Insider Answers: Should I seal my granite countertops?

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Insider Answers: Should I seal my granite countertops?

Granite is a natural work of art. Like a snowflake, one piece of stone is not like any other in the world. This is the one of the attributes of granite making it  unique and in such high in demand.

Likewise, no two granite slabs have the same absorbent qualities. For example, Black Galaxy from India may not absorb anything, whereas similar a black granite like GP Black from China is a virtual sponge.

Not all granite is absorbent nor will need sealed.   If a stone cannot absorb anything, even an impregnating sealer won’t absorb. Impregnating sealers are invisible and sit microns below the surface of stone and deposit solid particles in the pores while coating individual minerals below. If a sealer can’t penetrate into the stone, neither can a stain.
A good example is Absolute Black granite from India.  This stone is VERY dense and is virtually non-porous.  It does not require any sealing.
If you go to any big box store and ask a countertop salesmen why their product is better than stone, you will always get the same answer. “Natural stone is high maintenance needing to be sealed every year” but their “other” countertop surface doesn’t require maintenance.

Sealing every stone, and often so, is a myth and completely untrue. These lies are specifically designed to prey on uninformed homeowners. Competing countertop manufacturers try to pull uninformed consumers from  stone tops by exaggerating required maintenance.
In reality, a typical 60 sq/ft granite kitchen that requires sealing, will take 10 minutes once a year (at most) and cost less than $10
Sealers keep improving as well.  Ten and 15 year sealers are now commonly used in the natural stone industry.

With only one perceived weakness of granite for buyers, it’s easy to imply or outright lie saying  “every natural stone needs sealed.”

Reality is the very few stones used for countertops need sealing.

There is a very simple test to determine if YOUR natural stone countertops need to be sealed.  To test if an oil based product will be absorbed by your countertop, dab a small about of mineral oil in an inconspicuous spot and leave for 15 minutes.  After the time is up, wipe the mineral oil off the stone.  If the stone is not darkened by the mineral oil, it won’t be stained by and oil based product.

If the stone does show signs of darkening don’t be concerned.  The mineral oil will completely evaporate leaving no trace.  Now repeat the test in another area using water.

If there is change in the color of your stone with either water or mineral oil, then seal.  If there is no color change with these two liquids, you do not really need a sealer on your stone.

This is an excellent test on granite and most all natural stones.  One big exception is the material fabricators love to hate…  Marble.  Impregnating sealers will not protect marble against those water rings and spots.  Sealers protect against stains and those aren’t stains; they’re etches or corrosion. They are caused by a chemical reaction between the calcium in the marble and the acid in the product that caused them.  This is one of the many reason for the rise in popularity of more natural finishes such as honed, leathered and river washed.  These finishes are much easier to touch up if you have an accident and etch your beautiful marble.

It’s also important to emphasize that this applies to polished stone. When stone is polished, the pores are tighter and this inhibits he ability of liquids to penetrate the surface. With honed surfaces, liquids can enter some of the less absorbent stone more freely and may require an impregnating sealer.

So now we know how to test stone to see if sealing is actually required.  How often should they be sealed?  Simple!  When your stone no longer repels water or oil, it is time to reseal. You could always perform the test again, but I have an easier way.  After washing dishes if you can see a distinct darkening of your countertop, it is time to reseal.

All good fabricators like Rocky Tops Granite & Marble will seal marble and granite that need sealing when installation is complete. We actually seal ALL natural stone tops even if they typically don’t need to be sealed.  Our solvent based impregnators do an outstanding job of cleaning your new tops and certainly won’t hurt.  🙂

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