I have two types of granite in my kitchen--absolute black and on the 100" long island -River Gold. I believe in sealing, just to be on the safe side and in case your granite has some porosity.

If you've ever cleaned your countertop with some solution, sealing is the same thing. You first clean your countertop and wait until it dries. Tyhen you pour some sealing solution on a soft rag and wipe it all over the granite. Almost nothing is more simple than sealing granite.

Now if sealing changes the look of your granite and it displeases you--I guess you play the game and take your chances.

Greg

Thanks Greg, When I posted this question a couple of months ago someone said the type of granite makes a differance, if it needs to be sealed or not?

That's true - some of the dark granites are not porous and don't need sealing and in fact the sealer can build up on the surface and form a haze. Does water bead up on it - if so you don't need to seal it now. There's a pointer to a list somewhere on this forum of which granites are likely not to need sealing - do a search.

I will do a search. I remember someone said to leave a wet sponge on the granite for a few minutes. If it left a spot then it either meant it was the type of granite to seal or not seal. I can not remember which one he said?

If the sponge leaves a spot then the granite needs sealing - but there's more to it than that - ideally you should test a sample with lemon juice, red wine, and a bunch of other things to see if the stone stains.

I would not and don't seal my AB, one of the most dense if not the densest stones, but do occasionally seal my Shivakashi.

Karencon,

You have Shivakashi? That granite was torn out in an upstate New York kitchen. Here is a pod cast of the guy that measured the top prior to tear out.
http://www.buildclean.org/default/Podcast/flash.html

This top supposedly gave the fabricator lung cancer, but I have never found a second source for the info, supposedly the guy signed a non disclosure form to settle with the company that sold the material. If this was the only case, I would not think much of it since the info is suspect in my mind till proven.

But, there is a second case going on. Six month old top installed to get the home ready for sale. New buyer insisted on a Radon test but the home failed. The Radon inspector tracked the emission back to the Shivakashi granite countertop. The people now have a home they can't sell till the top is replaced, and have a three year old and a six month old baby. They are really pissed off, as I would be, and have hired an attorney. This is in the New England area, can't be more precise till the case is settled.

Do this, even if you don't think this is a real problem, get a cheap Radon detector from a hardware store or your state Radon office. Set it on your counter, then send it in for reading.

Or send me a sample if you have one left, I can check it for radiation levels, then send it to one of the scientists for testing if it is big enough.

This stuff comes from southern India, famous for it's monzanite that give the area a very, very high radiation and Radon level.

Now, not all slabs of even usually hot granites are bad, so don't freak out. Just get it checked. Might be a good idea to increase the ventilation of your kitchen and home till you know for sure.

Send me a private message with an email address and I'll get you in touch with the guy that found both Shivakashi tops that were hot. He can tell you more in private than I can divulge on an open forum.

Hey HGK, I wasn't able to get the link above. Thank you for your concern. I am familiar a bit with the debate on "hot granite" but wasn't aware that the Shivakashi was one of the major offenders. I have followed this passionate debate on the other thread. I certainly am not equipped to make a judgement and would be willing to do a radon test. My home on the beachfront has no basement and we are up on piers so I have never had such a test. I am not sure how to find your email either in order to backchannel.
Karen

Here we go again.

karen, please DO get it tested, and then come back here and post the results? PLEASE? This is getting tiresome. I couldn't get to the link, either. Big surprise.

If the sponge leaves a dark spot, it needs to be sealed. The list is below. click on the link, and then find the name of your granite on one of the two list links at the top of the page it takes you to-- A-L, or M-Z:

Here is a link that might be useful: Granite lists on findstone.com

Hey Bill, we are looking into testing, but seems there's also debate on how to test. I think our university offers some testing. Will post when it's done....... can't guarantee how quickly we'll get to it though.

Sorry about the link, I'll add it to one of the blog pages on this subject and add the link below.

Look down to this entry on that long blog page:

Latest News of the Testing effort Thursday, July 10th 2008

You will find the entire story. Some of this info was verified just this week, I have had to sit on much of it for months till a second source was found. As it is about to be published and I heard it first hand from the man himself, I don't have any doubts it is true.

I am going to contact you and get you and Stan connected if you are interested. And I am sure you will be interested once you have read the details and listened to Stan's interview.

Oh, turns out some of the info was garbled. It was the homeowner/owner/builder that had developed the lung cancer, not the fabricator. Two years and two months exposure. Again if it were the only case, I would discount it some. Right now, the safest thing is to test any Shivakasi found.

Here is a link that might be useful: New info on granite/Radon/radiation testing effort

Karencon,
no way to contact you through your screen name. I understand that you can set your profile to get messages, I think that is the case.

Leave a comment on that blog and I'll send you Stan's email.

HGK, I've reset preferences so I can receive backchannel
Karen

Gracie-2006:

Back to the YOUR ORIGINAL question...

As to whether or not to seal - there are varying opinions:

I am a Fabricator that has been doing this since 1985...

I prefer to seal everything that I supply to my customers,
and I like to use Porous Plus 511. This is what works for me.

I also educate my customers on "when" a stone needs to be
re-sealed. The "water test" is probably (in my opinion)
the easiest way for a consumer to tell if their stone needs
an additional application of sealer. Mine is similar to
my Brother Bill Vincent - his technique will work just as well.....

Mine goes like this:

1. pour out 1 Tablespoon of water on your stone
2. allow the water to sit undisturbed on your stone for 5 minutes
3. blot the water off of your stone with a dry towel
4. observe where the water was - after it is blotted off
5. IF there is a "dark spot" where the water WAS - you'll
need another coat of sealer.

hopefully this is what you were originally looking for...

best regards

kevin

Karencon,
I sent you an email. Check the spam folder if you don't get it.

Thanks,
Al

Sorry Al, we might have deleted it yesterday..so I didn't get it.

sent it from my email this time instead of Garden web's email program.

al "at" thecarpentershop.net is my email address.

RADON IN GRANITE
What a crock of cheap "salesmanship"
An article by Maurizio Bertoli, the founder of the "marble cleaning" company

This information is copyrighted by the Marble Institute of America, but may be reproduced, with credit given to the Marble Institute of America.

Solid Surface, The Journal of the Solid Surface Industry (Volume 1 Number 1) that was published several weeks ago included an article entitled "Granite & Radon". The introduction to the article stated "Scientific research poses disturbing questions about the safety of granite countertops" and copies of this article have circulated around the stone industry raising questions about radon gas emissions from granite countertops. The key advertisers in this journal were Corian and Formica.

The MIA has called upon several of the country's leading scientists in geology and geochemistry to assist in preparing a response to the allegations in this article that radon gas emissions from granite countertops may be hazardous. On reading the article, our consultants reacted with such comments as "ludicrous", "a fabulous collage of nonsense", "politically motivated", "unethical", and "bizarre".

Donald Langmuir, PhD, Professor Emeritus of Chemistry and Geochemistry at the Colorado School of Mines and President of Hydrochemical Systems Corp., both in Golden, Colorado, has prepared a response on behalf of the Marble Institute of America that evaluates and refutes these allegations. His report appears in full in this Special Bulletin. Dr. Langmuir received his BA (with honors), and his MA and PhD degrees in geochemistry from Harvard University. He served as a geochemist with the Ground Water Branch of the U.S. Geological Survey's Water Resources Division and subsequently taught and conducted research for 11 years at Pennsylvania State University, with temporary appointments at Rutgers University, the Nevada Desert Research Institute, and the University of Sidney, Australia. Dr. Langmuir has been a full professor at the Colorado School of Mines since 1978.

In addition to working with Dr. Langmuir and other scientists, the MIA staff also talked with the major U.S. granite quarriers and producers about the issue of radon emissions from granite. These companies have certainly not ignored the issue and several have had radon testing performed on their granites. The research done for these companies have shown that actual levels of radon gas emissions from granites are so low as to be insignificant and generally represent no threat to the health and well-being of people who live or work in buildings with granite countertops, floor or wall tiles, furniture or any other furnishings made from granite.

Marbles, limestone and stones other than granites are of such mineral composition that they generally do not contain measurable quantities of radon-producing material. In terms of building materials, radon emissions from concrete, cement and gypsum could be of greater concern.

What is Radon?

Radon is a naturally occurring gas generated by the decay of trace amounts of uranium found in the earth's crust throughout the world. It is an unstable gas that quickly breaks down and dissipates in the air.

Radon is measured in units called picocuries per liter (pCi/L). A picocurie is one trillionth (10 -12) of a curie, which is the amount of radioactivity emitted by a gram of radium. The U.S. Environmental Protection Agency (EPA) has established 4 pCi/L as the standard for indoor air; 20 pCi/L represents the maximum amount of exposure to radium that is now allowed by U.S. regulations.

The following is Dr. Langmuirs report:

Date: September 1, 1995
To: Marble Institute of America
From: Donald Langmuir, PhD, Professor Emeritus of Geochemistry, Colorado School of Mines, & President, Hydrochem Systems Corp.
Subject: The article 'Granite and Radon' published in Solid Surface

I am appalled and dismayed that any journal would accept a pseudo-science article such as this for publication. If this article had been submitted to a reputable scientific journal, the editors and reviewers would have demanded that the author supply scientific evidence to support his/her many unfounded and unsupported assertions and conclusions. Lacking such evidence they would have rejected it for publication. As a separate point, I am very suspicious of a paper that has no named author. Who is responsible for this attack on granite countertops? Is it someone who stands to benefit economically?

Two of the scientific experts who the author (or authors?) cites repeatedly in the bibliography as sources of the arguments have become aware of the 'Granite and Radon' paper. They agree with me that the author's conclusion that a granite countertop could emit a high and dangerous concentration of radon to a home is both totally fallacious and ludicrous. In fact, as you will see below, the amount of radon released from a typical granite countertop is certain to be completely negligible and well below detection by any known method of radioactive analysis. I would be delighted to have a granite countertop in my home!

As to my credentials to evaluate and refute 'Granite and Radon', I have been conducting funded university research and publishing in peer reviewed journals on the geochemistry of radioactive elements for nearly 20 years at Penn State University and the Colorado School of Mines. In recognition of this expertise, I was nominated by the National Academy of Sciences and appointed to serve as a member of the U.S. Nuclear Waste Technical Review Board by President Reagan in 1989, and reappointed to that position for a second four-year term by President Bush in 1992.

It is worth noting that the stone industry, whether advertising countertops, building materials or monuments, terms many stones 'granites' that are not true granites to a geologist. A true granite, which is often grey or pink, is chiefly comprised of a potassium aluminum silicate mineral (K-feldspar or potassium feldspar) and quartz (silica or SiO2). Rocks called granites by the industry also include magnesium silicates (e.g. peridotites and serpentines) and a host of other chemically different rock-types, most of which contain much less uranium than does true granite.

As admitted by the author of 'Granite and Radon', there have been no direct measurements of radon release from granite countertops. Model calculations suggested by Dr. Richard Wanty, using a standard, scientifically accepted approach and conservative assumptions, indicate that the radon release from a granite countertop is orders of magnitude below detection by any known analytical method. Incidentally, Dr. Wanty, who is a geochemist with the U.S. Geological Survey, co-authored or co-edited four of the expert references cited in the author's bibliography. He has performed research and published on the geochemistry of radioactive elements for sixteen years, and studied radon as apublic health issue since 1986. Dr. Wanty's worksheet reproduced below may be used to calculate the concentration of radon that would be released from a granite countertop. The worksheet is shown with an example calculation, assuming a ten-foot by seven-foot granite countertop.

The EPA standard, which is not to be exceeded in indoor air, is 4 picoCuries per liter of air (4 pCi/L). Eisenbud 1 indicates that the average contributions of radon from various sources to indoor air are 1.5 pCi/L from the soil (under and around the house), 0.01 pCi/L from public water supplies (0.4 pCi/L) from private wells), 0.05 pCi/L from building materials, and 0.2 pCi/L from outdoor air. These values are for the average house which is ventilated such that over one hour the air is changed 0.5 to 1.5 times. The vanishingly small amount of radon in household air that might be released from a granite countertop (0.00000074 pCi/L) as computed below, has been calculated assuming no exchange of indoor and outdoor air, which would further trivialize its significance. Note also that the radon content of outside air is 270,000 times greater than that released by the countertop.

There are certain properties of rocks that can increase their radon emanation efficiency, or in other words increase the release of radon from a given weight of rock. These are rock properties that maximize the exposure of internal or external rock surfaces to water or air, allowing any radon gas to escape. The author of 'Granite and Radon' argues that such properties, which include rock porosity, fissuring and mylonitization, will increase radon releases. This is probably true, however, a granite with such properties would be too brittle to make into a countertop, and too open to take a polish, and so would not be marketable as a countertop - unless the rock pores were first filled with a chemical sealant. Such sealing would also eliminate any possible radon release problems.

In summary, to show how laughable are the concerns expressed in 'Granite and Radon', the typical granite countertop in our example will release 7.4 x 10 -7 pCi/L of air. This corresponds to 2.7 x 10 -8 atom decays per second (dps). This represents 0.85 decays per year. In other words, less than one atom of radon is produced by the countertop in one year. This is hardly worth getting excited about. I would suggest that a good way to reduce our exposure to the radon present in outdoor air, would be to build an air-tight house out of granite countertops!

Enough Said!

Ciao and Good luck
Maurizio Bertoli

--------------------------------------------------------------------------------

Gracie, sorry that your thread has been hijacked.

Timss, thank you for post. I have been following the discussions on this topic and am "agnostic" about the whole thing. I do feel singled out however. We may or may not test our granite. We are not rushing out to do so. We've had it for 2 yrs. now. If there was significant radon being emitted wouldn't it have dissipated by now anyway. Always wondered why no one here on GW has this granite, maybe they all know something I don't. I don't know Al....assume he thinks he's right. It'll take more than this effort to slow down the stone industry. Even if my Shivakashi was a problem, I'd be out tomorrow looking for another granite that I love even more.

Hey Maurizio-- Thank you for that article, my friend.

hey Al-- go ahead and try to tell us Maurizio doesn't know anything either. I dare ya.

Soon the MIA will be completely discredited, including this bit of drivel. Maurizio Bertoli and I emailed about this article and he said it was "BS versus BS" he knows none of the above can be backed with evidence. Here is the revlent part of one of his emails.

"Dear Al Gerhart:

As I read your message I was really impressed.

Im always open minded and not only dont I have any motivation to defend the stone industry (I dont sell stone), but I do have, in fact, several issues for the way the stone industry is run.

So I said to myself: this gentleman may have something to say that interests me. After all, hes talking about scientific evidence

Sure, hes a promoter of solid surfaces and stuff, but if somebody does the right thing for the wrong reason it doesnt bother me one bit.

I also know that the articles that you found on my website are not scientifically credible. On the other hand, the "scientific" proof they are fighting was not scientific at all!

Now, why are these two articles not credible scientifically?

Quite simply because they make reference to a stone, granite, that represents only a scant 2% of all the stones traded as granite."

End quote.

Now Mauzio doesn't think the scientific studies I used were credible, no accounting for someones refusal to take an independent study at face value, but it is his opinion, not mine.

It is late and I am not going to do a full fisking of this article, but here are some things that jump out at me.

"Marbles, limestone and stones other than granites are of such mineral composition that they generally do not contain measurable quantities of radon-producing material."

Uh, the Saudia Arabian study said otherwise.....

" the amount of radon released from a typical granite countertop is certain to be completely negligible and well below detection by any known method of radioactive analysis. "
Well someone better tell Dr. Chyi and the MIA. Back in May they were forced to use their study that measured Radon in granite. So Langmuir was lying back then or the MIA is lying now.

"In terms of building materials, radon emissions from concrete, cement and gypsum could be of greater concern."

Utter bunk, concrete, cement and gypsum might have 10 to 15 uR/hr in extreme cases. More like 5 to 10 uR/hr on average. Concrete is regulated in some states to no more than 10uR/hr for any one material, and 5 uR/hr overall.

"This represents 0.85 decays per year. In other words, less than one atom of radon is produced by the countertop in one year"

He missed this by about 93 billion times. Each click of a geiger counter is one decay, many of the clicks are Radium decaying into Radon and Radon decaying down it's decay chain.

I did a full fisk of another nutjob that used some of Langmuir's quotes in the link below.

karencon wrote, "Always wondered why no one here on GW has this granite, maybe they all know something I don't."

There are many members here that have used shivakashi (esp. popular 5-6 years ago, now folks seem to gravitate more to the exotics w/ color & movement) - it is a beautiful stone, although it can be somewhat porous and absorbent. Do you know if your slabs were resined?

Als' been stirring up this granite/radon thing for a couple of years now. Realize this - it was only after his first attempts at discrediting stone (on which he furnished charts, graphs, pictures and reports from 'experts') failed that he started with this radon bit. Anyone remember how Al swore up and down that we were subjecting our children to food prepared on a breeding ground for bacteria or that our sink rails were bound to crack?

He's like a pitbull that has ahold on a pantsleg!

Hey Paulines, thanks for responding and for the clarification on the Shaivakashi use. In two years no ones ever really explained why you don't hear much about it. I know it kind of porous but I don't have a problem with it and I don't even seal much at all. Sometimes use a cleaner with sealer. I am not sure if it was resined. It did not come with mesh underneath which I read may suggest that it was. Why do you ask? My Shivakashi does have some movement and lots of variation in pattern.
So is Al the cracked sink front, bacteria guy too?

Karencon:

Probably somewhere around 90 to 95 percent of all Granites
are now being resined with Epoxy to help bind the stone, fill
pours, pits and fissures - this results in many more colours
being available to be brought to market now than what was
10 to 15 years ago. The mesh backing is usually found on
stones that are very brittle, and helps stabelize the slab
from the time it is proceesed at the finishing plant, until
it gets installed in a consumer's application.

As far as what Gracie is asking, again... IF you have a lighter
stone, it's a good idea to keep it sealed, and there are a
number of great products out there that will do the job for you.
You can find a link to my e-mail if you have questions -
just go to my website......the address is below

hope that helps you

kevin

www.azschoolofrock.com

I did a full fisk of another nutjob that used some of Langmuir's quotes in the link below.

Al, stick to that other blog. Using that as a reference for granite is like using Huffingtonpost, or Fox News as as a reference for politics. Can you say SLANT???

Oh this thread is making my head hurt.......... or is it the Radon?

Our company uses a sealing product called Stonetech by Dupont. It's water not solvent based. There is no build up so you cant overseal. Simple to spray on and wipe off. Once a year for darker stones, 2x for lighter ones. I have clients that never seal and dont have issues, then there is the client that seals every time she entertains. Stonetech also makes a daily cleaner which has a small amount of sealer in it so that you are boosting the sealer everytime you clean.

karencon,
It's not radon it's electro magnetics from our computers
I hear they're really bad for us
or was that eggs ?

Well,
I sent Karrencon Stan's email address for more info, but Thursday morning many of you will be able to read the entire story for yourself. I'll post the section and page number on the blog site, look in "recent info on the testing effort."

You are going to learn that several companies refuse to sell it any longer, as they should. Plenty more as well.

Like I said in the other thread, there are going to be some embarresed people on Thursday morning after finding out that they have been exposed.

I can not imagine attempting to convince someone that a material was safe all the while knowing there was proof that it was dangerous. I can't see how there could be enough profit in a few jobs to pay the damages from selling material that would have to be ripped out later. Besides, how do you sleep at night knowing that you would be responsible for families being exposed to this stuff?

I'll see you guys Thursday night.

there are going to be some embarresed people on Thursday morning after finding out that they have been exposed.

Does this mean I'm going to have to make an aluminum foil hat wednesday night?

Only if you have lost your regular aluminum foil hat. Try stapling it on, or drywall screws...

I know the ancient Greeks and Romans used stone for their countertops. Does this explain why they are dead?

Khat, funny!

But if you are serious, that is a fine example of one of the recognized dodges in debating, Argumentum ad antiquitatem, if it is old it is good. Universally rejected as a logical point.

I read in many places over the years that lead plumbing contributed to the demise of the Romans, lead poisoning dehabilitated their best people. Granite has very high lead levels, and of course as the milliniums go by, the lead actually increases as the radioactive decay chain winds down, it just doesn't get any better.

Radon progeny have been linked in two studies of alzhiemers and parkinsons disease, found in elevated levels of the brains of victims of those afflictions. Radiation also has been shown to contribute to mental retardation, which coupled with the Radon progeny, would explain the opposition's not understanding the science and logic of this debate.

I'm just saying.....

if it is old it is good. Universally rejected as a logical point.

At first I was going to say like hell it is, but I'll add the disclaimer-- it depends HOW old. In this, case it IS good.

Radiation also has been shown to contribute to mental retardation, which coupled with the Radon progeny, would explain the opposition's not understanding the science and logic of this debate.

You were talking about personal attacks Al? That's okay. Now I've got a reason to start, instead of just going after the crap you're spewing.

You know, I heard they had granite on the Shuttle Challenger. Matter of fact, I'd be willing to bet all the countertops on the Titanic were granite too. Coincidence? I think not.

*shaking my head*

I must have hit a nerve....

Nahhhh, I just like showing hypocrites for what they are.