|Granite Cleaning Issues
This issue, like most issues with granite, is intertwined with many other issues.
First is that one must know the exact composition of the individual granite
material in order to clean it safely. Then you must know the exact sealer used
on your granite. And of course, you must know the exact formulation of your
cleaner to prevent damage. Lastly you must wade through the conflicting
The first task is knowing the exact composition of your stone to be able to clean
it properly. How many granite owners are privy to this? Many just move into the
home after the top was installed and don't have a clue what type of stone,
whether or not that particular block in that particular quarry had calcite or not,
nor do they know what type trace minerals are present in the slab.
A good place to start is this thread, a question about Absolute Blacks, look for
chemical composition info on page two . You will see that knowing the exact
composition of your granite is almost impossible unless that particular block was
Another stone site said this about granite individual granite slabs :
"Two pieces of granite, from the same part of the world, in the same colours are
never identical. Each slab has different mineral properties and require different
kinds of attention. The supplier that you received your granite from should give
you personalised after care instructions for each of the different slabs."
They are one of the few stone sites that gives good info on granite such as this :
"Even though granite is a hard-wearing material, the polished finished does
need to be looked after properly. This can be done with giving attention daily to
what is being placed on the surface. You should never use granite as a surface
for cutting or slicing, make sure you use a cutting/chopping board to prevent
scratching. Also avoid placing acidic foods, for example lemon juice, carbonated
beverages and vinegar directly to the surface for a period of time as they can
corrode the surface. It will only damage the polish as it is more delicate than the
actual granite. Use a small amount of warm water with PH balanced washing up
liquid to clean the surface instead of using abrasive cleaning products."
The last sentence sums up the only truly safe way to clean granite, warm water
and a pH balanced cleaning solution, which we will cover a little later.
Knowing what sealer was used is the next bit of knowledge we need. The
cleaning solution must not damage the sealer, so the type of sealer along with
the mineral composition of the stone will tell us what to use for cleaning. Sealers
will be covered in another page of this site, but for now, you will need some
Sealers are either water based or solvent based, depending on the liquid
portion of the mixture that dissolves the actual sealer and allows it to flow into
the pores, pits, crevices, and fissures of the stone. Despite the description,
water based sealers still have some solvent contents.
Once the sealer has dried and cured, the solvent is less of an issue except what
type of chemicals have been introduced into the home. The actual chemicals
left in the pores slow down the entry of stains, giving a homeowner a chance to
blot up any spills.
Most sealer manufacturers will give plenty of info on cleaning the sealed surface
and what products to avoid. Of course the sealer itself will loosen the sealer,
and most slightly acidic or alkaline products will damage or strip the sealers, so
those are the main worries. Heat will also damage sealers and resins that were
applied prior to the slab being polished.
Before choosing a sealer, read the care and cleaning instructions carefully as
well as any guarantee that comes with the sealer. Most of the highly hyped
"Lifetime Guaranteed" sealers have a very weak warranty, with very detailed
instructions on how to avoid voiding the warranty. Basically, if you followed their
care and cleaning instructions, any countertop material would last forever!
Another thing they are counting on is selling a lot of counters before the
problems start popping up faster than they can afford to fix.
So hopefully by now, we know what minerals are in the granite and what type of
sealer is on the stone top. We know what the pH level of our cleaner needs to
be and what to avoid. Time to pick out a cleaner.
Most cleaner manufacturers will have a website with technical info on their
product. Look up what chemicals are used, commonly ammonia, alcohol,
water, some dyes and fragrances. The pH level will be listed. Neutral pH level
cleaners prevent damage by limiting ion damage. The term pH stands for
"potential of hydrogen". Wikipedia gives this excellent explanation of
understanding the pH levels :
"The pH scale is an inverse logarithmic representation of hydrogen proton (H+)
concentration. Unlike linear scales which have a constant relations between the
item being measured (H+ concentration in this case) and the value reported,
each individual pH unit is a factor of 10 different than the next higher or lower
unit. For example, a change in pH from 2 to 3 represents a 10-fold decrease in
H+ concentration, and a shift from 2 to 4 represents a one-hundred (10 ×
10)-fold decrease in H+ concentration. "
So getting close on pH is not a good idea. Exact levels are better. Why?
Because an acid solution will donate ions to your countertop surface and a
alkaline will strip them away. Basically, the high or low pH solutions eat away at
the basic atomic structure of your granite countertop.
Now all there is to do is pick a cleaning method, and different people will
recommend different methods. Many sellers of granite have an interest in
claiming that granite is easy to clean and maintain, so that explains their
methods, soap and water and sometimes a microfiber cloth. Sealer
manufacturers are more interested in two things, you not complaining that your
countertop sealed despite their sealer and of course they want to sell you more
sealer, so they encourage you to use their special pH balanced cleaner which
contains more sealer along with some solvents and soaps. Stone restoration
contractors seem to have the best advice, as they have little interest in
misleading or minimizing the risks.
In comparison, with solid surface you can use almost anything short of very
strong acids, caustic lyes, or oven cleaners. Even solid surface can have it's
molecules rearranged, but it takes a lot. The level of pH can be missed by five
or six levels with no harm, unlike stone that can be damaged by using one pH
level either way. And if it should happen, most damage can be fixed with a
Scotch bright pad and some Ajax powdered cleaner. Granite would need to be
re-polished - a half day's work for even a small spot along with several hundred
dollars in cost. Some stones will not be able to repair invisibly like solid surface,
so the repair might be visible. Methods are slowly getting better, but a perfect
repair is possible only in solid surface at this time
Disinfection solutions can damage natural stone, as reported by the Marble
Institute of America (MIA), the premier trade association for the stone trade.
Cleaning must be done with special cleaners to avoid damaging the sealer or
worse, the stone.
Uba Tuba discolored by a cleaning agent