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.
Roger,
I’d like to replace the tile in front of the front door. I have hard wood floors.
I bought the house with tiles broke and just covered with an area rug. Now I have some 18×18 slate tiles. Can I use these without grout for there really is no room to put any. The tiles are tight. Or do I have to cut down the tiles?
Hi Becky,
You really should cut down the tiles to fit the area and grout it. Home depot will cut the tiles for you if you mark them and take them down there.
I was actually more thinking of the moisture in there and the silicone getting crappy quick. Moldy etc
The only thing that make silicone do that is when it is not properly sealed against the sides as it should be and water gets behind it. Once water is behind it you can begin to grow mold. It will not do that on the surface if it’s sealed properly.
Thank you Roger. In trying to figure out how to do this easiest ,my guess is lay tile let cure..put silicone on one side of strip and install. .then fill other side while in floor? Not sure if I’m good enough with caulk gun to pull it of but I do appreciate your advice.
That would probably be the easiest way to do it.
Well I’m kind of anxious to try that however, I failed to mention this is a bathroom floor, and in reading other advice you’ve given I’m guessing this method isn’t the best there. Should I wait and try it elsewhere where it’s not so moist? Thanks again
If it would make you feel better about it. No real reason to be leery about it, though. It’ll work just fine. You just want to ensure you have a soft joint between differing materials.
I like your post and advice. If you go by the old adage the old only dumb question is the unaxed…I can change that. So I thought about using well machined strips of hardwood in between like 1/4 sewn white oak ..triple polyed. Is this at all workable? Thanks. Or sycamore…etc.
Hi Kent,
Yes, you can. You do need a 1/16″ joint between the tile and wood which you would then fill with silicone (NOT grout). You are essentially creating a bunch of little independent floors with perimeter joints. Not a stupid question at all, and it looks very cool when done correctly.
What type of grout would you use or recommend when creating an outdoor mosaic that can be installed poolside or inside a pool? and once the mosaic has been created what would you use to complete the final installation if it were going to be be physically inserted into a pool wall?
Any insight would be very much appreciated your responses to previous inquiries are fantastic.
Also based on your responses is this basically your rule of thumb:
1) 1/8 or less use unsanded grout internal installations
2) 1/8 or more use sanded grout internal installations
3) Epoxy grout for outdoor applications and wet areas and to avoid scratching.
Last question is it just a bad idea to use sanded or unsanded grout on kitchen counter tops?
Thanks in advance for your insight
Hi Jerome,
I would use epoxy grout and epoxy setting for both of those.
1. I use sanded for anything 1/16″ or larger
2. Same answer
3. Any grout can be used outdoors, epoxy is more durable and less prone to the elements.
No, it isn’t a bad idea. Epoxy is simply a better solution.
Hi Roger
Iam installing a walkway in front of a mausoleum using 52 solid granite tiles 2 1/2 inches thick and 16 in by 16 in. The foundation is 6 in reinforced concrete. The walkway starts out 5 ft 4 in wide including borders and in the middle it is 9 ft 4 in for placing two 4 ft benches the back to same. It is 16 8 in long.
What do you suggest ,is tenax domo 10 to glue down ok
and what grout to use in the 3/16 joints
Thanks Walt please e mail me your expert advise
Hi Walt,
The tenax domo 10 would be a good choice for epoxy setting material in your application, it will work well. Any good sanded grout would be just fine in the 3/16″ lines, I would likely opt for a good epoxy grout like Spectralock in your installation, though. Much more durability, color consistent and will last very well in that application.
Will leaving tile on a floor for 2 weeks before grouting it cause any damage to the tile?
Hi Marian,
No, it won’t.
Hi Roger,
I’m installing 20×20 rectified porcelain tile. What is the smallest grout line you would recommend?
Thank you,
Hi Sheila,
It depends on how consistent your tile is. It may say rectified, that doesn’t necessarily mean it actually is truly rectified. Lay four of them into a square and measure each corner to the opposite and see if they are the exact same size. If so you can normally go 1/8″ without problems, if they are not add the difference to the grout line size.
Sorry for the delayed response, my spam filter went ape shit last week for some reason, I just found your comment in the spam folder, I hope the answer found you in time.
Hi, I am installing 1300 sq feet of Rectified 24 x 24 Porcelain glazed tile (light beige in color soft marble patter look) on the floor in my entire house (Kitchen, living room and bedrooms). It is all on the ground floor, over concrete slab. I hate grout lines. Can I safely go with no grout line or do I need to go 1/32″? Also if grout is need which would you recommend and also which mortar given the large size of the tiles which I assume are not easy to handle? Tks!
Hi Eileen,
Did you read the post above? If you did it already answered your question. And you NEED to go with a larger than 1/32″ grout line. You can, of course, go with whatever you want, but I can nearly guarantee you that unless you use a 1/8″ or larger grout line you will not be able to keep the grout lines straight nor a consistent grout line size. It just won’t happen.
By the way – EVERYBODY ON THE PLANET hates grout lines. Everyone.
Instead of grout can you epoxy between marble tiles used on a counter top
Hi Connie,
You can use epoxy grout. You can not use epoxy setting material or regular epoxy glue.
I found the perfect solution for the no grout line issue. I use a small amount of clear or color caulk for the grout line, use a razor blade to remove any access and that way nothing can get between the tiles. Sanitary and looks fantastic.
Hi Art,
Have you ever seen the edges of a tub when the bead of silicone begins to come loose? It’s completely full of mold because water gets in and has trouble dissipating. The same thing will happen in the grout lines in a shower. Silicone is not a permanent product, it is meant to be replaced once it begins to lose it’s elasticity, that is normally every 5-7 years. I’m glad it works for you, but I would not recommend that to anyone.
My installer has put in a kitchen splash back without the grout I supplied. Thee tiles are very uniform and the finish is good. Any advice on what to do? Re-install or can I apply some protection in the gaps for hygiene reasons? Thanks
Hi Ben,
Yes, grout it with non-sanded grout. You need to have something in those gaps, that’s what grout is for. There is no product to fill vertical surfaces with in place of grout.
I installed Bevel Subway tile in our shower, we did not want grout lines in between each tile. Each tile butts up against each other. Is there a “liquid” grout I can purchase that will protect the space in between the tile?
Thanks!
Hi Dan,
No, there is not. Your best bet is regular unsanded grout.
I am installing 20 X 20 ceramic tile, what would be the smallest grout line you recommend?
Hi Jorge,
1/8″ is normally what I use if the tile consistency allow it.
Hi Roger,
Is it okay to install 3″x6″ glass tile as a backsplash with no grout and just butt them together (the area is about 40sf)?
Thanks!
Hi Devin,
No. Doing it with glass would be more detrimental than doing it with ceramic or porcelain. You NEVER want to butt any type of tile without grout lines. Stacked stone is the ONLY exception.
I plan to install 3, 1’x2′ tiles, vertical, behind stove. The 5″ backsplash around rest of kitchen has been installed – little room was left for tiles – to the point the two grout lines will need to be very tight.
I hoped to forgo grout & just butt ’em up against each other – BUT – given your advise, above article, one should never do this.
If one only has two grout lines – does your position remain the same?
I’d been thinking I’d epoxy the tiles together….. while heavy to install, they’d act as one piece [sans need for grout].
Your thoughts?
I did talk with tile folks [not about my idea] but they thought to cut a small amount of tiles to give enough room for grout. I’d prefer not to get into the need for tile cutting – specially such a narrow amount [possibly 1/2″ over the 24″ tile]
Hi Joslyn,
With only two tiles like that you should be fine, just make sure you don’t butt it directly against the cabinets or anything on the sides. It still needs room to expand, although less than 1/16″ should be fine. The epoxy will work.
I work at a home improvement store and have had customers ask if VCt can be grouted, never learned about this through training. Is this possible, if possible what type grout would you recommend?
Lisa
Hi Lisa,
Ummmm, I suppose it could. Unsanded grout would be the best option. I will say if it needs to be grouted someone is installing it incorrectly.
Hi I’m installing for the first time travertine and marble. My question is regarding the Armani Marble tiles (60cm * 30cm * 2cm), Do I need to use some kind of glue on the back of the tiles since they have this fiberglass squared net before applying it with the adhesive to the wall? I will be using a European Adhesive, Ceresit CM 25, it’s a flexible white adhesive for all natural stones.
Hi Alex,
Any stone with fiberglass reinforcement mesh on the back of it requires epoxy setting material. Thinset will not bond to it long-term.
So what you’re saying is, I should not use any thinset at all?
Correct. It needs to be set with epoxy.
Thank you roger
Much obliged.
Hey Roger, one more thing, could you please recommend some epoxy manufacturers/materials?
Laticrete LATAPOXY 310 is the only one I use. It’s the easiest and most reliable I’ve found.
Unfortunately I can’t find that in Europe, it’s a US only I think, but thank you anyway.
Latapoxy 300 adhesive is what I think they call it over there.
Hi Roger,
I am tiling a bathtub surround and there might be a gap of up to a couple weeks before I can grout the tile is this OK. I will not be using the tub during this time, will that effect the tile?
Hi Mike,
It won’t affect the tile at all. You can grout it next year if you want to.
Thanks for the tip on laying out 9 tiles on the floor and measuring diagonally. I bought rectified tile 18″ square for my new shower walls. My nine tiles measure 75″ each way so it seems I could go as narrow as 1/32 for my grout line. So I have to decide between 1/16 or 1/32. If I did 1/32 would that be much harder than 1/16? This is my first time installing tile.
Hi Lance,
Yes, it is harder. MUCH harder. I would recommend at least a 1/16″ grout line.
Roger, I’m installing tile in my bathroom. On the threshhold, I have the 1/4 in hardibacker butted up against the 1/4 plywood subfloor under the carpet outside the bathroom(the carpet is 3 inches back from the edge of the plywood). I initially taped and mortared the hardibacker to the wood subfloor just like you would tape/mortar all the hardibacker joints together. Will this be a sufficient bond between the two different materials, or should I cut out 3 inches of the plywood subfloor (up to the carpet) and put hardibacker there?
Hi Ryan,
Ideally you need to remove the plywood and replace it with backer. The three inches of ply will likely be fine, but I definitely would not guarantee that. May as well eliminate any potential problems while you have the ability to easily do so.
If the Lady wants a professional installation (looking) floor your best bet is a complete reinstallation.
Hi Joe,
Thank you for your opinion! However, no one here has any idea to which comment you may be referring as you did not reply to that comment but rather posted a new one not attached to another. You may be absolutely correct!
Roger,
I now work at a home improvement retail chain and was told by a customer that he always uses mortar as a grout. I tried to sell him unsanded grout as it was intended for that purpose but could think of no real arguments against the mortar other than color. Assuming the customer is ok with the basic white or grey, are there any major differences between using grout or mortar? Assistance would be appreciated, thank you.
Solo
Hi Soloman,
No real reason at all not to use it. It’s how all tile use to be grouted before 1950 or so before the introduction of modernized ‘colored mortar’, and later modern grouts.
I’ve just installed wall tile backsplash in my bathroom that comes in one square foot sheets. The tiles on the sheets are 1″ x 2″ and extremely varied in texture and depth. Some look like porous stone, some look like brick while others are polished granite. The sheets come with no grout lines between any of these tiles. I was able to install these tiles with no spaces greater than 1/32″. The spaces I do have are very few and far between. I cannot see how I can grout this tile without destroying its look by filling in the character of the stones with grout. Also, there is no way to use a float since the tile surface is like the texture of a stone driveway.
Any comments or suggestions.
Hi WTaylor,
Some mosaics are just not made to be grouted. It sounds like you have one of those.
Dear Roger.
I recently installed some Armstrong Alterna Luxury Vinyl Tile for a customer. When installed the client said she wanted the tiles butted against each other (against my wishes and advice not to). Now after the tile is laid and rolled and tight in place, she decides she would like the grout lines now. Is there any way at all to cut grout lines in the existing tile?
Hi Jeff,
None of which I am aware. A rotozip may work but I would call armstrong and see if they have any methods for that.