BOTH!! (how dya like THEM apples!) Seriously-- do the walls first, but leave out the bottom row. Take a piece of wood and screw it into the wall level, so that the second course can sit on it (what's called a "ledger" board). Once the walls are done except the bottom row, then do your floor tile. Finish the floor tiles, and then go back and do the bottom row. That way, the walls sit on top of the floor tiles, and you don't have to work on top of the new tiles any more than necessary.

Interesting Bill. To find the height of the top of the ledger board I guess I can take the width of the floor tile plus about 1/4 for the thinset that goes under that tile and add to that the height of the wall tile plus about another 1/4 inch for grout under the first wall tile?

In the new en suite we had built just last year, the 'bathroom specialist' instlled the wall tile first and then the floor tiles in the shower.

Yes, 9 months later the water was leaking from the shower into the basement in sifficient amount that we had to have the entire floor (and a foot of the wall tile right above the floor) of the shower removed, the floor reinstalled this time with the Kerdi Schlutter water proofing membrain and drain, then the floor tiled follower by the lower 1 foot of the walls.

$2,000 for the entire fix was an expensive lesson to learn. There are reasons why we couldn't go after the 'bathroom specialist' and had to pay for this ourselves. :-(

Here is a link that might be useful: Our Experience With Shower Leak

Dan-- Believe me when I tell you-- the order of which came first had nothing to do with your leak.

DIYer-- Set a piece of tile on the floor, and measure off of that and add two grout joints to get the height for your ledger board. That should more than suffice, unless your floor is out of level at all, in which case, it might be an idea to start off with a cut piece on the bottom.

Hi Bill,

I have to respectfully disagree.

Yes, in our case there were several causes of the water leaking. Improper water proofing membrain installation allowed the water from the multiple leak points to escape the shower and into our basement.

However, with the wall tile layed on top of the floor tile, water coming down from the wall through a gap in the caulking where the wall and shower tile meet would have (the theory goes) followed the downward slope of the floor tile to the drain.

Hower, with the floor tile next to the wall tile, the water coming down the wall tile and through any gaps in the caulking where the wall / floor tile meet could not follow the downward slop of the floor tile; instead such water found it's way underneath the bottom of the wall tile until it found another gap under the bottom of the verticle wall tile and out past the supposed water proofing membrain, underneath the wood frame, and so on until it met our basement.

At least, that was the case with us.

The link below is in the early part of a collection of articles we wrote describing and showing (with pic's) our adventures with our basement leak from the shower and what we did to fix it.

So far, 3 months later no leaks.

Here is a link that might be useful: Shower Leaking Into Basement

Hey Bill,

Thanks for your advice. I do plan on pouring some SLC to get the slab completely level. Once I have the floor level I will start the walls. If I do the walls from the bottom up I am left with a cut piece at the top and if I start the walls at the top I am left with the cut piece at the bottom. Which is visually the better way to go?

Thanks