I am installing a small area of Florida tile (green marble) on the floor as a fireplace hearth. The instructions state to use a super epoxy to adhere the tile to backerboard. It has to be a non-water based substance. I have a small area of 10 sqare feet to cover. The recommended epoxy to use from the manufacturer is: Laticrete Latapoxy 300 or Super-Tek Super Epoxy AM. The issue is that I don't need much, but the manufacturer's seem to only sell it in large quantities and it is very expensive. Any suggestions about any other type of adhesives to use in this situation?

Is this an actual wood burning hearth/ fire box. Or is the hearth for a free standing wood stove? You can get smaller quantities of thinset usually at the lumber stores. Also look at in the painting section. There are cementious patch tubs that has laticrete in it. If its not a fire box and is a hearth in front of the box and high heat is not an issue, I would use construction adesive ext. it comes in a caulk tube. It works well and its cheap. Liquid nail works well. Need more information?

no. absolutely do not use construction adhesive. It is compressible and the job will fail if you put pressure on it.
Use the proper adhesive or you will lose some expensive materials, your time, and have a job that will cost more to redo. If you use thin-set, be sure to use an acrylic admixture if it is not already made with it. Thin-set will usually work find for marble, but use white rather than the gray. And you can get it at most home improvements stores, almost any marble dealer/tile store and it will give you a little more setting time to adjust the tiles before it hardens. This work however, is not something I would suggest a beginner undertake.
Good luck
Mark

Florida Tile specifies the epoxy for installation because green marble is moisture sensitive. Do not use regular thinset. The moisture in the thinset will create a difference in surface tension between the top and bottom of the stone that will cause your tile to curl. Custom building products makes a product for setting green marble called "Green and Black Marble Thinset" in a 10 lb box. It's a rapid setting white thinset that uses about 30% less water than normal thinset and it's done using up the water in the chemical reaction quick enough to set the stone. It's rock solid in about 20 minutes. It used to be called "Opticure" and you might find it at a Home Depot or use their web site Custom Building Products :: Architects & Specification Writers :: Home to find a tile shop that has it. After you track it down, contact Florida Tile and see if they consider it to be acceptable. If they don't, contact Custom. If Custom says you are good to go, then use it. You want the piece of mind that your project is warranted by either the stone seller or the thinset manufacturer.

As an alternate to epoxy, it is appropriate to use thin-set made with acrylic admixture in it (polymerized), or regular thin-set and then add acrylic admixture. You use less water when you add the liquid admixture.
Marble will not curl, regardless of how much water you expose it to. Marble is used on exterior work, and has been used that way for centuries. Its used in statues, and in swimming pools. The main reason for acrylic admixture is that it binds to the marble and does not release when the marble gets wet.

If anyone has curling marble, let me know and I will come and photograph and document it for ripleys believe it or not, contractor edition. It will be the first item.

Most of us who lay tile just call this modified thinset, we use it to lay tile on Wonderboard or Hardiebacker but not on concrete floors.

OMG, this is ridiculous! :eek:

Will 21boat and markevansgroup please take a break from answering tile questions, since it is obvious you guys are not tile pros. I am not keeping track but this has happened before, (with boat anyway. Please keep to the subjects you are good at please. :)

Mugsy, sorry. Do as Bljack suggested. OR there are several "special" fast setting thinsets that can be used for certain black and green "moisture sensitive" marble. Ardex makes a great one. I believe it's S 16? You CAN NOT use regular thinset as you already knew before you came here.

Jaz

Much to my surprise the special Green and Black marble thinset claims to decrease the chance of warping. Custom Building Products :: Architects & Specification Writers :: Green & Black Marble
I have laid a great deal of ceramic and porcelein but not marble but I thought it a silly idea that marble tile could bend or warp. I think I'll just stick with ceramic.

Thanks Jaz, when I read that reply earlier, I didn't feel like arguing.

Warping is probably a better term but I don't know why curling has been used as the description. With some serpentine marble, those are where you could spend all sorts of time getting the pieces selected to get the veining carrying across the field and everything dead flat only to find when you go to grout that suddenly there is lippage all over the place as suddenly the edges are 1/8" or so proud of the plane of the tile's centerpoint.

I happened to stumble upon a link to a paper by Henry Rothberg given as a speech in 2005. There are some people in each trade where if those people speak, then their word is taken as gospel. Henry Rothberg is one of those people. Not only did he originate the Tile Council of America, and founder Laticrete, he's also invented thinset for helping to rebuild England after WW2 when portland was in high demand and suffering shortages in supplies. Until then, tile installations used tons of it as everything had wet set over thick mortar beds with portland cement.

http://www.laticrete.com.au/pdf/techdata/tds109.pdf

When installing a green marble you can NOT use a standard gray or white thin set. Green marble is mositure sensitive. If you use a standard white or gray thinset your tile WILL pull away. You will left with a tile that has curled away around the edges. Check out ANY big box store, in the flooring section there is a thinset that says its for green marble. They make it for a reason!! Don't believe me... read the back of the bag, gray & whtie thinset will say DO NOT USE ON (MOSITURE SENSITVE) GREEN MARBLE.