Since glass is porous it tends to crack more readily during freeze.
Unless the tile is above water line, I'd seek "frost proof"(?!) pool tiles.

Ken

Here is a link that might be useful: Tile

Glass tiles are beautiful and are available in frost proof.

Read this thread on glass tiles:

http://ths.gardenweb.com/forums/load/pools/msg0121003423537.html

Here is a link that might be useful: Glass Tile Thread

Glass is porous? You are kidding right?

Maybe every time I have a beer I am being cheated out all of the beer that absorbs into the bottle. (sarcasm)

In The Seattle Area Where PoolMissy and I live, we get about a 2-4" freeze during the winters that lasts a few weeks. I have yet to see glass tile crack due to freezing.

I have however seen glass tile pop off due to water getting behind it freezing, which can happen with any tile.

Glass tile, since it is typically thinner and usually smaller dimensionally gets less contact with the thinset bed than standard ceramic tile, so it may pop off easier than larger tiles. If it is installed properly it really shouldn't be an issue.

I was wondering the same about the glass porousness...

But because it is not porous, it does mean that in usual applications its possible not to get good contact. Folks (PBs) in the MD area that I talked to dont want to try it... But it should definitely be possible...

*********************************************************
As for glass being porous, in its normal state it is not porous.
However, as documented in the following page from the Corning Museum of Glass, under certain chemical conditions glass can be attacked by an acid solution, rendering the surface porous:

-----
Properties Of Glass: Chemical
http://www.cmog.org/page.cfm?page=316

"Acid corrosion behaves quite differently. By dissolving the alkali in the glass composition, a porous surface is left that consists of the silica network with holes where the alkali has been removed by the acid. This porous surface slows the rate of attack since the acid must
penetrate this surface layer to find alkali to dissolve.

Corrosion by water is similar to acid corrosion in that alkali is removed from the glass surface. Water corrosion acts at a much slower rate. At high temperatures, however, water corrosion can become significant. Gauge glasses for steam boilers are a case in point. These products must be protected from the superheated water by a sheet of mica or replaced on a schedule that insures that they will not be seriously weakened."
-----
So, to summarize, glass is primarily made of crushed white sand (silica), crushed limestone, and sodium carbonate. When exposed to an acid solution, a glass surface will eventually become porous; however, the rate at which this occurs depends greatly on the acidity of the solution and the temperature.
*********************************************************

Thanks for getting me straight here, guys. Those no-nothings over at Corning are stupid enough to agree with me.
Of course, for those few of us that have ever used acid in pools as well as installing any tiles below water, glass tile is not the first choice in freezing areas. But then I'm in California doing this for 23 years, so what do I know. Maybe you could use beer bottles in place of tile. But you know better ...........

Good Luck

Ken

I guess I thought this was a pool for humans.not an acid bath... Of course if you want to damage it for sure, turn up the heat as well...

On the other hand, it maybe a better arguement that glass tiles would get scratched up in case you have to continually scrub it.

"Those no-nothings over at Corning are stupid enough to agree with me. "

About what that you can acid etch glass? This is a well known fact, however to do this, they acid bath they are talking about is more than likely not a Do you show this article to clients to scare them away from wanting the more difficult to install glass tiles?

I have seen many 15 year old glass all tile pools, and besides the occasional few tiles that pop of there is no evidence of a porous condition.

If you drop a ceramic tile in an acid bath do you think the same could eventually be said?

Well this is getting foolish.

Just a bit of review.
1) My concern is that glass tile installed at the water line has an easier time of popping off than most ceramic tiles.
2) +90% of pool chemicals leave the pool water through the surface especially when heated
3) The hottest part of a pool on the average sunny day is at the exact point of water to tile contact. Since calcium and salt like to leave solution when heated most pools have that deposit at the water line. I'd rather not try to clean the glass tiles
4) 30% acid is not necessary to start the process

As to the personal attacks:

1) I never "scare" people into buying or not buying. I know that this is a very common practice among the highly unprofessional, unethical sales staffs so I can see where the average person may jump to that conclusion. The first time I saw the corning article was when I did a 2 minute search for glass porosity. I learned the nature of glass in Freshman Chemistry forty years ago.

2. I have installed 1000's of square feet of glass tiles above, below and at the water line. I do not, however advise their use at or over the water line when the setting is above 5000 feet or in areas that do not drain the pool down below the tile line prior to winter freeze. Southern CA and Florida are not a worry.
   3) I find glass tiles no harder to install than any others that are matted multiple piece.

I realize that a tendency to attack seems to be the way of forums but you may want to re-read the entire group of postings.

Opinions are by their nature always biased. Forums are built from opinions. If you can offer proof rather than hearsay and fairy tales it is a good thing.

I wish good luck to the original poster here with the tile choice.

Ken

Here is a link that might be useful: All tile pool

Didnt expect my post to go down this road but I still realy appreciate the comments and adivce by everyone when it came to glass tile. I think its look is very unique and would love to try and use it in the design.

Thanks again.

Well porkchop now you can get your glass tile it really requires a professional (someone who can show you there finished work in person)

I concur, glass tile is too expensive and temperamental for someone to "give it a shot".

"Thanks for getting me straight here, guys. Those no-nothings over at Corning are stupid enough to agree with me.
Of course, for those few of us that have ever used acid in pools as well as installing any tiles below water, glass tile is not the first choice in freezing areas. But then I'm in California doing this for 23 years, so what do I know. Maybe you could use beer bottles in place of tile. But you know better ..........."

Let me apologize for my sarcastic remarks.

However I would like to touch base on the porosity of glass tile one more time, now that I have a little bit of time to research a better response.

Regardless of the research that Corning has done, we have to ask ourselves what effect does pool chemistry, and a swimming pool environment have on glass tile??

I can only answer with my experiences constructing and servicing swimming pools and spas.

I cannot honestly say that glass is any harder or easier to clean than it's ceramic counterparts.

I cannot say that I have notice glass tiles freeze and spall, or crack like clay tile.

I cannot say that even if glass tile becomes porous, that I can tell the difference between constantly submerged tiles, and ones that have been in a dry location.

I cannot say that the effects of efflorescence is any better or worse with glass tile, but it doesn't seem to be removed easier.

I can say that the installation of glass tile is far more difficult, and the size, and slickness of the surface make glass tile far more supceptable to coming loose from its substrate.

We could argue the porosity of glass forever, just like you could argue whether or not glass is a liquid or solid, but if we focus on the tangibles. We can possibly chemically alter it to make it porous ( porous glass is used extensively in the medical field) , but I have never personally seen glass absorb water.

I would say that glass is not a bad choice for a tile as long as it's properly finished.

Im doing raised columns in glass all the way down to the pool floor, a slot overflow fountain in glass, step trim in glass and my waterline in glass.
We have 2 com-plete glass pools going in right now too.

I cant agree more that you need to have experienced installers of glass if you are interested. Its a completely different animal. Completely different materials used in the installation.

"Posted by racket (My Page) on Wed, Mar 12, 08 at 21:10"
"Let me apologize for my sarcastic remarks."

accepted and the same back atcha'

Ken

Here is a link that might be useful: Speaking of Glass

Racket - I see you are a pool contractor. My friend in Seattle needs a good one to retile and replaster the pool at his new house. How do I contact you.