i am planning to remove my old deck boards (which I plan to use in my pasture) and put down treated 3/4" plywood. I've been told i can put ceramic tile on that and grout it in, but i'm not sure so I plan to put backer board on top of the plywood and then lay the tile and seal the grout. Should I use regular thinset or construction adhesive to adhere the tile? Should I use grout with or without sand? How much grout space should I leave? This is an uncovered outside deck. Will this hold up outside?

Dh and I talked, JR. He thinks the pool is old fashioned concrete. Is that shotcrete? We treated it as concrete when we painted it. It is sorta rough although painting made it somewhat less rough. I've used the two terms (concrete and gunite) interchangeably. When we painted it there was literally very little color left to the pool. Bare gray concrete looking stuff and a little "white" paint. It may have been a blue at first and was bleached by the sun and water chemicals. Well, since the paint is holding up and not peeling and is at least 3 years later, we'll just assume that that was right. Still confused on the difference between the two though. Maybe I'll wander into a pool place and ask them to show me. Drats, drats and double drats! Neilaz, I'm definitely not going to scrape that stuff off! And I am definitely not paying someone to do it. There is WAY to much of it! I can understand why someone would put it down, but it's sorta like going into business with the devil. The cons outweigh the pros! I did a quick "paver" calculation. $$$$$! Maybe stamped concrete would work, but we came up with another plan. Thanks, Boogerhead. (Ok, gotta admit that feels a little odd to type! lol) As with you, the cost of things is definitely playing into what we do. We've finally come up with a plan for what to do with the house deck and pool decking. Actually dd#1 was the one who said, "Why not extend the deck over to the right under those trees so you can sit in the shade. Duh! That part of the yard is literally unused because of the slope and trees. That will make it usable AND provide shade. Out of the mouths of 15 year olds! We'll have to cut down two or three small trees and raise the limbs, but by golly it's a grand idea! So the current plan is to chop down the huge posts on the deck and extend it out over the pool decking and down the right side of the pool under the trees. We'll do this in safe levels so we don't have to put more posts up and we'll cover as much of the ugly Kool Deck as possible. I finally did see a picture of "wood decking" that went right up to the edge of the pool and did not like it. Looked like it came right out of the 70's. So we'll set it back a bit like Boogerhead's, which I liked when I saw the pictures. Eventually we'll go around the whole deck. Which brings me to my final question, Boogerhead. (Well, maybe not final final.) I can't remember, but did you use real wood that you painted (it was gray, correct?) or did you use one of the fabricated wood look products? Our current deck is painted gray wood and is peeling horribly! We hate it. Well, we hate the peeling. Hmmm, maybe a stain vs paint will work. Guess I'll start researching wood vs fabricated wood costs. Sigh! Maybe we'll be done by the time we have grandchildren. First kid just graduated. Now I have to decide if I can live with just 4' of the Kool Deck vs the expanse that is there right now. I'm a faux painter, maybe I can get two colors and make it have some character rather than flat ugly. I did some reading about it last year before I gave up in disgust because I hated the way it looked. Gotta dig out those notes. I realize now that trying not to look at it is not an option. Thanks for all your input! Robin in NC

As has been mentioned, for a bathroom floor, it does not have to be waterproof. Nor do you have to use a membrane or mat like Ditra or other equivalent materials. If you're using a small format mosaic, because of its waffle structure, Ditra prohibits using tile smaller than 2" on top of it. In general, due to bonding and differential movement issues, you don't tile directly on top of a wood subfloor. It's common to have a transition material between the wood and the tile. That material can be 1/2" cement board as mentioned by geoffrey, or Ditra (or equivalent) as used by Enduring. With proper subfloor in place, a low cost and fairly straightforward method is to use 1/2" cement board over your subfloor as mentioned by geoffrey. You then tile right on the cement board. Sometimes the half-inch thickness of the cement board can cause elevation issues with the tile meeting other flooring, cabinetry, plumbing fixtures, etc. That tends to lead people towards membranes like Ditra, or a membrane from Nobel, or if the floor is sloped and you want to level it, using a self-leveling compound. Membranes like Ditra and Nobel are fairly thin, only about 1/8" in thickness. That can help minimize elevation gain. The membranes can also act as uncoupling membranes, they help isolate subfloor movement under the membrane from the tile above the membrane. That can help minimize cracking, etc. If you're going to DIY, no worries. You just want to have a clear idea of the steps needed before you proceed. If you're going to sub it out, no worries. You still want to be educated in the steps involved, especially with the waterproofing in the shower. I'd venture that a tile sub hired through the tile supplier would have a decent track record, hopefully the tile store vets their subs prior to recommending them to customers. But I've been on these forums long enough and seen many cases of tiling stores turning their backs on customers when installations have gone awry. Biggest error I see on these forums when installing mosaic is a very slight misaligning of the sheets. When grouted, the individual 12" squares of mosaic are easily visible to the eye. I never accept deformed boxes of mosaic tile from any supplier. If the box itself is askew, often times the "squares" of mosaic inside the box will be deformed slightly out of square. Good luck with your installation.

Live wire is on to something here. Tile is supposed to be 20+ years of service. That's why you pay SOOOO MUCH for install. It is one of the most expensive products to install. It is labour intensive and material intensive. After paying $10+ per square foot for labour, you do not want to replace this anytime soon. Same thing for hardwood. Once a solid hardwood is installed and site finished (and you paid $15+ per square foot to do this) you do NOT want to remove it in the next 60 years. The longevity of tile is what you are paying for. Because tile can easily run 20+ years without an issue (assuming your subfloor is thick enough...BTW cement board does NOTHING to help with deflection rating...it is just something smooth to lay tile down on). So why would anyone voluntarily cause another $15-$20/sf installation of materials inside of 20 years if they didn't have to? Which begs the question, why install tile in the first place if you know, in your heart, you want another floor in 5-7 years? Tile is permanent. It is meant to take ++++effort and cause +++ damage when removed. That's the sign of a GREAT install. The harder it is to remove, the better the original work. That's why Saltillo and Terracotta tiles are SOOOO tough to remove. The CEMENT they use to lay the tiles is almost impossible to remove. And that's why they are so expensive to install. These handmade natural tiles such as Saltillo and Terracotta (and clay tiles in England) are LIFE-TIME floors. That is to say they will survive the death of several owners. In some settings they are hundreds of years old (ahem...some medieval churches in England have their ORIGINAL clay tiled floors). Those floors are INTENSELY expensive to replicate.