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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Christine Crews

I am having a steam shower installed and using 12 by 24 tile the installation has just begun by professional tile contractor. The grout line is much larger than I expendted 1/4. I don’t like this and I bought a ton of bullnose because I was told to and it is not being used. Around a niche should it not have bullnose? I hate to have them tear it all out but I also am spending a lot of money to have it done wrong.

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jmags

I must remove my kitchens 7yr old 12×12 tiles and replace with new (as they are discontinued)…i grouted the floors with nearly a 1/4″ grout line.

looked beautiful..
lasted a year ot two….
kids came home from college……. with dogs!

needless to say… the grout is always pocked and chipped up from the dogs nails. I try to keep up with repairs and coating (s)…..but , i give up.

i need a smaller grout line to reduce or elminate this problem.

any advice on tile/grout size that would yield us results that are lasting or unaffected by large dog nails.

..

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Tom L

Roger,
I am installing wall and floor tile in a shower. I am installing electric heat cables underneath. I have a waterproof membrane I am going to install between the cable and tile but I need to keep any water from seeping through the grout lines. What would you recommend?

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Roger

Hi Tom,

I would suggest coming to terms with the fact that water WILL get beneath your tile and grout – that’s why you waterproof showers. You didn’t mention the brand of heating wire or membrane, but the wire MUST be rated for use in wet areas if you’re putting it in your shower.

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Key

Hi Roger,
Hope you can help me. We are installing wood like tiles in our living room. We want use 1/16″ grout spacer, but in the tiles box,minimum 1/8″ is recommended. Do you think, 1/16″ is okay?
Thanks
Key

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Roger

Hi Key,

It depends on the consistency of your tile and the flatness of your substrate. I normally use 1/8″ on floors.

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Aarti

Hie Roger,

I am installing 32inch by 32inch tiles in my living & kitchen(white color tile) and 4 feet by 8 inch vitrified plang tile (proper wood feel) in our master bedroom. I want to know what should be the ideal size of the grout ? Thanks in advance :D

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Roger

Hi Aarti,

Provided the consistency of the tile allowed it I would use 1/8″. The ideal size? Whatever the homeowner wants. :D

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Nancy

Hello Roger, I recently had my bathroom floor tiled. 12 x 12 Lowes done the work, grout is 1/2 inch in some areas 1/4 in others . Manager blew me off when I called with this mess, not sure what to do. Thanks

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Roger

Hi Nancy,

Go up the chain of command – find the number for the district manager of your lowes and start with him or her.

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Ulla

Hello,
I bought 4″x16″ white shiny tiles for my walk-in shower wall.
What size grout space would you recommend? I was told that 1/8 is too narrow and would not hold up as well as a wider space.
What are the pros and cons of the various grout lines/spaces apart from personal preference?
Thanks

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Roger

Hi Ulla,

The only difference in grout line size requirements is how the consistency of your tile is. If it is consistent then you can use any size you like. One does not hold up better than another – that’s incorrect. The only time a grout line would actually get weaker is if it were larger, like over 3/16″ or so, and the grout has to span a larger area.

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Susieq

Hi! My question is: How DEEP should 1/16th grout lines be? Tiler left grooves between my tiles with all upper edges of tile exposed close to 1/16th of an inch- great for catching dirt! When I questioned him about it and asked how I was supposed to keep it clean, he told me “just sweep it out!” (Even I know it will get stained from the dirt!) AND he used sanded grout!

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Roger

Hi Susie,

They should be flush, or nearly so, and the edges of every grout line should be flush with the corner. It will dip down in the middle a bit, the larger your grout line the bigger the dip.

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Roger

Hello Roger,

Great name isn’t it!? I have read a lot about grout lately… probably a lot more than I’d like to admit… and my employer needs to know about :lol: I am just finishing a floor with 24/24 tiles and a 1/16 grout line… all and all, it went really well. My question is what should I be aware of using spectralock with 1/16 grout lines? I’m reading mixed information as to whether it will actually work on 1/16 lines (since I guess it has sand in it?). Have you ever used it on lines this small? Any words of advice?

– Other Roger

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Roger

Hi Other Roger,

AWESOME Name! :D

I use spectralock in 1/16″ grout lines all the time. The ‘sand’ in it is a very, very fine sand, you won’t have any problems with it at all.

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Suresh

Hi..I’ve got wood like floor tiles laid in my kitchen…150x900mm….is 1/8 grout lines too thick?….how dark shud the grout colour be?

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Roger

Hi Suresh,

It depends on the facial consistency of your tile. Normally no, 1/8″ is never too big, although it may be too small if the tiles aren’t consistent. Grout color is purely a personal choice, I like to match the base face color of the tile so it blends in.

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Marc

I am getting ready to install Mannington Rectified Porcelain 18×18. I have read on this blog that i can go with a 1/32 grout line. I am considering using the Tuscan Seamclip to help achieve better accuracy (along with making sure floor is flat) These actually are 1/32 themselves, so i figure i could use these as the spacers.

The question is, which is the best grout for this. Doing the math on my Sq/ft I know i don’t need a ton of grout, so cost isn’t that big a deal. I just want to buy the best possible grout I can. I have considered Fusion Pro grout i have seen in the big box stores. Do you recommend this? Would something else be even better? The grout says only 1/16 on the container… so maybe i can’t use this?

Thanks for the tips and any other comments you have towards the above are welcomed.

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Roger

HI Marc,

Fusion pro will work fine, it’s good stuff. It may take a bit of work to get it in there, but it works. Yes, you can use those as the spacers, but I would pull them with pliers if you do that. Kicking or hitting them with a mallet may damage your tile having the straps directly against both.

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Ranae

I am having 8X48″ porcelain wood look tile floors installed. I attempted to talk to the tile contractor about having the tiles touch/little grout line (he could not speak English)…as the job is going on the tiles are touching but there are no spacers and no room for a grout joint. I purchased this project through Lowes. They told me there would be at least one person who could speak English on the job. I now have nearly all of a room laid (big room) with no room for grout. I thought there would be some grout line, but not the typical. More like 1/16 or less I am really nervous and I know I want some grout line. Should I stop this job? Thank you

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Roger

Hi Ranae,

Yes you should. I would call the supervisor at lowes and get them out there. That is unacceptable.

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Liz

I’m installing 6×6 tiles to even the floor up under the new bathro vanity (don’t ask why we don’t just use a shim, I guess you have to keep the husband happy. But the tile that we have that matches the best is t the same size as the existing tile (7×7) so the grout lines aren’t going to match up unless I use a larger grout line 1/2 at least. Remember that all of this will be hidden under the vanity so it won’t be seen. I’m only worried the what is seen will still look “ok” it’s the part that is right in front of the kick space on the vanity. So like a 2″ wide strip.

Haha so here’s my question. Is 1/2+ grout going to be a problem under the vanity?

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Roger

Hi Liz,

No, it won’t be a problem.

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Mark

I am laying 6×24 inch tile in a L shaped bathroom the small section is 25.25x32in could I lay the tile horizontally which would be one tile across it would leave me with just over 1/2 inch on each side? Would that be too large of a grout line? When the moulding is placed it will actually cover most of the space but I was wondering if a 1/2in grout line would be structurally sound, also what size grout line would you suggest for the rest of the job thankyou

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Roger

Hi Mark,

A 1/2″ grout line is huge. Since your molding will cover most of it you would be better off ripping some 1/2″ strips down for the sides to both make a consistent grout line with the rest of your floor and to support the molding. I normally use 1/8″ on floors if the tile allows for it.

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Jerry

I am in the process of having 2 bathroom “professionally” remodeled. The tile installer installed new boards around the shower to place the wall tile. However, the final bull nose tile rested on the existing wall. He finished grouting today and I notice that the outside grout went from about a quarter inch thickness at the bottom of the wall to in excess of a half inch as it get to the top. The company reason was my walls are not straight. From a professional stand point what should my expectation be as far as uniformity and how can I hide or disguise the thick grout border. Would you suggest painting the same color as the wall? Thanks

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Roger

Hi Jerry,

I’m not quite understanding. Is the inconsistent gap between the back of the bullnose tile and the existing drywall? If so then their reasoning is correct. And having a level, flat and plumb tile installation over an unlevel wall will show that. While there are ways to fix that it involves either reshimming the existing wall or not having a level tile installation.

You can paint that the same color as the wall, that will hide it some. A piece of wooden trim will hide it as well, but may look like crap.

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Elaine

I am installing 12×24 porcelain tiles on bathroom floor in a brick pattern. The space is fairly small. The grout is matching so there will not be a great contrast. I only want to use a 1/8 inch grout line. Will this look okay? Should I use sanded grout? Thank you!

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Roger

Hi Elaine,

It will be fine with 1/8″ grout lines.

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The_nthian

The wife has chosen 4″ by 16″ tiles for the new ‘shower only’.
My question is about the choice of notched trowel to use…with rectangular tile how do you choose? Do I base it on the short side so it doesn’t ooze or the long side for coverage? As well, does it make a difference whether they are horizontal or vertical, i.e… Do I base it on the vertical aspect for sufficient strength or am I over thinking this?
Thanks in advance mate…

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Roger

Hi nthian (?),

long or short, horizontal or vertical, none of it matters. The correct trowel size is the one that gives you proper coverage beneath the entire tile.

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Bill

Roger,
Off topic a bit – I love the shower you’re showing on this page! Can you tell me about it? Is that slate? Who’s is the vendor. Any info would be greatly appreciated. Thanks!

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Roger

Hi Bill,

If you’re speaking of the photo in the upper right-hand corner I have no idea what shower you were looking at. Those photos rotate randomly, it could have been one of about 75 or so. I have done one slate shower, I don’t remember the manufacturer, but I know it was REALLY good slate and ran about $25/square foot. You can read about that here: TileArt Slate Master Bathroom

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Dawn

Hi,
I am going to tile my kitchen back splash with 3 x 6 glass tiles. When reading your information I noticed that with small tiles you recommend the 1/16 or 1/8 spacers. I believe I read (some place else) that with glass tiles you should not go any smaller then the 1/8. The tile may crack if there is any movement in the wall. I would like to use the 1/16th because the tiles will fit better and look good. What is your opinion? Want to get started soon.

Thanks,
Dawn

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Roger

Hi Dawn,

It can be done provided the consistency of the tile allows it.

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David. J. Harrison

Hi.
I am about to waterproof the bathroon floor in my apartment, I wish to use a Beige water proof adhesive/grout all in one, would you recommend this & if so do I need a special type of adhesive as its going onto a waterproof floor paint?
Thanks
David

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Roger

Hi David,

I can give you zero advice until I know exactly what ‘waterproof floor paint’ is. :D

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John

Hi Roger,

I’m tiling wth 12 X 24 tiles on the wall around the bath/shower (already did the floor). I will have an accent strip of glass mosaic about 4 inches wind all around the room and serving as my backsplash on for the vanity.

Couple questions. I am using sanded grout with 1/8 inch lines. When i grout the glass, do I need to protect it somehow first to prevent the grout from scratching it?

Also the glass tile is 1/4 thick, the field tile is 3/8 inch. Should i put extra thinset on on the glass to make it flush with the other tile or is that usually not something people worry about.

Thanks. John

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Roger

Hi John,

Sanded grout will not normally scratch your glass, it’s more durable than that. Always test first, but I’ve only ever had two glass tiles that scratched with sanded grout – both were over $100 a square foot. Go figure. :D

Extra thinset, ditra, backer, etc. Anything to bring it out flush with the wall tile. Only worry about it if you want your tile to look normal. :D

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janelle

Hi there. Great info on this thread. I’m getting ready to tile my 11×13 kitchen using 18 inch tiles. I bought a ’78 Florida home and for some reason the cool thing at the time was a small step down into the living spaces (about three inches). The substrate is concrete slab. I want to tile the face of the “step” (the vertical part) from the kitchen to the living room. I was thinking the best thing to do was tile the face of the step and cut the tile so it’s flush with the horizontal part of the slab, then finish tiling the entire horizontal surface. Is this a good idea? Also, the slab is not completely level (1/4 inch in some areas). Do I have to level it out first or can I make up the difference with thin set? Thanks in advance!

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Roger

Hi Janelle,

You can do that, but it would be best to have a membrane like ditra on the horizontal portion of the step. You can level it out as you instal the ditra. If you do go directly to the step, you can level it out with thinset (in layers), but it may not work as well and 1/4″ is a LOT to make up with thinset.

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DIY Oger

Hello there floor elf,

I love your site, it makes an old grouchy Oger feel right at home with you the elf, doing all the work and me the Oger taking all the credit for a job well done.

Well, now that the pleasantries are over, how about you giving el grouchy your take on SpectraLOCK Pro Premium Grout in white. Thanks to you the smart aleck…er….knowledgeable elf, the missus won’t scratch me warts until I get the freaking cave hole…errr bathroom done! :wtf:

So I have liberated a few boxes of Emser Times Square white polished porcelain tiles 12″ x 12.” These bad boys will make any king proud to lay his delicate stockinged feet on.
I want to use that fancy grout of yours with 1/8 or 1/16 grout lines if the tiles measure square and proper.The missus wants white grout to match the tiles. :censored:

As king of my bog, I said a light gray grout of maybe some of that blingy Dazzle in pearl or silver shadow….hey Ogers dream big too baby! What say you?

Is SpectraLOCK Pro Premium Grout in white up to the task of staying white (for all intents and purposes, a bathroom floor)?

Does Dazzle rub off under moderated mopping or bristle brush cleaning?

Oh yes, before I get back to raiding the pastures for sheep, trashing a few villages and cracking a few skulls, what’s the difference between the pro premium and the 2000 industrial grade?

See you around floor elf ;> :evil:

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Roger

Greetings Ogre,

Concerning the durability of the spectralock it is stout enough to be molded, cured and lobbed over moats and castle walls by a mildly hefty catapult without disintegrating on impact.

I’m unsure if the dazzle component would turn it into shrapnel at landing, but I doubt it. The dazzle components are embedded into cured, inert epoxy and I have not heard that the component weakens the overall structural integrity of your munitions. It would be a spectacular, shiny explosion, though. :D

Your munitions would also manage to remain white, no matter how many castle walls or dragons it smashes through.

The industrial grade is only different in that it would stand up to commercial cleaners the wenches use in industrial settings. For regular castle cave holes with normal cleaning the wenches missus won’t have any issues with regular pro premium.

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Jack

Hello Roger, currently doing my bathroom using 12 x 12 tiles on the floor and walls with a 1/8 spacer grout joint. I know a joint this size can take either sanded or unsanded grout. If you had your druthers which would you prefer and why. Thanks

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Roger

Hi Jack,

Sanded, because it doesn’t shrink.

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Joe P

Roger,

I am installing an accent border made if small travertine/stone strips of tile attached by that backing mesh stuff. There is practically no space between the strips unless I curve the mesh to spread out the tiles. How would I grout something like this? I haven’t put it on the wall yet.

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Roger

Hi Joe,

Some of those mosaics have nearly no space for grout. Just go over it really well with the grout, wipe it down, then go over it again right away. After it cured inspect it for any spots that may have been missed and just fill them in with more grout. It’s pretty tedious, but works well.

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