Q1) When my marble wall & floor dries up, perhaps after I have had a shower, whitish marks appear on the marble surface. What are they? How does this happen?

Marble contains over 55% calcium carbonate, which is a porous material that is sensitive to acidic and high-alkaline materials. This porosity and sensitivity is why it stains so easily. As a result, natural marble requires special care to maintain its shine and colour. Damage such as loss of shine, typically arises due to irregular maintenance, application of improper cleaning methods and inappropriate use of cleaning agents that were never designed for use on natural stones.


Most of our bath soaps used in showering is pH5.5 balanced, neutral to our skin. However, this is slightly acidic to natural marble. Very often, people only use water to clean their bathroom marble floor and wall. To protect marble in a bathroom setting, it is strongly recommended that residues from soap, shower foam, bath gel, shampoo and massaging oil

are immediately cleaned away. Allowing these residues to sit for too long on the surface will result in streak marks that will eventually roughen the texture. The surface of the stone will also become dull and develop unsightly whitish marks. The whitish appearance is commonly known as ‘soap scum’. When this change in appearance occurs, it unfortunately cannot be reversed by normal cleaning methods and the marble will have to then be re-polished. Obviously, this is quite expensive.

Q2) How do I treat soap scum on my bathroom’s marble surface?

It can be repaired with our SCL Marble Polishing Powder. A severe case of soap scum resulting in the surface taking on a rough texture should be polished with a diamond polishing pad prior to using the polishing powder. Diamond polishing pads are readily available from us.


Q3)Can I apply SCL Stain-X penetrating sealer or SCL Water-Based penetrating sealer to prevent soap scum from happening on my bathroom’s marble surface?

No. Irregardless it is our SCL Penetrating sealers or other brands of sealer; a penetrating sealer is not designed to form a coat on the marble surface. Thus a penetrating sealer is never an acid resistance sealer. Clean with our SCL Stoneclean-Xtra solution at least once a day could prevent soap scum from happening.

View our “Triple-S” method of cleaning on bathroom shower’s floor area from the Residential Care.

Q4) Can I apply a Wax Coating to prevent soap scum from happening on my bathroom’s marble surface?

Using waxes will clog the stone’s pores and traps the moisture and salts inside the stone. Natural stone is a porous material that has small microscopic pores that allow it to breathe (exchange moisture with the atmosphere).

When the stone becomes dry, it extracts moisture from the atmosphere through its pores and when it becomes too wet, it pushes the excess moisture out of the stone through its pores. When you put any kind of wax on the surface, it closes up the pores and the moisture cannot get out. This creates pressure within the stone and pitting occurs.

Q5) What is “Pitting”?

“Pitting” is detected by the presence of small chips on the surface of the stone. Pictures are as shown below.


Q6) How does a stone “Pit” and “Spall”?

Firstly, pressure from trapped moisture and salt cause the pores to expand resulting in small pieces of stone breaking-off. Usually expands from the veins and eventually become part of the stone that show the stones crack. We called this condition “pitting”.

Secondly, the moisture trapped inside the stone brings salts up toward the surface but they cannot escape. The salt crystals get trapped just below the stone’s surface causing crystal growth (recrystallization) in the pores that cause stress on the stone and cause the stone to flake off. We called this condition “spalling”.

If the conditions bringing about this action persist, scaling may continue and flake off layer after another.


Q7) What causes a stone to “Pit” and “Spall”?

There are few possibilities to cause pitting and spalling on marble and granite?

  1. Continuous present of water enters the stone and contains large amount of salts. Some stones are very susceptible to spall. For example, green marble, asian yellow spall easily, especially when installed in wet area.
  2. Cleaning the floor with alkaline detergent and floor cleaner with wax formulation. The crystallization of alkaline salts contains in the detergent stay in the stone after mopping. When water evaporates, the salt crystallizes. The expansion of the salt causes pressure within the stone that forces the stone apart.
  3. Stone floor treated with a thin film of liquid wax, so called a “sealer”. Applying such sealers will make stone floor shining. Do not confuse liquid waxes with impregnators and penetrating sealers. Impregnators and penetrating sealers do not harm a stone because these sealers allow vapors’ transmission and stone to breathe. Penetrating sealer does not form a coating on top of the stone therefore it does not make a stone shine.

Q8) My marble appears to have developed a “mouldy” substance. What is this?

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You are experiencing a phenomenon called “efflorescence”. This is a fairly common problem and in most instances, efflorescence is observed on a newly installed marble floors that are less than 6 months old due to excessive use of water during wet polishing.

Efflorescence is actually a mineral salt that has migrated to the surface with water. When water enters the setting bed or the marble becomes saturated with water, the water dissolves some of the salt minerals in the stones. The water then rises to the surface carrying the salts. When the marble dries and the water has evaporated, the salts are left behind and you have efflorescence.

Efflorescence is neither harmful to the stone or to humans. However, left untreated, it will eventually stain the marble floor. If efflorescence has been untreated for more than nine months, the marble will likely have signs of severe staining, in which case polishing using a diamond polishing pad will be needed.

Q9) How do I treat “Efflorescence” on my marble floor?

Immediately after polishing, use SCL-Stoneclean daily to avoid staining from efflorescence. SCL-Stoneclean is a proven efflorescence stone cleaner. It only takes an easy process. Mop with SCL-Stoneclean 3 times a day (morning, noon, evening) for the first 2 weeks immediately after polishing work is completed. If you could not afford the time then mop with SCL-Stoneclean at least once a day continuously for 2 weeks and longer(if needed). You may reduce the mopping from 3 times a day to once a day when efflorescence’s condition has improved. Continue mopping with SCL Stoneclean once a day until efflorescence goes away completely. Daily mopping of the floor with SCL-Stoneclean will restore the marble’s condition back to its original state.

Dilution ratio to treat efflorescence: mix 8 capfuls of SCL Stoneclean with ½ bucket of water (approximately 4 litres of water). Rinsing with water is not required. Leave the floor dry naturally.

TIP for treating efflorescence even quicker Ventilate your rooms as much as possible to help release moisture trapped in the stones.


SCL STONECLEAN (pH7.0) is a proven product to treat efflorescence. Available at Home-Fix DIY stores and E-Store: www.stoneclean.sg

Q10) How long will it be before the efflorescence disappears completely?

Under normal conditions, you should see improvement after about two weeks of daily mopping with SCL-Stoneclean, with the efflorescence completely subsiding after only six months.

Q11) Can the treatment of efflorescence be speeded up?

Yes. You can bring up the salt minerals to the surface faster by ventilating your rooms as much as possible to release moisture trapped in the stones.

You can also do this by leaving your air-conditioning on 24 hours a day for a few days and mopping the floor with SCL-Stoneclean more often than the recommended once a day.

You should also remove all rags and decoration floor mats temporally to hasten the drying process.

Q12) Can the treatment of efflorescence be speeded up using a dehumidifier?

Using dehumidifier to force dry the moisture inside the marble does not speed up the drying any faster. Adversely, the dehumidifier’s air in the room causes wooden fixture such as wooden door frame and wooden cupboard to warp.

It is best to treat efflorescence with natural ventilation and let it dry at its own pace.

Q13) Having dealt with it, will the efflorescence recur?

No. Efflorescence will only recur under circumstances such as re-polishing the marble floor or in ground-floor houses in which the waterproofing membrane has failed, resulting in water impregnating the floor from the ground.

While treating efflorescence, we strongly advise that your mop be wringed as dry as possible. After efflorescence has completely disappeared, wet mopping of the floor will not trigger a recurrence of efflorescence.

Q14) Can standard floor cleaners available in the super-market remove efflorescence?

Avoid using any standard floor cleaner that is not known to remove efflorescence as it may contain alkaline pH cleaning agents, which will only contribute more salts mineral to the floor.

As a general matter, there is nothing wrong with using a dilute alkaline-based cleaner on most marble and granite surfaces; however the results are unpredictable as some solutions may have a chemical reaction with the stones, resulting in the floor changing or losing its crystalline colour over time.

Q15) Can mopping with water alone remove efflorescence?

No. A simple mop and water combination will not pick up any dirt including efflorescence. You will simply be pushing the dirt with your mop from one corner to the other.

Q16) Can I just use water to clean and maintain my marble surface after efflorescence has completely disappeared?

Water is often spoken as “good old H2O”. Water is two atoms of hydrogen join to one oxygen. The whole collection of atoms is known as a “molecule” of water. Water molecules are good at attracting each other. But they are usually bad at being attracted onto the dirty surface that you’re trying to clean. Unless the dirt dissolves easily, water just doesn’t attract it away from the surface. Insoluble, oily or greasy soil is usually left unmoved. Another drawback is that water is not very good at holding the dirt away from the surface if it should come off. This is because water:
  • water is a poor wetting agent – it prefers to stick to itself
  • water does not lift dirt or oil-based residues from the surface well
  • water is not good at holding dirt in suspension.
Consider the simple act of washing one’s hands. Water does not harm one’s skin; however, one requires hand soap to wash a pair of oily hands! Now you know why!

Q17) Can’t I just use standard floor cleaners available in the supermarket after efflorescence has completely disappeared?

Yes, you may. However, we strongly recommend that you continue to mop the stone floor with SCL-Stoneclean as it is specially formulated to safely clean all natural stone surfaces without harming the natural crystalline structure of the stone.

This is because SCL-Stoneclean is formulated with a neutral PH balance and without wax formulas.

Q18) Can I treat my marble and granite floor with the crystallization or waxing method?

Natural stone is a porous material with small microscopic pores that allow it to “breathe”. When the stone becomes too dry, it extracts moisture from the atmosphere through its pores and when it becomes too wet, it pushes the excess moisture out through its pores.

Using crystallization and waxes will clog the stone’s pores and trap moisture and salts inside the stone, creating pressure within the stone. Over time, pressure from the trapped moisture and salt causes the pores to expand resulting in small pieces of stone breaking-off and creating holes in the surface of the stone. “Pitting” and “Oxidation” will occur.

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Q19) What is “Crystallization”?

Crystallization is easy to use, no messy work compared to Waxing and Powder polishing It is not designed to fill fissure hairline crack, open vein and pinhole. It is used as a maintenance product to maintain the lustre of a marble floor.

Today’s, many maintenance people do not choose to maintain their stone floor’s lustre by using the old conventional waxes because old conventional waxes give unnatural plastic appearance and poor quality waxes will yellow and cause permanent staining to some stone types.

More than a decade ago, conventional waxes popularity were replaced by “Crystallization”. Crystallization system was introduced to many users as easy application spray & buff dry and stripping is not required; it gives natural shine; it will form a new compound and make the stone harder, less easy to scratch and stain proof.

Crystallization is commonly adopt by cleaning companies maintaining high traffic area such as hotel lobby, shopping mall, etc.

Q20) Why is Crystallization not recommended to be used regularly to maintain lustre on marble?

Crystallization works by designing its chemical to react with the calcium in the marble in high heat. Heat is generated by fast speed heavy polishing machine, buffing with steel wool pad.

The chemical reaction soften the calcium in the marble and the heat created by the steel wool pad bind the wax to the stone surface unlike the conventional wax is sitting on the stone surface.

As such, stripping off old wax is not required. Regularly use crystallization product eventually, this system forms a new compound that subsequently harden and become a coating. The thin hard coating will prevent moisture from escaping the stone. This cause the stone to oxidize and pitting can occur to certain stone.

Oxidization and pitting usually only happen after the 3rd year regularly using crystallization product for maintenance. If there is moisture found underneath the stone floor, oxidization and pitting can happen within a year.

Q21) To seal or not to seal a natural stone – That’s the big question…

Natural stone is porous and acts like a sponge in the presence of moisture and fluids. Liquids can be absorbed into the stone, causing staining, corrosion and discolouration. Closing the pores in the stone is commonly done by “coating” or by using an “impregnator”. Before we answer this question, we will first give you a short briefing on the two methods.

Coating is the application of a film on top of the stone as a barrier to prevent water, oil and dirt from entering the pores of the stone. Coating is generally economical, easy to apply and will provide stain proofing, while adding lustre and shine to the floor surface. On the other hand, coatings are much softer than the stone and therefore will scratch, scuff and mar very easily. This will require frequent buffing, burnishing and reapplication. They can also build up causing an unnatural plastic appearance. Poor quality coatings will yellow and can cause permanent staining to some stone types.

In order to determine whether you should seal with a coating or a penetrating sealer, you need to understand the definition of what sealing natural stone means. Sealers in the stone industry are called “impregnators” simply because they impregnate the interior of the stone with silicones or resins that funnel through the pores of the surface, helping prevent fluids from penetrating through the pores; however, impregnators do nothing to protect the top surface of the stone. They do not prevent traffic patterns or scratches and they will not prevent etching from acid spills on polished surface marble. An impregnator will keep the acid out of the stone, but not off the top surface. Impregnators or penetrating sealers are preventive measures that provide extra protection to the stone. Even though the stone has been sealed, it still needs to be maintained and cleaned with proper care products. It is just like taking care of the paint on your car – if you wax or seal the paint, you still have to wash it on a regular basis. In addition, sealers will last longer and work better when the stone is properly cared for.

Sealers need to be reapplied because they do not last forever. Overtime, the sealer loses its strength and bonding to the stone and eventually evaporates away. A good way to measure the strength of an impregnator/sealer is to apply moisture to the surface. Test for darkening of the colour. If the stone darkens less than 5 minutes and take at least 30 minutes to dry, this means that the moisture has penetrated and a fresh coat should be applied.

The time it takes to break down an impregnator can be accelerated by certain conditions. For example, in a high traffic floor area the impregnator wears as the stone surface wears down. This is due to the fact that impregnators/penetrating sealers only penetrate approximately 1/16” of an inch or less. Some stones are more or less porous than others, therefore, the sealer may go in further or less. Some sealers require one application and others require two or three applications.

A fact to remember: Frequent high-pressure washing will cause irreversible damage to a stone surface because the pressure will break the bond of the natural minerals structure in the stone. If the natural stone is sealed with impregnator/penetrating sealer, frequent high-pressure washing will also break the bonding tension of the impregnator inside the stone. Impregnator is designed to penetrate below the surface; it allows vapour transmission and stones to breathe. Since the stone is still capable of breathing, water can be forced through the stone by pressure. Impregnators in general cannot be used below grade to resist frequent cleaning by hydrostatic pressure. If high-pressure washing must be used, the jet pressure should not exceed 1000psi and the pipe should only be used with a fan tip spray nozzle.

Q22) How do SCL Stain-X, SCL Stain-B and SCL Water-Based Penetrating Sealers work?

Most of the standard impregnator sealers available in the market are a mixture of silicones, siloxane and usually a mineral spirit. The mineral spirit is added to the mixture because it acts as a carrier for the silicones – it drives the silicone into the stone in liquid form, and then evaporates out of the stone, leaving the silicone behind. The silicone then begins to “cure” into a solid form, forming a fluid repellent membrane in the pores of the stone. This all happens within five to ten minutes.

SCL Stain-X penetrating sealer is the popular sealer available today and it contains orange fragrance petroleum distillate which carries the resins into the stone. The solvent vapour evaporates within minutes, which makes it extremely user-friendly.

SCL Stain-X penetrating sealer does not contain any silicones because silicones are soft and not very durable. SCL Stain-X penetrating sealer is a unique blend of resins and co-polymers that dry to a very hard condition. When our sealer bonds, it cures much harder than any other sealer in the industry. SCL Stain-X penetrating sealer penetrates into stone and does not remain on the surface; as a result, it cannot be abraded. It cures without changing the colour of a polished surface stone, yet it allows the stone to breathe and release moisture vapours.

Now that we know how sealers work and what they are supposed to do, the question is do we seal or not to seal the natural stone. The answer is ‘YES’. Sealing the top surface of the natural stone is recommended to give easy maintenance. SCL Stain-X Penetrating Sealer is applicable on marble, granite, sandstone, terrazzo, agglomerate, homogeneous tiles, grout joints and all others natural stone.

Q23) Can an impregnator be used as a waterproofing agent?

No. The idea of an impregnator or penetrating sealer is to make the stone water resistant, not waterproof. To make the stone waterproof, you would have to totally block the pores of the stone. However, this would suffocate the stone and cause it to break apart.

Q24) Will application of an impregnator make stone more slippery?

Impregnators are designed to penetrate below the surface. There will be no effect to the slipperiness of the stone.

Q25) If I apply impregnator to the back of the stone tile before setting, will this cause a bonding problem?

Yes, chances of bonding failure may happen few years later. Since most mortars are water-based, they will want to repel the water. We would suggest using a fast curing, dry adhesive setting material.

Q26) Can I use SCL Stain-X penetrating sealer on any other surface other than stone?

Yes. SCL Stain X penetrating sealer can be used on concrete, brick, terracotta and most porous hard surfaces.

Q27) Does SCL Stain-X penetrating sealer prevent acid etching?

Stain X does not make the stone acid-resistant. A coating may prevent acid etching. However certain coatings may block the breathing capability of the stone, trapping moisture within the stone and leading to pitting and spalling.

Q28) Impregnators, penetrating sealers and epoxy coatings, are they the same?

An impregnator, impregnating sealer and penetrating sealer, they are the same. An impregnator, impregnating sealer and penetrating sealer, they are different from epoxy coating/sealer. Impregnators/penetrating sealers are single component sealer designed to enter into the porous stone to reduce microscopic pores inside the interior of the stone to prevent staining. They are unable to fill open veins, pin holes and fissures crack line.

Open veins and holes are the nature characteristic of stone. Filling and patching holes in stone surfaces are part of the fabrication process of the stone happening everyday in the quarries. Now a day, due to the higher expectation from an end-user, re-application of Epoxy Sealer on site after installation and re-polishing to bring back lustre has becoming a standard performance in the contracts to ensure that all open veins and fissure hairline cracks are properly filled to prevent any rejection from owners.

Epoxy sealer is a “two-components” system that are made of Bisphenol-A resins and Epichlorohydrin by different ratios. It is designed to fill cracks, holes and open veins to reduce rejection rate. It has a clear colour and UV resistance. However, Epoxy Sealer does not have the ability and properties to fill microscopic pores unlike the single component Sealer which is commonly known in the stone industries as “impregnators/penetrating sealers” which gives hydrophobic properties.


After 48 hours of Epoxy Sealer’s application when the resins have cured and hardened inside the open veins and crack lines, the excessive resins  (i.e. a very thin coat)  on top of the marble surface is removed using the Diamond cutting system leaving behind the epoxy sealer that has filled the open veins and crack lines. The rest of the resins are removed from the stone surface.

Q29) My exterior stone and man-made tile appear to have developed a “white” substance. What is this?

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White salt weeping from the edge of the joints between the stone walls, the white deposit is a build-up of salts. The white lime is commonly known in the stone and tile industries as the “limes putty” or “lime deposits”.

Q30) What causes it and how does this happen?

Generally, it is due to poor installation of cement mortar or no water-proofing membrane. When there are cavities underneath the stone, these cavities hold excessive water from the rains and also water from washing the floor. When water penetrated and stayed too long underneath the stone, it dissolved the salt minerals from the setting bed and cement mortar. When water evaporates, it rises to the surface carrying the salts along. When the stone floor dries and the water has evaporated, the salts are left behind. These salt minerals travel through the joint lines as these are the weakest point and eventually deposited white limes on the surface.

Many times, severe limes continue to recur, it is caused by owners themselves/cleaning contractors unknowingly using high pressure-jet washing for their external stone. High pressure-jet washing provide easy and economical washing to external stone surface. However, high pressure-jet washing forces excessive water into the cavities underneath the stone, allowing more salt minerals to come.

Owners/Cleaning contractors should avoid using high pressure-jet washing for external stone. The power of pressure will break the surface tension of the penetrating sealer inside the stone and also weaken the bond of the natural minerals structure in the stone. High pressure-jet washing causes irreversible damage to a stone surface. In fact, frequent high pressure-jet washing not only bring lime deposits, it will activate algae growths. If pressure-jet washing have to be used, the pressure should not exceed 1000psi and should only used a fan tip spray nozzle. A scrubbing machine and a proper stone cleaning agent are the correct method to adopt.


Daily uses High alkaline cleaning agent on natural stone is another probable cause of “Limes Putty”. You can use a lower pH alkaline chemical periodically to remove stubborn stain. Daily cleaning and maintenance on natural stone should be a neutral ph7.0 stone cleaning chemical such as SCL STONECLEAN (pH7.0). Weekly and Periodic cleaning on external stone ideal to use SCL STONECLEAN-Xtra (pH9.6).

Q31) How do I remove “Limes Putty”?

Remove limes using SCL Lime Remover chemical and thereafter, neutralize the interior crystalline structure of the stone with SCL Stoneclean-Xtra (pH9.6). SCL Lime Remover is a ready-to-use product. Saturate SCL Lime Remover onto the limes for several minutes. Wear gloves when handling this product. Scrub away the limes with the help of the black pad. Big chunk of limes required a scrapper. After removing the limes, rinse the stone surface with the diluted SCL Stoneclean-Xtra solution to neutralize the interior structure of the stone. SCL Stoneclean-Xtra is required to dilute with water. Mix 1 part of SCL Stoneclean-Xtra with 15 or 20 parts of water. Finally rinse with water thoroughly. After washing the stone surface, leave the surface dry naturally. The salts will return and will need to be cleaned when this occurs. When removing limes on man-made tile, SCL Stoneclean-Xtra is not required. Immediately rinse with water thoroughly after using SCL Lime Remover chemical.

SCL Lime Remover chemical & SCL Stoneclean-Xtra chemical do not stop the “Limes “Putty” from coming back. They are only a remover agent. To stop the Limes permanently from recurring, re-tiles the stone and make sure there are no more cavities beneath the stone. Another method you can adopt if you do not wish to re-tile. Carry out the “injection” method.

Sealing the stone with penetrating sealer is a temporarily solution to retard the "Limes Putty". To seal natural stones at outdoor area, seal the stone with penetrating sealer at least once a year. If high pressure-jet washing is frequently used, seal the stone with penetrating sealer once every 3 months


Available at Home-Fix DIY stores and E-Store: www.stoneclean.sg

Q32) How do I identify stain, stun mark, efflorescence and etch-mark ?

A stain is either a spot or a spillage and it takes after the colour of the material. The color of the liquid enters into the stone surface that will not wash out with a normal cleaning agent. A stain usually will not affect the shine level of the marble/granite surface. To remove stain that has entered into the marble/granite stone, a “poultice” cleaning method is needed. A stain is such like spillage from oil, coffee, tea, wood, cardboard, blood, etc.  


Stun mark appears as white mark on the surface of the stone and are common in certain types of marble. These stuns are the result of tiny explosions inside the crystal of the stone. Pinpoint pressures placed on the marble cause these marks. Women's high heels or blunt pointed instruments are common reasons for stun marks. Stun marks can be difficult to remove. Grinding and/or honing can reduce the visibility of stuns, but some travel through the entire thickness of the stone.  


Etch mark is commonly address as a stain. An etched mark is also caused by spillages. There spillages are usually acidic or alkaline. An etched mark does not take after the colour of the spillage. The spillage mark is always white in colour irregardless of the stone colour and the spillage colour. Spillages will cause etched mark wine, coca-cola, liquid soap, pet’s urine, vomit, toilet-bowl cleaning agent, etc.
Etched-mark required polishing.  


Efflorescence is also commonly address as stain. It is neither a stain nor an etch mark. Efflorescence does not appear as a spot or a spillage’s shape. It gives a moldy appearance on the entire floor. The moldy appearance is always seen at the pointing area and at the veins line.   32-4

Q33) How do I remove penetrated stain on my marble surface? What is the “POULTICE” cleaning method?


The poultice cleaning method is a long process to introduce however this method is proven to be the most effective way of removing stains that have penetrated into the interior of the stone. Poulticing is to reverse the staining process. In other words, poultice powder with the appropriate chemicals will literally suck the stain out from the stone. Each application required leaving the poultice on the stains area for 1-2 days, depending on the age of the stains. Any stains occurred on natural stones are unpredictable. Some stains could have penetrated deeper and spread wider inside the stone. Identifying the types of stain is already half the battle won.