Eliminate Cracks in Tiled Wall Corners: Caulk vs Grout

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Eliminate cracks in tiled wall corners: use caulk not grout.

Have you discovered cracks in the corners of your showers and/or bathtub surround? You most likely have grout in the corners and, instead of grout you should have caulk.

End of post!

Shortest post ever!

…but maybe you’d like to know more about the how and why this [no longer] mysterious phenomenon occurs…

Why is my shower / tub surround / wall / countertop to backsplash transition only cracking in the corners?

All houses move.

Crack in grout between floor and tiled walls.

Have you noticed how your house pops and cracks on a hot day? Or how the house shudders when a particularly large gust of wind howls by?

Temperature changes cause the materials of a house to expand and contract. Pressure changes from wind outside as well as air conditioning system and cracks in your windows and doors are just a few reasons causing the house to flex. Or you have your foundation repaired and the lifting not only shifts your walls but even horizontal surfaces like countertops against tile backsplashes.

Showers and bathtubs are all subject to this phenomena. Any place where there are multiple separate surfaces is more likely to move due to these forces.

Another example of cracked grout in a tiled bathroom corner.

Dear lord, let’s not even talk about if you have foundation work done: What to Expect from Foundation Repairs: Before, During and After

Caulk vs Grout

Grout is a cement type product. Any movement in cement causes a crack. Cementitious materials have no elasticity.

Crack in sidewalk due to movement.

Caulk, however, is elastic.

Even if the caulk hardens over time due to a dry environment or hard water, it is easy to remove and replace. This is not true for grout.

There are many choices when it comes to caulk. What kind of caulk should I choose?!?!

The possibilities are endless!

It’s more than a little overwhelming to look at all the caulk choices when you walk down the paint aisle.

AND THEN there is the caulk in the tile aisle–which is really what we’re going for in this post:

You specifically want silicone or siliconized caulk. It is waterproof. You do not want painter’s or outdoor rated caulk. Absolutely no construction adhesive (we’ve actually seen this!).

Custom Products sanded ceramic tile caulk.

Custom Products sanded ceramic tile caulk directions and uses. Trying to save you a trip to the store here…

But caulk looks so obvious and grout comes in colors?!?!

Just in case you are not aware, you are not limited to just clear, white, or almond colored caulk.

DAP Kwik Seal Ultra colors. Also a good product, but not quite what we’re looking for…

It is possible to color match caulk with the grout color.

See, this…

Custom Products caulk color choices to match with Custom Products grout.

…matches with ALLLLL these grout choices:

Custom Products grout color choices to match with Custom Products caulk.

Second, you get to choose if you want sanded or unsanded grout. What you want depends on the size of the grout line. A general rule of thumb is anything more than ⅛” is sanded. Everything below that measurement is unsanded.

Never fear, there is another whole setup further down the tile aisle with unsanded “caulk”:

Custom Products Non-Sanded 100% silicone “caulk” colors.

With a fancy name with words like “Commercial” it’s just plain 100% silicone that is also happily color matched with those same grout colors!

Commercial 100% Silicone Sealant offered in Delorian Gray.

While I’ve singled out corners in tiled walls, caulk should be used on all places where there is a change in angle.

• The corner walls? Yes.
• Inside a shower niche? For sure.
• The outside edges of a shower niche? Definitely.
• Around all sides of a corner shelf? You betcha.
• On the outside edge of a wall? Of course!
• On a shower bench or shaving foot rest? No exceptions here!!!

Caulk should be applied pretty much any joint where tile meets at an angle more than zero degrees.

I’d even suggest caulking the top of a bullnose tile along a backsplash too.

Why was grout used in the first place?

This is an official DIY blog, but it is also my personal DIY blog so I’m going to lay a very opinionated statement out there: uneducated homeowners and lazy contractors. To be fair, perhaps it wasn’t you who either built the home or sponsored the follow-on remodel…now you are left picking up the pieces. And hey, if it was you, we all learn sometimes, even if it is the hard way (hey, I’ve been there too–Planning to Remodel a House Two States Away). Good on you for finding the right answer.

And thanks for stopping by so you are now educated!

Some contractors will not stop to change from grout to caulk. Not only does the change in material cost time, but it also costs money. In the big scheme of things a tube of caulk is not much. And yes, by time cost I mean the time it takes to snip off the end of the tube, load the caulk gun, apply the caulk, and make a clean finish profile versus just keeping that grout float moving.

However, when the grout cracks it is a royal PITA to remove and replace with the right product: caulk.

See, I even made this mistake myself. Cracked grout along the bathroom countertop was just one of the many side effects of repairing the foundation. Sucks, but it is now caulked. No, those are not my hands, but someone has to take the pictures…

Proof!

Elbow grease and basically a chisel is what it takes.

It could be worse. Worse is what happens if the crack is undetected and it is in a shower or bathtub enclosure.

In your best case, your superior waterproofing (Install Schluter KERDI Like a Boss) will handle any water that makes it behind the tile and continues to guide it towards the drain (or if you don’t know what is behind the tile you pray there is superior waterproofing). In the worst case, tiles start popping off or mold growth forms behind the tiles due to water seeping through the crack(s).

Early detection and replacing grout with caulk is key.

The other benefits of caulk in the corners of your bathroom surfaces:

It is easy to remove and replace. Get a good chunk out at one end and pull. Hopefully, most comes out at one time.

The secondary benefit here is to the bottom edges of your corner shelves, shower niches, and around the outside of your tub. These places are subject to standing water. When water pools there continuously you are likely to discover mold somewhere down the road. While I am a proponent of religiously using a squeegee (as well as the right squeegee), misses do happen. It is easy to remove and replace this eyesore with caulk, restarting the clock with no proof it ever existed before.

Pointing to where I caulked around the tub enclosure/shower shelves too.

But it’s not all roses. You can’t just caulk a corner and call it good.

The cons of caulk.

The bad part about caulk is not permanent. It is expected maintenance. Meaning, you should replace it periodically. I say periodically intentionally because when you should replace it depends on so many factors: humidity, how often water pools, movement of the walls, etc.

You can avoid cracking and caulk with maintenance free profiles.

Maybe you want to get advanced and you are tackling a remodel. Consider using a profile edge on your corner transitions.

I used Schluter profile edges in our walk-in shower to eliminate repeated caulking (and in all reality to also make it look slick and modern).

Schluter DILEX AHK in shower corner and along the floor.

Schluter DILEX AHK (pointer finger), DILEX AHKA (thumb), and Jolly (middle finger–not an indication of how I feel about a product named Jolly!) on shower bench seat.

Shower curb transition to the pre-exsisting tile floor using Schluter DILEX AHKA.

You’ll never have to replace silicone caulk.

Ever.

You also now know why I selectively chose Delorian Gray as my sample caulk color choices above. 😉

However, as with many good things, it certainly is not as cheap as a tube or two of caulk and it will take longer to install. With profile edges all edges of the tile are on display. So extra care has to be taken for perfectly cut tiles. Compare that to a corner where one tile edge is hidden behind another and care is not necessary to keep the profile edge clear of excess mortar and keep it straight.

So keep your scrap and make your window sills fancy:

Window sill tile finished with excess Schluter Jolly profile.

If you are reading this prior to a remodel, remember to use caulk or be adamant about this issue with your contractor! Save yourself the headache of an inevitable crack from using grout.

Do you have any additional questions or tips? Let’s discuss in the comments below!