I'd say no, due to needing a slope, and that they will be really slippery once wet/soap on them.

Yes a skilled tiler could figure out the slope, but you would not like the result. At best it would look like a star of tile pieces centered on the low spot.

Check the coefficient of friction both wet and dry. Those numbers should be on the box the tile came in. It could be labeled as COFW and COFD or letters to that effect. The higher the COF the less slippery the tile will be.

Mosaic tiles are used because they are already "broken" into small pieces that conform to the underlying drain slope of the floor. We have 2-inch white tiles because we could not find a mosaic match the stone and wood look of our walls.

It really does depend on the tile and its wet coefficient of friction. The more slippery the tile, the smaller you want it. Most large format can be cut into smaller tile, but it's possible the cut tile edges will have to be dressed to match.

As to how small you need them to be based on the showeritself, it depends on the shape and slope of the mud. A planar surface like a curbless can take large format, uncut, as long as the tile is not too slippery. I've done a few of those.

A center-drain inverted (and truncated) pyramid slope with four distinct sloping planes can take large format as four triangular pieces. I've done a few of those.

For a standard "bowl"-shaped slope, again, it depends on the size and shape of the bowl...but usually four inch squares is a safe starting point. Above that, you can get excess rocking and lippage since the flat tile can't conform to the curved bowl. In larger showers you may be able to go larger than 4". In smaller showers you may have to go smaller.

One other thing I've done a couple of times with large format that we figured would be too slippery in full tile size was scoring light lines across the surface of the tile. They provided a bit more traction underfoot. Doing that is of out-of-the-box, so it depends on the tile, and of course, the owner. And the installer. They turned out well. I've done that in showers and once on a tiled exterior balcony.

Large tiles in a shower are really not a good idea. You've received excellent details on why.

Thanks, all. MongoCT, very helpful advice. I'm meeting with my tile installer tomorrow so I am going to walk through options with him. Another idea I had was to install small cut pieces of the large format, and then place a teak grate over them to reduce any slipping risk.

I am also going to get a large piece of the tile wet and throw some soap on it to see how slippery it really is. It does have a texture, so it might work just fine in the shower.

We took our large format tiles (marble in one bathroom, porcelain in the other) and had them cut into 3" squares. Not introducing a new material, making the shower floor nonslip and solving the slope problem.

How about a single sloped shower into a linear drain?

If I were you, I would pose this question in a thread over at the "Tile Forum". I know what you want to do is being done successfully. But you do need a tile installer with experience doing these minimal modern showers. Good luck!

Thanks! I will post over in the tile forum. Germain, the plumbing has already been installed and we have a center drain, so we can't change to a linear drain at this point, although I should have pushed harder for a linear drain -- my contractor didn't want to do one.

"Another idea I had was to install small cut pieces of the large format,
and then place a teak grate over them to reduce any slipping risk."

I've done a few of those as well, I have one in my own house up in Maine. For clarification, you'll still want to tile the entire shower floor, then install the grate over the fully tiled floor. The grates can feel pretty nice underfoot. The grate can also slow evaporative drying.

Large tiles only work well with a linear drain. Failing that, you don't want to go larger than 4"......preferably 2"......Yes, you could cut down the larger tiles, but would probably need to "dress" the edges to make them more comfortable. Grout? Don't worry about it. Grout affords you a non slip surface, particularly on the more slippery tiles. Choose wisely.......

MongoCT, good to know. I also like the warmth the wood grates bring to the space, since the tile is all white. Is your grate teak or ipe wood?

Germain, I suspect the reason my contractor didn't want to do it was because he hadn't done many before. He told me installation would be "significantly higher" than a normal center drain, which usually means he doesn't want to do it or isn't sure how to do it. So I didn't press forward with it because even though I like the look of linear drains, I wasn't willing to pay a fortune for one.

Thanks, Stonetech. I'm seeing quite a few decent looking installations of larger format tile with center drains, so I'm hopeful that this look is not limited to linear drains. I'll keep you all posted on how it works out and if we can figure a solution. many thanks.

Keep the tile full size and install a linear drain.

"Is your grate teak or ipe wood?"

Teak.

I agree with the advice to go with a linear drain and use large format tiles. A linear drain works fine, even if the drain is in the center, as long as the drain runs pretty much the full width of the shower.. My shower is 55"X84", with a 48" linear drain across the center. The floor slopes to the center from both ends. The tiles are 12"X12" and they are not slippery ar all. There are plenty of tiles that have minimal slipperiness, even in large format. And it's great to have few grout lines to keep clean.

My tile setter recommended nothing larger than 4" x 4" on the floor of my shower. I'd already decided on a 2" x2" hex so he was happy and the floor came out well with a center drain and no lippage under foot

Jeff-

Sometimes even 4X4 is stretching it with a conventional center drain where the slope is pitched and coming from all directions. With a linear drain the slope is only from one end to the other, or from both ends to the center. That means the floor stays in one or two flat planes and any size tile can be used.

Yes, I understand the topography, which is why I went with 2 x 2 hex. If the gradient is only in one plane then larger tiles should work just fine.

We can't do a linear drain because the plumbing is installed and it is plumbed for a central drain. But we are still going to use large format tile in a diamond cut pattern, and will likely put a teak grate over top to reduce any concerns of slipping.

Pipdog-

How slippery tiles are varies greatly. I have two showers: one where the tiles were super-glossy porcelain (which was fine in large format for the walls), but what went on the floor was 2X2's to increase the number of grout lines for traction; another (picture above), where the tiles have a sheen, but are incredibly non-slippery, and I went with 12X12's. What I'm saying is to not assume you need a teak grate until you see what the floor is like after the install. And, as I explained above, a linear drain can be used with a central drain (unless the tile bed has already been installed).

Hi sirenaeg, I'm happy with the large format tile in the shower, no issues with slipping at all after a year and a half of use. Here's how it turned out in our guest bath:

Schluter instructions say no smaller than 2" on Kerdi so I plan to use 6"x24" in 4'x10' shower with very gradual slope in two planes plane toward 4' linear drain. I bought tile on the end cap at Home Depot that said they are 50% more slip resistant and they show pictures of kids running in on the tile floor all wet and dripping. If we slip on the 50% more slip resistant tile I like the idea of scoring light lines across the surface of the tile but it sounds like alot of work. Maybe we can just wear flip flops.

@pipdog the shower floor looks amazing. Do you mind me asking what tile the floor is as well as what you used for the curb that makes it look so put together? Hoping to do the same with my shower.

@pipdog Did you use matte finish tiles for your large format?

I can't figure out why large format tiles are ok (not slippery??) in a linear drain shower but not ok in a center drain shower. Let's assume you can get the slope right in a pre-formed center drain shower. If it's not slippery in one, why would it be slippery in another?

https://www.tcnatile.com/images/pdfs/DCOFBrochure_Aug2013_Comp.pdf

So I've run into a scenario where the tile I want for my shower floor has a DCOF of greater than or equal to .42. So it meets the minimum, but have no idea what the actual DCOF is. I called the tile place and they looked up the specs from the Spanish manufacturer, and it's not available. They think its because each batch may be different. The tile I am using is 12x24 in matte finish. I think it will be ok as a large format shower floor. Just wish I could find the actual DCOF, or at least something more firm than "maybe greater than .42"

Thanks for the link @Creative Tile Eastern CT.

I put matte finish tile on shower by my pool and it feels ok non slip until my grandson uses half bottle of body wash. I suppose tile with deep rough texture would be better on wet soap? Or remember to rinse Aaron's soap off the floor before you walk in?

Charlie-

I don’t know where you’re getting it, but I don’t think anyone has suggested that particular tiles have their slipperiness change based on the type of drain... that’s not true. The size issue only relates to whether shower floor slope/geometry will allow a larger tile.

Any size tile w any drain , hire wisely smart people.

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I also want to install large tiles in my shower and my tile person keeps telling me it’s not a good idea or that it would be slippery. My tile is 12x24 and I suggested he could cut off 1/3 to make it smaller but he insists he has to make them much smaller to a 2.5 x 4, such tiny tiles when i want the large tile look. I have heard cutting the large tiles in the diagonal would work! But can’t find a tile guy to do it!

Pic a Porcelain w proper DCOF and get what you want. Your tiler likely is telling you they've not got the chops. Or its not in the budget.