Natural stone can be classified into two general categories; siliceous stone or calcareous stone. Knowing the difference is critical when selecting cleaning products.
Siliceous stone is composed mainly of silica or quartz-like particles. It tends to be very durable and relatively easy to clean with mild acidic cleaning solutions. Types of siliceous stone include granite, slate, sandstone, quartzite, brownstone, and bluestone. Calcareous stone is composed mainly of calcium carbonate. It is sensitive to acidic cleaning products and frequently requires different cleaning procedures than siliceous stone. Types of calcareous stone include marble, travertine, limestone, and onyx. What may work on siliceous stone may not be suitable on calcareous surfaces.
Because Granite is a natural product it will provide great colour and grain variations to your bench tops. Granite bench tops are elegant, durable and less subject to stains and scratches than other natural stone bench tops. This natural product is aesthetically appealing and can be manufactured to suit anyone’s requirements.
Interiors gain stature with granite while still providing an extremely hard working and low maintenance surface. Because granite is harder than marble and decidedly less porous it is often specified for high traffic areas such as kitchens.
Right across the globe, granite’s use in both domestic and commercial developments is increasing due to the huge range of colours and textures available. Highly polished granite retains a relatively maintenance free surface indefinitely. It suits any interior and makes a wonderful style statement.
MARBLE, TRAVERTINE + LIMESTONE
Marble, Travertine or Limestone has become the stone of choice for bench tops due to its unique, natural beauty and incredible colour varieties that enhance beauty in all its surroundings.
Because marble, travertine or limestone is more porous than granite, these bench tops are the preferred surface for bathroom installations. With its classic beauty and texture it is suitable for both domestic and commercial use.
HOW TO TELL THE DIFFERENCE
A simple acid sensitivity test can be performed to determine whether a stone is calcareous or siliceous. You will need a few drops of vinegar and an eye dropper. As this test may permanently etch the stone, select an out of the way area (a corner or closet) and several inches away from the mortar joint.
Apply a few drops of the vinegar to the stone surface on an area about the size of a ten cent coin. If the stone is calcareous, the vinegar will etch the stone. If little or no reaction occurs, the stone can be considered siliceous.
Rinse the area thoroughly with clean water and wipe dry. This test may not be effective if surface sealers or liquid polishes have been applied. If an old sealer is present, chip a small piece of stone away and apply the vinegar to the fractured surface.
A polished finish on the stone has a glossy surface that reflects light and emphasises the colour and marking of the material. This type of finish is used on walls, furniture tops and other items, as well as floor tiles.
A honed finish is a satin smooth surface with relatively little light reflection. Generally, a honed finish is preferred for floor, stair treads, thresholds and other locations where heavy traffic will wear off the polished finish. A honed finish may also be used on furniture tops and other surfaces.
A flamed finish (or exfoliated finish) is a rough textured surface used frequently on granite floor tiles.
STONE COLOURS & APPEARANCE
Granites and marbles are quarried throughout the world in a variety of colours with varying mineral compositions. In most cases, marbles and granites can be identified by visible particles at the surface of the stone. Marble will normally show “veins” or high concentrates of minerals. The minerals in granite will typically appear as small flecks distributed uniformly in the stone. Each type of stone is unique and will vary in colour, texture and marking.
Sandstones vary widely in colour due to different minerals and clays found in the stone. Sandstone is light grey to yellow or red. The dark reddish brown sandstone may also be called brownstone. Bluestone is a dense, hard, fine – grained sandstone of greenish – grey or bluish – grey colour.
Limestone is a widely used building stone with colours typically light grey, tan or buff. A distinguishing characteristic of many limestones is the presence of fossils that are frequently visible in the stone surface.
Slate is dark green, black, grey, dark red or multi-coloured. It is most commonly used as a flooring material and for roof tiles and is often distinguished by its distinct cleft texture.
CLEANING PROCEDURES + RECOMMENDATIONS – FLOOR SURFACES
Dust mop interior floors frequently using a clean non-treated dry dust mop. Sand, dirt and grit do the most damage to natural stone surfaces due to their abrasiveness. Mats or rugs inside and outside an entrance will help to minimise the sand, dirt and grit that will scratch the stone floor. Be sure that the underside of the mat or rug is a non-slip surface.
Normally, it will take a person about eight steps on a floor surface to remove sand or dirt from the bottom of their shoes. Do not use vacuum cleaners that are worn. The metal or plastic attachments or the wheels may scratch the surface.
Clean stone surfaces with a few drops of neutral cleaner, stone soap or a mild liquid dish washing detergent and warm water. Use a clean rag mop on floors and a soft cloth for other surfaces for best results. Too much cleaner or soap may leave a film and cause streaks. Do not use products that contain lemon, vinegar or other acids on marble or other calcareous stones. Rinse the surface thoroughly after washing with the soap solution and dry with a soft cloth. Change the rinse water frequently. Do not use scouring powders or creams; these products contain abrasives that may scratch the stone.
BATH + OTHER WET AREAS
In the bath or other wet areas, soap scum can be minimised by using a squeegee after each use. To remove soap scum, use a non-acidic soap scum remover or a solution of ammonia and water (about 1⁄2 cup ammonia to 4 litres of water). Frequent or over-use of an ammonia solution may eventually dull the surface of the stone.
VANITY TOP SURFACES
Vanity tops may need to have penetrating sealer applied. Check with your installer for recommendations. A good quality marble wax or non-yellowing automobile paste wax can be applied to minimise water spotting.
FOOD PREPARATION AREAS
In food preparation areas, the stone may need to have a penetrating sealer applied. If a sealer is applied, be sure that it is non-toxic and safe for use on food preparation surfaces.
OUTDOOR POOL + PATIO AREAS
In outdoor pool, patio or hot tub areas, blush with clear water and use mild bleach solution to remove algae or moss.
SPILLS + STAINS
Blot the spill with a paper towel immediately. Don’t wipe the area, it will spread the spill. Flush the area with plain water and a mild soap and rinse several times. Dry the area thoroughly with a soft cloth. Repeat as necessary. If the stain remains refer to the information below.
Surface stains can often be removed by cleaning with an appropriate cleaning product. Deep–seated or stubborn stains may require using a poultice. Below is a list of stains that you may have to deal with, and the appropriate chemicals to use for their removal.
TYPES OF STAINS + FIRST STEP CLEANING ACTIONS
Oil – Based (grease, tar, cooking oil, milk, cosmetics): an oil-based stain will darken the stone and normally must be chemically dissolved so the source of the stain can be flushed or rinsed away. Clean gently with a soft, liquid cleanser with a household detergent OR ammonia OR mineral spirits OR acetone.
Organic (coffee, tea, fruit, tobacco, paper, food, urine, leaves, bark, bird droppings):
these may cause pinkish – brown stains and may disappear after the source of the stain has been removed. Outdoors – with the sources removed, normal sun and rain action will generally bleach out the stains. Indoors – clean with 12% hydrogen peroxide (hair bleaching strength) and a few drops of ammonia.
Metal (iron, rust, copper, bronze): iron or rust stains are orange to brown in colour and follow the shape of the staining object such as nails, bolts, screws, cans, flower pots, metal furniture. Copper and bronze stains appear as green or muddy-brown and result from the action of moisture on nearby or embedded bronze, copper or brass items. Metal stains must be removed with a poultice. Deep seated, rusty stains are extremely difficult to remove and the stone may be permanently stained.
Water Spots & Rings
(surface accumulation of hard water): buff with dry 0000 steel wool.
Ink (markers, pen, ink): clean with bleach or hydrogen peroxide (light coloured stone only) or lacquer thinner or acetone (dark stone only).
Biological (algae, mildew, lichens, moss, fungi): clean with dilute (1/2 cup in 4 litres water) ammonia OR bleach OR hydrogen peroxide.
DO NOT MIX BLEACH AND AMMONIA! THIS COMBINATION CREATES A TOXIC AND LETHAL GAS.
Paint: small amounts can be removed with lacquer thinner or scraped off carefully with a razor blade. Heavy paint coverage should be removed with a commercial “heavy liquid” stripper available from hardware or paint stores. Do
not use acids or flame tools to strip paint from stone. Paint strippers can etch the surface of
the stone; repolishing may be necessary. Follow the manufacturer’s directions for use of these products. Use only wood or plastic scrapers for removing the sludge and curdled paint. Normally Latex and acrylic paints will not cause staining. Oil-based paints, linseed oil, putty, caulks and sealants may cause oily stains. Refer to the Oil- based Section.
Fire and Smoke Damage: older stones and smoke or fire stained fireplaces may require a thorough cleaning to restore their original appearance. Commercially available “smoke removers” may save time and effort.
Etch Marks: etch marks are caused by acids left on the surface of the stone. Some materials will etch the finish but not leave a stain. Others will both etch and stain. Once the stain has been removed, wet the surface with clear water and sprinkle on marble polishing powder. Rub the powder onto the stone with a damp cloth or by using a buffing pad with a low-speed power drill. Continue buffing until the etch mark disappears and the marble surface shines.
Efflorescence: this is a white powder that may appear on the surface of the stone. It is caused by water carrying mineral salts from below the surface of the stone rising through the stone and evaporating. When the water evaporates, it leaves the powdery substance. If the installation is new, dust mop or vacuum the powder. You may have to do this several times as the stone dries out. Do not use water to remove the powder; it will only temporarily disappear. If the problem persists, contact the installer to help identify and remove the cause of the moisture.
Scratches and Nicks: slight surface scratches may be buffed with dry 0000 steel wool. Refer to the section on etch marks and follow the polishing procedures. Deeper scratches and nicks in the surface of the stone should be repaired and repolished by a professional.
DO’S + DON’TS
DO dust mop floor frequently
DO clean surfaces with mild detergent or stone cleaner
DO thoroughly rinse and dry the surface after washing
DO protect floor surfaces with non-slip mats or rugs and counter top surfaces with coasters, tivets or placemats.
DON’T use vinegar, lemon juice or other cleaners containing acids on marble, limestone, travertine or onyx surfaces.
DON’T use cleaners that contain acid such as bathroom cleaners, grout cleaners or tile cleaners.
DON’T use abrasive cleaners such as dry cleansers or soft cleansers
DON’T mix bleach and ammonia, this combination creates a toxic and lethal gas
DON’T ever mix chemicals together unless directions specifically instruct as such.
RECOMMENDED CLEANING PROCEDURES – PORCELAIN/CERAMIC TILES
There are generally three stages of tile cleaning.
The installation cleaning should incorporate removal of excess adhesives and grouts resulting only in a light haze remaining on the finished surfaces.
There is usually a need for post installation cleaning that will remove any building soiling including plaster, paint, etc.
Routine maintenance will provide a cleaning regime that should ensure the cleanliness and safety of the floor while maintaining the integrity of the tiling system.
Understanding the nature and requirements for a particular floor are key to its performance and service life. This will vary according to the type of tile and any treatment applied to protect or enhance the tile, e.g., pre-sealing, waxes, grout release agents and physical protection layers. An understanding of the surface characteristics of highly slip- resistant tiles will often dictate which cleaning methods should be used.
Damage can occur to flooring if incorrect chemicals or methods are used.
Personnel responsible for post installation cleaning and maintenance should be given specific recommendations for cleaning and full information concerning any particular possible risks of misuse.
Maintenance of tiled surfaces is fairly easy to achieve where appropriate processes are used. Daily sweeping and washing to remove soiling remains the most basic method along with periodic sweeping, vacuuming, wiping and/or mopping.
Loose soil provides an abrasive load that can damage glazed surfaces, leaving a hazy or soiled appearance in high traffic areas. These areas soon start looking different to areas unaffected by abrasion, detracting from the bright polished finish favoured by people. In addition to the worn appearance, the cleaning of this area will become more difficult as the surface alters.
Soil traps can be created at entrances to collect loose soil prior to walking on the flooring. A doormat should be sufficient to remove most of the soil. The same precautions should be taken in areas where animals or pets may enter.
Cleaning with warm water or a weak mixture of pH neutral sulphate-free cleaning agent then followed by rinsing with clean water should remove visible soiling. To avoid streaking and detergent build up use minimum amount possible in the dilution. Adequate rinsing of the floor or using a no rinse detergent is also helpful.
To remove in ground dirt use a weak mixture of neutral detergent and clean warm water applied with a soft brush, then sponging and copiously rinsing with water.
Extract liquid off the floor using either a microfiber mop or a wet vacuum cleaner fitted with a squeegee head.
Greasy deposits can be removed with a detergent incorporating an organic solvent or a highly alkaline detergent (pH>9), but these should be used for only occasional cleaning. Overuse of such chemicals can result in damaged grout or hazing of glazed tiles.
It is essential that a detergent used on a regular basis is of a type recommended for cleaning vitrified/ceramic tiles. Household soaps are not recommended as they can result in a buildup of soap scum.
Abrasive cleaning agents should only be used on unglazed tiles. Appropriate abrasive methods can be used to remove stubborn stains on polished and profiled glazed tiles.
Regular use of “scrub and rinse” cleaning machines fitted with abrasive pads (as opposed to the finest grades) may damage the surface of some tiles and can cause the surface to gradually decline in thickness.
Tiles with profiled surfaces are prone to soil and cleaning agents building up on the surface. Adequate dwell time and agitation is required when cleaning these tiles to dislodge soiling prior to complete removal. Agitation can be achieved using appropriate cleaning pads or brushes. Such methods will dislodge most forms of soiling including build-up of past cleaning agents and soil that collects in recesses. Steam and high pressure cleaning methods may occasionally be appropriate in some installations.
It is important to ensure that the cleaning agent is completely removed by a final rinsing with clean water.
SURFACE SEALING MATERIALS
The application of linseed oil, permanent sealing compositions or polishes is not recommended since they are not absorbed into the surface and tend to make the surface slippery and difficult to clean.
Temporary tile sealers may be used to facilitate cleaning after laying and grouting; these proprietary compositions can be readily removed after completion of the grouting operation by using normally alkaline detergents and rinsing. Where temporary sealers are employed, they should be used strictly in accordance with the manufacturer’s recommendations.
RECOMMENDED CLEANING AGENTS OR CHEMICALS
– Warm water or a weak mixture of pH neutral sulphate-free cleaning agent
– Mildly alkaline maintenance product formulated for every-day use
EFFLORESCENCE, RESIDUAL CEMENT FILM AND RUST STAINS
– acidic cleaner