Can this bathtub be fixed, or will it have to be ripped out and replaced?

[Jack Gray]

A bathtub in an upstairs bathroom has begun leaking through the downstairs ceiling.  This is in a single family house I renovated in 2016 and turned into a rental.  The bathtub was installed new at that time, and we had about $10,000 of custom tile work done around the tub.  I've had 2 separate plumbers out to look at it, and they cut a hole in the downstairs ceiling to access the underside of the tub.  According to both of them, the plumbing connections to the tub are in good shape but the tub itself is rusting internally around the drain area.  From above, the tub looks fine.  From underneath, you can see water stains and rust forming around the drain area.  Removing and replacing the tub would be a nightmare because it would require redoing the tilework.  Is there any possible way to patch or seal this tub, so that it wouldn't have to be replaced?  

Underside of bathtub

[Ryan Spath]

That's a frustrating situation, especially after investing in custom tile work! Based on the plumbers' assessment that the tub itself is rusting internally around the drain, and seeing the water stains and rust from underneath in your provided image, here's the reality and some potential options:

The Unfortunate Reality:

If the tub itself is rusting internally around the drain, especially if it's a metal tub (like cast iron or steel with an enamel coating), it means the protective coating has failed, and the metal is corroding. This is a structural issue with the tub's integrity.

• Patching/Sealing from Below: While you can see the rust and stains from below, effectively sealing the tub from the underside to stop a leak originating from the internal rust around the drain is highly unlikely to be a permanent or reliable solution. Any patch from below would be trying to seal against a surface that is actively corroding and constantly exposed to water from above. It would likely fail, leading to more water damage and frustration.
• Patching/Sealing from Above (Drain Area): You might consider drain repair kits or epoxy coatings, but these are generally for minor chips, cracks, or surface rust. If the rust is internal and causing a leak through the tub material itself, these surface-level patches are unlikely to hold back the water long-term, especially with the pressure and movement around a drain.

Why Replacement is Almost Always the Best Solution (Even if Painful):

1. 1. Long-Term Reliability: A patch on internal rust is a temporary fix at best. The rust will continue to spread, and the leak will almost certainly return, potentially causing more extensive and costly damage to the subfloor, joists, and downstairs ceiling over time.
2. 2. Tenant Satisfaction: For a rental property, you need a reliable, leak-free bathroom. Frequent leaks and repairs are a major headache for both you and your tenants.
3. 3. Preventing Further Damage: Water leaks can lead to mold growth, rot in structural wood, and damage to electrical systems, all of which are far more expensive and dangerous to fix than replacing a tub.
4. 4. Insurance Implications: Insurers may not cover damage from ongoing, known issues that weren't properly addressed. A failed patch could complicate future claims.

Addressing the Tile Work Challenge:

You're right, redoing custom tile work is expensive and a major deterrent. However, consider these points:

• Strategic Demolition: A skilled contractor might be able to remove only the necessary rows of tile immediately surrounding the tub, minimizing the amount of tile that needs to be replaced. This would require finding matching tile, which can be a challenge for a 2016 renovation.
• Tub Re-lining: This is an option where a new acrylic liner is custom-fitted over the existing tub. However, if the existing tub itself is leaking internally, a liner will not stop that leak. The water would still get between the old tub and the liner, and continue to leak through the rust hole. Tub re-lining is primarily for cosmetic improvements or surface cracks, not structural leaks.
• Tub Cut-Out/Walk-In Conversion: Some companies can cut out a section of the tub side to create a walk-in shower, which might involve less tile disruption, but this is for accessibility, not necessarily leak repair.

Recommendation:

Given that two plumbers have identified the internal rust as the source, the most responsible and cost-effective long-term solution, unfortunately, is to replace the bathtub.

While it's a significant upfront cost due to the tile work, it will prevent recurring leaks, potential structural damage, mold, and tenant headaches. It's an investment in the longevity and value of your rental property.

When you get quotes for the replacement, explicitly ask contractors about strategies to minimize tile removal and whether they can source matching or complementary tile. You might also consider a tub material less prone to internal rust if it was a steel tub (e.g., fiberglass/acrylic or a new cast iron tub if budget allows).

Let us know what you decide and how it turns out.