Tub drain outlet rough / uneven / broken -- can not seal

[John Everett]

Hi Everyone,

I have been struggling to seal a second story tub drain after I noticed a leak in the ceiling drywall. The bottom of the fiber glass tub is rather uneven and one side of the outlet appears to be chipped away (see photo). I tried using silicone to attach the drain washer but this resulted in the water running up along the underside of the tub and dripping elsewhere.

Any suggestions would be Very appreciated.

Thanks !
John

 

[WorthFlorida]

The black rubber gasket that goes between the drain shoe and the tub may have dried out. Get a new on and do tighten down the drain to seal it up. The gasket needs to compress some. It can be installed from the top.

The most important part is you need to use stainless plumbers putty under the drain flange that threads into the shoe. Water is working itself under the drain flange and this must be sealed. It not leaking from the gasket.
Throw away the silicone, it doesn't fix anything.

https://www.plumbingsupply.com/how-to-replace-a-bathtub-drain-flange.html

 

[Sponsor]

 

[John Everett]

Thanks !

I tried a new gasket and a generous amount of putty which squeezed our after 4-5 good turns.
The gasket was rather firm and I suspect the chipped underside of the tub will continue to be a challenge.

I repaired a deep chip on the top side next to the drain with epoxy putty, I may have to
sand it to make it more flush since the drain flange overlaps the patch.

Perhaps this would be a good time to fix other dings and try an epoxy paint refinishing kit.

Some more questions ...
1. If the chipped output continues to prevent a proper seal, are there products such as an oversized soft gasket that may help?
2. Can the tub output be rebuilt with expoy putty or other material to create a better matting surface?
3. The shoe threads may be damaged -- it took a couple of tries for a new drain to thread without effort.
Can I use thread tape on the metal drain threads even though I'm threading into a PVC shoe?

The black rubber gasket that goes between the drain shoe and the tub may have dried out. Get a new on and do tighten down the drain to seal it up. The gasket needs to compress some. It can be installed from the top.

The most important part is you need to use stainless plumbers putty under the drain flange that threads into the shoe. Water is working itself under the drain flange and this must be sealed. It not leaking from the gasket.
Throw away the silicone, it doesn't fix anything.

https://www.plumbingsupply.com/how-to-replace-a-bathtub-drain-flange.html

 

[WorthFlorida]

Unless the water backs up the only way water can get under the tub is from under the flange of the drain itself. The drain threads into the shoe and acts like a funnel. There is no pressure to back the water up through the treads. It all works on gravity.

The thick gasket on top of the shoe allows wiggle room for the tub to flex some with the weight of the water and person so not to break the plumbing and compensate for every tub, this hole is not exactly the same on every tub. Yes, it will stop water from water getting under the flange when the plumbers putty finally fails, if ever, but the plumber's putty is the first defence to stop water in this never exactly the same drain hole with every tub.

 

[John Everett]

Thanks --

I appreciate the insight.
I will work on improving the putty application!

J

Unless the water backs up the only way water can get under the tub is from under the flange of the drain itself. The drain threads into the shoe and acts like a funnel. There is no pressure to back the water up through the treads. It all works on gravity.

The thick gasket on top of the shoe allows wiggle room for the tub to flex some with the weight of the water and person so not to break the plumbing and compensate for every tub, this hole is not exactly the same on every tub. Yes, it will stop water from water getting under the flange when the plumbers putty finally fails, if ever, but the plumber's putty is the first defence to stop water in this never exactly the same drain hole with every tub.

View attachment 55338

 

[John Everett]

Quick update - turns out that the tub does not leak when my two 50 lbs. kids use it together but does leak when I use it (190 lbs). I suspect the chipped outlet in the photo and flexing of the fiberglass tub floor is causing the gasket to leak.

Perhaps a new shoe (because I may of stripped the old one) with thread paste and good amount putty may lessen the need for a perfect gasket seal.