To Seal or Not To Seal - That is the Question...
15/03/11 13:13
When doing research regarding granite counter tops or other natural stone surfaces like flooring, showers or walls, the question always comes up: Do they need to be sealed? Other, secondary questions then loom in the background: Is it hard work? Are the sealers toxic? What if it comes in contact with humans or food? IsnĘžt buying a manmade plastic surface then a safer option than having to deal with all of these issues?
The answers for all these questions range all over the place and can be very confusing, if not outright contradictory. The various “experts” will tell you anything their sponsors tell them to. If they want to sell sealers or other solid surface counter tops, they will tell you that your stone will not last a minute if it is not sealed properly. They will proclaim, depending on what they want to sell, that these sealers need to be applied regularly and maybe even by a specially licensed contractor. Both the manufactured surface crowd
and the sealer dealers will tell you that this process is tedious and might even hint that it could be a little dangerous!
The truth is very far from all this. To begin my clarification, I will explain the role of impregnating sealers and how they work. Penetrating (impregnating) sealers are simply designed to prevent liquids from absorbing into stone, and by doing so, to prevent stains from forming. Sealers are not designed to prevent mold growth, etching or scratching or to make stones less likely to show dirt. Impregnating sealers are not designed to form a layer on top of the surface of the stone either - but more about this later.
Sealers consist of two parts - a solid that will do the actual sealing and a liquid that will act as a vehicle for the solids to get where they need to go. The liquid could be either a solvent or water. The solids are dissolved in the liquid and, once applied to a porous surface, the solution will penetrate into the body of the stone. After a while (solvents will evaporate quicker than water) the liquid part of the sealer will dissipate and leave the solids in between the crystals of the stone. This in turn makes it more difficult for other liquids to penetrate.
So - in short - sealers are designed to solve the “problem” of porous surfaces. Proponents of sealers will have you believe that all natural stones are porous, and that they all need to be sealed, lest a hundred other evils overcome you. What they either do not know, or refuse to tell you, is that not all granites (or marbles, travertines or limestones) need to be sealed. Many stones simply will not absorb sealers, much less anything else.
If a stone would not absorb any other liquid, sealing it would pretty much be a moot point. In many cases there simply is no “problem” that needs solving!
The next logical question would then be how one should determine if a stone needs sealer or not. The answer is a pretty easy one, and the test is one that needs no special tools or knowledge. Drip some water on your stone. Let it sit for a little while and then wipe the drops off. If there are dark spots where the water used to be, your stone needs sealer. If not, your stone does not need to be sealed.
Unfortunately a lot of people believe that sealing a stone - even if it does not need it - could do no harm. This is also not true. Earlier in this article I mentioned that impregnating sealers are not designed to form a layer on the surface. Now I will tell you why:
The solids in impregnating sealers are not designed to hold up to the exposure to everyday kitchen events like coffee spills or cleaners. They are never supposed to even be in contact with these things if the sealer is applied correctly. Sealer residue left on the surface of dense stones could result in strange behaviours like “water marks” or ghosting. This in turn could lead people to believe that they have a problem with their stone and the sealer “experts” will then tell them that applying more sealer should solve it! It becomes a vicious circle. The home owner eventually believes - quite wrongly - that having natural stone is a bad idea and that they really should have gone with a man-made surface. The solution to this problem would simply be to remove all sealer and leave the stone au naturel - as it should have been in the first place.
This brings us to the other bugaboo: periodic resealing. Due to the often repeated“advice” and “expert opinions” most consumers believe that sealing needs to be done on a rigid schedule - once every three months, twice a year, every year. Again, simply not true.
“How often then?” you may ask. The answer is when it is needed, and the test is the same as the one you used to determine whether sealing was required in the first place. It is true, too, that with modern sealer technology, the periodic resealing only needs doing once every five or ten years - and resealing is a simple and safe procedure. Hardly the obstacle some people would have you believe.
At North Island Granite, Ltd. we educate our clients in stone selection and post-installation care. Natural stone, if chosen and selected properly, is on of the easiest to maintain, best looking surfaces on the market.
The answers for all these questions range all over the place and can be very confusing, if not outright contradictory. The various “experts” will tell you anything their sponsors tell them to. If they want to sell sealers or other solid surface counter tops, they will tell you that your stone will not last a minute if it is not sealed properly. They will proclaim, depending on what they want to sell, that these sealers need to be applied regularly and maybe even by a specially licensed contractor. Both the manufactured surface crowd
and the sealer dealers will tell you that this process is tedious and might even hint that it could be a little dangerous!
The truth is very far from all this. To begin my clarification, I will explain the role of impregnating sealers and how they work. Penetrating (impregnating) sealers are simply designed to prevent liquids from absorbing into stone, and by doing so, to prevent stains from forming. Sealers are not designed to prevent mold growth, etching or scratching or to make stones less likely to show dirt. Impregnating sealers are not designed to form a layer on top of the surface of the stone either - but more about this later.
Sealers consist of two parts - a solid that will do the actual sealing and a liquid that will act as a vehicle for the solids to get where they need to go. The liquid could be either a solvent or water. The solids are dissolved in the liquid and, once applied to a porous surface, the solution will penetrate into the body of the stone. After a while (solvents will evaporate quicker than water) the liquid part of the sealer will dissipate and leave the solids in between the crystals of the stone. This in turn makes it more difficult for other liquids to penetrate.
So - in short - sealers are designed to solve the “problem” of porous surfaces. Proponents of sealers will have you believe that all natural stones are porous, and that they all need to be sealed, lest a hundred other evils overcome you. What they either do not know, or refuse to tell you, is that not all granites (or marbles, travertines or limestones) need to be sealed. Many stones simply will not absorb sealers, much less anything else.
If a stone would not absorb any other liquid, sealing it would pretty much be a moot point. In many cases there simply is no “problem” that needs solving!
The next logical question would then be how one should determine if a stone needs sealer or not. The answer is a pretty easy one, and the test is one that needs no special tools or knowledge. Drip some water on your stone. Let it sit for a little while and then wipe the drops off. If there are dark spots where the water used to be, your stone needs sealer. If not, your stone does not need to be sealed.
Unfortunately a lot of people believe that sealing a stone - even if it does not need it - could do no harm. This is also not true. Earlier in this article I mentioned that impregnating sealers are not designed to form a layer on the surface. Now I will tell you why:
The solids in impregnating sealers are not designed to hold up to the exposure to everyday kitchen events like coffee spills or cleaners. They are never supposed to even be in contact with these things if the sealer is applied correctly. Sealer residue left on the surface of dense stones could result in strange behaviours like “water marks” or ghosting. This in turn could lead people to believe that they have a problem with their stone and the sealer “experts” will then tell them that applying more sealer should solve it! It becomes a vicious circle. The home owner eventually believes - quite wrongly - that having natural stone is a bad idea and that they really should have gone with a man-made surface. The solution to this problem would simply be to remove all sealer and leave the stone au naturel - as it should have been in the first place.
This brings us to the other bugaboo: periodic resealing. Due to the often repeated“advice” and “expert opinions” most consumers believe that sealing needs to be done on a rigid schedule - once every three months, twice a year, every year. Again, simply not true.
“How often then?” you may ask. The answer is when it is needed, and the test is the same as the one you used to determine whether sealing was required in the first place. It is true, too, that with modern sealer technology, the periodic resealing only needs doing once every five or ten years - and resealing is a simple and safe procedure. Hardly the obstacle some people would have you believe.
At North Island Granite, Ltd. we educate our clients in stone selection and post-installation care. Natural stone, if chosen and selected properly, is on of the easiest to maintain, best looking surfaces on the market.