Replies

1. 
   Qtrmeg_ | Oct 20, 2000 03:18pm | #2

   *
   I would add a layer of 1/2" underlament, nailed 6" on the edge and 8" in the field.

   You do have to soak the tiles before you set them, as they are some kinda porous. I would soak a batch in a 5 gal bucket and pull them out a bit before you set them so they aren't dripping wet when you try to butter them.

   You do have to butter the backs, as they are some kinda unflat and twisted.

   The latex additive is to give the thinset some flexiblity, (I think), but don't buy the thinset from HD, or some similar store, buy it from a tile supply store. Hd's thinset is junk.

   I would layout the whole area before you set one tile, to make sure you don't end up with any funky 1/2" rows and to best account for any out of square issues.

   Snap lines every 24" in both directions and set one square at a time. Stand back and eyeball the set and adjust as needed. You can use a rubber mallet to pound the tiles into the thinset, but I wouldn't bother, just make sure you sort of twist them into contact, and try to get them on as level a plane as you can.

   Oh, and you know those cute little plastic crosses everyone likes to use now to set tile "square"? Forget about it, they are useless.

   If you get too much mud in your groutlines, slide the tiles togeather a bit and wipe the excess out with your finger, and wash any thinset off the face of the tiles as you go. These are a couple of concepts newbies seem to have to learn the hard way.

   Also, stay off of this floor for twentyfour hours. Thinset doesn't like to cure when applied too thick and there will be spots that are on the thick side.

   Anyhow, good luck, this is one of the hardest tiles to set, but if done well one of the nicest looking floors.

1. 
   jim_pelot | Oct 20, 2000 08:33am | #1

   *Qtrmeg - many thanks for the tips and insight. One further question: should the additional 1/2" be exterior plywood, and should an expansion gap (to be caulked)be left between them, or should the 1/2" be T&G to add strength to the floor?

1. 
   Qtrmeg_ | Oct 21, 2000 05:05am | #3

   *Jim, there was some talk around that cdx ply had a coarser face that promoted better adhesion, but most of the cdx I see now is junk and I won't be using it for underlayment, use a good thinset and the veneer isn't an issue. As for the gap issue, I give the stuff a little breathing room and leave it at that. Spend your time prepping the sub-floor and keeping the crap out of between the layers. You have an 8" nailing pattern for the field, see if you can have every other row of nails hit a joist. Caulk? where did you hear that nonsense? Nevermind, and don't even start with me about glueing the underlayment down, either.I don't know about any 1/2" t&g, but you may want to see if you can keep your underlayment seams out of a traffic area, if you can't I will allow you a few extra fasteners, just don't go nuts, someone will have to take this floor up someday. (fasteners for me are nails, but I imagine the screwlovers will post later)And I thought you only had one more question?

1. 
   jim_pelot | Oct 21, 2000 04:21pm | #4

   *Yeah, the one about plywood! Thanks for the advice

2. 
   jim_pelot | Oct 21, 2000 04:21pm | #5

   *
   Wow, I've read the excerpts from this discussion in FH, but this is my first on-line session.

   I am planning to lay 400SQFT of handmade glazed terra cotta tile. The area in question has 3/4" T&G plywood flooring over manufactured webb joists.

   Can anyone recommend whether I should add another underlay of 1/2" ply, or should I use lath and a mortar bed?

   Also, any tips on actually laying the tile would be appreciated. I've been told that I should butter the back of the tile, in addition to using a 1/2" square notch trowel. One person told me that dampening the back of the tile will help thinset adhesion. Another recommended using only liquid polymer rather than water in the thinset, to minimize water absoption into the tile and possible staining.

   Thanks much,

   DIY Jim