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.
Hey Roger,
Need your advice here. I’m getting ready to install 12″ x 12″ mosaic pebble tiles on my showerbase floor. The pebbles look like they’re polished & they vary in color from light to dark. What color grout would you recommend? Do I still use thinset to set them in & what’s the best way to grout these babies? I would like to use Laticrete epoxy grout if possible or should I use a different type of grout? Should I seal them first or can I go right over them with the grout? Looking forward to your reply.
Keep up the great jackassery! 
You rule!
Hey Brian,
The best color to use? Pick your favorite color and use it. Mauve maybe? I dunno, it’s a highly subjective thing. What I think looks good you may not. Just keep in mind that if your pebbles are the rounded top type that you will see more of the grout than you will the pebbles. There is a lot of space between those pebbles. So whatever you choose make sure you like it – you’re gonna be stuck with it.
Yes, use regular thinset (a large notched trowel) to set them. It’s gonna make a hell of a mess, so be prepared for that. If you want to use epoxy be ready to shell out some cash, too. Pebbles are going to use 4 -5 five times as much grout. The last pebble shower floor I grouted with epoxy used 4 1/2 full units – that’s about $500 worth of grout – for 16 square feet. Like I said – a lot. Just go over them with the grout as normal, fill all your spaces, then as you wipe it down just wipe it down to the height you like.
Brian,
We used mosaic pebble tile on our shower floor and went with a sand-color grout so it looks like rocks on a beach; more natural. I sealed all tiles before grouting, and then re-sealed again after grouting. I chose a ‘wet-look’ sealer for natural stone which brought out more of the rock color.
Thank you very much Roger & Sharon for the helpful input. Sharon, sounds like a great look. I’ll be looking at doing it that way, too. And Roger, I don’t know if it will make much of a difference but most of the pebbles are touching each other with small spaces in between. They are the rounded top pebbles like you mentioned. Maybe it’s an optical illusion or maybe I’ve had too many beers or maybe I don’t know what the f@!$ I’m doing but it doesn’t look like it would take as much grout as you say. But who am I but a meager DIY’er. Also, is a 1/2″ notched trowel too big? Thanks again.
Hey Brian,
1/2″ will probably be fine – I dunno how big your pebbles are. (That did not sound right at all…) I know it doesn’t look like it – but they’re gonna take a lot of grout.
Thanks so much for all the great information. I’m building a stone tile shower with a bulkhead wall (pony wall / whatever wall). Stone tiles are 12″. A couple questions:
1) The top of the wall is 6″. On the wall, where the side tiles meets the top of the wall, do you recommend a) cutting side and top tiles at a 45angle and butting them up against each other or b) finishing the sides of the top tile (buffing) and overlaying them on the side or c) something else? What do I put in this space? grout or calk or nothing?
2) The shower is irregular in that it has 5 walls with one angled wall. Where the angled wall meets its companion walls, I was going to butt the tile up against each other like a “v”. Should I leave a space for caulk? If I don’t leave a space, do I put thinset into the gap under the tile edges or leave the “v” behind the edges empty?
Well – that was more than two questions if you count all those other ones in the middle :). I’m looking forward to your wonderful advice :).
Hi Kathy,
I prefer to bullnose and polish the top pieces and install them over the wall pieces (B). If you 45 them you’re left with a square corner which is fairly brittle right on the edge – there isn’t much tile in that spot on the 45’s. Just grout it.
On your walls just leave a 1/16″ or so gap and caulk it. You can put thinset behind those V gaps if you want – you’ll use less caulk that way.
Hi,
I have recently scraped out all the grout and caulk (change of planes) from my stand up shower. The tiles on the floor and wall are stone. The shower was leaking water and actually popped a tile off the outside wall. I am gonna apply clear silicone at the bottom portions of the shower door. My question is, should I use sanded or unsanded caulk for inside the shower where the planes change, ie. wall corners and floor corners? Are there any advantages in using one over the other?
Thank you for you help.
Rob
Hi Rob,
You can use whichever you want. Non-sanded caulk will shrink so be prepared to do it probably twice depending on the size of the gap. The advantage of sanded caulk is that it won’t shrink – the sand prevents that.
Just as an aside – if you are regrouting your shower due to a leak or because a tile popped off the wall it won’t fix that problem. Grout (and tile) are not waterproof. The shower substrate – the wall behind the tile – should be absolutely waterproof before one piece of tile is installed.
Hello-
About 2.5 years ago I added on to my house, and this build included a new Master bath (yay!) and a kitchen renovation. But of course nothing is perfect and I have had workmanship issues with the contractor. Prior to approaching them unneccessarily and in the spirt of fairness, can you advise me on grout cracking issues? Specifically:
1.) between counter and tile backsplash (black grout) and in corners
2.) shower-much cracking there, in corners and floor where there is a “lip” between shower stall and floor, and tiles themselves are not exactly flat and lined up along the shower wall specifically where the decorative glass accent is. I was really unhappy with the tile work, although the installer took photos and put it in his book of examples for future use, anyone who has seen the work loves the tile and design but not so much the grout lines and plane of the tile. (He has since been let go from contracting firm.) Being unhappy and having a water problem / excessive movement problem are two very different things (and I have learned code enforcement officials see them as two VERY separate things) so I am hoping you can advise if these cracks are of concern or just ugly! I should say the owner of the contracting company has seen the cracks and not been overly rushed to correct the situation. And I do not know if the shower was caulked in corners at all. Can you provide some advice–should I just try to caulk or is it more of an issue? Thanks!!
Hey Kristi,
Those actually aren’t problems that will compromise or otherwise harm your installation or the structure around it AS LONG AS your shower was correctly waterproofed. If so then your shower is completely waterproof before a box of tile is even opened – caulk is technically mostly for aesthetic reasons.
All the areas you’ve described sound like a change of plane (a corner or where vertical installation meets horizontal). Per TCNA guidelines all changes of plane should be caulked rather than grouted – specifically for the reasons you’ve stated. At changes of plane the two different surfaces will expand and contract in different directions – this cracks the grout. Grout has no give to it – it won’t flex. When the two substrates expand in different directions it’s gonna give somewhere. Caulk or silicone has enough flex to compensate for that.
If it would be easier for you – and it sounds like it would be – rather than trying to get the builder to actually do something you can simply scrape out all the grout and use caulk or silicone in those areas. Don’t panic!
It’s no biggie, it just looks like hell.
Hi! This is a great collection of wisdom, thank you!
I have removed all grout and caulk from my shower stall. It has marble tile walls and ceiling, and ceramic tile on the floor. The stone tiles are about 1/16 inch apart, while grout lines on the floor are 1/8 or slightly more.
The question is, Do I have to use different grouts for each application, sanded on the floor and unsanded on the rest? Come to think of it, the grout seemed to be receding on the floor, it was wearing away. Would this effect be reduced using sanded grout?
I am using bright white, so color matching should be fairly simple.
Thanks again!
Hey Bob,
Yes, unfortunately you will need to use both sanded and unsanded. The grout in the floor will last much, much longer and look better with sanded grout in it – you won’t have those problems. You can also use epoxy for everything – you know, if you have a couple of hundred extra dollars burning a hole in your pocket.
You can use epoxy for both.
I have installed 1″ glass mosaic tiles for my shower floor and was wondering what type of grout to use, because my grout lines vary from 1/16″ to 1/8″. I used sanded grout on the walls because I had consistent 1/8″ grout lines using 12″ sq. tile. But with the mosaic on the floor the grout lines aren’t as consistent. Can I use the sanded grout, or do I need to go with the nonsanded, or an epoxy?
Thanks
Hey Brian,
Epoxy would be ideal for that particular application. If not epoxy you can go ahead and use regular sanded grout – you just have to make sure you get it packed into the smaller grout lines really well. Test it first to ensure it won’t scratch your glass easily.
I have a two year old shower that is leaking. Rubber shower pan was installed but I think mice or some other critter has chewed through it (at least that is what it looks like when I opened up the drywall. Is there some way to “patch” the shower pan without tearing out the entire shower?
Also, the grout lines have cracked and I’d like to know if I can simply silicone over the cracked grout until I determine if I have to rip out the entire shower. I have some grout lines that are a 1/2″.
Thanks so much!
Kim, Jacksonville, FL
Hi Kim,
There is no real way to patch a liner once the shower is installed. You can always try but it may actually lead to more problems if you think it’s patched and it’s still leaking. If you have cracked grout something is moving – which means something is not built properly.
You can put silicone over it if you want but I can tell you now, even though I can’t see it from here, you will likely need to replace that shower. Here’s why:
1) You will not be able to effectively patch the liner to get it to a permanent waterproof state like it needs to be.
2) If your grout is cracking something is moving. If the shower has been in for over a year then the movement is likely due to swelling which is caused by water getting where it shouldn’t be getting.
3) If water is getting where it shouldn’t it can (will) compromise the structure of the house around the shower – that leads to a whole new set of problems.
4) 1/2″ grout lines is extremely excessive – I’ve never seen a grout line over 1/4″ that was acceptable and only then it was in quarry tiles. It’s a huge pet peeve of mine – doesn’t really matter to the installation, though, I’m just a jerk like that.
Sorry to be the bearer of bad news. But yes, you can put silicone over your grout lines if you want to.
OK, so I have two inside corners in my bathtub surround, obviously, and I was all set to put in a sanded caulk to match the grout I have already used… and all of a sudden, I am being told that I should match manufacturers of the grout with the manufacturer of the caulking, the implication being that there is some potential for some negative chemical reaction between the grout (from maker A) with the caulk from make B. In particular, this seems to be a bit of a rant against Polyblend, which is said to be inferior in some way, by the folks at Mapei. I am less concerned about whether the Polyblend grout is inferior (it is a tad late, after all), but am interested in your thoughts… is this just so much marketing BS, or what?
Hey Nigel,
It’s partly marketing BS and part simply a negative view of polyblend in general. A lot of people have had problems with efflorescence on polyblend grout. Now I don’t know if it is simply because Home Depot sells polyblend (I’m sure that’s at least a small part of it) but I think most of it stems from DIY’ers using it incorrectly. I have not had any problems with polyblend grout – but I absolutely hate the stuff. Nothing to do with inferiority of the product or anything – it just has a different feel to it when I work with it, different set times and such. It’s just so different from the grouts I normally use that I hate it.
With all that said I have never – ever – heard nor witnessed a negative chemical reaction or problem of any sort mixing grout and caulk brands. It may be simply a matter of Mapei trying to cover their ass – I dunno. It comes down to this: once the grout is set it is basically a colored cement – no matter the brand. It is my opinion that any brand of caulk should have absolutely no problem with any brand of cured caulk.
Tell ’em to chill.
Roger, thanks a bunch for that, I figured it had to be hype, but it’s reassuring to get hear it from a professional. Interesting to hear your thoughts on Polyblend,too: I found that if you follow their mixing instructions you get something dry and crumbly that’s just useless. Grr.
Chillin’ here (this is Edmonton, Alberta, after all).
I’m replacing a tile fireplace surround with a raised hearth – first time doing any tile work.
I have mulitple planes that intersect:
1) Vertical surround & hearth horizontal surface
2) Hearth horizontal surface & vertical sides
3) Hearth vertical sides – left, front & right
Do I need to caulk each plane intersection, and if so, how do I get a finished look such that I have common colored grout lines through out.
Thanks,
Roger
Hi Roger (great, now I’m talking to myself again),
The only intersection that needs to be caulked are the inside corners – where two tiles meet to form an ‘L’. Outside corners, such as the horizontal hearth and vertical sides form an outside corner – grout those.
Since inside plane intersections are the only ones which require caulk it should just be the hearth vertical surface where it meets your vertical surround and, if your vertical surround happens to go down further than the vertical sides of your hearth (all the way to the floor), that inside vertical corner should be caulked as well.
Epoxy Grout Question,
I have installed a mosaic tile back-splash and I have 1/8th gap between bottom tile and Granite counter top. I also have two corners. I plan to use an Epoxy like CEG-Lite. I like what I have read about epoxy and stain resistance. My concern is if I use epoxy between the bottom tile and the counter-top could flexing cause the tiles to crack. I am also trying to figure out if these epoxy grouts have any flexibility.
I did use flex-bond motor to set the tiles. This claims some flexibility.
Hey Chris,
Epoxy grout has absolutely no flex whatsoever – none. Flex-bond mortar does have a bit of give but I don’t honestly know if it would have enough to absorb the normal movements in a countertop. On top of normal, seasonal movements on a countertop there will be times when you may slam a 25lb. frozen turkey onto it – less than ‘normal’ movement and causes considerable movement, even if just for a second.
I always caulk that junction between the kitchen countertop and tile specifically for things such as that. (I’m assuming here that it is indeed a kitchen?) Here’s the scary part
your granite countertop would be more likely to chip or crack than your wall tile. The stresses against the wall tile will be dispersed along the vertical plane of it, against the granite it is the horizontal plane. Think about two people carrying a large sheet of glass – you don’t carry it horizontally, you carry it upright because all the support is dispersed through the entire vertical plane. Same principal.
Physics lesson over – caulk that space at the bottom of the backsplash.
I have a tile shower in my basement and am getting water in the room next to the bathroom when more than one shower is taken. I have checked the pan, the supply piping and the drain. The only thing that i can think of is that the grout is letting water through and there is somewhere that that water is getting past the backerboard. Can I seal this or caulk it some how to get this to stop?
Hi Cbass,
Do you have a tile or acrylic shower floor? You haven’t specified. If tile then your problem most likely lies in the membrane in the floor. You probably have a combination of the liner lying flat on the floor (no pre-slope), cut corners in the liner rather than folded, and/or plugged weep holes in the drain. The more specifics you give me about the type of floor, how (as much as you know) it was built, and where, specifically, the shower is leaking from the more likely I will be to accurately let you know what is happening.
In some shape or form your shower was constructed improperly. A shower should be absolutely waterproof before a piece of tile is installed. It doesn’t matter the type of construction – backerboard, kerdi, redgard, etc. – it should be able to contain and retain water inside the shower itself whether or not there is tile installed in it.
Tile and grout are not waterproof. So unless you have epoxy grout it is actually completely normal for the grout to soak in or let water through to your substrate. That’s why your substrate needs to be waterproof. There is no product that will eliminate a leak in a shower when applied to the tile. Sealer does not do that either, it simply helps with stain-resistance.
Sorry to be the bearer of bad news. If you give me more specifics about your shower I can try to help nail down what is actually going on and how best to solve it.
I have fiberglass pan floor. It is not coming from the floor because i stoppered the drain and filled the pan and it held the water for over 24 hours. I put a cap on the shower head so I know it is not the supply and I put a garden hose to the drain and got nothing there. This is why I feel it had to be coming from the tiles or more specifically the grout. It is not a quick leak, I cut a hole in the wall on the other side of the shower and can see water pool over time but it is like 45 min before it happens. (like 2 or 3 showers in a row). Let me know what other info you might need to solve my problem. Thanks for the help.
Cbass
With the amount of time it’s taking to pool and you mentioning backerboards in your original comment I think the problem is that you have hardibacker, or some comparable cement backerboard, with no vapor (moisture) barrier behind it. You stated you cut a hole in the wall on the other side of the shower. When looking into that you will probably be able to see the backerboard attached directly to the studs without plastic or tar paper (roofing felt) between it and the studs. Is that correct? And if so, I’m betting that if you reach in there and feel the backerboard it feels damp.
If that’s the case then the problem is a lack of vapor barrier. In a normal backerboard installation there should be a vapor barrier attached to the studs then the backerboard is attached over it. That way any moisture that gets back there hits a water barrier and is directed down into the drain. If you read this post: Installing hardiebacker on shower walls it explains the proper way to install it. If that is the problem then the shower walls should be replaced and installed properly. At the very least the wall that is soaked and begins to leak needs to be replaced. That, however, would be temporary, eventually the other walls will begin to do the same.
In a normal backerboard installation the backerboard will actually retain water with every shower. It eventually dries out, but depending on how often the shower is used this level of moisture will build. At some point the weight of the water in the backerboards will be more than the backer can hold and gravity will take over – that’s when it begins to leak. Your shower wall (the back of the backerboard) will feel more wet after a shower.
If, by chance, there is a vapor barrier behind it then your problem likely lies at the bottom of that barrier. When the barrier is attached to the studs it also needs to be attached to the flange or lip of the base. It needs to be lapped over that on the shower side of the wall. This way, when gravity does take that process over, the water will run down and into the tub. If it is not attached there it will do exactly what it’s doing. If this is the case you can take out only the bottom row of tile, either place that barrier over the lip or flange of the tub (or if it isn’t long enough attach another piece behind that one at the top over the flange at the bottom – layered like roof shingles), replace the backerboard and tile.
So if you have a barrier back there only the bottom row needs to be replaced, if you have no barrier then it’s a larger project. If, by chance, neither of these is the case please let me know where I went wrong in my assumptions – I tend to do that sometimes.
Let me know what you have there either way.
Hope that helps.
There is no water barrier behind the cement board. So I take it I am up a creak and the only solution is to redo the whole shower? I am getting sick even thinking about the time and expense that is going to be. Are there any other ways of fixing this problem?
Hey Cbass,
Unfortunately no, there aren’t any products that will waterproof your tile after the fact. Sorry to give you the news – I hate that part. Before anyone tells you differently (incorrectly) a tile sealer will not waterproof your tile. They only slow the absorption of liquids through the tile and grout. Many of the people with this particular problem (and there are a LOT of them) have everyone tell them it can be fixed with tile sealer – it cannot. Sealer only slows the absorption of liquid through the tile and grout. While this may work (very) short term to prevent that much moisture getting back there, it still gets back there.
I’m not sure how much wall framing you have around the shower but if you continue to use it that water will eventually begin to wick into the wall studs – they will not dry out between showers, they will continue to swell with each use and eventually you will have a larger problem than you currently do. As I said before at the very least the main wall that is doing this (it’s usually one specific wall first) needs to be replaced. As I’ve also stated that would only be a temporary solution as the other walls will eventually do the same.
The only correct solution is a properly built shower substrate. Sorry to be the bearer of bad news.
I caulked the “change of planes” in our walk-in shower on Saturday. When I looked at the caulking on Sunday morning, I noticed there are some cracks in the caulk. What caused the cracks? Does caulk crack if the joints are too large? Does caulk expire and possibly old caulk in the tube caused the cracks? Do I need to remove the caulk and start over, or can I just caulk over the top? Nearing the end of this 1 yr bathroom remodel and it was disappointing to see the cracks!
Hey Kevin,
Did you caulk the change of planes with matching, sanded caulk or regular caulk or silicone? The sanded caulk that matches the grout contains, well, sand. The sand prevents it from shrinking but it will still shrink! Just not as much. If you are using regular caulk or silicone it will shrink as well. Depending on how large the joints are it may cause it to crack. Expired caulk will also crack.
The good news: It’s common. And you can simply go over it with more to fix it. My guess would be that the joints were simply a bit too large and the caulk shrunk as it cured causing it to crack. Just go over it again with more and you’ll be fine.
By the way – you just posted the 1000th comment on my blog – Thanks!
Thanks again!
I should have waited for your response before doing anything.
I have something like a carpenter’s knife and I thought I would just press it into the grout to break it up. At first it worked but then I noticed that the tiling that is connected to that grout (which isn’t a flat square but kind of like the outer rim of a pie in that it bulges out) started having these little fracture lines forming it in. Crap!!
First thing saturday I’m going to home depot and buying a grout saw.
I have a little dremmel with a bunch of attachments…. maybe one of those will do.
Thank you great for your willingness to help!
Hey Tim,
You are very welcome. The dremel has an attachment to remove grout but it’s very easy to chip the tile with it. If you use it be very, very careful.
Thank you so much for taking the time to give this information.
This site and your ability to explain is just amazing. It’s making sense for me – and that’s saying alot!!
I have a standing only shower. Where the plastic flooring (it’s plastic not ceramic – is this bad?) meets the tiles it’s starting to mold
I thought it was caulk in there. So I picked up everything i thought I needed to remove the caulk. As soon as I started trying what I thought was caulk was only slightly chipping away. My little plastic tool with the hook on it was grinding down. So I thought this must be grout.
It’s breaking up in small, hard bits. Is this grout?
Thank you greatly.
God bless.
Hey Tim,
The ‘plastic’ floor of your shower is likely a common acrylic or fiberglass pan – it’s just fine. It sounds to me as if this is grout in that space. The big box stores carry little ‘grout saws’ which are about seven bucks. They normally come with a couple of blades – the carbide one is usually easiest to use (it’s the one that doesn’t look like a saw).
Mike:
Thanks for the information. My steam shower is grouted and not caulked where planes meet, and after about 5 years some of those grouted joints have failed. I want to replace with caulk. Do I need to remove all the grout in the joints that have not failed, or can I caulk over the good grout. I’m not worried about a color match.
Thanks.
Hey Steve,
You need to remove all that grout. Even if it’s in good shape now it will eventually have the same problems that you see with the failed joints. Scrape it all out and caulk it all.
DO YOU CAULK CORNERS BEFORE YOU GROUT OR AFTER ON NEW TILE SHOWER WALLS.
THANKS
HARRY N
Hi Harry,
If you have the time to allow the caulk to cure first (overnight) then it is always better and easier to caulk first.
I’m so glad that I found your cite. Grout was used at the “changes of plane” in my two showers. I bought the house 2 years ago and now the grout in these corners is cracking. What’s the best way to remove this cracking grout and replace it with caulk? I’m a novice at do it yourself so any help and advise you can provide is so very much appreciated.
Hi Claudia,
There are several ways to remove grout from the corners. The easiest would probably be to get a grout saw. This is just a carbide blade on a handle available at Home Depot or like stores for about five dollars. You simply saw the grout out of the corner and it will turn to dust. You can also, if your careful, scrape it out of there with something like a screwdriver. You just need to be very careful about scratching the tile as you do that, though. You can also get what is called a 5-in-1 painters tool, it looks like a putty knife on steroids, and scrape it out with that.
Hi-
Thanks for the website! Question-
The manufacturer’s matching caulk is not silicone—is it ok to use it in the corners and then go over it with a clear silicone to waterproof?
Also—i made myself an extra long shower niche—i sloped the bottom like you instructed on your other step by step, but is it overkill to use silicone caulk on the grout lines (since it’s more than one tile length long) because the water might channel out through the grout lines? I also used kerdi behind….
Thanks!
Hi Cara,
Most manufacturer’s matching caulk’s are acrylic-based polymers. That simply means that, unless it is a steam shower or gets industrial use (teenagers don’t count), then the acrylic-based will be fine. You can go over it with silicone BUT! silicone will sometimes make a colored product like grout or caulk, look darker than it actually does. That means it may end up no longer being a matching caulk.
There is no real need to use silicone on the grout lines in your niche. As long as it is properly waterproofed there won’t be any problems at all. The water will not channel out through the grout lines. It will either run down the waterproofing behind the tile or dissipate (evaporate) back out through the grout lines. If you use silicone it will change the color of that grout line. If you are worried about it you can always seal the grout. That doesn’t waterproof it but it will help it reject a lot of moisture that would normally enter the grout. It basically makes it not as porous.
Do you caulk the top edge of the shower curb… using a tile or marble top on the curb. (I’ve heard you should never use tile on the top btw, not sure if that’s true or why) Appreciate your response.
Hi Jeremy,
No, I do not caulk the top edge of the curb except at the ends where it turns up at the wall. Other than that it gets grout. I often use tile on the top of curbs – I’ve honestly never heard that from anyone so I don’t know where someone got that idea. It may be a conspiracy.
If you want to use tile on the top go ahead.
Hello,
Yep I have another question. How long does the grout have to cure before I can caulk my corners? I to wait 72 hours before sealing, but wasn’t sure if the same was true for caulking?
Thanks and thanks again for taking time to put together such a great website,
Rustain
Hey Rustain,
You can caulk the next day. The grout will be set up enough to run caulk wherever you need. I actually caulk the same day but you need to be careful with the grout lines if you decide to do that.
Wow! Someone who actually has CORRECT information and the patience to explain it completely. You should be proud of yourself for providing accurate assistance. Please keep up the great work.
Harry
Hey thanks Harry!
Nice to know there are people that recognize it. Now if we could find some way to get rid of all the inaccurate information people spew out everything would be peachy.
Roger-
I’m glad I stumbled onto your blog. I’ve been dealing with a grout-replacement issue for several months, and I had gotten all materials and was ready to go when I thought I’d better do a little more research.
Basically we had a classic “drain fly” issue, but the larvae were breeding behind a hairline opening where grout at the base of our shower had pulled away from the vertical wall tile surface. Needless to say that when i chiseled the grout out of the floor/wall lines, there was a lot of moisture that had built up behind it (my guess is on and off for a couple of months). There was also corner grout elsewhere in the shower that was failing. I suspected it was: A) a movement issue, B) the installer may have just used sanded everywhere including the smaller joints, or C) the original grout mixture didn’t have a proper water-to-mix ratio.
Even though I have grout to use for this application, I am leaning toward using a sanded or non-sanded caulk now (just a Polyblend product from Home Depot), but I don’t think I am going to get an exact match to the existing grout. Is there anything I can do to either lighten or darken the caulk either while I am caulking or after?
Thanks,
Kevin
Hey Kevin,
The only thing that I can think of is maybe after caulking your corners let it cure (usually only three or four hours) then try going over the top of it with clear silicone. This won’t effect, negatively nor positively, the caulk itself but the color of the caulk through silicone may change. Think about grout with silicone over the top of it. It doesn’t necessarily effect the grout but the light going through the silicone changes the way it looks.
I honestly don’t know if that will work or not. Get a board or something and place a bead of your caulk on it, let it cure, then place silicone over it to see how it looks.
The only other easy way I can think of would be to try and find a matching caulk or silicone (I know, I’m a ridiculously obvious bastard sometimes) but if HD doesn’t carry what you need you can check out Laticrete’s ‘Latisil’ which is a silicone color-matched sealant. It comes in a large variety of colors and you should be able to find a cross-reference chart for it somewhere to match your particular grout. (You can always match your grout color with their grout color and get the corresponding Latisil)
If you want the hard way – you know, the way I do everything – you can actually take clear silicone, mix your unsanded grout with it, place it either back into the tube or in a ziploc, cut off the corner, and caulk it with that. The match is nearly identical (just a hair darker from the silicone) and it won’t crack out of your corners because it is flexible silicone. The one BIG caveat with this – before you’ve had practice doing this you will make one hell of a mess, have a firehose standing by. But this method gets the results I need when other options are unavailable.
Hope that helps.
Roger, I have grouted the floor (3/8″ joints) with Custom’s Polyblend sanded grout. I let it cure well over 72 hours before applying 1 treatment of Custom’s Tile Lab penetrating sealer (the pricy one at the HD). After giving that a few days to set I noticed when wet, the grout discolors after about 30 seconds. It does bead up but eventually I can see absorbtion. I am aware of the need to let water in and out of the grout so it may dry out, but I am looking to follow the same procedure for my shower joints (wall and floor, 1/8″ joints) and am a bit concerned. My prior shower was tiled with the classic 4″x4″ white tile with 1/16″ grout lines and I never noticed them absorbing water. Additionally, I have moved away from a acrylic shower pan to a tiles floor so there will be water hitting horizontal joints for the duration of a shower. Have I not applied an appropriate sealer? Should I apply additional coats of the sealer? Is this much ado about nothing.
Thanks
Mike
Hi Mike,
The penetrating sealer does just that – penetrates. You have a decent sealer but you will need to add another coat to your grout. The first coat will essentially soak completely into your grout, which is good, and “seals” the pores in the grout to an extent.
Apply another coat and let it dry. Check to see if water beads up on the surface of your grout. If it does you’re good to go. If it doesn’t simply add another coat. Sometimes it may take as many as three or four coats. Just keep applying coats until the water beads up.
Please note that any type of sealer will not make your grout waterproof, simply water resistant. The purpose of sealer is to help prevent stains for the most part. When you do your shower floor you may notice that the grout will get darker during and after a shower, it should dry out relatively quickly though. This is normal and does not lead to any type of problem (provided your shower is constructed properly).
Hope that helps.
Thanks for sharing your expertise. I have seen much on the debate of grout v. caulk, what the Tile Council recommends etc. It was the more mundane issue of what should be done first that slowed me down.
Thanks again.
Mike
I have installed a 2″x2″ mosaic tile shower floor and am getting ready to do the walls. I have read much about the recommendastion to caulk the change of planes. On the floor, should I caulk the perimeter prior to grouting or after? How do you ensure the area were grout touches caulk is tight?
Thanks
Hey Mike,
As I’ve stated the caulk at the change of planes is the industry guideline. And I don’t always do it that way.
When I do caulk it I actually find it easier to caulk before grouting. If you do it that way you do not have to dig out any grout that made it’s way in there while you were grouting. To ensure the grout is filling the grout lines against the caulk just make sure you pack it into the space really well as you grout. As long as it’s full you should be fine.