A couple of questions for the pros ... I've never worked with 12x24 tile, Im going to be installing 12x24 Porcelain Tile on a concrete slab and as well on the wall (4-5' high). Floor has old glue from carpet and vinyl tile so I was going to use Mapei Ultraflex 2 or 3, I would assume a 1/2 trowel is needed. Is installing 12x24 Tile on the wall a bad idea? Is there a specific Mapei product I should use when installing these tile on the wall? Trowel size? Can I use the Mapei Pre-mix glue for the 12x24 tile wall installation?

As for expansion joints that have been cut into the slab, I would assume I would have to purchase some sort of expansion joint to lay before tile is installed or do I just leave the expansion joint exposed and use silicone (no grout) for those lines? What do you recommend if the expansion joint ends up in the middle of the tile when laying them? Obviously I'm going to do my best to work with the expansion joints but I know for sure there are 2 lines that will not work with my layout. Do I just cut the tile and leave 3/16" - 1/4" gap?

I forgot to mention...for cracks in the slab would Mapeguard 2 be the correct product? Can I use Ultraflex 2 or 3 over this?


Thanks!

12x24 can be a challenge, even for a pro. I'm assuming you're going to put them in a brick pattern, and if so, a word of caution: Those size tiles can be crowned sometimes, so you might look into one of the leveling systems, like Tuscan or LASH to keep everything flat. Tuscan is probably a better system, but has a higher startup cost. With the LASH you can by only what you need to complete the job, and only be left with the spikes at the end. Or buy the Tuscan and when you're finished I'll buy the gun from you for 10 cents on the dollar.

You can certainly install those tile on the wall, but get some solid spacers for that. Most of the soft rubber ones will crush under the weight. Look at the multi-spacer http://www.multi-spacer.com/ or the Roto Wedge http://www.advancedtiletools.com/wedgevideo.html. Again, the leveling systems are a big help.

Ultraflex 2 or 3 are great products. Most importantly, skim thinset on the back of each tile to obtain maximum contact. It's especially important with larger porcelain tiles like you have. You can use the same thinset on the wall. Say "NO" to the premix stuff. 1/2" square notch is okay, although I like the 1/4x1/2x1/4" trowel. It's the same amount of thinset, but the notches are closer together.

Expansion joints must be honored through the tile. You have a couple of choices. You can by metal expansion strips through Schluter (or wherever you can find them), or you can use a color-matched caulk to fill those joints, which should be the same size as the grout joints so they'll blend in. If you're lucky, the expansion joints will be square with your tile layout so they won't stand out so much.

Mapeguard 2 would probably work, although I have no experience with it. I use the paint-on membranes like Redgard or Custom's Fracture-Free, which is cheaper than other crack-iso systems. Any anti-fracture is going to be compatible with thinset, to my knowledge.

Would any tile supplier or big box store carry the Redguard or Fracture Free stuff?

Which Mapei Product do I use for wall application...would the ultraflex 2 or 3 be ok or is there something better? I know Mapei makes one that doesn't run when you apply it to the wall (dryer mix) would that be the better one? I forget what its called but I think its part of the ultraflex line up.

Thanks for all the information!

Home Depot carries Redgard, you'd probably have to go to a tile supplier for any others.

Ultraflex 2 would be fine for a wall application. There are some non-sag thinsets out there, but if you're starting at the floor and working your way up the wall, and using spacers, there's really no reason to use a non-sag. If your thinset starts running down the wall, you've added too much water.

Ive decided to go with Ultraflex 2 for floor and walls. I bought the RedGuard for the crack and will apply that after I clean up the floors.

When applying the expansion gap piece, I assume you install it at the same time you install the tile...correct?


Thanks for all the help!

Paul