One of the most asked questions by do-it-yourselfer’s is whether they should use caulk or grout in the corners. Industry standards state that a flexible material be used at all changes of plane. But! – if you ask a hundred different professionals you will more than likely receive fifty of each answer. While there are pros and cons of each, I am in the camp that uses caulk. That being the case, I will discuss using grout first. I’m backwards like that.
Using Grout at Changes of Plane
While the phrase “changes of plane” may sound a bit uppity or technical – it’s not. It simply describes the corner or edge of any surface that changes direction such as a corner, a wall to a floor, or a wall to the tub edge. Many professionals simply grout that corner as they do any other space between the tiles. There are a couple of things that must be taken into consideration before choosing this method.
- Your walls and the framing of your shower must be absolutely rock solid. I do mean absolutely. Grout is a cement-based product and as such is not meant to flex. If your wall moves your grout will eventually crack – it’s that simple.
- The space between the tiles at the change of plane must be large enough (for sanded grout) or small enough (for non-sanded grout) to be able to support the grout. That simply means that if you are using sanded grout you cannot butt the tiles against each other at the corner and expect to be able to force grout into it. It will not stay if the grout has no grout line to hold onto – if it is simply attempting to grab onto the face of the tiles at a 90 degree angle. There must be a grout line at the changes of plane.
- You must decide you are going to use grout at the changes of plane before you install the tile. You can then make sure to leave a line for the grout as well as adding additional support for any spots that may move even the tiniest bit (which it should not do anyway).
If you have taken the above points into consideration and still decide to use grout in the corners – go ahead. The big advantages of using grout here is that it will match all the grout lines and it will never have to be replaced. So although extra care must be taken to properly use grout at your plane changes, the advantages for some people are worth the extra time.
Using Caulk at Changes of Plane
There are several advantages to using caulk in corners and any other area where there may be a plane change or where tile meets another material such as your bathtub or sink.
- Unlike grout you are able to use caulk in a corner where tiles are butted against each other. It will stick to the face of the tile rather than needing a space between the tiles to grab.
- Caulk is flexible. If there is any movement the caulk is flexible enough to move with it and remain in place. It will not crack out or fall off.
- Caulk is waterproof – grout is not. Water will collect in corners such as where your tile meets the tub more than it will on the face of the tile.
- If your caulk does crack out or need to be replaced it is easily done.
The only two disadvantages to using caulk instead of grout are that you need to periodically remove and replace the caulk and, depending on your choice of grout, you may not be able to find a caulk that matches exactly. The first reason I consider to simply be regular maintenance and the latter is less of a problem since most major grout manufacturers sell matching caulk.
When to Use Grout
The only time I will use grout for a plane change is when I am using epoxy grout. Epoxy grout is bulletproof! OK, maybe it’s not bulletproof but you can hit it with a hammer a couple of times before it chips. (Don’t do that.) If you are using epoxy go ahead and grout the corners and changes of plane as well. Although it is not flexible it will grab the tile well enough to prevent it from splitting or cracking out. Precautions must still be taken but the Epoxy is strong enough to withstand normal structural movement.
How to Decide
Given the above parameters I believe caulk to always be the best choice. What you must understand about tile installation is no matter where you are installing the tile, it is always a structure that moves, no matter how minutely. Concrete moves, (the ground beneath it) that’s why it has expansion joints – to control where the movement goes. Most shower installations are over a wood structure of some sort. Whether you have drywall, backerboard, or a membrane, if you go far enough behind the tile, you’ll find wood. Wood moves, it’s just a fact of life. Humidity, weather, even the structure’s foundation all affect how much it moves. By taking proper precautions you can minimize the movement, but it’s still gonna move. Taking structural movement into consideration caulk is, for me, the logical choice.
Hi Roger,
I love your site.
I’m really at a loss as to what to do here. I understand that (a) the tub-to-walltile joints should always be caulk because it’s a change of plane, (b) one should never caulk over grout, especially in this location, since it’s a surefire recipe for mold.
My plumbing/tiling sub installed the tub tile and it rests directly on the tub edge. For the tiny hairline spaces between the tile and the tub (1/16″ or smaller), he decided it was a good idea to grout it with the intent to caulk over it later.
Now I understand the proper thing to do in these instances is to remove the grout, pack the space with bond breaker tape or a closed cell backer rod (per Laticrete support’s advice), and then only use caulk in the joint. But as you can see, there’s not much room here for the inserts, let alone the caulk. I’m not even sure the grout can be removed in such tight confines.
What is the best thing to do here short of pulling out all the tile and recutting? That’s not really an option unfortunately.
Thanks so much!
Hi omg,
You need to just remove the grout and silicone there. You don’t need the backer rod or the breaker tape – those are for large spaces (like 1/4″ or larger).
Roger: Questions about leaving gaps at the change of plane for both the tile and the cement backer board.
Backer board – I’m putting backer board on the ceiling as well as the walls. I believe I put the ceiling board up first. Do I butt the cement wall board directly to the cement ceiling board or leave a gap? If gapped, do I fill that with silicone?
Tile – which goes on first, the wall tile or the ceiling tile? My thought is the ceiling tile first, then bring the wall tile up and leave about 1/8 gap between wall and ceiling tile and fill with silicone that matches the grout color. Is that right?
Thanks again for the help. Great site!
Hi Ken,
The ceiling should be gapped, but it should have silicone in the gap to keep thinset out of it, then it needs to be taped and mudded.
I normally do the walls up to the last row, then install the ceiling, then finish up the wall. But yes, you’re correct about the gap and silicone, but you only actually need about 1/16″.
Do you consider shower corner shelves (the preformed ceramic kind) to be a change of plane? Trying to decide whether to caulk or grout between the shelves and the tile.
Hi Cameron,
You can do either. I normally silicone it, but I’ve grouted as well without problems. Doesn’t mean you won’t have any, just means I haven’t.
We are using sanded caulking to fill in change of plane where the tile walls meet but some of it has cracked. Called tile store and they said to put more over it, so I did and am waiting to see how that works. My concern is that we have a gap of not quite 1/2 inch between surfice of tub and tile,oops! I know its only supposed to be 1/4 inch,asked tile store their suggestion was to grout that gap no caulking would work. What would you suggest? Help
Hi Larry,
I would go get some backer rod (it’s just cylindrical foam) and stuff that in the gap, then apply silicone over that. Sanded caulk will work, but it loses elasticity much sooner than silicone, silicone is much more forgiving of movement.
Thanks for your reply, could we use our color matched sanded caulking first over the backer rod then appy clear silicone over the caulking? So we could have our color match the rest of our caulking and grouting,since the silicone only comes in white,clear and almond?
Yes, you can. But all the grout manufacturers have silicone that matches their grout – every one of them. You’ll likely have to order it online, but it’s available. Silicone is available in every color you ever want.
Roger
Question about tiling a niche, using epoxy grout (for the first time). I am using a mosaic sheet for the back wall of a niche. Is it better to butt the tile used for the sides of the niche tight up against the mosaic and use calk or would it be better to leave a grout line?
Thank you!
Hi Danny,
I usually leave about 1/16″ in all the corners of the niche, then silicone them.
Hi, I am tiling a shower wall with a premade pan. My question is about the flange where you screw it to the wall. Is there a way to make it so the screws don’t show? Can it be tiled over?
Hi Rachel,
Your wall substrate should either run over the face of the flange or sit on top of it. Your tile should go all the way down to within 1/8″ or so of the horizontal portion of the pan edge. So the tile should cover any of those.
Roger,
Great website, very informative. My question concerns the “change of plane” tile area in my shower. Between my shower wall and mosaic tile floor a larger than normal gap was left after the shower was tiled, whether a cause of wood expansion or poor tile workmanship not sure. Regardless, I have been fighting the problem with conventional caulking grout as recommended by many grouting websites. However, the gap in certain places is probably less than 1/2 an inch at most, but the depth goes the entire depth of the tile which I believe my be a quarter inch. No matter how much caulking grout I pump into the opening it never fills up good enough and I feel that water still penetrates behind the tile. I have a membrane shower pan that goes 12″ up the wall, so I am not to worried about water leaking, but the gap just is not filled right and constantly develops mildew and is always wet in the gap behind the grout when I remove to replace. I wanted to try and use regular sanded grout to fill in the gap better since it will solidify, and then maybe build up enough of the gap with cement grout to add a layer of caulking grout on top. Any suggestions? Thanks.
Sal
Hi Sal,
Go to a big box or hardware store and get some backer rod, it’s just cylindrical foam you stuff into the gap to take up most of the space, then silicone over that.
Hi Roger,
Tried to read all the frequently asked questions to minimize asking the same old questions and wasting your time. Here’s the skinny. Have a tiled shower that has black and green mold around the edges. Figure I’ll re grout the whole floor as the grout is literally GONE from around the drain. In the process, the grout Dremel tool hit pockets where the grout disintegrated and minutes later I could see the grout change in color as the water started to fill those holes. So figure I’ve got water in my pan. No biggie, we have another shower, I’ll wait it out. It’s been a week and we still have moisture. Are we screwed? AS in- take out the tile and figure out what’s going on with the pan? House is 25 years old- built by owner who was a contractor. He cut corners everywhere, including setting the tile in this same shower with no grout line, so it all looks shitty. Really did not want to spend a fortune but what is your advice? Wait as long as it takes for the pan to dry out and then grout/caulk the hell out of it? WHy is the water getting stuck in the pan? Can’t seem to find the drainage holes in the drain- is it possible it was not installed correctly? I smell $$$$$.ANy help would be appreciated!
Hi Kitty,
It sounds like your weep holes are clogged. That may have been done when the liner was installed, if they weren’t blocked off properly. This will cause your shower floor to retain water, almost indefinitely. You can remove the tile around the drain, out to about six inches, and dig down to open up your weep holes, block them off properly, replace the deck mud and reset your tiles. That should solve the problem (I’m assuming – I can’t see it from here, but it’s worth a try…)
I found your web and highly appreciate it. I am a DIYer to repair all needed around the home: a small, old but still stable town home.
I am repairing a shower because some loose tiles on the bottom of one wall, total 9 pieces. Now, I am put the tiles on…… and so on. I have some questions for you:
1) at the bottom of the last row of tiles, a grout line existed there, it is hard to clean all because they stayed there decades. Can I caulk directly on them?
2) the existing shower have the walls not built straight. So inside corner gap is not even space: inside corner gap from 1/16″ to half inch (top to bottom), should I, 1) fill those gap as needed with caulk saver (or great stuff form spray) first, then caulk on them, 2) just fill up with caulk layer by layer, use different caulk: sanded caulk for big gap and no-sanded caulk for small gap,
What kind of filler is good for shower: exterior, moisture repellent caulk saver, spray foam from GREAT STUFF, ……..
I cannot find something special for shower use, can you suggest one?
There are only bottom tiles loose. So I just remove those files, bad grouts and some caulking to repair. I have not very much but always in irregular case.
Hi Effie,
1. The grout should be removed and replaced with caulk or silicone.
2. I would cut a larger tile to fill the entire space. But you can use a foam backer rod to fill most of the gap, then caulk or silicone.
100% silicone is always best in a shower.
New shower , new tile . Tiler put a rim of grout around the top of the shower tile bordering on the ceiling. Plus he put a couple of long but not deep gouges in the ceiling The grout line feels like cement and isn’t pure white like ceiling or tile. How to make this look nice and seemless. Should I just paint the grout line next to ceiling and just paint over the gouges as well ?
Thank you for your help .
Hi Elsie,
The grout should be removed and replaced with silicone. The drywall can be repaired with drywall compound.
Hi,
I had a new shower installed in my 1800’s house awhile back. Of course the corner of the shower settled a bit after the first year or so and I had a decent crack in the Mapei Keracaulk along that corner wall at the level above the drain pan plastic. I experienced some shower leakage, which I could see via the ceiling in the basement below the shower. There were no obvious plumbing leaks so my contractor chalked it up to the “crack in the wall” and recaulked the area. Six months later I can’t tell whether or not it has stopped leaking since the dark stains on the AdvanTech flooring do not respond to heat or dehumidification (they are not wet to touch). My contractor thinks everything is “fixed” now, but I notice that some of the Keracaulk along the floor/wall line is bubbled and soft. Any thoughts? I really don’t want to have to rip everything out, but I don’t want mold/mildew. Thanks!
Hi Kristin,
It’s still leaking. Caulk will not fix a leak in the shower substrate, which is where your waterproofing is (or should be).
I had a guy come and repair a spot in our tub where the faucet had leaked and the dry wall was crumbling, and tiles coming away from the wall. In the end, he grouted where the wall met the tub (change of plane).
What shall I do now??? This occurred yesterday. I wish he’d asked me. I expected caulk there, and would have stated so. It may have been “epoxy” grout. Should I call the guy back and ask him to remove the grout and install caulk?
Also, my husband is the one who installed tile in our floor to ceiling shower. And some of the corners have some grout in them. Can we caulk over the grout?
Thanks!
Suzanne
Suzanne Hughes
Hi Suzy,
All grout should be removed in any change of plane and replaced with silicone. Caulking over grout doesn’t work, the grout cracks anyway and debonds the silicone.
Roger,
Can i caulk over the bottom grout line just above my shower pan? 100% silicone caulk? is there another option for keeping the grout dry and mold free?
Hi Keena,
If you have grout in that space it needs to be removed. Yes, use 100% silicone there. Your grout WILL get wet, eliminating mold is simply a matter of water management – getting it to go where you want it to go. Don’t forget weep holes.
@TheFloorElf&/orRoger… This is by far the best site (for me anyway) for what I needed to learn, which at this moment, I needed information on re-caulking my circular shower bottom… should I start in the inside or outside? I know common sense would be start from the inside. But, I needed some reassurance. So glad, your site came up first on my list of the search. Your image of a beautiful custom shower held my interest. Then read the first paragraph, and that did it, I was hook line and sinker.
Thank you kindly.
Hi Paula Ann,
Yes, start on the inside.
just had a tiled shower installed…the person doing it put a line of silicon over the grout along the bottom (change of plane) of the shower as well as the corner up to the ceiling. I find it looks too thick and opaque (though not white). He did not put caulking where the metal part of the shower wall touches the tile wall and there are gaps (he caulked on the outside) I worry about water getting into the gaps and creating mould. Should there be caulking on the inside of the shower? I find that the caulking does not look uniform and may have to have him do it all over again! Thanks for any advice.
Hi Andrea,
There should be silicone both on the outside and inside of your shower door frame.
Hi Roger
We just had a glass mosaic tile backsplash installed in our kitchen, that looks great…except in the corners. The installer used a white caulking and I find that the line of caulk looks crooked and looks like it is in some of the grout lines? Is it possible to remove? I’m not sure what would look better, clear caulk? Thanks
Hi Cathy,
Yes, you can remove it. Clear may look better, or a silicone that matches the grout would look even better than that. You can just cut it right out of there.
I bought your tile design/art book PDFs and read it twice last night. So much information. I am not tiling a shower but want to learn good practices to know how to judge tile work. I also need to design tile for master bath remodel having a tub-to-shower conversion. It will be good size — 4×6 approximately. Not sure about final inside dimension because don’t have new plumbing run or Durrock up…using Rediguard or Artex liquid as waterproofing element I think vs Kerdi board I think…
I want to use Subway larger than 3×6 and include some mosaic or other tiles as design element. I am cautious about buying tile without accurate shower dimension…is that being overly cautious? I have so much about planning to achieve a good design and eliminate construction problems like not pre- blocking for grab bars.
Also you commented on translating a shower design in one tile size to another/large — something that was NOT a good idea…but I can’t find the reference after looking 3 times… Could you explain about resizing a shower design in larger/smaller tiles??
Thanks so much for such good info.
Hi Vicki,
Yes, that is being overly cautious. Are you trying to find the EXACT amount of tile you need? Because if you are, you’ll be short. If it’s 4×6 and you’re going to the ceiling multiply the total length of all the walls by the height of the wall. For instance, if you were replacing where a tub goes – 3×5 – you would multiply 11 x 8 = 88 square feet. One five foot wall plus two three foot walls equals eleven times the hieght of the wall – eight. A rough measurement is more than enough to figure out how much tile you need.
I have no idea what you mean by translating a shower design from one to another? Could you be a bit more clear on what you mean by that?
Hi Roger, the Schluter website says their profiles are maintenance-free. That sounded nice so I thought I would use Dilex EKE for the floor/wall corners and also the wall/wall corners. Do you have experience with them and if so, do you like them?
Schluter takes forever to send stuff so while I’m waiting, I thought I’d plan out the niche placement and apply the membrane. If I am using the 11/10 (7/16″ x 3/8″) for the floor, how high off the floor should I plan to place the first course of wall (subway) tile? Would it be 7/16″ or should I add some space?
Thank you so much for taking on all these questions and imparting your wisdom!
Mary W
Hi Mary,
Yes, I like them a lot. I would begin the first row 1/2″ off the floor. Actually, I would begin at the second row, measuring 1/2″ plus your tile height on the wall, then cut the bottom row if it’s needed.
I had a handyman build a tiled shower that should have been left to a contractor. It’s been about a year and sure as heck the grout has cracked at the plane changes. I am unable to get all of the grout out but I did use a grout removal tool to get most of it. Can I caulk over grout? Also does this need to be etched before I caulk it? How long do I need to let these corners dry before applying caulk? Seems like that leftover grout holds some water.
Hi Jeff,
If you can’t get it out you can silicone over it. As long as the tile is dry you can silicone over it. Silicone will bond to damp grout.
Thanks for the reply. I let the shower dry with a fan running for about 3 days then used caulk that matched my grout (got it at Lowes) and caulked every intersecting plane. I really don’t trust caulk but I guess we shall see. Next time (I’m sure there will be a next time) I’m going with epoxy grout. Then I’m gonna dump 2 gallons of concrete sealer in there slosh it around and call it a day!
We have yet to move into our home. Our builder has already grouted our tile, but there is of course some cracking of the grout in the corners. Is it ok to apply a layer of sanded grout on top of the grout In all of the corners?
Thanks in advance!
Hi ??? (Are you Lee or are you Jeff?),
No, because it will crack again. It would be okay to dig all the grout out and silicone it, though, as it should have initially been done.
We have yet to move into our home. Our builder has already grouted our tile, but there is of course some cracking of the grout in the corners. Is it ok to apply a layer of sanded grout on top of the grout In all of the corners?
Thanks in advance!
Hi Jeff,
No, because it will crack again. It would be okay to dig all the grout out and silicone it, though, as it should have initially been done.
I have installed mosaic tile above my tub surround. It does not get wet where I installed the tile. I was planning to caulk the corners and the area where the tile meets the surround. I left room for the caulk. Do I caulk those spaces before or after I grout?
Hi Connie,
You can do either, I do it after grout.
O.K. Roger…here we go again…this time my customer chose real slate 12″ x 12″ for the walls of the shower. I convinced them to use faux slate porcelain 2″ x 2″ mosaics for the floor only! I am using Kerdi board this job and Schleuter shower pan and drain..other than the sheer weight of each tile any pointers as to how to keep them on the wall…no slipping, proper mortar etc. Also can the edges be sanded down to a bullnose edge or is Sleuter strip in order…noticed that thickness is NOT uniform…Hate Slate!
Hi Ramon,
I hate slate too. Just support each row with the row below it. Regular unmodified thinset will be fine. Yes, it can be sanded down for bullnose, but depending on the slate it may begin to ‘cleave’, or separate along the layers, when you do it. An edge trim is normally a better choice.
I noticed that most tile caulk comes as sanded or un-sanded. Do the same rules apply as sanded and un-sanded grout (1/8″ gaps)? I’m trying to figure out what to use for my shower corners and floor changes of plane where they are butted up against each other. There are more colors available with the sanded caulk but if the 1/8″ gap rule applies then I guess we’re stuck with a smaller color selection.
Thanks for all of your help.
Hi Sue,
You can use either, it’s sticky. As a general rule yes, the same rules apply. But you can use sanded caulk in butted corners. (WHY are they butted?!?)
We went ahead and butted the tile because your article above stated:
“1. Unlike grout you are able to use caulk in a corner where tiles are butted against each other. It will stick to the face of the tile rather than needing a space between the tiles to grab.”
Now you have me nervous. Is there an issue?
Hi Sue,
It depends on how much your walls move. No way to tell unless a problem arises. It may be just fine.
Just wanna say thank you roger . and ask if you have any tips on minimizing lipage on a uneven wall ? never noticed it till now , first ever tile job or ida corrected this before the backerboard went on live and learn but to far to back up now . Redgaurded and all so just wondering if theres a way to minimize the lipping ? thank you roger
Hi Jeff,
I would use a larger trowel to give you the ability to adjust the tile in or out as needed.