How Large Should Grout Lines Be?

by Roger

The size of grout lines for tile is something that comes up on almost every tile installation. The secret no professional will tell you is there is really no set or absolute proper size for your grout lines. There are some guidelines that need to be followed but the actual size is more of a personal choice than it is a set width.

Grout line guidelines

Since grout line widths are generally a personal preference I’ll let you know what mine are. I separate most tiles into three different categories:

  • Small format tile – Tiles up to and including 8 X 8 inches square.
  • Regular – 12 X 12 up to 16 X 16 inches square.
  • Large format tile – 18 X 18 inches and larger.

These are not technically official category names for tile sizes – it’s just what I call them. I’m weird like that.

Small format tile

A lot of smaller format tiles are self-spacing. That means that on either two or four sides of each tile there are what are called “lugs”. Lugged tile have small bumps or protrusions on the sides which are set directly against the tile next to it. Most of these tiles are made specifically for vertical applications, those are shower walls, backsplashes, etc., rather than floors.

The lugs on the tiles allow them to be stacked atop one another and keep the grout lines consistent throughout the installation. For tiles with lugs on only two sides of each tile you must make sure they are all stacked in the same direction, that the lugs are not butted against each other. Normally the lugs will create grout lines that are 1/32 to 1/16 of an inch.

For small format tiles that do not have lugs I will usually use 1/16″ spacers. Depending upon the texture and consistency of the tiles I may use 1/8″ spacers on occasion. For instance 8 inch slate tiles will usually look better with a slightly larger grout line.

If you prefer larger grout lines but have lugged tiles – don’t panic. You can still use spacers with the lugs. To ensure consistency you need to make sure that you either put the spacers between all the lugs or between the spaces the lugs are not. In other words do not put a spacer between the lugs on one tile and between spaces where there are not lugs on another. To figure out the size of your grout lines you also need to add the size of the lugs to the size of the spacer if you use the spacers between them.

Regular format

Regular format tiles are what I install on most of my jobs. More often than not I will use 1/16″ grout lines on vertical surfaces and 1/8″ lines on floors. I just think it looks better and as long as the tile is consistent enough, that’s what I’ll use. I will usually use the smallest grout line the tile will allow.

The best way to figure out how small you can go is to lay out nine tiles in a square and measure from corner to corner in both directions. If they are within 1/16 inch you can go that small with your grout lines. Some tiles such as slate and some quarry tiles will not be consistent enough to use a grout line that small. The largest grout line I will use is 3/16″ unless otherwise specified by the builder or customer.

Large format

Large format tiles are a bit tricky. These, more than either of the other two, are more dependent upon the tile itself. While most people will purchase larger format tiles specifically because they do not want a lot of grout lines, sometimes the tile will not allow it. Although this is rarely a problem, you need to be aware of it and make sure you check the tiles before you try to go with a very small grout line.

The easiest way to check larger format tiles is simply to measure corner to corner in each direction to ensure squareness. As long as they are the same in both directions, they’re square. Then measure several different tiles from different boxes. With a very good tile you should get exactly the same measurement every time. If that’s the case, you can use a 1/16″ grout line and not have any problems.

Large format tiles with 1/16″ or 1/32″ grout lines and a grout that matches the tile color closely looks great! If done correctly it will almost look like a single large slab of tile.

Which do you prefer?

As you can see there is really no absolute answer. If you like smaller grout lines, as long as the tile will allow it, use them. If you prefer larger, use larger. As a general rule do not go larger than 3/16″ although under certain circumstances such as some slates and quarry tiles, 1/4″ is acceptable.

If you choose to use smaller grout lines you must ensure the tile will allow it. If you don’t you may end up with lines that “jog”. That means the lines will not be perfectly straight and will jump over just a bit with every tile due to inconsistencies in tile sizes.

If you prefer larger grout lines you need to take into consideration the “grid effect”. If you do not use a grout that somewhat matches the tile color you may end up with an installation that looks more like a grid made of grout than tile with a grout accent. The smaller the tile, the more pronounced this effect may become.

No matter which you choose, you must make sure you use the correct type of grout. If your grout is chosen and installed correctly your good tile installation can turn into a great one. Make sure you consider your grout as much as you consider your tile. It can make or break your whole look.

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Handyman033

I am looking to grout LVT 16×16 stone look tiles in my kitchen. I know I have to use a special vinyl tile grout. What is the smallest grout line I can have?

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Roger

Hi Handyman,

I have no idea, you need to contact the lvt manufacturer – they can tell you that.

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Mark

I am considering tiling over an existing formica countertop, I have been reading up on this and am getting some mixed info on weather this is a good idea or not, do you recommend this and if so, how do you recommend doing it?

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Tom

Roger,

Love your info, I got most of your books. I’m a first time tiler so I have a basic question. I am tiling a small bathroom, floor 25 square feet and a small shower 3X4. I am installing 12X12 Porcelain tiles on both the floor and shower walls. My question is around the grout lines. you mention 1/8 inch for the floor and 1/16 for the walls. I was going to purchase the Proleveling system https://regentstoneproducts.com/About/ProductDetail/PROLEVEL. however they only have 3mm – 1/8″ spacers, the next size down is the 2mm – 3/32″ spacers. Would I have any issues with just using the 3mm – 1/8″ spacers for the whole job? Seems ok but just wanted your opinion.

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Paula

Dear Roger,
The tile guy installing my kitchen backsplash is having so many problems with my subway tile 3×6. He started on one wall with 1/16″ grout line, turned the corner and then about 1/2 way along the adjacent wall is now using anywhere from 1/8″ to 3/16″ grout line on but only between the vertical lines while keeping the horizontal lines 1/16″. He says he is doing it so the bullnose edges end perfectly at the end of the wall. I’ll ask you later about the tiling around the window sill.

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Kip

Hi – I am grouting a wood plank looking floor called “Club white”, kind of a weathered wood look. The floor will be laid over an existing tile floor (very stable and almost impossible to remove). A few questions – 1. what type of cement do you suggest (cement thin set or the premade acrylic type)?
2. what size gout line would use?
Many Thanks

Reply

Roger

Hi Kip,

1. If you’re speaking of the grout the acrylics are a very good product, but regular cementitious grout will work fine also.
2. If the tile allowed it I would use 1/8″ on the floor.

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D freeman

I am putting down 12×24 slate montauk blk. Should I use grout color closest to tile color or slight variation for sleek look using 1/8 grout lines

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Roger

Hi D,

Whatever you think looks best is the correct choice.

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Jacquie Copeland

My contractor will be installing Happy Floors porcelain tile that looks like wood. It is 5590-c. Is there a way to not have any grout lines. I read that you need to use MUD. I want it to look like wood, and have either no grout line, or the smallest grout line posssible. The tile is from Italy. What do you suggest?

Thanks.

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Roger

Hi Jacquie,

You need grout lines – period. No, there is no way to not have grout lines. Provided the tiles allow, you can use 1/16″ lines. I have no idea what you mean by ‘you need to use mud’.

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Annie

I am having 4×12 gloss ceramic tile (light gray with white epoxy grout) installed on my kitchen backsplash. Do you recommend 1/16 or 1/8 for the grout line? Also, what product do you recommend for the joint between the counter top (quartz) and the backsplash (i.e. grout, silicone caulk or something else)?

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Roger

Hi Annie,

I would use 1/16, but it depends on the consistency of the tile. Always use silicone at changes of plane.

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Annie

Thank you! What is your opinion on using epoxy grout (Laticrete), as it will be behind the stove and I want it to be highly resistant to staining.

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Roger

Hi Annie,

The search function will give you all the answers you need. Like this. :D

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Brian

Hi Roger,

I just finished installing the tile and grouting on my new shower under my father-in-laws guidance as he is an architect and been in the construction industry for years. That said, he recommended that we use 1/8″ spacers for the shower wall and thus have 1/8″ grout lines now and was planning for us to use 1/4″ spacers for the floor once we get around to doing it.

The wall tiles are glass subway type tiles that are 4″x12″ and the floor tiles are normal ceramic floor tiles that are 6″x18″. Also, he had us use Polyblend Non Sanded Grout on the shower walls. What are your thoughts? Was 1/8″ the right call for the shower and since it seems that you wouldn’t recommend going above 3/16″ on the floor, should we stick with 1/8″ or will that look weird given the tile size differences. The wall tiles are a light clearish blue color with white grout and the floor will be a medium gray with similar matching grout.

Thank you

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Roger

Hi Brian,

I would have used 1/16″ on the walls, but 1/8″ is fine. 1/8″ is also fine on the floor, and it’ll look a lot better than 1/4″. If the grout has not shrunk enough to crack then it’s just fine.

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Wendy r

Hi Roger, i have a small question i am having 20×20 tiles installed in my kitchen floor. I wanted the tiles to be directly next to each other but was told i hve to leave a gap. Ive seen this tiling with like no gaps… 1/16 is what i see you have recommended. In my case would a 1/32 be ok?? I believe Its a porcelain 20×20 …

Reply

Roger

Hi Wendy,

I would highly recommend NOT using 1/32 on a floor, and I recommend 1/8″ on floors, not 1/16″ (walls). The consistency of your tile will dictate how small they can be.

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Cris

Hi Roger,

We just finished tiling our laundry room wall. We used 1/8″ grout thickness (sand grout) in a sand color for the standard 3″ x 6″ bright white subway tiles. If it helps, we have existing floor tile that is in huge (17 1/2 square) that has the same 1/8″ grout thickness (tiles are a multi shades of sand) so both the wall tile & floor tile have same grout thickness. The grout looks way too thick w/the wall tile and the first and primary thing you notice in that room now. Is there anything we can do short of ripping out the entire wall of subway tile? Thanks in advance! -Cris

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Roger

Hi Cris,

About the only other thing you could do is remove the grout and regrout it with white grout. That may diminish it a bit. They look so large because the tiles are so much smaller.

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Cris

Thanks so much Roger! I will try regrouting with white grout. Appreciate it!

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Travis

Roger,

I’m tiling my shower, my one question is how much of a gap between the shower wall tile and shower floor tile and corners of I plan on using 100% silicone caulk for those changes of plain?

No gap and tight buts out a gap

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Roger

Hi Travis,

1/8″ – 1/16″.

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Kevin

OK I am getting ready to tackle my bathroom, two things. Number one I have never done tile on the wall and I have never done epoxy grout. So what I am going to ask is 1/4 grout lines to wide for the floor let alone the wall or will that size of a gap be OK to use? The tiles are going to be 12X12 on a staggered pattern. Thanks for your time.

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Roger

Hi Kevin,

1/4″ is HUGE. My normal grout line sizes are 1/8″ on floors and 1/16″ on walls. 3/16″ is normally the largest anyone goes. Epoxy would be a pain in the ass on wall tiles with that large of a grout line.

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Paul

Roger,
A tile retailer and installer told me that he installed a 4 tile sized travertine with zero grout space. He said he can do that because the tile doesn’t expand and contract. I like the idea of a small grout line esp with travertine but what kind of problems will he encounter with zero grout space? How do you place a soft joint in this case? I guess you would have to create one…or risk tile pile?

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Roger

Hi Paul,

It will chip and crack the tile. It DOES expand and contract. Soft joints can be run through a pattern provided it is a continuous line (doesn’t have to be a straight line).

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Stephanie

I removed the ceramic tile in our bathroom and most of the ditra came up with the tile. However, I have been unsuccessful at removing the felt layer that remained attached to the floor. Is there a trick to remove this or is it ok to lay the new ditra directly on top?

Reply

Roger

Hi Stephanie,

No real secret to it. You can use a grinder with a scarifying wheel if you want it all up, but you can scrape as much as you can then go over it with the new stuff. It’ll be just fine.

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Debra Johnson

Greetings, Mr. Floor Elf:
I uploaded a couple of pictures of my project section (Just Say NO to Pergo) in the hope that you can help me. I bought a house with Pergo installed. It got wet. It curled up on the edges. I pulled it up in a small powder room and those photos show what I found. It looks to me like I have partial coverage with mortar over I-don’t-know-what. No subfloor or joists in sight. And a crack in it. And it looks like it might still be wet around the edges to me, but I am not sure. My question is: can I avoid breaking or grinding this crap? Would it be a stupid move to just level and skim coat with thinset and then Ditra and tile over it? Go ahead – be honest. Thanks!

Reply

Roger

Hi Debra,

Provided that when you splash a little water on that floor it is soaked in within about thirty seconds then yes, you can install ditra over it.

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Southern by Choice

Crossville “Speak Easy” / rectified / manuf. suggests 1/8 grout line. I’m confused…if it is truly rectified (I think they used to upcharge for this) then 1/32 should be enough…right? I’m going to have about 700 sq ft of this tile installed…I want to be sure.
Thank you so much for your time and advice.

Reply

Roger

Hi SBC,

You NEVER want to install that much tile, of any type, with that small of a grout line. Yes, rectified means they should all be identically sized, but they will still be ‘cupped’ to some extent. Using a grout line that small will accentuate that cupping from tile to tile, so you’re going to end up with lippage. Go with 1/8″.

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Frank

What grout size would you use for subway tile?

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Roger

Hi Frank,

If it’s 3×6 subway I would use 1/16″.

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sandra

Hi Roger,
My porcelain tiles are popping up after 7 years and I have to replace all the tiles in my house. What would you suggest to be the cheapest, easiest way for me to do this and control the dust? Would you suggest a DIY? It was just done horribly the first time around.

Thanks.

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Roger

Hi Sandra,

A hammer and crowbar is the most dustless way of removing tile.

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chuck

When the tiles have a straight edge i agree with your spacing. What about the tiles that have a “wavy” type edge? How would you space those out?

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Roger

Hi Chuck,

The corners on tiles like that are always uniform. Get them to the spacing that you like, then measure the distance between the corners, that will be the grout line (and spacer) size.

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Ray

Hi,
My wife has a friend that had her tile installed without any gaps (that is how my wife described it) and she loves it. What is the story on this? Is there no grout, very little grout? Are they special tiles? The tiles I looked at in the store don’t have perfectly square edges so when you push them together they still have a small gap at the surface even when they are touching at the base.

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Roger

Hi Ray,

I have no idea what you’re asking me here. I will say you are absolutely correct, there will always be gaps. If your wife was able to accomplish this with a ceramic or porcelain product – even once – have her give me a call – I’ll hire her. I don’t know what type of story you want? :D

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Steve

Roger,
I think I might have made an ooops! I set my mosaic tiles on the floor of my shower. I am not as neat and clean as I should be at installing my mortar and it’s all over the top of my tiles and the grout lines are filled solid with mortar, am I supposed to use a grout saw and clean all these grout lines or am I screwed now it just going to look like shit,. Ps. It’s perfectly fat no lippage so I have that going for me

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Roger

Hi Steve,

You need to remove it somehow. A grout saw or dremel / roto-zip are your likely bets.

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Tim

Hi,

The guy I hired to do my bath installed the shower tile with no gap for grout. I’m wondering if there is a way to fix this with destroying the tile and redoing the whole thing? Would it be possible to use a saw to cut in grout lines as when you are removing grout to be renewed? Btw the guy was sent packing…

Reply

Roger

Hi Tim,

Unfortunately no, there isn’t an easy solution. Removing it and replacing it correctly IS the easiest solution. The saw will remove sandy grout, but won’t remove porcelain.

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