Your first option, the bottom 36" of the wall being 6" by 12" slate and the upper 60" of the wall being 12" by 24" porcelain...I'm not real big fan of having larger tile stacked on top of smaller tile.

IT CAN look fine, but to me most of the time it results in a top heavy wall.

The generic idea of mixing the two materials on the same wall, no problem, Just compare their thicknesses, if they are different, have a plan for it.

As far as the patterns and the grout lines, compare the actual sizes of the tiles and make sure you can pull off a stacked bond with equal-sized grout lines in the slate and the porcelain.

As to the patterns you mentioned...honestly, it's all what each of our eyes prefer. I recommend a sheet of paper and markers or colored pencils the rough colors of your tile. Draw in the proposed grout lines for your pattern, then color the tiles in. Doesn't have to be perfect.

To help visualize, try this, a little drawing and coloring lesson:

The height of your walls is 8'. The sum of the lengths of your three walls is about 12-1/2'. If you tape a couple of pieces of paper together to make a single sheet 12-1/2" by 8", that flat piece of paper represents your three walls. Your east wall will be about 3" wide, your south 4", and your west 5-1/2". Fold it to represent the three walls of your shower. Lay it flat on the table again, and draw your grout lines, then color the tile, then stand the paper up on edge so it represents the three walls of the shower, the shower alcove.

It'll give you a simple idea as to how the tile sizes and colors go together in your various patterns.

In Lesson Two we'll finger paint. And please... do not eat the paste!

mongoct:

I really like your idea of creating a miniature version of our shower on paper. Will do that and see how it looks. I have an 11 year old 'artist' that would love to help out (and she doesn't like the taste of paste).

Since posting, I spoke with two salespeople/designers at tile stores. Neither of them liked the idea of 36" of slate on the bottom with porcelain on top. Both independently said that the texture of the slate is too different from the texture of the porcelain and it would look odd. And, I agree with your assessment that larger tiles on top of smaller tiles won't look good. (Had not thought about that aspect)

Both salespeople also said that if I wanted to incorporate the slate with porcelain, I could use the slate as an accent and it would be okay since the texture would not be as noticeable. One suggested a 12" tall band of slate all the way around starting at 36" from the base. The other suggested the same, but a 24" tall band. What is your opinion on the horizontal band idea? Is 36" a good place to start it and how tall should it be?

Personally, I wanted to try something different than a horizontal band to give the shower a more unique look. Would a couple of 24-48" VERTICAL bands of slate work, provided I ensure the floor is also slate? Maybe one on the center of the 66" wall, and one in the south section of the 37" wall where the niche is?

The last idea I had was to keep all three walls as porcelain, but break it up in a more subtle way using 1" metal profiles as shown below. I think three rows of profile may work, perhaps evenly spaced at 2', 4', and 6' above the floor. Opinions?

I will definitely lay these out on a miniature paper models as you suggested, but would also like to get your opinions on these ideas.

As always, thanks for sharing your wisdom and insights.

Slate is hard to clean, porcelain is easy to clean. You cannot use lime-away or scrubbing bubbles or any of those kinds of products on slate. Mixing the two will create cleaning issues that are not a big deal, but you should know about them. You also have to reseal the slate every so often- once every three months to once a year, depending on the product. Slate will hold on to lime deposits and soap scum.

That second photo of the porcelain tile is gorgeous- if I was in your shoes I would go with that. You should bring some home and see how the scale looks in your bathroom.

Renee

I really don't have an eye for "modern design" if that makes sense. Not that I have much of an eye towards any design. But by nature, I'm more of a traditionalist. But when I do design I always have to draw it out.

Your vertical stripe idea sounds interesting, but it's outside my design comfort zone if that makes sense.

I like some modern and minimalist, but at other times it seems stark and silly to me. I just don't have enough experience with it.

The photo you linked to in your above post...I think it would look just fine if you put the slate in between the two horizontal metal inserts. Say 36" of porcelain, then 48" of slate, topped with 12" of porcelain.

Transitioning 36" off the floor is fine.

Renee:

Thanks for the heads-up about slate maintenance. Latest idea incorporates only a 3" band of slate so I'm not as concerned about maintaining it since there is not much of it. And, I'm looking for porcelain flooring which has somewhat of a slate look.

mongoct:

Latest idea is a total of 3 horizontal bands. Two of these bands will be 1" strips of metal, and the third will be a 3" strip of slate. I'm in the process of drawing this out on miniature scaled paper. I'll also use masking tape on the existing durock shower walls to get a feel for how it will look. Thinking about having all of the bands separate, maybe metal at 3' above floor, slate at 6' above floor, and metal again at 7' above the floor.

That could look just fine. Don't forget to compare the thickness of the slate versus the porcelain.

Ideally you'd want them to be the same thickness so the faces of both types of tile will be in the same plane.

Just put the slate and porcelain next to each other. The slate is about 1/16" to 1/8" thicker than the porcelain. I hope I don't need to use extra thinset behind all the porcelain to make up the difference. Can I get away with a "normal" thickness of thinset behind the porcelain and then a little less than "normal" for the slate? Note that "normal" is in quotes since I don't know if there is such thing as a normal amount to use.

Also have a question about the metal profile which I'll start a new thread about.

1/8" is a big difference, 1/16 not so bad, but since it is slate- you don't want the edge exposed to water. You would not want to build out all of that porcelain. Can you find slate that is the same depth?
Renee

Renee:

I have seen a few different pieces of slate and all of them are thicker than my porcelain. Is there a way to cut or grind the backside of the slate to make it thinner?

Renee:

I was in a granite store today looking for a solid piece for my shower curb. The store had only one tile for sale -- a 12x12 slate about the same color as mine. Only difference is that this slate is the same thickness as my porcelain. Apparently, one of their granite suppliers had a bunch of this slate and wanted to get rid of it.

The granite store is selling it for $1 per square foot . I have a couple pieces that I'm testing out (soaking, applying lemon juice, etc). If all goes well, I will use it as an accent in the shower, and buy a bunch more for future tiled areas in my bathroom.

Nice! What a score. Good job tracking down the right product. I love slate more than just about any other kind of material, and I can't wait to see your shower. It will be magnificent.
Renee