Stone Myths

Stone Myths

 Over the past 20years I have heard many stories about the reasons stone will fail, turn color, fade or what ever. Many of these stories are funny and almost all of them are just plain false. The following is a brief synopsis of these stories and myths along with the real reason for these conditions.

 

Green Marble warping;

Many season installers who have tried to install green marble tiles with ordinary thin set or other water based setting materials have experienced warping problems.  I cannot tell you how many times I have encounter the same problem as an inspector. The following are some of stories I have heard for the reason that green marble will warp.

 “Green Marble will warp because it contains living plant material. As water is added to the marble the plants start to grow and this makes the marble warp.”  This is an absolute true story. I heard an installer telling a customer this and about fell to the floor, trying not to laugh. When I asked him if he was kidding, her said no and really believe this was the reason.

 “Green marble will curl on the edges because the installer did not put enough setting mortar on the edges. The green marble will have a tendency to lift off the floor where there is not mortar and hence it will curl.”  This falsehood isn’t as bad as the first one, but it is just as wrong.

 FACT:  The real reason green marble warps is a condition known as hysterisis. Green marble’s are very sensitive to moisture and what happens when water enters the stone, it causes the marble to release any internal stress it has and hence it warps.

  Your Stone Floor has an Effervesce problem,

 The key word here is effervescence. I have lost count on how many times I have heard contractors refer to efflorescence as effervescence. Lets clear this up right now. Efflorescence is the deposit of soluble salts on the surface of the stone. It is caused by water that carries the salts from the setting bed or the stone to the surface; it is often deposited as a white powder like residue on the surface of the stone. Effervescence is what happens when something fizzes. A good example is when one drops an alkazelser in a glass of water. The fizzing is referred to as effervescence.  I have never seen a stone effervesce, unless someone was pouring acid on it.

Along the same topic I have had so-called experts instruct people who have an efflorescence problem to seal the stone to help it. This is wrong, sealing will only block or reduce the pore size of the stone and this in turn will not only cause more efflorescence, it could also cause spalling.

 Your Stone Floor needs to be homed!

 No, this is not a spelling mistake, the word use was HOME.  I have run into several sales people who have called the honing process, homing.  Maybe they also worked with pigeons , but I have never heard of homing a floor. The proper term of course is HONE, which means to abraded a stone.

 That’s not a crack, it’s a fissure!

Now I don’t want any letters or emails from you fabricators out there. The following is an explanation of both of these terms. Many fabricators will try and  blame cracks that occur in stone installations on natural fissures that occur in the stone. Sometimes they are right and sometimes they are wrong. If one looks up the word ‘fissure” in the dictionary, guess what? A fissure is a crack. What I believe most fabricators need to do is describe the natural fissures in the stone as “natural occurring as part of the formation of the stone.  Cracks on the other hand should be called “Breaks” caused by external forces on the stone. This would mean that if someone stands or sits on the stone, it could develop a break.  Of course, the most likely place for a break to occur is on a natural fissure. For this reason it must be handled carefully and the stone needs to be examined carefully.

This is a tricky topic and is open for debate, however, you need to communicate to your customer what the difference between natural occurring fissures and those caused by external forces.

 Vinegar and water

 To clean your marble or limestone, just use some vinegar and water. Now, hopefully most of you in the stone business know that vinegar is an acid and it will etch calcium based stone. However, I cannot believe how many times I have heard tile installers make this recommendation. In case you don’t know…never, never use vinegar on any stone surface. Marble and limestone’s are generally the most susceptible but there are also some granite that will become damaged from vinegar.

 

 To remove oil from stone saturate it with water and the water will force the oil out.

I heard this one recently from one of my students who told me that some expert told him this is how you remove oil stains out of stone.  Believe me, it does not work. In theory since oil will float on water you would think that this makes sense. However, the oil is trapped in the pores of the stone and no amount of water is going to force it out. The best way to remove all is with a poultice and a degreasing chemical. For instructions on poulticing see our web site at www.ntc-stone.com.

 

 All Marble have Veins

 This is another fib I hear all the time. Many people in our industry believe that if a stone has veins then it must be marble. Of course this is totally false, since veins can be observed in granite and limestone as well.

The Darker the stone the softer it is!

Again, Untrue. There are some really dark granites that are as hard or harder than some of the lighter colored granites. The same can be true for marble and limestone.

 Of course we should not forget the myths about granite harboring bacteria and emitting harmful radon gas. In past articles I have dealt with both of these falsehoods. Here is a brief summary.

 

 There is a report circulating that granite countertops are unsafe, harbor bacteria and can produce disease. This is absolutely FALSE, NIOSH and the CDC have no reports of granite or any other stone used as a countertop as being unsafe. Think about this for a moment, if stone was unsafe and unsanitary why would there be cutting boards sold made of stone. Why would stone be used in food laboratories. There has been no known proof of any illness caused by using stone as a countertop.

 There have also been rumors that granite contains harmful radon gas. This again is untrue. There is so little radon in granite that one would have to live to be 10,000 years old for it to have an ill effect.  There is more likely more radon coming from the ground and the concrete that your house is built on.

 As the years progress and I get grayer, I hear more and more falsehoods and myths. I keep readers posted any new ones I hear.