Help with tiling bath in new construction

[Tony A]

I just noticed the OSB in the photo. Is that a potential problem? I removed my OSB bench in the shower but maybe it wont be a problem with a tub surround. Just curious.

[cx]

I'm thinking that piece of OSB is something temporary, Tony, I'm reasonably sure he had plywood on the deck surface. You're correct, that is not a suitable application for OSB in my opinion. Probably get by with it, but I wouldn't do it.

And I'm not one of the anti-beaver-barf crowd.

[lexrn]

I think I'll use the 2x4 wedged in for support. I already have the nails but the screws are at Lowe's - at $10 a box and a 2hr round trip.
The top of the bench is plywood and will be tiled just like the tub deck. The sides are osb and will be covered with wainscoting.
Now, about that greenboard: I think I'll caulk at the bottom and, since I have a bucket of Red Guard, maybe I should put a coating on it and also the cbu? Could it hurt?

[peterd]

How thick should the plywood on the deck be?

-Peter D

[bbcamp]

Mary Jane: Waterproofing the tub deck is probably a good idea. On greenboard? If you need to waterproof it, you should replace it with CBU, doncha think?

Peter: 3/4", same as a floor.

[lexrn]

I don't really think wetness will be an issue - it's just that I have all this Red Guard and hate to think of it going to waste!

[lexrn]

The liner passed inspection! I've put the backerboard on the tub deck, picked up some tiles and bullnose and now I have some design questions: the bullnose extends over the backerboard by about 1/16" and rests on the chair rail (there will be wainscoting on top of that osb) - is this okay? On the outer long side of the deck the tiles space out almost perfectly. Should the backsplash go on top of the deck tiles (with 1/4" spacing) or behind them?
And finally, the last tile on the back wall would be cut to about 4 1/4". Would it be better to cut the first tile also so that they are symmetrical?

[lexrn]

Here's where the end tile would go...

[John Bridge]

symmetry is good if you can achieve it.

I usually do the deck first and then the splash. 1/4 in. gap is too much, though. A sixteenth is adequate. If you get more movement than that, you in a heap o' trouble, girl.

[lexrn]

I'm trying to figure out how to mark the tiles to make the concave cuts. It doesn't look like I can just mark the backside because the tiles are cut on the wet saw face up...hmmmmmmm

[Tony A]

Mary Jane,
If you're talking about the curved cuts around your tub cutout, you might want to try an angle grinder with a wet/dry diamond blade. I used one to cut the circle for our toilet flange. I'm thinking you could mark the tiles from underneath then cut them with the grinder. It takes a little practice but you'll catch on quickly. Just make sure you wear safety glasses, secure the tile well before cutting, and have a firm grip on the grinder.

[lexrn]

I think what I really want to know is whether it makes any difference which side is up when you cut on the wet saw (or any other saw). If it doesn't matter, I can mark the tiles from underneath (just like I did the cbu) and cut them face side down.

[Brewbeer]

Not sure what kind of wet saw you have, but if it is the kind where you slide the tile across the table through a fixed blade (kinda like a table saw), you might get scratching on the surface of the tile if you are sliding it upside down. Putting masking tape on the finished surface of the tile, or wet paper towel, help me control the scratching on the few tiles I have to run through my saw upside down.

[lexrn]

Yeah, the kind I have is the fixed blade. I'll put some protection down and give it a try. Thanks for answering!

[lexrn]

I'm drenched and I look like I have pancake makeup on my face! I'm also half-way done...