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.
Hello Roger,
Just grouted (Mapei Keracolor S grout) on our newly renovated bathroom floor. However, the grout dried with varies colors. Mapei offered us free bottom of Grout Refresh to fix the color. I understood that if we use Grout Refresh, we don’t need to use sealer on the grout. My questions are, is Mapei Grout Refresh a good sealer? If not, can we use Aqua Mix Sealer’s Choice Gold (for low VOC) on top of Mapei Grout Refresh for extra layer of sealer?
Monica
Hi Monica,
I’ve never used the grout refresh so I don’t have much info on it. Provided it is a penetrating sealer then yes, you should be able to use the 511 over it. If it is a topical sealer (coating) however, you’ll need to do one or the other.
Roger,
I am about to install the grout for my kitchen tile. My question is do I use caulking for all edges, including cabinets, baseboard, and adjoining hardwood floors?
Are there any areas where I could get away with using grout?
Thanks,
Mike
Hey Mike,
Yes, and no, use silicone or caulk for all those edges. Your installation will expand and contract, you need flexibility. Grout has none, silicone and caulk do.
Hi Roger
We are ready to grout and caulk our newly tiled shower. Our tile shop has advised us to use a sanded caulk in the corners. We were wondering what is the difference between sanded caulk and silicone caulk and which is better? Which would you recommend? Thank you!
Hi Mary,
Sanded caulk is acrylic-based rather than silicone. It will work, but you’ll need to replace it more often. Acrylic dries out and loses elasticity whereas silicone does not. Either will work, I always recommend silicone.
Hello Roger,
Do you know anything about Sashco Sealants White Lexel Adhesive Caulk? If so, is it a good product? The other one that I can find is GE Silicon II.
Thanks,
Monica
Hi Monica,
Never heard of the Sashco but I know the ge silicone II is very good stuff. I use it quite a bit.
In my shower I have a window. I want to tile completely around it. So would you use caulk on the edge where the window ledge meets the shower wall?
Nope, grout outside corners around a window.
I am tiling a bathroom countertop. I put te backsplash up first. In putting the countertop tiles in place, do I need to leave a gap at the point where the tile and backsplash meet or just butt them up tile to tile. I see from your other posts that caulk would be used if there is a gap. Thanks.
Hi Jim,
You need to leave at least a 1/16″ gap there and silicone it.
What are your feelings on using premixed urethane grout (e.g., Star Quartz Lock)? Are the claims true that the polyurethane resins produce a stronger bond between its sand particles and it is color and stain resistant? Is it worth the extra cost? Also, is it as strong and durable as the epoxy grout mentioned in your article and thus able to withstand structural movement? Or, should I just caulk the corners?
Thanks!
Hey Steve,
I don’t know that it produces a stronger bond between the sand particles – a different bond, maybe, not necessarily stronger. My experience with it is that it is color consistent and stain resistant like epoxy. You always, however, do want to silicone your corners. I only epoxy my corners when I build the shower from the frame out, and there are a LOT of factors that go into doing that. Both epoxy and urethanes are worth the money simply for the ease of cleaning factor.
My bathroom consists of a toilet and an open shower, I have fitted a shower curtain, but I want to fix a waterproof barrier between the shower and the toilet bowl, so that when you shower, the water stays in one area. I have tried some sealants, but I have found that they don’t adhere to the floor tiles. Is there something I can use that will do this job.
Hi Rick,
Not too sure what you mean by ‘fix a waterproof barrier’? Do you mean something like a shower curb to the existing tile (that’s what I’m coming up with) or something else?
If the former you can get a thinset approved for use over tile (ultraflex 3, laticrete 254 platinum, etc.) and build your curb and bond it to the tile in that manner.
If the latter you’ll need to give me a bit more information as to what you’re attempting to do there.
Thankyou VERRY informative and very helpfull
Hi Roger,
I have a new tiled shower, with gray grout and matching colored caulk in the vertical corners. The tiles go right up to the white painted ceiling… I’m wondering if I should use the gray caulk for the tile-to-ceiling corners, or go with white caulk. Can you comment on what is most typically done in this situation?
Peter
Follow-up question… 100% silicone vs acrylic latex… The latter is paintable, but apart from that, are there any reasons to choose one over the other? If caulking between tile and wall (or ceiling), after all painting has been done, can 100% silicone safely be used?
I normally only use 100% silicone. It can be used safely in every application.
Hey Peter,
I normally use gray silicone in that application, but either will work. The colored usually looks best because it’s on the same plane.
Thanks Roger!
I’ve read all (or most of) your tips on tiling and grouting – thanks so much! I’m finally finished with the tiling and ready for grout and caulk. I’m planning to caulk the vertical corners of my tub/shower surround, as well as the inside edges of my niche.
My question is this: do I grout or caulk first? I know you’re not supposed to get grout in the seams where you’re going to caulk, so it seems like it would be better to caulk first. What do you recommend?
Hey Joanna,
You can do it either way. The only reason I don’t do silicone first is that I normally grout and silicone the same day – I have to do grout first. It is easier if you silicone first, let it cure, then grout.
Hi – I am not a experienced DYI person. I have a tile shower (ceiling and walls) with a swanstone shower pan. I have periodically used a spray sealant to go over the grout lines. This has worked well for three years of maintaining a clean non stained lines. The tile to top of shower pan is showing cracks and staining. I have taken out grout and re-grouted. I was going to use a silicone to cover this area only. Is this a worthwhile thing to do or just use the spray sealant here as well. After re-grouting, I am confident I can do this easily again but hopefully not soon. Also, as in previous post , the grout at the tile floor to base of tub is cracking. What do you recommend, re-grout or silicone? I have learned so much from your web site. Thanks Dee
Hi Dee,
Both areas you’ve mentioned are changes of plane. Beyond that they are different materials. This means that they will expand and contract at different rates – hence your cracking grout. Scrape all the grout out and silicone it, that will solve your problems. Do not simply silicone over it, the grout will still crack, but then you’ll have a bigger mess on your hands. Silicone only at the changes of plane.
We recently bought a 112-year-old house. The upstairs bathroom is right under the roofline and the previous owners – a remodeling company that bought the house when it was in foreclosure – redid the bathroom. The problem is that the entire tub and shower area was tiled (including the slanted ceiling) and grouted, and the grout in the corners is coming out in pieces. Our area is in drought and we had an extremely hot summer, so I have no doubt there has been some shifting. My question is this: how do you get the grout out of the corners without damaging the tile? Can you still use a saw?
Hi Diana,
Yes, you can still use a grout saw. Just be careful not twist it or tweak it sideways, just straight up and down. Take your time, it doesn’t work by speed.
I am remodeling my wobblymansion, er, manufactured home. It is NOT on a slab or stem wall, and even though I have lots of supports underneath, I know there will be movement. My master bath is 8′ x 10′, and I am concerned about the flex in the floor, especially with a bathtub full of water. I found a beautiful floor tile in 6″ x 24″, but I’m concerned with cracking. Is it possible to caulk all the joints instead of using grout? My thinking is that caulk seams would allow for movement without cracking the tile. I would do it myself, and can take the time to do it well.
Or should I give up on tile for the floor and use something else that is inherently flexible?
Also I want to tile the shower and entire back wall (10′ long, 7′ high) with glass tile. The shower will take up half this wall, the free-standing tub will be in front of the rest of the wall. Should I caulk a vertical seam between the shower and the rest of the wall to allow for movement?
Thanks for your help.
patty
Hi Patty,
If you install another layer of 3/4″ plywood over your subfloor it will likely be stout enough for your floor tile. You still need a proper tile substrate like backerboard on that, but it should handle your tile just fine. As long as you’re using glass mosaic tile (2×2 or smaller) then your glass wall will be fine as well. Yes, you need silicone at any changes of plane.
Hi, Roger
After building my alcove shower out of hardi and waterproofing it with Kerdi over the mud floor and Ardex 8+9 liquid membrane on the walls, I plan to tile the walls and niches per your hints. I was thinking on using either Schluter Dilex-EKE for ALL changes-of-plane inside corners (including at the wall base/shower pan), or simply using a silicone caulk.
With your experience what method would you prefer for longevity?
Although a pain to install, I have used the EKE on a recent tub surround project – but it’s too early for results.
And if silicone is a better alternative, what brand type should I look for (Latasil is not available locally, but Mapasil and the new Premium GE product is readily available – it has a 10 year mold guarantee)?
Hey Jack,
Both products are comparable in my opinion. The EKE lasts and works very well. The determining factor is normally simply price. Any 100% silicone works just fine.
Roger,
I’m planning to install a mosaic tile backsplash in my kitchen, but the countertops on either side of my range differ in height by about 1/8″. I plan to continue the same tile pattern across the countertops and behind the range. What is the best way to deal with the height disparity? The easiest option would be to leave a 1/8″ gap for caulk on the higher countertop and a 1/4″ gap for caulk on the lower countertop. Would this work? Should i cut 1/8″ off the bottoms of the tiles on the higher countertop instead? Are there other options I should consider?
Thanks
Hey Stan,
It will look better if you cut 1/8″ off of the higher one. You can also install the higher one with a 1/16″ gap and see if you can just work the mosaics behind the stove so they slope down ever-so-slightly so that by the time you get to the lower counter (30″) you’ll have about a 1/8″ gap there. you’re only sloping it 1/16″ over 30″ at that point, which will never be noticed.
that posting was a a mishap w the computer. You definitely don’t need to waste your time. I apologize…
Thank you again.
No worries Nini.
A great big Thank You in advance for your Advice.
Lowes carries Laticrete SprectraLock Stainproof Grout. It is not SpectraLock Pro. Tell me, are you familiar with this product? It seems to be a mini unit and comes in premeasured packs that go together: Part AB mixes with Part C, the color powder. Should this product from Lowes be measured out as you have described in your article, or can it just go together as the instructions on the included pamphlet describe?
Hi Nini,
I just answered this exact question on the other post. Please don’t post the same question twice, I do get and answer them all. If I must answer every one twice I’m answering over 100 a day at that point. Just once is fine, I’ll get it, really.
Thanks Roger. The grout was sealed when the shower was built about 9 months ago. However, grout was used in the corners and where the floor meets the wall, and tiny cracks had appeared in grout. So the contractor returned and scraped out the grout in those areas and caulked with silicone. He mentioned coming back to seal the shower floor again. I have heard that grout needs to be re-sealed every year; am I correct in thinking that re-sealing would not be a bad idea? And would it harm the caulk if sealer were applied to it too?
It is never a bad idea to seal again, especially on a shower floor where there is a lot of abrasion from water. Sealer will not negatively affect the caulk or silicone. There’s always a chance, of course, that there is a chemical incompatibility, but as a lot of sealers are actually silicone-based it’s extremely rare. I’ve never seen it.
After you have caulked the corners and changes of plane in the shower, should the caulk be sealed? If so, how long should you wait to seal the caulk?
Hi Brenda,
No, caulk and silicone does not need to be sealed.
Can I grout the corners in the shower, between tub and wall, and between shower wall and ceiling and then caulk over it? There are gaps between the tub and wall that are as much as 1/4″ and I read that caulk does not fill gaps bigger than 1/8″.
Also, should the grout not be finished like a caulking job where grout is on the surface of the tile as well as in the joint itself.
Hi David,
You can but it will still crack out. The reason for using silicone is due to movement, silicone can compensate for it, grout will not give, it will crack instead.
Grout should only fill the grout lines, there should be no grout left on the face of the tile.
Hello Roger,
I was reading on Laticrete site that a backer rod should be used before using the Latisil silicone caulking. I plan to use a silicone caulking at the change off planes in the shower. I have yet to decide if I will be using Latisil or another brand of silicone. Does a backer rod need to be used in the shower areas before using the silicone caulking? Also, there are areas where there are voids at the change of planes ( floor to wall ) that have a significant void, should these be filled with backer rod a little bit then silicone’d??
Thanks so much.
Hi Nini,
Technically yes, backer rod or breaker tape should always be used. I oftentimes don’t (don’t tell anyone
). I will use it to fill in larger areas so the bigger voids are perfect areas for it.
Hello,
My husband is the tile setter and I’m the grouter. He left space in the corners to grout but corners are such a pain to grout that I would prefer to use caulk using the same color caulking as the grout. Would that be acceptable or is the space too large since he didn’t butt them up against each other in the corners? And if your answer is that I need to grout, do you have any easy tricks to get the grout into the corners with a float? Thanks for your time!
Hi Dianne,
The corners, and all changes of plane, should not have grout, they should have silicone. As stated in the full article above your comment dealing with that exact question. Do not grout your corners, it will crack out.
Your answer is one that I’m happy with! I’m much more adept at caulking than grouting. Thanks for taking the time to answer and for creating an awesome site with great information.
thanks for this advice, on you tube none of the instructional vids on grouting or caulking a shower point out this again thanks.
I HAVE A FULLY TILED SHOWER. A LEAK HAS BEEN DISCOVERED SOME-
PLACE ON THE FLOOR. I WANT TO RETILE THE FLOOR USING MEMBRANE
AND THINSET . WILL THIS SOLVE MY PROBLEM?
Hi Bryant,
If you remove the existing floor and build one with a membrane that is constructed properly then yes, it will solve your problem.