestone, creating dull, etched spots.
Professional applications of stone sealers are effective in preventing stains from penetrating limestone. Professional resurfacing of dull, scratched or worn limestone will create a hard, smooth finish that resists soiling and stains. A professionally resurfaced floor is also easier to clean because the smooth surface does not have uneven spots that trap dirt.
Cleaning Without Damage
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. Mops and wet vacuums should not have any metal parts; these can scratch limestone.
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. Apply the cleaner with the mop, and then rinse the dirty mop in the second bucket of rinse water. Agitate soil in textured areas with a soft, natural brush. Vacuum up the dirty water or squeeze the mop dry and mop up the dirty water on the floor. Rinse the mop again.
Empty both buckets; clean them well and rinse the mop. Refill both buckets with clean, warm water. Apply the rinse water to the floor. Vacuum up the rinse water or squeeze the mop dry and mop up the rinse water on the floor.
Do not use green, nylon scrubbing pads; they are harder than the limestone and will scratch it. 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.
First determine whether the stain is water based (wine, etc.) or oil based (salad dressing). 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, 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.
Limestone is a natural material, and contains traces of various minerals. Deep underground these minerals often do not have any opportunity to oxidize (rust) but when exposed to the air, they oxidize. Some stains are naturally oxidizing constituents of the limestone and cannot be removed or lightened.