Should I put caulk over missing grout in shower corners?
Shower corners and changes of plane require flexible silicone caulk rather than rigid grout, which inevitably cracks and crumbles when walls shift. Applying caulk over crumbling debris without proper clearance prevents a watertight seal, causing water to pool in unplaned corners and behind damaged joints.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 13.5× more often in r/HomeMaintenance than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1chip out the old stuff and add a new waterproof silicone beadDid this help you?
- 2Caulking directly over the damaged grout areaDid this help you?
- 3Cutting out remaining old grout with an oscillating multi-tool, cleaning and killing mold, patching with fresh grout, and allowing it to cure before caulkingDid this help you?
- 4using a higher pH degreaserDid this help you?
- 5using a hydrogen peroxide based cleanerDid this help you?
- 6using white vinegarDid this help you?
- 7Using regular shower spray, dish soap, bleach, electric scrubbers, and specialized grout cleaners weekly.Did this help you?
- 8Applying temporary tape to see if it lastsDid this help you?
- 9Paying a professional to redo the workDid this help you?
- 10refill the patches instead of regrouting the whole thingDid this help you?
- 11check for any loose grout, remove it, and fill the missing areas if you can match the groutDid this help you?
- 12Scraping out bad grout with a diamond tip tool, drying the area, and applying new grout or matching grouted caulk/silicone in corners.Did this help you?
- 13Scraping out the old grout and replacing it with 100% silicone caulk designed for bathroomsDid this help you?
- 14Using specialized tools or a razor blade to remove existing grout jointsDid this help you?
- 15Matching colored silicone caulk to the existing grout color or using white caulk with a white tubDid this help you?
- 16Grinding out the cracked bits and replacing the grout with a sanded caulk matching the grout color.Did this help you?
- 17scrubbing the area with a stiff brush and vinegarDid this help you?
- 18scraping out loose grout and applying a sealerDid this help you?
- 19adding a bead of silicone around the drain areaDid this help you?
- 20Scraping out the cracked grout and applying 100% silicone or a matching kitchen/bath sealantDid this help you?
- 21Applying a bead of silicone directly over the existing groutDid this help you?
- 22Opening up the wall below to inspect the waterproofing membraneDid this help you?
- 23using a sanded color matched caulk for wall cornersDid this help you?
- 24cleaning with a steamer and mold killer product before applying a clear liquid grout sealerDid this help you?
- 25removing the old grout and replacing it with colored silicone caulkDid this help you?
- 26using an oscillating tool with a carbide grit finger to clear out old groutDid this help you?
- 27Using Dawn powerwash monthlyDid this help you?
- 28Sporadic baking soda applicationDid this help you?
- 29Using Weiman's stone productsDid this help you?
- 30Using Black Diamond Grout cleaner with a drill adapter brush or hard manual brushingDid this help you?
- 31Using a steam cleanerDid this help you?
- 32squeegee walls after every showerDid this help you?
- 33removing and reapplying anti-mold siliconeDid this help you?
- 34using CLR and a bag tied around the shower head overnight followed by scrubbingDid this help you?
- 35caulk it for a temporary fixDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Most of the grout is still in decent shape but the stuff that connects the floor to the sides around the perimeter is starting to crack and fall out in chunks.”source ↗
“I am struggling to find a specific example of how to do it. I’m also not sure if I need to match the variety of hard grout or if I should try to use the kind that resists moisture and mold.”source ↗
“Not sure if this is actually a big problem that needs to be completely redone or can I just touch up some of these problem spots?”source ↗
“There is a crack all along the outside edge of the shower. Do I need to grind and regrout, or could I use a silicon caulk?”source ↗
“Will this seal against the grout between my shower tiles?”source ↗
“What should I use to cover this Crack in my fiberglass shower?”source ↗
“Hi, new homeowner here. I noticed this crack along the grout in my shower, what's the best way to reseal?”source ↗
“Should I reseal with one or the other? Do I need to fully cut out the old stuff first in the corner?”source ↗
“Tried the exact same thing on my cracked shower pan. It lasted a few months but mine was a lot worse than yours.”source ↗
“Should I be looking at regrouting the whole thing or would patching it up be enough?”source ↗
“Previous homeowners have grout around the edge of the tub where the tub meets the tiled wall. It’s missing chunks of grout and it also looks awful. Should this area be caulked instead?”source ↗
“We are first time homeowners and are so grateful to live here, but it all feels so overwhelming. We want to care for our home the best we can.”source ↗
“This is our only bathroom so it’s going to be tricky to time everything right.”source ↗
“I hope it's not leaking under. That's a big part of the reason I don't want to wait much longer, in case water is sneaking into places it doesn't belong.”source ↗
“I was replacing the caulk on this tub and what I guess is grout behind the caulk broke off. Should I just caulk over it?”source ↗
“Poor shower remodel by previous owners. For one this back corner holds water because it wasn't planed correctly.”source ↗
“They didn't use silicone here and the grout is cracking. Same for another corner.”source ↗
“Noticed this crack developing on my shower floor. How screwed am I, can I just caulk it for a temporary fix or am I going to have to tear it out and replace it now?”source ↗
“So it does or does not need new grout first? I’l only assuming it is grout it’s something that chipped out while removing the caulk.”source ↗
“The second picture is a close-up. you can see how cracked and damaged it is.”source ↗
“Should I scrape out this grout and apply silicone, or am I backwards?”source ↗
“should i scrape out the grout and just use silicone there?”source ↗
“Guys, i’m completely lost on what to do here.”source ↗
“In fact, I tried it already once (using Kerdi Board) and had to rip it back out.”source ↗
“There’s just too much info out there on how to do this and I’m completely overwhelmed.”source ↗
“Basically the challenge of being inexperienced and not having a clear defined single path of fixing it. I’ve watched 100 videos. Little things go wrong along the way and it creates a bad result.”source ↗
“Are the areas with the white residue where grout previously was? Do these just need rerouted and should anything be done around the drain?”source ↗
“Hi all! The shower grout is grey, but looks like soap scum (I think?) that has built up. What can I use to clean it to restore it back to the grey?”source ↗
“I rent my apartment so I am not sure what kind of grout or tile this is, but it is IMPOSSIBLE to get clean.”source ↗
“I feel like I have tried everything I know - regular shower spray, dish soap, bleach, electric scrubbers, grout cleaner, etc. and I clean the shower at least once a week!”source ↗
“The tile itself doesn’t really stain but the grout constantly is discolored and even has a pinkish tone to it.”source ↗
“It is embarrassing with guests because it consistently looks dirty even though I clean it regularly!”source ↗
“Grout was dark grey. It’s been a red color now yellow.”source ↗
“Anybody 1. No why it’s yellow? 2. K ow how to get it clean like the rest of the grout???”source ↗
“I squeegee the walls after every single shower, so there's not as much moisture build-up, but the floor and surrounding areas have seen better days.”source ↗
“Nope, my apartment. I work 60+ hour weeks and am pushing myself to do it.”source ↗