I should have added: Marble can be tricky, as some of it is very porous, some can even be a bit translucent. Use a thinset that matches the color of the tile. Usually white thinset. That will prevent gray thinset from shadowing through the tile. Backbutter the marble tiles to ensure you get a full coating of thinset on the back of each tile. Some thinset here ant none there could also result in a mottled or striping look with the finished tile. Marble can wick water, so the after tiling it may have a mottled appearance for a few days as the thinset cures and the tile dries. Polished marble can be scratched by sanded grout. Depends on the care of the installer. However, thinner grout joints (less than 1/8") should lead you to use unsanded grout. A dark grout can stain the edges of light colored marble, leading to a "dirty look" aroudn the perimeter of the tile. Mongo

cinnamonsworld there is no other thickness thicker than 1/2"so that should be a clue that it HAS to be sufficient. All the other factors are what you have to look at. There are many. Can you talk about the studs? That would be a good start. Just btw and in case you wanted to know more, the Hardi company used to make ONLY 1/4" thick backerboard, and that was fine. One could buy twice as much and double it up to match existing 1/2" drywall next to the shower. I've used it, as 1/4" only. I would feel comfortable using 1/4" thick Hardi again, and for your tiles. I might add blocking. Or studs. It all depends on being there, on-site, and seeing the space. Of course, others may contradict me and tell you 1/4" is not "really" good. Not that anyone is going to throw themselves at your shower walls. Just realize that the studs and blocking are what really prevent flex. Cement board flexes a bit no matter what thickness. Using 1/4" you get a bigger shower. In a small space, this can make a difference. Studs. HTH

Oh, there are lots of local tile stores, but my contractor knows someone at Dal and I was going to get a particularly good deal, so now I'm going to have to take a deep breath and go pay looking and pay more and I'm getting to that point where I just want it to be easy. Rectangular is definitely a contemporary look, just not one I personally love, except when it's small enough to get called subway tile, if that makes sense. It's funny, for one bathroom, what we're actually looking to do is a contemporary version of the one minette99 posted a picture of in this thread http://ths.gardenweb.com/forums/load/bath/msg060043154774.html. I have cobalt blue 1" square blue glass tiles and I'd like to do big white squares part way up (instead of her subways), the blue glass tile, a more contemporary white trim and then very pale blue walls. The vanity will be natural maple with slab doors, black silestone countertop and American Standard green tea faucets. So I thought big white tiles set diagonally on the floor, with some of the blue glass pieces used as dots, the same white tiles done stacked on the walls. But hmmm on possibly the difficulty of finding the true white tile with a high enough COF and also thinking about what Susan said about it looking dated very quickly. I'm probably headed back to the stores.

Resummarizing here because it wont let me edit my main thread, with photos.. plywood is often used for observatory builds because its a smoother surface to seal off, i assumed it was ok.. Summarizing again: I've tried using some online deck building tools to generate the materials needed for what should really be a simple build for this, but i'm getting weird results and had some questions. I thought home depot had an online one, but only found an offline tool, lowes online did work, but in both cases they generated ridiculous materials lists and prices close to $10k. I know that a build like this should only cost $300 to $400. (with everything i have below and $69 to ship, its around $480 as of now, so higher than planned) On top of the deck will be the nexdome with 2 bay (astronomy plastic dome weighs around 300lbs i think). The first issue is the soil/ground. I have to make things level, so that i dont need extra height on a concrete pier, to keep the whole structure say 12" off the ground and not need a railing. Here is a shot of my ground so far, i wasnt sure if i should just get a bobcat and push it forward till level, or if tossing the extra dirt that is "high" on the upper part, to the lower part would suffice or cause a settling issue later? Either way, once down to level, i figure ill either just leave it as just dirt under, or put down plastic to block weeds and cover with a thin layer of gravel. Back to the deck build itself: 12x6 vs 12x8: I've seen many do the 12x6 route, but I wasnt sure, so for now i have it figured as roughly 12-13 12x8s? I have two 4x4x8's figured, but i'm thinking there will be at least 6 posts, with the deck surface at least 12" off ground, may need a few more to go into cement block Onto the blocks (going with blocks instead of posts in the ground, so when we move, we can just take the whole thing and go, or disassemble): I think these are the right concrete deck blocks? But now that i'm thinking about these, it looks like they are really meant to go under the 12x6 going longwise? So perhaps for the posts that will be 12-14" tall, i need something else here? (I figured 6-9 of these max) One of the online builder tools generated the list using these wood to wood triple zinc framing angles, again i'm not sure these are needed? I know i need joist hangers, unsure on the quantity, but these 2"x2x18 gauge triple zinc face mount joist hangers **the part on these i'm unsure on, is since this is low to the ground, how ill go about attaching these,since the floor needs in place, so i guess i need to tilt the whole structure to do this Many regular decking forums dont suggest using plywood for the floor, but i've seen many nexdome floors done with it, i was assuming it was this plywood: Severe Weather 3/4 inch common square southern yellow pine sheathing 4x8's $39? I was estimating i need 3 of these. Then I was figuring using all deck screws and not nails (in case i need to remove them), or maybe nails (which type?) for the hangers. These #8 2" ceramic I thought were the right ones? (or maybe 2.5") Here is the view of the joists as generated by the home depot offline tool, generally i was figuring a joist every 16, not sure about the extra ones near the pier location: Another question is on the underside, in the one online generator it shows these things that i'm not sure on, ie: the posts have those brackets and there are i think the right angle brackets: The other part i think i'm missing here are "toggle?" bolts that go into the posts? With nuts on the other side of some size? Any thoughts on all this so far, is this a pretty accurate list of things to do this simple deck?