Shower Pan Possible Leak

[TurdFerguson835]

Chasing a leaking in my split level home. Preform shower pan has an Oatey 42150 installed on concrete slab and I can see water weeping through concrete block below the shower in the lower basement. Shower drain line appears to be cast iron but the Oatey drain has a PVC elbow slipped in between.

This doesn't align with anything I can find for this drain online, can anyone explain this setup to me?

 

[Terry]

Unusual for sure. PVC into a cast hub?

Normally I see leaks where the plumbers putty has failed on the drain under the flange. I now use Silicone.
This drain looks to have the rubber donut to seal to the PVC coming up. That's a possible leak too. I'm assuming you don't have access to the p-trap connection.

 

[Sponsor]

 

[TurdFerguson835]

Correct that is what it looks like to me. No access to p trap as it's on top of concrete slab.

Looks to me like I have no way to get access to resolve leak without pulling up the pan. And with this odd cast iron p trap situation looks like that needs to be replaced with PVC.

 

[Jadnashua]

There are approved methods to put a plastic riser into a cast iron hub with a 'donut'. IF that was what was done, you wouldn't see the donut.

Some shower drains for receptors like yours rely on a rubber gasket around the riser to seal. Some, it's just a simple friction fit, some rely on a nut on the bottom to wedge it tight (but on a slab, you couldn't use one of those).

So, it could be from the drain, but it could also be from a problem with the walls, and even the supply plumbing.

To isolate if it's the drain, you may need to buy or rent a drain plug, fill the pan up from an external source, and let it sit overnight to see if the level drops. If it does, it's the drain, if it doesn't, it (may) not be...depends on how deep you can get the plug. If the drain just goes into the trap like a funnel without a water-tight connection, if there's any restriction or backup in the drain line, it could overflow out underneath the pan.