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.

{ 447 comments… add one }

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  • Paul

    Hello Roger,
    Great information. I’m a first time tiler swimming in a sea of questionable tile professionals. After 20 years, I am getting rid of the carpet in the bathrooms. If I kept it longer, it would be considered retro and thus fashionable again for CA tract housing, but my dog is tired of the look. I am setting 20″ x 20″ porcelain with 1/8″ spacers over Ditra with 3/4″ sub and 1/2″ ply addition with joists 19.2″ O.C. I used Lowes Mapei modified under the Ditra XL. The dry set spacing looks good and the tiles (Marrazi) are consistently square. I am having trouble finding a thinset for which you have recommended. I returned the Mapei Floor & Tile unmodified since it appears to be Mapei’s low end. Eventually I hope to find some Laticrete 317 or comparable. A few questions: 1) should I be looking for a “Large format” mortar? 2) With the large format, my biggest comcern is lippage. There are a few proprietary aids (LASH) in this endeavor and I wonder if they are worth it or just more work while the skim sets on my mortar. 3) Because I have a dog, I am setting a diagonal pattern with a 2 inch Bronze style tile at the corners of the 20″ x 20″ cutting the corners to accommodate the tile and 1/8″ grout. The 2″ tile is less thick and I swear it looks like resin, though denied by sales rep at BB Store with same manufacturer and used in a display. WRT order of operations, should I set the large tiles first and go back and set the 2″ or set them as I go (slow)? Also if the 2″ is resin (shiny plasticky back), will it bond to unmodified? 4) WRT large format tiles, should I plan to trowel thinset to Ditra AND back of tile? 5) I have 2 door jambs in this tiny 40 sq ft bathroom that I’ve trimmed 3 times already (as I’ve learned more and more and added layers (ply, Ditra) and changed tile/style thickness). I am using Schluter’ s trowel 11/64″ x 11/64″. How much will the double layer of thinset add to thickness of the tile? Or what would be a safe clearance under the jamb above the Ditra with .40 inch thick tile? Thanks. I appreciate your expertise and candor and I’ve learned a lot. I”ll keep my day job and some of the carpet…

    • Roger

      Hi Paul,

      1. Any large format mortar is going to be modified. That said, I would use a large format mortar with tile that size.

      2. Lash is difficult to work with and requires a considerable amount of mortar beneath the tile, another reason to use large format mortar. They are worth using, they work very well. I regularly use the mlt system on my large format tile.

      3. It IS a resin-based product. It may bond with unmodified, but I wouldn’t. (Another reason to use…well, you get the point…) You can install them in either order. I install them as I go but you should install them after your field tile is set. It will allow you to adjust them up or down with more or less (large format) mortar to get them properly flush with the field tile. The way I do it is a HUGE pain in the ass.

      4. It depends on how flat your substrate it. Normally just combing it onto the ditra and back-buttering (skim-coating the back with the flat side of the trowel) is sufficient.

      5. Lay a tile upside down on the ditra with a piece of cardboard beneath it and mark your line. That is the correct height. :D

      • Paul

        Thanks, Roger. I’m glad I asked those questions. One of the benefits of going slow….Any recommendation on the type of modified thinset? Would it be better to prefill the waffles in the Ditra and let it set prior to setting tile since it is modified and will take longer to cure?
        Many mahalos….!

        • Roger

          I would pre-fill the cavities. Any good medium-bed mortar will be fine. Custom’s marble and granite (?) or mapei’s ultraflex 3, or Laticrete 4xlt are all very good.

  • Bridget

    Roger,
    We have moved into a new house that needs complete bathroom renovations

    • Roger

      Hi Bridget,

      Congrats! Did you have a question? :D

  • Dave

    I am installing 18″ (17.75″ actual) tile in a diagonal pattern in three new construction bathrooms. The tile does appear to have some inconsistency on exact measurement from tile to tile. Should 1/8″ tile spacing still be manageable for an amateur? Thanks

    • Roger

      Hi Dave,

      It should be, just take your time and don’t be afraid to cheat the grout lines where needed. With inconsistent tiles they always need to be cheated a bit to keep everything lined up.

  • Kathy McTopy

    Hi Roger,
    We are tiling our porch outside (over concrete)… we live in Texas and it gets very hot in the summer. Should the possibility of expansion, in the hot summer, make a difference on the size of the grout line we should use? We were wanting a 1/16, but weren’t sure if we should use a wider one for expansion?

    Thank you!
    Kathy

    • Roger

      Hi Kathy,

      You should use at least 1/8″ and make sure you have soft joints every 10-15 feet in both directions as well as perimeter joints.

  • Jim

    Hi Roger,

    thanks for all the good answers listed above. my great room in the basement is about 800 sqft, and we plan to lay the 12×24 contemporary tile. should we use 1/8 or 1/16 grout line for the floor if we want to have contemporary look?

    • Roger

      Hi Jim,

      With large format tile like that you’ll need to use at least a 1/8″ grout line.

      • Jim

        Thank you, Roger. Is 1/8 still too small or should I use 1/4?

        • Roger

          3/16″ would likely be ideal, but you can get away with 1/8″ if you take your time.

  • Jeff Ward

    Hello Roger!

    quick questions…not really! :roll:

    Ques #1 – I am installing 12″ x 12″ natural dark gray slate (12 x 12 – yeah right :lol1: – no two tiles are exactly the same size, thickness or square and some are even shearing thin layers off as they are being removed from the boxes! :censored: )…

    So, I decided to go with 3/16″ spacers (generally) to give me a a little “wiggle room” and keep the top of each course level and shim from the bottom which makes the spaces 1/8″ in some places due to the discrepancies…

    I am trying to keep the sides as plum as possible…in most cases I am within a 1/16″ of an inch…would this be acceptable to a pro like you?

    Is this a good process to be following…so far my first two courses off the ledger are level at the top…and with the spacers in there don’t look bad as far as I am concerned…gonna remove them tomorrow

    Ques. #2 – I plan to use sanded grout that almost matches the slate color…does this seem acceptable for a natural stone look and to help with the discrepancies in “lippage”? :(

    Ques. #3 – My big problem is “lippage” in a few places on the faces of some of the tiles……as the thickness of many tiles is very different… I am using a 1/4 x 1/4 x 3/16 trowel and thinly back buttering each tile before pressing and wiggling into place…Since it is natural stone…should I be overly concerned about this lippage on the walls? :bonk:

    I did manage to get the bench seat tiles lined up with no lippage and the proper slope… :rockon:

    Ques. #4 – What size trowel should I use to put down ( 1 1/2″ – 2″ size) 12 ” pebble mats on the floor and up a 12″ band on one of the walls to avoid too much seepage of the thin set?

    Your wisdom and knowledge are truly appreciated – if this one comes out well I WILL send pics…

    Regards

    Jeff

    • Roger

      Hi Jeff,

      You can only do so much with those stones. The best you can do is at least get consistent inconsistencies. :D That just means as you walk your way up the wall keep the top of each row level and let the bottom fall where it falls. All the bottoms of the grout lines will be straight.

      Yes, sanded grout and matching is about the best you can do.

      I’ve already said you can only do so much with them. Applies to the lippage as well. Use a 1/4″ x 1/4″ for the mosaics.

  • Alan

    Hi, I am laying ceramic tiles on two surfaces that butt together. One is a concrete slab and the other is a stenciled concrete slab. I was going to use silicon down the join and start the tiles off that each side using a flexible adhesive. Do you have any advice or hints that might be of help.
    regards Alan

    • Roger

      Hi Alan,

      You’re doing it correctly. As long as you have a soft joint directly above that transition your installation will be just fine.

  • Jerry

    Hi Roger! I’m installing tile in a closet that used to have carpet. Should I install the baseboards first or the tile. Also, should the tile be placed under the baseboard or butted up against it. Thx for any help you can provide!

    • Roger

      Hi Jerry!

      Install the tile first, under the baseboard.

      • Jerry

        Hello again Roger! What is a good leveling compound to use? Also, most of the information I’ve read on leveling compounds states to mix an entire bag. Is there a ratio I can use so I don’t have to mix an entire bag? Also, will a trowel work to smooth out the compound or do I have to use a gauge drake and spreader? The closet is only 2′ x 4′.
        Again, my thanks for your help!

        • Roger

          Hi Jerry,

          Just weigh out a certain percentage of the entire bag and divide the water amount by the same percentage. Laticrete or Custom’s levelers are both very good. You can use a trowel for it.

  • Larry

    Hi Roger, I am redoing the tiles around the house with 12 X 24 rectified porcelain tiles. I’ve 2 flooring companies came out for quotes and one stated we can do 1/16″ grout while the other stated that 1/16″ is for wall and we should do 1/8″ on floor. What is your recommendation in this case (we like to have as little grout as possible but will go with a larger one if 1/16″ will create issues in the long run).

    Thanks

    • Roger

      Hi Larry,

      It depends on the substrate and the tile and what each will allow. 1/16″ is not ‘for a wall’. It can be done on a floor but you HAVE to have completely flat tile and completely flat substrate for that. I would use a 1/8″ minimum on the floor with tile that large. Perhaps larger if they are not consistently sized.

  • J Vanessa

    Hello,
    My contractor, who has done nice work on the travertine tile in one bathroom and a glass tile backsplash in our kitchen, recently completed our second bathroom while we were away. We used 12 inch square porcelain tiles for the both the walls and floor, same product on both. Prior to my trip, the contractor’s workers had started the wall tile and we agreed to “the smallest possible grout line” – which was 1/16. ( This was also what we had done in the other bathroom, on both the walls and floor – also using the same tile for each.) In the kitchen, the glass tiles were butted against each other, also creating the smooth look I prefer.
    When I returned, walls and floor were complete, but I have been very unsettled by the look of the floor. It was done with 3/16 grout lines, creating a very different look than the smooth look of the wall with its 1/16 grout. He explained this on several grounds – first that the floor required sanded tile ( this I knew, but we did manage a 1/16 grout line on the floor in bathroom one), and then that we would have had too small a line of tile toward the back of the bathroom ( doesn’t make sense to me). In addition, the grout seems to be very indented compared to the tile, so that a tiny bit of the side of each tile shows, creating a slightly darkened line. In contrast, the wall tiles flow together almost invisibly. Recall that we are using the same tile, same size, floor and walls ( with an accent line).
    I find the look very jarring. I prefer a smooth, monotone look, and that is also why I like the same tile on both wall and floor. Do you have any thoughts on this? Is it very unreasonable to complain so, or should I just let it go? Thank you. I hope I didn’t give you far too much information for a rather simple problem!

    • Roger

      Hi J,

      I assume you mean he told you the floor required sanded grout? (You typed sanded tile) It does not need sanded grout, the type of grout is dictated by the size of the grout line, not the other way around.The ‘too small a line’ – doesn’t make sense to me either. The larger the grout line the larger the ‘dip’ of the grout between tiles.

      It is completely up to you as far as what to do. I regularly use 1/16″ on walls and 1/8″ on floors, even with the same tile. Normally you need a bit larger on floors because you have larger runs, different substrate and prep. It is completely normal. The reasons he’s giving you, however, are not the reasons to do that. If the tile allowed 1/16″ on the wall it should not need 3/16″ on the floors, that is a large discrepancy.

  • Sam

    Hi Roger,

    I am in the midst of bathroom renovation. We will have walls and floors tiled, the tile size is 12*24. I wanted to have the grout line as thin as possible, to have the single large slab look. I asked my contractor to use 1/16 grout line, he refused. He said it’s impossible, and said the tiles won’t hold together strongly. How can I convince him to do the 1/16 grout line?

    Many thanks!
    Sue

    • Roger

      Hi Sue,

      With large format tile like that there is a minimum grout line you can have. Those tiles are cupped toward the center. So having the highest part of the tile (middle) directly against the lowest part of the tile (ends) with only a 1/16″ grout line between them will make your floor look like none of it is level. It is best to widen the grout lines a bit and find a grout that matches your tile color. It has nothing to do with the tiles ‘holding together’, but they need to be bigger than that.

      • Sam

        Thanks Roger.

        Our tiles are very square, same size. I think they are called rectified tiles. Do you still think that would be a problem for 1/16 grout line.

        Sue

        • Roger

          Not all rectified tiles are created equal. Even if they are *EXACTLY* the same size (rectified tiles are cut after they are baked) they will still be cupped. It’s still an issue.

  • michael

    I was kicked off of a tile installatphojob today. Why? The home owners wife originally wanted 1/4 in grout lines but the tiles are 13×13 so I dry set a section of the floor with 1/8 spacers and a section with 1/4 spacers. He chose 1/8 spacing. Who wouldn’t? He didn’t consult his wife about the change and apparently she flipped out after seeing a photo of nearly 300 sq ft of beautiful tile with 1/8 spacing. she tells him to tear it all out and start over. :censored: he tells me its my fault for making the suggestion to use a smaller line. I was so shocked I didn’t know weather to be mad at him or feel bad for him. Well after several hours I’ve decided it’s like this…she’s obviously got bigger balls than him cause there’s no way in hell I’d destroy that much set tile based on her Vision of a photo taken from a cell phone.can you believe some people? What a couple of bitches.. .excuse my language. :rockon:

    • Roger

      Contract, contract contract! :)

  • Chris

    I am laying 12×24 porcelain tiles in a herringbone pattern. The tiles actually measure 11 13/16 x 23 13/16. I told the designer that the tile size makes it necessary to make the grout spacing at 3/16 as otherwise there would be a drift in the pattern of 3/16 per tile. She says I’m crazy, and I’m about ready to walk off the job. The math is simple, in a herringbone, or other complex patterns that use non-square (rectangular/ diamond cut out/ octagonal) the actual size of the tile plus the grout size needs to equal the tile advertised size, or am I completely wrong!

    • Mark

      Chris, I have to agree with your designer. As long as your tile setter is grouting on all four sides of the tile, there will be no drifting of the pattern. The first few tiles will set the pattern and continuity of all the remaining tiles. If the tile setter places the first few properly, you’ll be fine and no drifting will occur. That said, given your desired herringbone pattern and the size of the tile, I encourage that you use no more than a 2/16 inch grout line. You’ll like it. 3/16, in my opinion, is too wide for most interior finishes, unless you’re laying Mexican or some other rustic-looking tile.

    • Roger

      Hi Chris,

      It does not need to reach what is called the nominal size. The only difference is that over a span of ten feet your grout lines will not be ten feet apart, they will be each tile size plus grout line times ten. Provided you use a consistent grout line (1/8″) in all the tile the pattern won’t drift at all.

      For instance, if you grid out the floor with full 12″ tiles, you would grid perhaps a line every 5 5/8″ (with 1/8″ grout lines). The pattern will fit perfectly. If you have 11 5/8″ tile with 1/8″ grout lines you would simply grid out that line every 5 feet exactly, your pattern will still fit perfectly. As long as the tiles are consistent you will be able to set the pattern.

      The ONLY time you run into the nominal size problem is when you have tiles of different sizes that should be manufactured to a specific pattern. For instance, a pinwheel pattern with 12 and 6 inch tiles. The 6 inch tiles would actually need to be less than 1/2 of one full tile. They need to be 1/2 of one full tile minus 1/2 of your grout line because you have two grout lines in every 1/2 tile for every full tile.

  • Nayna

    Hi Roger,

    I just had bathroom wall tiles installed around the tub surround. I wanted the smallest grouting for the tiles, so I had my contractor use 1/16 grout spacers. The tiles have lugs, so once it was grouted, the lines look really large. Is there a fix for that?

    Thank you

    • Roger

      Hi Nayna,

      Unfortunately once the tile is installed you’re stuck with it. I know that’s not what you wanted to read.

  • matt

    Hi Roger,

    I’m tiling a shower with 6.5×6.5 and 10×10 porcelain tile floor and walls. I prefer 1\8 grout lines.

    The base of the tile is bigger than the surface of the tile. so if I use a 3mm spacer that goes deep (e.g. horse shoe shaped spacer, leveling system, etc) it creates a 3/16 grout line. If i use a 3mm spacer that doesn’t go deep (e.g. those soft crosses that i assume are not good for walls because they’re soft)it creates a 1/8 grout line.

    What is typically the acceptable approach with a tile like this? I feel like the 3/16 grout line is getting to wide? Should i use a deep 2mm spacer (horse shoe or leveling system) in order to get a 1/8 grout line?

    • Matt

      Hi Roger,

      I’ve been studying the tiles more closely and should add some info…

      – The 6.5×6.5 tiles have 2 edges that bulge at the back half of the tile, and two edges that are smooth.

      – The 10×10 tiles have a bulge at the back half of all four edges.

      For the 6.5″ tile, seems like I need to position smooth edge vs. bulging edge for consistent grout lines throughout (adds about 1mm to grout line width when positioned this way)? Should I use a 2mm spacer to achieve a 3mm (1/8) grout line?

      The bulges on the 10″ produce an extra 1.5 – 2mm grout line width. Should i be using a 1.5 – 2mm spacer to achieve a 3mm (1/8) grout line?

      Just curious…why are the tiles manufactured this way.

      Thanks in advance. –Matt

      • Roger

        They are manufactured that way to get them out of the form. If they were rectified they couldn’t pop them out easily. That’s why rectified tiles are cut after they are formed and baked (one reason).

    • Roger

      Hi Matt,

      I use the soft spacers on floors specifically for that reason. It remains a 1/8″ grout line.

  • Tiffany

    Hi Roger. I’m redoing my bathroom and putting 12×12 tiles on the floor and walls. The wall is a mosaic tile and the floor will be a slate tile. What size grout lines do you recommend?

    Thanks,
    Tiffany

    • Roger

      Hi Tiffany,

      With slate you usually want about 3/16″, they can be highly inconsistent (the tiles). I prefer about 1/16″ for walls and any type of mosaic.

  • Steve

    Q. How thick should the grout lines be?

    A. As thick as the gap between the tiles. :bonk:

    (Maybe you meant; How thick should the gaps between the tiles be?)

    • Roger

      Hi Steve,

      The gap between the tiles is the grout line.

      Q. How wide is your tile

      A. The same as the distance from edge to edge. :bonk:

      :D

  • Lindsey

    Hi Roger,
    I plan on tiling my kitchen. I removed the wall paper and under it is what seems to be a sheet of thin faux looking tile something from the sixties… kind of wall covering… it is it seems to be stuck on very well in most places we gouged it a couple places and the top layer kind of chips off in some areas… … I’m wondering if tiling over this will be ok or is removal necessary?
    Thanks so much! wonderful site.

    • Roger

      Hi Lindsey,

      Unless I know exactly what it is I recommend removing it. Even when I know what it is I recommend removing it. :D

  • Effie

    Hi,
    My tiler just told me I need to pay $25 extra per m2 for a 1mm grout line for my 60x60cm porcelain tiles in the bathroom. He is already being paid $60 per metre and wants extra as he says there is a lot more work in smaller grout line as he uses special grips to hold tiles close together. Is he trying to rip me off? He also said that tiles could be uneven or chip if too close together. Any advice?
    Effie

    • Roger

      Hi Effie,

      A tighter grout line requires a lot more work, and perhaps a leveling system. It is common for an upcharge under these conditions. How much of an upcharge is relative. There is no ‘normal’ amount, so I can’t tell you whether that’s more than normal or not.

  • Maureen

    Hello Roger,

    According to the James Hardie installation guide at http://www.jameshardie.com/homeowner/pdf/backer-install-us.pdf

    on existing floors:

    • HardieBacker® cement board may be installed under or over Vinyl Composition Tile (VCT) and other resilient flooring. For best results, remove existing floor covering, especially if it is in poor condition.

    • If installing HardieBacker cement board over existing floor, ensure the floor is flat and floor covering is thoroughly adhered to the subflooor.

    My bathroom floor has peel and stick vinyl tiles. They are in very good condition, and the floor is flat and level. Is there any real reason to remove the tile before installing the hardibacker on top of the vinyl? If so, why do the installation instructions say it can be put over the top?

    Love your site … thanks!

    • Roger

      Hi Maureen,

      If your existing floor is over wood and you can install thinset under the backer and screw it down then there is nothing wrong with that at all. If you are relying on thinset to bond your backer to the floor then you are 1) using it incorrectly and 2) it won’t last. The hardi needs to be mechanically fastened with screws to the subfloor.

      • Maureen

        Thank you so much for the quick response! This will save a lot of work, as I believe if I remove the tile, the glue that is under it will not be good, then I’d have to remove/replace underlayment also. I plan on following the instructions you’ve given for installing the hardi … thinset, correct screws, tape. One other question I have is the thinset. When I looked at it in the big box store, the label doesn’t specify whether it’s modified or unmodified, and some of them say for walls, and some say for floors. How can I tell which thinset to buy?

        • Roger

          The bag will always state whether or not it’s modified. It may say ‘polymer fortified’ or polymer modified’ or something similar, but it will always say. Most thinsets you get at a big box store will be modified, it’s actually difficult to find a non-modified. You can read through this to see what an unmodified it, but they’re scarce at big box stores: Unmodified thinsets.

          • Maureen

            Oh, I was looking at the pre-mixed tubs. I hate mixing stuff myself. The results are always too thin and wet, or too dry. That’s why I don’t cook, either! Can I use a pre-mixed thinset?

            • Roger

              No, you need to use the powdered stuff. If you follow the mixing directions on the bag it’ll come out perfectly. :D Pre-mixed ‘thinset’ is not thinset, it’s mastic with sand in it.

              If you have any more questions can you please post it as a reply to this one? I have (literally) over 20,000 questions on this site. If your question is not posted as a reply then I have no idea what you’re talking about and need to go search for your previous question and my answer to it. Thanks.

  • Nicole

    Hi Roger,

    We had 18×18 porcelain tiles installed during our home renovation project. We made it perfectly clear that we wanted the thinnest grout lines possible, even to the tile setter as he was working. The end result is a 1/4 inch grout line, with a light colored grout that is already staining. The company we hired says that the 1/4 inch grout line is perfectly normal, and that anything thinner would be impossible. Also, instead of re-grouting the light color (which they helped me choose), they are pushing a grout stain. Given your experience, could you tell me what the best course of action for fixing this floor? Would a grout stain be any good? I read that it is very similar to paint. I feel at the very least this floor should be re-grouted.

    Thank you! Any advice would be greatly appreciated. :)

    • Roger

      Hi Nicole,

      Your particular tile dictates acceptable grout line size to an extent, but 1/4″ is HUGE! It’s absolutely ridiculous, to be honest. Grout stain does work very well, but it’s up to you if you want them to regrout. I don’t know how good it would look on 1/4″ grout lines, though.

      • Nicole

        Thank you, Roger.

        I know it is ridiculous. They are adamant that 1/4 inch is industry standard, so it looks like I am stuck with it unless I want a lien on my house. Unfortunately, every tile job that was done on the house was done poorly, so I have already had to fight to have a floor and shower tile ripped out. Your response does make me feel like I maybe should be fighting this one as well. I appreciate your help. :)

  • Stephanie

    Hi Roger,
    My contractor just installed 3×6 carrara marble subway for the kitchen backsplash with no spacers, so each tile is butt up against each other. I assumed subway should have a 1/16 or 1/8 grout joint so I did not specify and came home to see it like that. Some areas look ok, but others have obvious lippage. After expressing concern he attempted to remove some of the pieces that looked really bad, but since the tile was installed so close to each other it caused the tile around the removed tile to chip and so on. Now I end up with chipped tiles and less lippage. He said removing more would make it worse.

    It was now grouted over and it looks worse than ever making the lippage areas look “3d” and the chips are of course filled with grout. I’m sure he will re-do if I ask. The question is, will it cause more problems ripping everything off and possibly needing new drywall and doing all the prep? I worry that it might affect our newly installed quartz countertop since it was grouted from ceiling to countertop. OR…should i just ask him to remove the eyesore chipped pieces to the best of his ability and call it a day. We could have hired a tile expert to install this, but due to budget our contractor offered to do the install, but if I knew it would look like this I would have paid extra to have it done right the first time. Thanks for any suggestions!

    • Roger

      Hi Stephanie,

      It’s completely up to you. Ask yourself this question: Would you pay someone to install a backsplash that looks like that? My guess would be no. In that case have him remove it, repair the wall (it will get torn to pieces) and install it correctly. The ‘fix’ is simply a band-aid, akin to use after cutting off your arm. It’s ‘something’, but it’s not the right something.

      • Stephanie

        Thanks Roger. Contractor’s solution as an alternative to gutting is to sand the polished marble making it a honed finish to get rid of chips and lessen the look of lippage. I like honed and polished equally, but my concern is if this even a good option? Can this be done even with grout installed? Thanks!

        • Roger

          Yes, it can be done. But it needs to be done by someone who knows how to do it. It requires more than simply ‘sanding’ it.

  • Matthew

    Hi Roger,

    Quick question my wife and I picked 12 x 12 tiles and decided we liked the larger grout lines so we went with 3/16″. The tile was placed at the front door and back door so we were not coming in and stepping on our wood floor. So we placed transition strips in between the tile and wood floor. We happen to like the grout lines larger, do you think the grout lines are to large for a smaller area (15sqft at front and 15 sqft at back) just in front of the doors? We like it and have had several people say they like it and some not so much. Any suggestions you have would be great before I mortar the tiles in place.

    Thanks

    Matthew

    • Roger

      Hi Matthew,

      Grout lines are a subjective matter. It really makes no discernible structural difference between 1/8″ or 3/16″ grout lines. If you like the larger ones there’s no reason you can’t do that.

  • Tiffany

    Hi Roger, your website has been super helpful! One quick question – for a tiled kitchen backsplash, is greenboard an acceptable substrate for that? We currently have greenboard up, and we’d prefer to not put another layer up for the tile to go on if possible. Thanks so much!

    • Roger

      Hi Tiffany,

      Yes, you’re fine with that.

      Get to tiling! Whaddya waitin’ for? :D

  • Bill

    Hi Roger. I just found your web site and love it. I’m going to be putting 12×12 inch ceramic tiles on my shower walls (from tub to ceiling). The walls are green sheetrock. I’m just checking if using an adhesive is better than mortar here. Thanks.

    • Roger

      Hi Bill,

      Doesn’t matter what you put it up with if you’re installing it over green sheetrock, it’s gonna fail anyway. Green sheetrock (greenboard) IS NOT a proper, nor approved, substrate for tile in a wet area. It disintegrates when it gets wet. And it will get wet. It’s that simple. You need an approved substrate up there like densshield, cement backerboard, or you can use kerdi over the greenboard. But you need something behind your tile to waterproof your substrate and prevent water from making your wall disintegrate. If you download my shower waterproofing manual it will go a long way to explain what you need.