Not sure, but I have understood that subway tile does not need any spacing at all if needed. But between those options I would go with 1/16, less is more :) I prefer a more seamless look.

I should add, we're going with a dark pearl grey grout.

I would go with 1/16". With the dark grout on white tile, it can be a little less forgiving than white grout, so it may be less obvious if something is a little off with a smaller grout joint. If the tile has little bump on the sides, it has built in spacers and you can just butt them together, as well.

There is a bump on the sides, but when we put the tiles right up against each other, there's pretty much no space between at all.

I'd prefer 1/16 and I'd go lighter on the grout. The fatter grout will overpower that size of subway and look too busy in the dark gray. Maybe something like this?

1/16 with that grout, for sure

One thing we have decided on is the darker grout. We have a dark slate/almost black counter, and we're in love with the vintage look of the dark grout.

Then go skinny for sure.

Awesome. 1/16 it is!

Thanks for everyone's advice. Since this house renovation project has been almost a whole gut job, we've haven't been able to see things in context, as we can't live in the house (we're staying with my parents since we've moved out of our apartment while the renovation finished up). We have 5 projects going on at once! This has made many design choices white difficult, relying only on our ability to visualize in our heads.

If your tile has built in bumpers as show in the photo below, butt the tiles side by side to create a 1/16" grout joint. If you choose to have a slightly wider grout joint, use pennies as spacers.

Our tile does have those bumpers, but when we put them together, it's incredibly small. I don't think it leaves a 1/16 space? I'll have to measure when I get home.

They are lugs. If you look at the tile from the side you will see besides the lugs the tile itself is slanted towards the face starting from the lugs. This is what create the grout line. Also how the tile person actually grouts will later the size of the grout line.

If a tile person over cleans his grout the grout gets washed out of the larger portion of the space and into the narrower part of the "V". You can have the same tile spaced using the lugs and have different size grout lines. With todays waterproofing systems and advanced thinnest the grout is just decorative especially with butt installed tiles.

With darker grout look into Mapei Flexcolor grout. It has a sanded grout appearance and is more difficult to apply on vertical surfaces but it gives a very durable finish that has a dead on color that can even be touched up and still have the same color. Dark color cementitious grouts are notorious for color issues especially if the installer over washes or doesn't mix as per instructions.

The Flexcolor is premixed and the color is accurate throughout. There will be sand everywhere but in the end the extra effort is worth it. With the Flexcolor I would use 1/16th spacers but remember it will give you a larger grout line as the tile itself already has 1/16 built into it. The larger line allows the sanded type grout a space to get into. No it isn't regular sanded grout it isn't even sand it just has a sanded appearance and feel to it. 2 different products.

I'm going to agree with Brickwood Builders. Ceramic tiles aren't perfectly sized like a rectified porcelain would be. The dark color grout will show up every imperfection in the pattern.

Meant to say I'd use 1/8" grout for reasons stated, more forgiving of those imperfections.

Our tile is Anatolia Soho matte white 3x6 porcelain subway tile, if that helps.

Maybe ask your supplier if they think it will lay up very evenly with the 1/16 joint. That said, you mentioned you like the vintage look, so I'd still go with the 1/8.

Well, now I'm confused. I'm guessing this is a 1/16 built in spacer? So a 1/16 spacer then give me a 1/8 grout line?

When the tiles are butted side by side they will create the 1/16" grout joint. If you want a 1/8" grout joint, use 1/16" spacers.

Ahh. That makes much more sense. So my original picture with the bigger spacing was actually 3/16 spacing (the 1/16 built in spacer plus the 1/8 plastic spacer).

The bigger the grout line the better for you if your skill level is not the best. Helps with the variations in material and mistakes made if any.

@Gregory Boccuti

I am trying to make the same decision you were a year ago - Subway tile (though ours is square), using a medium-darker grey grout for a sort of vintage feel, and don't know if I should do 1/16 or 1/8. What did you end up doing and would you share a photo?!

good like

I am getting ready to install 3x6 white subway tile in my farmhouse bathroom shower/bath area....I have no idea what spacing I should use! Need advice please. I am using dark gray grout. Suggestions?

Read the comments above

Do you have any pictures of the finished product with the 1/8” grout lines and the pearl gray mapei grout you used? I’m deciding on the exact same thing, and wondering if pearl gray will look too dark with that size grout joint, or even with smaller joint. Thanks :)

we used pearl grey from mapei with 1/8" grout lines, and we love the result. But we wanted the look with very visible grout (vintage look).

Caroline that looks amazing!

So I’m putting old look tile on my bathroom walls and wanted the look of a uniform pattern (ie no grout lines). We used silicone at the joints instead. However, it doesn’t look right because of lippage. Thoughts on installing this type of tile? I fear 1/8 grout lines will completely ruin the effect but as it is it doesn’t look great either.

*wood look

I think tile tight spaced has a more modern feel. Spaced looks more vintage. Too spaced looks 70s.

Had my tub surround tiled using beveled subway style tile. They did not use spacers which resulted in a 1/16 grout line leaving uneven grout. Also using a pearl gray (darker) grout resulted in very spotty grout lines (anywhere from almost white to almost black). The project was gutted back to the studs and is being re-done using 1/16 spacers to leave 1/8 space for the grout. Luckily on the General Contractor's dime and not mine.

I go with 1/16"

Some tips for you:

There are several factors that affect the size of grout lines:

• the edge (smooth or serrated)
• the space in which you plan to use it (floors, walls—interior or exterior)
• the type of ceramic used to make the tile (porcelain, stoneware, or laminated stone)

I have a slightly irregular edge of my tile and want to vertically stack my shower wall tile. I must use 1/16 grout. Do you think this will look good?

Irregular tile edges and a 1/16” ground joint? That sounds like a recipe for disaster. When you say ‘must,’ who is insisting? The tile manufacturer? Your installer?

The tile is not completely clean cut on the sides. It is a glazed tile from Spain. In order to get the vertical placement for stacked l need to use 1/16” grout between tiles. It may have more variation than machine cut sides. My installer needs to use that grout width to have it lined up appropriately.

Many many Zellige companies say use dry stack or 1/16…. Otherwise the imperfections with look bad instead of good…. I’m going to do 1/16 with my zellige soon.

So… 1/16 and imperfections give a less refined look correct? My tile has a slightly undulating surface. I think 1/16 grout should appropriate. You agree?

They will look much better set in a traditional brick pattern.