Replies

1. 
   crt2cu2 | Dec 11, 2002 08:58am | #1

   Sniper,

   I am no expert on tile but will relay to you what local tile installers have insisted that I do for prep work on counters and bathrooms.  First, avoid particle board alone for moisture defect reasons.  If p. board gets wet in any way it will expand and ruin tile work.  Use a special 1/4 inch plywood intended by manufacturers over the particle board then lay the tile on the ply. Or, even more preferably, use the cement based backer board as underlayment for the tile, especially in high moisture risk installations around tubs and showers.  The tile installers also sometimes soak pure stone tiles such as yours in water before applying cement like adhesives (thin set mortar).  I am not sure why but suspect wet stone gets a better bond with the basically concrete type of cement they use.  This is just what I've seen and heard from subcontractors who seem credible.  You may want to get more advice from others.

   sawick

1. 
   johnhardy | Dec 11, 2002 09:49pm | #3

   I can't speak for stone, but when I was in high school I helped out my best friend's dad, who was a brick mason. He would dip the bricks in water on a hot day. The reason? He didn't want the dry bricks to suck out too much water from the mortar. I'm sure the same reasoning applies to the folks who put the stone tiles in water before laying them.

   John

1. 
   JMF688 | Dec 12, 2002 03:38am | #4

   I recently put 12"x12" granite tile around a customers fireplace between my cabinets and my granite countertop guy said to use a high quality premixed mastic.  It worked well but took quite a while to completely dry especially in areas where I put it on thicker to aid in leveling the tile.  Good Luck.

1. 
   Sancho | Dec 12, 2002 04:02am | #5

   Just finished doing a kitchen w/granite tiles. I used 3/4 ply. If you use MDF especially inna kitchen you take the chance of moisture getting through and turning it into termite droppings. I set backerboard and used thinset to apply the granite. I did use mastic on the backsplash. But there was bleed through (splotches on the granite). It took about 3-4 months (No kidding) for the mastic to totally out gas and the splotches to go away. You need to use some adhesive that is specifically designed for granite ILO mastic but you can do what I did and wait for it to out gas. Oh yea dont go cheap on the sealer use a high quality sealer for the granite also.Hope this helps   

   At Darkworks  Customer satisfaction Job One..Yea yea were all over it , I got my best guys on it.........

2. 
   LRutherfor1 | Dec 11, 2002 08:10pm | #2

   I agree with sawick on the method.  "Wonderboard" backing over MDF is what I've used for several jobs, and haven't had a failure yet.  You should use a marble/granite thinset.  It is specially formulated for natural stones.  The only other suggestion is when you grout, make sure not to rub the grout too hard, you can score the face, and polishing is tough to do right.  Good Luck,

   Len (Len's Custom Woodworking)

3. 
   DennisS | Dec 12, 2002 07:16am | #6

   As a tile setter in a previous life, I can tell you you're inviting more trouble than you care to deal with by installing tile, granite or otherwise, directly on particle board. In fact, my former life was back when we mud set everything, including counter tops. Meaning the plywood (waterproof, preferable marine grade) subtops were held down a good inch from finished ht. A dry pack (moist sand/cement mixture) was 'floated' level over the counter and the tile set with pure cement sprinkled over the dry pack then wet down with a waterbrush.

   Soft bisque clay tile had to be soaked at least 30 minutes to saturate them with water to avoid sucking all the water out of the cement and producing a weak bond. Once this installation was done and cured a few weeks, you could literally lift the entire tile/mud bed slab up off the counter in one piece if you wanted to.

   No amount of sealer applied to the surface of granite or tile will prevent moisture from migrating down between the grout joints. Fact of life; count on it. Sealing, varnishing whatever the particle board will affect the bond between the granite tile and the board.

   Since you've already got most everything framed, from the sound of it, the better material to use would be "Hardi-backer" rather than Wonderboard. Hardibacker is only 1/4" thick. Can be cut with a saber saw (buy lots of blades!) and is a cement based board that will not deteriorate in moisture laden environments.

   There are sheet membranes that can be applied over this and Laticrete makes an adhesive (thin set mortar) designed to bond to various sheet mebranes of this nature. Actually, it might be OK to merely install this membrane material over your particle board and dispense with the backer board. But in no instance would I accept tile of any kind installed directly over particle board without some sort of continuous waterproof membrane designed especially for the purpose.

   *Don't* ask for advice at the handy corner BigBox home centers. I've watched their tile installation demos and workshops and about split a gut watching what they recommend as tile installation proceedures. You're dealing with a condition (the tub area) that's going to be wet about as often as it is dry. You simply can't afford to take every precaution to prevent any of that water getting to things that don't like being wet!!

   ...........

   Dennis in Bellevue WA

   [email protected]

1. 
   fourquarter | Dec 12, 2002 10:18am | #7

      

   Just to back up previous posts:

   My housemate is an A-1 tile man and we just finished putting granite down in his brother's kitchen. either 1/4" or 1/2" backer board of some sort ( though I'd shy away from Wonderboard from past experiance ) on top of your Particleboard deck. We used 1/2" glued down with a product called "Eagle Grip" ; caulk tube adhesive, then screw the s**t out of it, about two billion screws seems right. If you don't use a backer, the moisture from your thin set will swell you deck and if the tiles don't pop off now, they will later.

   Also, do yourself a huge favor and buy a dimond wheel for a 5" grinder ($40 or so) and use it to cut that backer board. 10 times faster than a jig saw and you'll spend that in Bosh blades anyway if you have a sizeable job, not to mention the additional time it'll take. We trimmed the radii for the sink hole with a jigsaw and it ate blade upon blade. Good Luck!

   Kelley