This is a question I get asked from time to time. The short answer is no, you should not. Although grout does not add to the stability of the tile installation (unless it is epoxy grout), you still need to grout it.
Why you need grout
A lot of natural stones, namely granites and marbles, are manufactured to be consistently sized. For the most part all the tiles are identical. This makes a lot of people want to install them without grout lines. Although in some people’s opinion butting the tiles against one another looks better than having even the smallest grout lines, it is not a recommended installation procedure.
Even if all the tiles look like they are the same size I can nearly guarantee they are not. Unless they are “rectified” they will differ, even if only a tiny amount, from tile to tile. Attempting to butt the tiles will result in a “jog” of the lines between them. The larger the area, the more those lines will run off. By leaving even 1/32 of an inch grout line you will be able to compensate for the difference in tile widths.
You also need grout to ensure that nothing can get between your tiles. Look at it this way: would you rather have a very small grout line filled with grout or a very, very small grout line filled with spaghetti sauce? No matter how tightly you attempt to butt the tiles, there will still be the tiniest space between them. Not grouting them leaves open the possibility of all types of unruly things filling them. Then you have to clean them out risking the possibility of damaging one of the tiles.
The final reason I’ll throw out there is that no matter what substrate you are using there will always be movement. Always. Placing the tiles against each other will eventually damage them. If you continuously rub the edges of two tiles together one or both will eventually chip (and you need to get out of the house more, or at least find another hobby). The expansion and contraction of wood or concrete will do the same thing. Although you can minimize this using different underlayment materials, it will still move.
I hate grout, I really do. If it were up to me I would install most tile and all granite and marble with no grout lines at all. I can’t do it. Even though it will look better initially, eventually it will ruin the tile. The best thing to do is use the smallest grout line your particular tile will allow and get a grout that closely matches the tile. For most granite and marble tile I install I use either 1/32 or 1/16 inch grout lines. In most other tile I will use 1/16 or 1/8 inch lines. I try to use the smallest grout lines the tile will allow.
To figure out how small you can go, place nine tiles in a 3 X 3 foot square butted against each other. Measure corner to corner diagonally both ways and see how close they are. If they are within 1/16 inch that is the size grout line you can use safely.
Please resist the temptation to install your tile without grout. Grout sucks, believe me, I know. By choosing a matching grout, though, you’ll be happier in the end and your tile will last significantly longer.
Update: The photos below were sent in by a reader asking why his tiles were cracking. They are travertine tiles and the cracking is a direct result of having the tiles butted against each other with no grout lines. This is what can happen.
I wqill be doing a patio above our carport with outdoor tile. I have heard two schools of thought on the base. The first plywood (why not pressure treated?) and the second floated concrete. There will be a roof over the patio but we live in Florida and do get rain. What do you recommend the base should be? And I was so sorry to read we have to do grout but after reading it makes sense.
Hi Sherry,
First things first – how is your ‘carport’ built? The term carport, to me, means simply a supported roof under which to park a vehicle. If that’s all you have it will not support a tile installation. You need a solid joist structure beneath whatever substrate you choose.
There are any number of things you can use as your substrate, as there are any number of ways you can build a proper deck substrate. Most of them begin with plywood, even floated concrete normally has plywood beneath it. Pressure treated wood has moisture infused into it. Because of this, when it gets wet, it will not swell. It will, however, contract when heated as some of that moisture dissipates, it can warp. Warping is no good beneath tile.
Since you don’t have freeze-thaw conditions down there your easiest option would be a double-layer of plywood (over a proper joist system) with cement backerboard over it. A membrane over that, such as ditra or hydroban, is a good idea but not required.
We are installing natural travertine tiles to our 8 x 12 formal foyer so it won’t get a lot of traffic or mess like a kitchen. We were told at Menards that we could do it groutless. Since we will be sealing the travertine with Miracle Seal & Enhance would the sealer keep things from collecting between the tiles? In not, can we do 1/32 inch grout for travertine? I really would love to do this groutless though.
Hi Jen,
No, you should not do it groutless. Along with things getting into the gaps, there is also the movement issue which I’ve described above. Your floor will move. Your tiles will move with it. If the tiles are butted, your tiles will rub against one another. If they rub against one another your tiles will chip or crack. If your tile is consistently sized you may be able to lay them with a 1/32″ grout line, but I wouldn’t recommend it on a floor. 1/8″ is the minimum recommended grout line – I would suggest that.
Seriously scratching my head as how to grout my latest project. I have tiled an accent wall in the bathroom with a “wave glass mosaic” tile. The type of tile that undulates. After I got the tile up and stood back I was feeling very good about my accomplishment until… I questioned how do I grout that?
Any tips?
Anita
Hi Anita,
Run.
Those are a pain. It gets messy but use an epoxy grout float and get plenty of grout forced into it, then scrape off as much as you can (epoxy grouts are soft rubber almost like a squeegee). Then use a sponge to wipe it down – wrung out very well, you don’t want any more water than absolutely necessary. Let that set for about 30 minutes then clean the rest up with damp micro-fiber towels.
Like I said – they’re a pain. They look very cool, though.
Thanks!….I have to tell you that my first reaction was to run.. then cry.. then to crack open a bottle of wine… but then I remembered your warning about drinking and tiling
. But it’s good to know that it is not impossible… I shall roll up my sleves tonight and let you know how I make out… oh and maybe a glass or two of wine won’t hurt 
Anita
I have split faces stone on a wall above the waterline of my pool. I really think I should grout it because of potential issues with bugs and debris between the stones over time. What do you think? If I were to do it, how would be the best way to go about it (e.g should I use special tools, or rags and or sponges)?
Thanks in advance.
Hey Andre,
If you have small split-faced stone (like 1×2 pieces) then it’s best to seal it with a good sealer and just use a grout float. That method will also work with larger stone (3×6 or larger) but it is often easier to use a grout bag with those. Either way it is easier to seal it well first. This helps with cleaning grout off the fact of it. An epoxy sponge will help as well – it has more texture to it and is a stronger material. It will dig more grout off the face. Go over it with the epoxy sponge, then with a regular sponge. Once finished go over it again with a micro-fiber towel (wet) and that should take most of the rest off.
We have marble tile on the countertop and the grout lines are not level with the marble. The indentation is harder to clean. is there a way to level the grout lines to be even with the tile. When we try adding grout, the grout subsides when it dries leaving the indent.
Hey Charles,
All grout shrinks to an extent as it cures – it releases moisture. If you want full grout lines you’ll need to remove what is currently in place (I assume unsanded grout – which shrinks the most) and use either a sanded or epoxy grout – both of which have minimal shrinkage while curing.
Hi Roger,
Just came across your site and wow, I am so glad I did, I am having my kitchen, the wash area and bathroom done this week. All my rooms are small but the rooms connect one to the other, which is the best size tile to use for this type of job? I have a contractor instead of a tile specialist so I am really leary, they want to put Travertine tile down really close together but I know now they need to use grout no matter what. If they did the work using 18′ by 18′ would it still look nice? Thanks again for your site it has helped me already and I would appreciate any other advise you can give regarding my questions. Have a great day. Rue
Hi Rue,
Any type and size tile at all would work fine for that. The way it looks when it’s done is entirely dependent on the level of skill of the person who is installing it – it has nothing at all to do with the type or size of tile. Larger tiles are more difficult to do this with due to the amount and types of cuts in some layouts, but that, again, goes to the level of the installer’s skill.
When I do those I normally snap at least two or three lines to get the pattern and layout to line up. If you stay on the line you won’t stray from the layout – know what I mean? I would ask him to be absolutely honest about whether he feels comfortable with your installation or not. He likely does, but if you ask it ensures that any risk or unsureness lies with him, not you.
Hi Roger,
Thanks so much. I did decide to go with a tile expert instead who has over 20 years experience. I will surely ask these questions. Thanks again for your advise and have a good evening.
Rue
Excellent choice Rue!
Hi Roger,
I plan on installing 3×6 honed marble subway tile for my kitchen backsplash. The area is very small, 10 sqft total. I didn’t want grout lines, but after reading here I think I should. What size is the smallest you recommend. Do you have a favorite product for this type of application? And lastly, do I put spacers between counter and first row?
Thanks!
Linda
Hi Linda,
You may be able to go with 1/32″, 1/16″ would be easier. Just get a non-sanded grout and grout it with that. You do need a gap between the tile and countertop – that gets filled with silicone.
I was wondering, is there any reason that instead of grout that I can’t use Keracaulk for the areas between tiles?
Yes – caulk (any brand) is not a permanent material. Over time is will begin to lose elasticity and start to shrink. Once that happens it will pull away from the seal and allow all sorts of nasty stuff between your tiles. Perfect if you want to begin a mold garden.
You should use grout.
Hi, my husband tiled the top of our shower and he thought it would like great with no grout lines, which i did not know this was his plan, but he had it all completed by the time i returned home. I didnt find your site until after it was installed. Is there anyway we can still add grout? The tiles are tight to eachother, but you can see the small open spots, does not look good at all. Please tell me there is something we can do. Thanks, Stacy
Hey Stacy,
Unfortunately about the only thing to do is to remove those tiles and replace them with grout lines. You can use a grinder with a diamond wheel to cut grout lines, but done incorrectly it may compromise your waterproofing and damage your tile.
I have a bathroom with underfloor electric heat.
The tilers tried to set the tiles too close together, such that the groutlines are uneven, and so tight that the grout cracks and pops out. I’ve had the grout redone, but the same thing happened. Since I’ve got underfloor heat, removal of the tiles is not really possible.
I was having some other tile work done by someone who seems very knowledgeable. He suggested that he could open up the grout lines by cutting with a small wet saw, set so that it wouldn’t cut deep enough to damage the underfloor heat. Then he woukld use epoxy grout. Does this seem credible – I have visions of chipped corners all over?
Hoping you can help
Walt
Hey Walt,
It can be done – but only by someone who really knows what they’re doing. The fact that he suggested it tells me that he does, in fact, know what he’s doing. I’ve done it once and it was a pain in the ass, but it worked well. It is NOT something anyone in their right mind would suggest without having the ability to do it. So as long as he seems semi-sane in most respects doing that shouldn’t be a problem. (I say ‘semi-sane’ because he’s still a tile guy – we’re all a bit *ahem* off-center
)
Hi Elf,
First let me say it is a pleasure to find your site. I think it’s great that you offer your professional advise ( With your sense of humor as well) to people in need. As a retired 20 yr. flooring installer for many years.( Retired due to serious back injury) My years were vinyl flooring. You know the stuff, The stuff that looks like tile but it’s not, lol. I am attempting my hand at granite tile for my U shaped counter top. I am using Black absolute on top of water proof 3/4 plywood screwed to cabinets, 1/2 Hardiebacker in thinset (Versa bond) screwed every 6 inches with the proper screws. ( Way over priced). I re enforced cabinet edges. I cut and polished a 3/4 bevel on the front and epoxyied a bottom rounded front piece of tile to the tile for a bullnose piece I made and polished. I epoxyied using Total edge system from Bonstone corp. I am about ready to install the tiles and am looking for your opinion of what I have done so far. Does it sound secure enough? I was planning on using Flexbond for my thinset and using an epoxy grout. I have also been told both to seal and not to seal black granite. May I ask your opinion on that too. Reading through some of your postings I have already learned not to butt them together as my original plan. I am now leaving a 1/16 space between. Are there any helpful hints you can give to laying the tile edges level and even, as well as grouting with epoxy grout. I am pretty nervous about all that. I will look forward to your opinion and any advise you can offer.
I thank you much for your time.
Steve
Hey Steve,
As long as by ‘waterproof 3/4″ plywood’ you don’t mean pressure treated, it sounds nice and solid. The best way to get everything nice and flat is mainly just take your time and don’t be afraid to pull one up and add more thinset if needed. The flexbond will work well – it doesn’t shrink so your tiles will stay where you put them as it cures. Whichever epoxy you’re using just make sure you follow the directions to the letter – and pay attention to the time limit. If it says you have 80 minutes of working time – that’s what you have – seriously.
Sealing black absolute is not a problem if you use a good impregnating sealer like miracle sealant’s 511 impregnator pro then you’ll be fine. I find most of the problems arise when people use a topical or enhancing sealer on it. The black is a nice, even sheen and when you add to that it needs to be exact. If it isn’t you’ll be able to see it from my house. An impregnating sealer will not change the look of the granite – you won’t have any problems with it.
Hi Roger,
I would like to thank you for your reply and advise to my earlier question.
Well, I will be setting the Granite tiles on my countertop this weekend. I am nervous, but I have always been very meticulous so I think it will come out great. I read in your comments not to grout the seem where the counter meets the back splash, I take it I should use a matching caulk, Is that correct? My other question then is the corner seam of the hardiebacker from the counter to the back splash. Should I use the mesh tape with the thin set there too as the other seems or should I leave it open? I am using the Flexbond as my thinset.
Thank you much for your time and replies.
Steve
Hey Steve,
You can use caulk or silicone there – silicone is normally a better option, more flexible and lasts longer. You can get color-matched silicone from Laticrete or TEC to match your grout. (Google Latasil) Do not mesh tape and mud that seam, either leave it open or fill it with silicone – again I prefer the silicone. I don’t like any open areas where nasty stuff can reside in kitchens.
We purchased tile plank flooring that looks like wood. There is no tongue and groove on the tiles. Do we lay the planks side by side and grout or do we leave a 1/8″ grout line. Also, there will be a heat mat underneath. Does this change the installation process? Any special grout/thinset we should use. Thanks
Hey Marianne,
You need a grout line in those just like any other tile. It does not change the process much except you must either use an slc to level the floor after installing the heating or be very diligent about getting the floor flat as you set the tile. Any good modified thinset will work just fine.
Is there a special kind of grout you use for the tiles in a wet area? Epoxy grout? Siicone?
Hey JL,
There is no such animal as a silicone grout of which I am aware. There is sanded, unsanded, urethane-based (or similar), and epoxy. Any of which can be used in a wet area. Read through this to figure out which you would prefer: Which grout to choose
Thanks so much for your answer. Not sure why you think you’re a jackass. Seems to me you have and make more sense than all the experts combined. About the silicon grout…..it is a Polyblend ceramic tile caulk to be used around tubs and sinks and it says it is silliconized for ease of use and is to be used where horizontal and vertical surfaces meet. I just wasn’t sure if it should be used for the whole thing or not. It comes in colors. I now have you in my favorites because reading all these comments and questions is a really big education for me. Thanks again. JL
It’s kind of like the ‘loudest voice’ rule: those who speak the loudest often have the least to contribute. Only those who are confident they are not a jackass purport to be a jackass.
I try to keep the levity around here because, let’s be honest, reading about tile installation for most people is not exactly a riveting experience. If I make you giggle I keep your attention and you actually learn. Not necessarily you in particular, anyone that … aaah shit, nevermind. 
The product you’re speaking of is an acrylic-based caulk used to finish up the installation. Per standards any change of plane, that is where horizontal and vertical surfaces meet as you’ve mentioned, as well as corners where two walls meet and anywhere tile meets a different material such as the acrylic tub, must be filled with a flexible sealant. These include the caulk which works fine, or color-matched (or clear) 100% silicone, which works better because it remains flexible longer. It should not be used in the entire installation.
Any caulk or silicone is not made to be a permanent product, all of them will dry out over time and need to be replaced periodically (I’m talking about years here). Once it does begin to dry out it shrinks a little bit at a time. This causes the seal between the caulk and tile to break loose and open slowly. Once that happens it should be replaced. It’s completely normal but most people simply fail to replace it when needed. I’m sure you’ve seen the clear beads of silicone in tubs with all the nasty colors behind it? That’s why, the silicone shrunk, seal was compromised and it wasn’t replaced – nice little breeding ground for all sorts of nasty stuff.
Caulk will normally last about 3-6 years, silicone goes about 5-8 years. Silicone is more flexible and lasts longer. Now that I’ve totally grossed you out on a Sunday morning I’ll go away and leave you alone.
Hi Roger
This is the first time the shower has ever been tiled. The gray color areas look almost like cement; especially in the corners and near the tub but also between the some tiles on the wall.
Quite a bit of the “white” grout turns gray when wet.
Thank you for your quick response and I love this site!!
Then it’s probably thinset. If the thinset is not cleaned out of the grout lines as the tile is being set, or before it is grouted, the thinset can show through when the grout gets wet – especially white grout. The grout, and thinset beneath it, should be scraped out and those spots regrouted. That will likely take care of it.
Thank you! Now I finally know what has to be done.
I just had contractors redo a bathroom with white grout around the shower tiles; however, some have areas of gray (looks dirty) and when the tiles get wet a lot the white turns gray. Can you tell me why? Do I need to remove all the grout before I redo it so it all looks white?
Hi Kathy,
You mentioned you had them redo the bathroom, does that mean they just regrouted or that they installed all the tile? Is there gray, or a darker, grout beneath the new white grout? If so, they likely did not scrape out the existing grout enough. When regrouting the grout must be removed to at least 2/3 the depth of the grout line. This is required not only so the grout will adhere correctly, but so any grout beneath it will not show through the new stuff.
HI
I had asked about no grout lines and understood the whys but being the over thinker I am, I had to ask one more question about grout, Could I press a brass u channel(the kind that is used in stain glass work) over and into( as long as it go all the way to the floor), the grout, I am going with the thought if you can’t get rid of it hide or celebrate it.(I think I know what you are going to say but I need you to say it
Hi Skip,
I don’t know that it would work on a flooring application, but it may actually work on a wall. I would still be worried about the space between the sides of the channels and the tile. Different materials expand and contract at different rates. The differential in that expansion may cause the lines to open up or squeeze the u-channel enough to be a problem. I just dunno, but if that doesn’t cause a problem I don’t see why it wouldn’t work in an application such as backsplashes, wainscots or fireplaces. Don’t know that I would do it in a shower application.
What is the best wat to grout with epoxy with out making a big mess on the marble tiles?
Just use enough to do about 5 – 10 square feet at a time, take your time, and follow the instructions to the letter. Other than that, it’s just practice.
I grouted my floor today. I used mocha. It looked great at first, about 6 hours later the grout looks lighter in some areas. I most likely did something wrong, but not sure what. Is there anything I can do to fix this.
Thanks,
Mike
Hey Mike,
What you likely have is called efflorescence. It is normally caused by using too much water for your grout either when mixing or cleaning. Since it is not consistent throughout it is likely from cleaning with too much water in those areas. The white is caused by minerals from the water being left on the surface after the water evaporates. You can get rid of it either by scrubbing with a 5:1 mixture of water to white vinegar or you can simply get a drywall sanding sponge and lightly sand the surface of the grout. Just like burnt toast – scrape it to the color you like.
This morning it is now all the same color, but about 3 shades lighter than the sample color. I mixed exactly as package says, but possibly to much water when cleaning. I tried the sanding and vinegar, but no luck. Is there any other way to darken this grout about 3 shades darker.
Thanks again,
Mike
I picked up some Cocoa MAPEI GROUT REFRESH. This is the next darker color up from the mocha. I was able to fix my floor in 20 minutes.
I have snap and click tiles 16×16. Do I have to grout for this type of tile? Also what is the best type of adhesive to use?
Hi Mary,
I have no idea. There are about 50 different snap and click ’tiles’. Some require grout, some require a rubber ‘grout insert’, and some do not require anything. Read through the instructions or contact the manufacturer of your particular product. Most snap and click product are floating installations, which means they do not require adhesive.
No brilliant retort here just a huge Thank you for your advice (and I will be using grout.)
Here are a couple of pictures:
http://i103.photobucket.com/albums/m143/arash3725/IMG_20111107_170441.jpg
http://i103.photobucket.com/albums/m143/arash3725/IMG_20111107_170506.jpg
In the first picture you see one of the boards at the corner of the room already laid down but not screwed in yet.
Thanks again for your time and advise Roger, I greatly appreciate it.
The required thickness of floor beneath your tiling substrate is a double-layer 1 1/8″ to achieve proper strength and deflection.
Just want to make sure that you know I am NOT installing the hardiebacker directly on joists (Im not that stupid, Im a PE). I am installing it over 1×8 old horizontally installed floor substrate that is installed side by side diagonally (not perpendicular) over the 4×8 floor beams that are installed at 16oc themselves when the house was built probably in the 1940s.
Ok thanks Roger, considering the fact that you already know there is 1×8 old subfloor which is pretty sturdy under the feet I will consider returning my 1/2 ton worth of hardieboard and firing the installer who suggested it. Thanks for your help!
By the way, the hardieboard is very straight, plywood is always warped and twisted.
The issue is not the flatness of the plywood, it’s the structural stability (or lack of) in the backerboard. The plywood will be flat when you screw it down, no?
Hi Roger,
I have 12×24 vein cut 1/2inch travertine being installed in an old house. The subfloor is 1×8 planks from the 1940s installed diagonally and in good shape. My contractor is recommending installing 1/2inch durock (not wonder board) screwed directly over the planks and installing the travertine over it. I was wondering if there is any layer that is missing here like the black paper or plywood under the we don’t really have room for plywood in fact I was hoping I can go with 1/4 durock. This is a kitchen so not sure if I need moisture barrier underneath? The house is on a raised foundation about 2 feet off the dirt beneath it. Also the planks are diagonal, should I install the travertine in the direction of the floor beams or perpendiculr?
Thanks for your advise!!
Thanks!
Hi AZ,
To have a proper installation you’ll need a minimum of 1/2″ plywood over the planks, then the backer. You can use 1/4″ backer – it is simply there as a proper substrate to adhere the tile. It lends absolutely no structural stability at all – 1/2″ or 1/4″. That isn’t what it’s designed to do. Natural stone needs extra stability to last so you need that extra plywood beneath the backer, and you need thinset beneath the backer to fill any voids as well. It doesn’t make any difference which way you install the travertine relative to the joists.
Thanks Roger! The subfloor is 1×8 planks and we purchased 1/2 hardie-board today to screw down. You think we made a mistake? There is a 3/8 thick old oak wood flooring right next to the area which the owner doesnt want a big difference in height. With hardieboard and the 1/2 travertine Im already 1/2 above. If you really think we are making a mistake then I have to return all those 350SF of Hardieboards and buy 1/4Inch. So why do they have 1/2 then??
Thanks for your help! Loved the book too!
1/2″ is made mostly for walls in that it will match up with 1/2″ drywall outside the shower and it will hold better between 16″ o.c. studs. The sheer thickness gives it more stability in a vertical application between the studs. The same does not apply when a 150-200lb person walks between the joists.
The deflection ratio needed for natural stone is twice what is needed for ceramic or porcelain. That means the floor needs to be twice as stout for stone than it does for ceramic. I know it sucks and I deal with height differences every day too. But you need to explain to the customer the need for a properly built substrate for the long-term durability of their natural stone installation.