Second-floor bathtub is cracking and flexing with no backup bathroom
Old second-story bathtubs can develop flexing cracks and sagging ceilings underneath from structural wear. This leaves homeowners stuck between needing a full replacement and having only one bathroom in the house to rely on.
What the numbers show
Counted from the threads quoted below. How we count
- This comes up 14.3× more often in r/Plumbing 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.
- 1Using flex tape as a temporary fixDid this help you?
- 2Drilling the ends of the crack, applying spray foam, and using a tub epoxy kitDid this help you?
- 3Replacing the tub entirely and inspecting joistsDid this help you?
- 4Calling a professional fiberglass repair specialistDid this help you?
- 5Using porcelain touch-up glaze or kits like Porc-A-FixDid this help you?
- 6Applying temporary spray paintDid this help you?
- 7Spraying with CLR and scrubbingDid this help you?
- 8Getting it reglazed by a professionalDid this help you?
- 9Installing a fiberglass drop-in insertDid this help you?
- 10Replacing the tub entirelyDid this help you?
- 11Injecting spray foam underneath through a hole in the adjacent wallDid this help you?
- 12Applying epoxy resin or patches for a temporary fixDid this help you?
- 13Using a bath liner or insertDid this help you?
- 14Starting to save money and shopping for quotes to completely replace the tubDid 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.
“Fairly deep cracks around 2/3 of the drain. Pretty sure on the right it is completely through. I wouldn’t DIY this myself but isnt there some epoxy that can patch this? (Enameled iron tub)”source ↗
“This is the current state of my bathtub and I wanted some input. 1. Is this okay / is this damaging something underneath? 2. How to fix this short term? 3. How to fix long term?, 4. Estimated cost?”source ↗
“now we only notice this sponginess after but It may be this sound That is in this video Which is really the only evidence I have of the flexing. It just feels a little bouncy otherwise it doesn't seem to Deflect the light that much if you look at the glare of the bathroom surface.”source ↗
“My overall question is, should, what do I do at this point?”source ↗
“Do I do nothing? Is there nothing to be done? Or is this bad enough that I need to do something?”source ↗
“I recently moved into a two-story century home, and recently I realized that there are a bunch of hairline cracks in the bottom of the bathtub (located on the second floor of the house).”source ↗
“the areas around the cracks will flex when stepped on/pressed with fingers.”source ↗
“the ceiling on the first floor underneath the tub definitely is also showing a visible/linear dent, but without any signs of water damage.”source ↗
“I'd love to swap out the tub and repair the ceiling, but the problem is that this is the only bathroom in the house and I'm afraid the repair will take a few weeks to finish.”source ↗
“Replacing the tub not an option.”source ↗
“Sprayed it with CLR and let it sit for 2 min before scrub down, didnt really do anything to remove it.”source ↗
“I tried spray painting it but it keeps chipping so you can see some white flakes in there.”source ↗
“Once the enamel is gone the metal underneath just keeps rusting no matter what you put over it”source ↗