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.
You mentioned that it would be okay to use Epoxy grout in corners and changes in plane. I used the Quartzlock grout which is a urethane grout (they consider it a good alternative to epoxy), would it be acceptible to use that grout instead of caulk in corners and changes in plane?
Hi ErinRandy, is that a nickname, last name, or statement?
Nevermind – I digress.
You can use Quartzlock in the corners if you want. It does lend some flexibility to the changes in plane. It may not, however, be enough flexibility for your particular structure. I simply don’t know. Worst case scenario is you’ll need to remove it from the corners at some point down the line and replace it with silicone. No big deal.
You can use epoxy because it is stronger than most internal forces in the planes of the wall. And I only do that when I build the shower – so I know what it’s gonna do. It’s two totally different reasons. Epoxy – strong, no flex Urethane – strong, flexible.
Go ahead and give it a shot. You’ll probably be fine. If not it’s just a matter of replacing it with silicone – it won’t compromise anything in your shower.
I love your site Roger!
I will read more later to make sure I can glean from others’ experiences what applies to mine, but I’m stuck on my shower for months now as I slowly work through being too cheap to use a contractor and yet being too respectful of the job to rush it. I will be back later to hopefully ask you some more questions. Plans for now are Redgard over Hardibacker, then ceramic tile, a modest sized walk-in shower — it’s about 3/4 backered and I have worries about every seam, screwhead, transition and joint I can see. Any questions I research online seem to always have not the ‘it depends’ I expect but a firm ‘this is the way!’ and then lots of people going with both approaches. Now I know why people pay others. Still, I remain determined to do this myself and learn the DIY way. I enjoy that part, I just don’t want to experience the ‘oh you really screwed it up and it leaks’ part.
Thanks
Hey Mike,
I’ll be right here. If it helps any you don’t need to be worried about the seams or screw holes if you’re using a topical membrane such as redgard – they have nothing at all to do with the waterproofing. All these are addressed after the substrate is up. So put down your beer and get back to work!
Hey Roger,
I need to seal natural stone tiles and grout. Should I seal with a waterproofing agent before I caulk the appropriate areas or after?
Rob
Hey Rob,
Before. Some sealers will make silicone look cloudy or lighten the color, leave a film, etc.
Hi Roger, just grouted my tiled tub surround in my bathroom and I left all changes of plane without grout so I can caulk them… as caulk seems to be recommended for changes of plane. I have a couple of questions though. I grouted my tile in the tub surround with ivory colored sanded grout from Mapei. My gaps are 3/16 inch.
1) First, the caulk that Mapei sells to match the ivory grout is called Keracaulk Sanded Siliconized Acrylic Caulk. This obviously means it is not 100% silicone. What worries me is that it says it is not for use in areas prone to constant water exposure. Some of my changes of plane are in a niche that is built into an area that will receive a great amount of water spray (I know this is a no no for niche building, but the niche looked best there and I did waterproof it with RedGard to be safe), so will this caulk be fine for these areas that will receive quite a bit of water during showering? Or should I just grout the changes of plane here instead?
2) Do you always use 100% silicone in all areas of a shower or tub surround? I was wondering if I could use siliconized caulk, or acrylic latex caulk in parts of my tub surround? Like where the tile meets the ceiling? I’m assuming that where the tub meets the tile surround, you would only use 100% silicone… but maybe where two tiled walls meet in the surround you may use other types of caulk.
3) Third question is regarding the debate between caulk and grout for changes of plane. I know that caulk is generally recommended for changes of plane because it allows for movement more than grout, and thus should not crack, and it is more water resistant. However, it looks like caulk can crack too from what I have read online, but maybe not as easily as grout. In addition, caulk can be a real pain in the A## to remove (especially silicone), and if you have a tub surround you’re supposed to annually remove and recaulk your tub. Whereas grout doesn’t really need to be regrouted unless it cracks or gets super dirty, which may not happen for years. Wouldn’t it make more sense to just grout for changes of plane, and then hope it takes years to crack, in which case you then just regrout? Or is it really more beneficial to caulk?
If you are using Mapei #39 Ivory you can get Laticrete #17 Marble beige (latasil) and it matches perfectly. Acrylic-based caulk tends to dry out over time and lose its elasticity, it will need to be replaced more often. Every year is a bit of an exaggeration, though. If properly installed you should not need to replace silicone more than every 5-6 years. Acrylic-based may be about every 2-4 years depending on how fast it will dry out and begin to crack. Grout WILL crack within the first year. Seasonal changes will move the walls – every year – grout will absolutely not compensate for any movement.
You can grout the changes of plane in your niche, although silicone would be better. The length of your changes of plane in a niche are small enough that cracking should not be a problem, there won’t be a lot of pressure moving those planes differently. I always use 100% silicone – it just lasts, plain and simple. You can use siliconized or acrylic caulk, but you’ll be replacing it more often. If you grout you’ll be replacing it about every six months.
Thanks Roger, you’re the best! That was very thorough and informative and you have made sense of some things that I was having trouble understanding. Thanks again:)
Love your articles! I have a question about tiling a tub surround. There is a gap between the wall board and the top of the tub(not the flange that comes up, but the flat edge of the tub) of about an inch. How do I address this gap for tiling purposes? It seems a little big to fill with caulking, and I know that I can’t grout right to the tub so any suggestions? Everything I’ve read says to leave a 1/4inch gap at the bottom of the tiling, between tub and tile,to caulk but this seems excessive. It needs to be filled with something so I don’t have a void behind the tiles, doesn’t it? I’m sure I could mickey mouse it with caulking, just fill the gap up, but I don’t know if that is right. I really don’t want to be doing this bathroom again in 6 years.
Thanks in advance
Hi Tracy,
There actually can be a void behind the tile right there. Anything you put in there is going to crack or fail due to differential movement between the tub and wall. The tile actually just hangs over that gap. You should leave a 1/16″ – 1/8″ gap and silicone it – not 1/4″, that’s huge.
Thanks so much Roger. I got the same answer from a contractor friend last night at a party, but we had both had a couple glasses of wine, so it’s nice to get confirmation from someone who is not in their cups
Tracy
Roger,
Thanks for the article. I have a 4 year old home and a standing shower in the master bath with a shallow tub for the floor (not tile) and tile on the walls. As I was scraping off caulk where the tub meets the tile large chunks of grout (about .5 to 1″ deep) came out from the edges. This made me nervous that there might be water damage (as I’m not handy) but now just believe the settling of the house cause the grout to crack over time. Should I fill these spaces with caulk or fill it with grout and then recaulk over the edges as I had originally intended?
Thanks!
Daniel
Hey Daniel,
Any edges of the tile or changes of plane (like where the tub meets the tile) should have silicone or caulk. The only place grout should be is between the tiles.
I gather now from your article and other resources I’ve read. I went ahead and filled the gaps with caulk. I wonder though why the home builder chose to use grout between the tub and the tile and then caulk over it also. *scratches head*
Thanks!
They grout it because it’s quicker and matches the grout. They place silicone over it because they think it waterproofs the corners and they aren’t educated on proper waterproofing techniques. They go with the lowest bidder – and they get the work that reflects that.
Roger:
When it comes time to caulk the tile to the tub and the floor to the tub, at both these junctures do we fill the tub with water? Does it matter if the water is hot or cold? How far up should we fill the tub, and does it matter if we stand in the tub or not?
Hey Jane,
When caulking above it fill it, when caulking below it don’t. It is there to add weight to the tub so after the silicone cures the natural state with an empty tub will be compressing the silicone. That way when you fill it and get into it the weight won’t stretch the bead and debond it.
Doesn’t matter if you stand in it at the same time, just roll up your pants.
I have porcelain tiles on my kitchen backsplash. I’m thinking of caulking the seam by the sink area, where the backsplash meets the countertop. My tile guy put grout on the seam and I’m concerned water splashing from the sink to the backsplash will eventually ruin the grout. Can I use silicone caulk over the existing grout, which is probably less than 1/8 inch thick as the backsplash shifted down when the window guy hammed in the window sill. Or do I need to remove the existing grout before applying silicone?
Or am I better off sealing the grout with a sealant such as the the Aqua Mix Sealer?
Thanks in advance for your feedback.
Hi Helen,
The water isn’t going to be much of an issue but movement in the two different planes will eventually cause the grout to crack. You need to remove the grout – even going over it with silicone won’t prevent it from eventually cracking. Just remove the grout and replace it with silicone.
I have colored grout. So if I remove it and put clear silicone in the seam, wouldn’t this look aesthetically unpleasing? Because the silicone is clear, wouldn’t you be able to see the gap where the countertop and backsplash meet? I also don’t want to use white silicone. Are they any other options? How about epoxy grout? Do these come in a variety of colors?
Laticrete and custom building products both make color-matched 100% silicone to match your grout. I would use one of those. Epoxy is a completely different animal and not really the correct thing for your application.
Laticrete color-matched silicone
Thankyou, I think you its a fact of life things move is reassuring.
Roger I am talking about the tile not substrate. Im asking if the inside corners and where the walls meet the pan should be caulked first, before any grouting? If so , then when U start grouting how does the grout transition into the silicone caulk, its gotta meet up in the seams. Thx 4 getting back to me so quick cuz Im doing this today
Grout first, then caulk. Don’t worry about getting grout in the corners – about the time the grout is ready to be cleaned up, you can use something like a small slotted screwdriver and run it up and down the corners to remove any grout. Just be careful not to twist the screwdriver or move it around too fast – you could catch a tile edge and possible chip it / break it.
got your reply. Thx “A grouting I am a going”
What kevbo said.
That is the easiest way to do it.
With that typed, you can actually do it either way – a lot of guys caulk or silicone first – I do it every now and then. The grout is simply installed all the way to the bead of silicone and will actually ‘tighten up’ that joint as the crystals in the cement grow and compress the silicone. But grout first is a better, more efficient way.
So R U saying that all corners and where the walls meet the floor should be first caulked and allowed to cure before any grouting is done? How is the grout and caulk transitioned together ?
Hey Rich,
Nope, this article only refers to the transitions and changes of plane in the tile installation itself, not the underlying substrate.
Roger,
Would grouting the corners, followed by a bead of caulk make any sense? I have colored caulk to match the grout.
Nope, the grout will crack and compromise the seal of your caulk. Just use caulk, it’s made to compensate for movement.
One other comment if I may: the colored caulk you have – is it 100% silicone or are you referring to the sanded/unsanded acrylic matched caulke? If the former – pretend I did not reply. If the latter, these caulks are not suitable for wet/water applications, namely that joint at the shower floor/wall plane which will be exposed to a lot of water and remain wet for long periods of time.
Roger,
I’m getting ready to tile my shower walls. Doing them first and the floor last. Should there be a gap at the bottom, or should the tiles rest directly on the motar shower pan. If a gap, should it be caulked or grouted between tile and shower pan?
MP
Hey Mike,
There should be a gap at any change of plane – that includes the tile to the floor. You don’t need to do anything there between the tile and pan. Leave a gap between the floor tile and wall tile and caulk or silicone it rather than grout.
My .02 is that you will get a better overall joint / look if you tile your floor first to your perimeter edges and then the walls 2nd. This will leave the gap in the vertical plane and hides any out-of-squareness much better than on the horizontal plane. When you look down you will see the outer joint / tile cuts if you meet your floor tile to the wall tile. Just my opinion.
I would like to know what kind of grout to use on myshowers floor i am regrouting there is a 1/4 inch gape and less for some areas. I bought sanded grout but have heard I made the wrong choice. And also in the corners it was grouted but was separated but reading your earlier posts I think I will caulk I plan to do this tomorrow please help I have one other issue but it’s hard to explain I could send a picture if you have a email address that you feel comfortable giving out , I totally understand if not
Hey Joe,
Dunno who told you that was the wrong grout but they’re wrong. Sanded grout it what you need for that. You can upload any photos you want to my site and I get them in a special super-secret area here in the back of the website. It’s guarded by midget ninjas and one large rabid ferret. You can do that here: Upload tile photos to FloorElf. Be sure to add your name to the photo so I know who it’s from. You can also email me at Roger@FloorElf.com – that email has no midget ninjas guarding it, though.
Two years ago I had my shower redone by a low-bid contractor. He’s long gone but he left me with a floor that is not sloped properly. After two years of using a squeegee every day it is time to fix it. I believe the only way is to rip out the floor and reinstall with proper slopes. My worry is that I will be unable to find the same tile as was used originally. Have you ever seen shower floors that have different tile than the walls and ceiling? Any creative solutions? Or is there an alternative to ripping out the floor?
Thanks,
Sucker in Texas
Hey Bart,
I do a lot of shower floors with different tile. Just find one that compliments or offsets your main tile and use it. No real alternative to fix the slope other than rebuilding it. If you get a tile that’s real close just turn it on the diagonal – no one will ever notice it’s different.
Hi Roger,
I am a 48 yr old female in Sydney, Australia. No this is not some sick stalkers letter. I just wanted to let you know that my husband and I are renovating our bathroom and that your information has helped us a lot. Don’t you love how this internet thing closes the gap between our countries. “thanks mate”
Hi Tracey,
Thanks for letting me know! Always wanted to visit Sydney. One of these days…
We have been struggling with this matter as the silicon in our shower went crappy after only one year.
Enjoyed your article very much and appreciated the good advice and good humour
Glad I could help Eric.
Hey Roger. Let me start saying this was a great article as I have seen this question danced around and argued about constantly on countless forums. I am glad to have read this as I have recently taken on a shower regrouting project. Now on to my question…recently I have purchased a duplex, one unit I reside in and the other I rent out. The idea being that later I can move and rent out the entire duplex. The issue I am having is that there was some settleing on the backside of the house which both of the units all tiled master bathroom showers sit on. The settleing of the house has stopped many years ago and the foundation is sound, but because of the settling the corners of the shower are below the water line and dont fully drain out if you were just to let the water sit there after showering. It is nothing extreme to the point of a lot of water pooling in the corners, but as I would imagine any amount of pooling water is never a good thing. The grout around the edges on that side of the shower is pretty much shot, I have scraped and dug out all grout (rotten and good) around all of the edges of the shower. I then repeatedly shop-vacced any sort of dampness that was in the corners or edges after removing the grout and placed a fan on it for days allowing everything to dry out completely. I would like to use something that I will not have to maintain very much and will last, so I am thinking of using Epoxy grout so that I will not have to come back and bother my renters and scrape caulk out every 3-5 years or so and reapply. Some of the corners I had to dig into quite a bit to get the “bad” material completely out and I was wondering if I can pack as much grout into the corners and call it good or if there is other stronger more sealing material I will need to build up the corners with to allow for a better seal? Also is the Epoxy grout going to be a good route to go? I have dug up the bad grout and I am going to regrout the edges and “reseal” the old grout that is still in good shape on the tile floor of the shower. Any advice or concerns you may have would be apprecaited.
Hey Ian,
Short of rebuilding the shower floors the epoxy grout would be your best bet at this point. You can fill those cracks with the epoxy and likely have no problem with it – depends entirely on how much your house moves. IF your house moves enough to overcome the bond of the epoxy to the tile – the grout will not crack, the tile will. Keep in mind that although epoxy is waterproof this is not going to waterproof anything because tile is not waterproof. But the epoxy will definitely last.
Roger –
First off, thanks for your article and advice.
My tiled shower has what seems to be a large gap between tiles in the corner … I’d say a little more than 1/4 inch at the widest point. The walls where the shower is built do tend to move some. Long story short, I had concerns about this movement and I hired an independent structural engineer. Our floor joist under that wall is lacking support and causing the wall to move some. The structural engineer said it is not something that we NEED to fix and so at this point I don’t plan to fix it. So, I would like to know your opinion on the best way to seal this rather large space in the corner of my shower that will likely continue to move in the future. The material will need to cover a large gap and be flexible enough to allow some movement. I heard something about a blocker or blocking rod … not sure what that would be or if I am on the right track.
Thanks again.
Hey Rob,
You can use backer rod and silicone. The backer rod is available at any big box store and is essentially a round rod of foam which can be stuffed into the gap to take up most of the space then go over it with silicone. The silicone will handle the movement.
Roger, thanks for the tips. I am hoping my corner re-grout will go well. You are not a jackass.
Based upon emails that I received from subscribing to posts in this thread, there was a post which was removed (and rightfully so) which equated the floor elf to some sort of fool who give advice like a tile setter from the 1960’s.
To that – I’d like to say this: I would rather take any and all advice from a tiler from the 1960’s than from some “California contractor for 20 years”. 20 years would put us back to the 90’s. As a contractor from Massachusetts, I’ve torn apart enough bathrooms with horrendous tile jobs installed in the 80’s and 90’s to know that these guys could have learned a thing or dozens from the guys of days gone by who did quality work.
Cheers to Mr. Floor Elf for giving some quality, sound advice for those looking to do some quality, sound work!
Thanks Kevbo! Yeah, my site got trolled yesterday, it was pretty humerous because while I was working my ass off in a shower at 2pm the ‘real tile pro’ was dumping brain feces all over my comment sections. Other readers attacked him back, made me laugh my ass off and feel all warm and fuzzy when I got home.
You can see what I left and my response here if you care to. And you’re correct, I’d listen to hundreds of setters from the 60’s before I’d give one of these guys the time of day. People used to care about what they produced.
Thanks again.
In the shower corner, can you or should you use clear silicone caulk and then top it with the colored caulk that matches the grout? Will one caulk adhere to the other. Or is the colored caulk enough?
Thanks!!!
Hey Margaret,
Ideally a color-matched silicone (that matches the grout) would be used. Caulk will not stick to silicone (silicone WILL stick to caulk – weird, right?
). If you can’t find silicone then just caulk will be fine.
can you grout and then caulk over top with silicone in corners of the shower?
Hey Devin,
You can, but the grout will eventually crack and compromise the bond of the silicone, then it really looks like crap. So it’s not a good idea to do that.
any cogent diifferences between “phenoseal”(vinyl caulk) and Silicone caulk?
Hey Rick,
Yup, Phenoseal is not waterproof, silicone is. Phenoseal is only water resistant and is not for use below the water line.
From Dap:
DAP Phenoseal Vinyl Adhesive Caulk Does It All is a water based adhesive/sealant formula which is not recommended for use in below waterline applications (FOR BEST RESULTS: Do not use below waterline.)…
Based on the description of your application, we would generally recommend the use of a 100% Silicone Rubber Sealant.
This was sent to a customer after seeing re-emulsification of the product on and behind a shower seat. This simply means that when exposed to standing or continuous water phenoseal may turn to goop, a technical term meaning white gluey mess.
Stick with silicone.
A “seasoned” tiler champions the use of “phenoseal” (vinyl caulk) for all his caulking. Any real differences with that and Silicone caulk ?
Would that be different than a ‘seasoned’ user of the product in their own home?
I bet it would.