c. Wall tile outside shower will be installed using Durabond D2001 tile mastic, using standard wall tile installation methods. This should not be used for installing natural stone. Request they use the D25. Also, what brand/type of grout, unsanded, would you recommend and what brand of sealer? As for grout, Durabond/ Hydroment is a good product, as are Laticrete, TEC, Mapei, or Custom. If you're down south, I'll also add SGM to that list. Concerning sealers, You want a good solvent based penetrating sealer, and the 3 easiest to aquire "good" sealers are Aquamix, Miracle, and Stone Tech. Should I request that the limestone be pre-sealed before install/grouting? Not necessarily. Although if this were a DIY project, I'd say without a doubt, these guys should only know that you expect them to do a professional job, and that includes no excess grout on the face of the tile, and no staining of the tile. The reason I say this is that in most cases, I personally prefer to grout unsealed stone, and that includes Jerusalem stone. It's a personal preference, but if I were to go to someone's house, and they were to demand that I seal it first, we'd have a problem. I don't care to be told how to do my job. You can make clear the fact that you want it to be right, and they'll be paid when they make it so, but beyond that, let them do their job.

I would absolutly follow Mongo's advise that he posted above on Fri, Mar 22, 13 at 22:31. Ditra is put under all kinds of stone and ceramic. As I understand it, it is a decoupling membrane that helps prevent shearing (horizontal) movements from cracking the tile. The subfloor and joist deflection issues help with preventing vertical movement that can also crack the tiles. How I understand it from the Ditra instructions is that, depending on the subfloor, you select the appropriate thinset to lay the Ditra. Then you lay the tile on the Ditra using appropriate recommended thinset. The orange will be completely covered. It will raise the floor a bit (1/4"?) more because the Ditra has a dimension to it. It is not recommended to be used for tiles smaller than 2" because of the waffle shapes. I bought the appropriate thinset that Schluter recommended at my HIGH END tile shop. It was expensive but a gem to work with. I have never used low end thinset and don't plan to. I have linked the site that makes Ditra. Look it over very well. There are great illustrations on how it works either on this site or others. When I did my floor (first time floor tiler) I used it and, while I took part of it up to get the lumps out, I thought it went well. The beautiful jobs of tiling by Bill V, and Mongct are all on top of Ditra, I believe. Here is my DH adding extra joists 2x8's to our under qualified 21"oc floor. Now it is 9-10" oc: Here is after I put down the (specific recommendation from Bill V.) underlayment of plywood onto the subfloor that was existing, and thick and newly re-enforsed. The only mistake I made was I snapped lines for the grid every 4" instead of the 6" that Bill stated. My mistake, but was not a problem for my DS to do:) Next came my warming floor system, stratigically laid out and planned to the hilt using drawing after altered drawing to get it to all work out. I am proud that I am only 8" short: Here is the floor with the self leveling compound being poured. It has a plastic lath that I put over the wires. I was recommended by the Moderate End tile store where I was going to buy my warming system. I changed my mind because I wanted 240v. But I had the lathe and I then read a tutorial over on the JB forum about using the lathe, so is used it in my installation. So: the BillV recommended underlayment, warming wire and 2 thermostats (1 is laying there not hooked up, as a backup down the road if needed), plastic lathe stapled closely, primer, self leveling compound: If you want to do self leveling compound read Staceyneil's thread on the topic from several years ago, I think it is in the bathroom forum. Here is my Ditra, set with the recommended thinset. After this picture was taken, I did take out some areas, about a foot square, in several places and reset them. I did this because there were large lumps, and I'm a 60yo lady with not as much strength as I used to have. So the thinset was uneven in a few spots. You can see it here. Not all of the lumps needed taking out but several were just too high. When I took it up and reset it it was fine! At this point you can seal the seams with Kerdi tape if you want to water proof it. I was going to do that :( but I forgot!!! If you are installing Ditra in a bathroom, don't forget:) Here I am setting my tile in the pattern I've chosen. Mongo was taken aback when I posted this because I turned the pattern on him :) He had initially helped me plan this out in a 90 degree angle. After it had been all laid and grouted with Spectralock epoxy grout: I post this to help you see the process and that it isn't difficult. The difficulty seems to be when people don't want to make adjustments with installations. There are a lot of people using this stuff. Edited to add: Please correct me if I am incorrect in anyway. This is how I installed my floor and I may have made an error either in the installation or my description. Here is a link that might be useful: The Schluter Site. This post was edited by enduring on Sat, Mar 23, 13 at 12:47

Do you mean during demolition, we should avoid cracking subsurface (mortar)? If mortar survive from demolition, no crack, travertine or limestone tile can be installed on previous mortar, is it correct? Correct. Have you installed travetine tile on previous mortar in shower area? Not travertine, but I HAVE installed tile over old mortar beds. How to avoid cracking mortar during demolition? If the mortar bed is good, it's shouldn't be too difficult. 9 times out of ten, it'd take a stick of dynamite to budge a well installed mortar installation.

I'm going to give you a little hint that not even very many installers know. Everyone thinks that the solvent based sealers are the cat's meow, and as sealers, they are. They last alot longer, and will do their job alot better. BUT--- as a grout release, not a one of them will stand up to a water based sealer. Years ago, when I lived in south Florida, I did alot of Saltillo (terra cotta) tile. As I'd set it, I'd spray it down with Aquamix's water based sealer. As much of a nightmare as most people think it is to grout terra cotta, using that stuff as a grout release, it was like grouting glazed tile. A couple of years later, I was up here doing a Saltillo floor for my last employer, and they gave me Porous Plus-- supposedly the absolute best sealer for that purpose. I went thru twice the sealer, at almost TEN TIMES THE PRICE PER GALLON, and it STILL didn't do as good a job. I would submit that you'd get the same results with limestone, no matter HOW coarse the texture. Check it out. Water based sealer isn't that much-- only about 20.00 a gallon-- pick up a gallon (and DON'T let them talk you into using ANY kind of solvent based sealer-- not Porous Plus, Not Bullet proof, NONE of them), and seal a piece of tile. Let it dry overnight, and then smear it with grout. Let it sit for about 20 minutes, and try and clean it. I have a pretty good feeling it'll put all your fears to rest.