Possible Shower Pan Cracked?

[TinyHouseDisaster]

Hi all - we have a walk-in shower that was built about 5 years ago as part of an Accessory Dwelling Unit in San Diego. They did a "hot mop" on the shower and it was inspected/signed off by the city prior to the tile being installed. We are now seeing signs of water damage on the wall opposite the shower where the wood floors are and the baseboards (buckling wood floors, bowing baseboards). We called a plumber and they did a test where they plugged the shower drain and filled it up about 3 inches and marked the water line to see if it would go down. The water went down almost 3/4" overnight.

My question is: Does this one test for sure indicate that it is the shower pan/hot mop that has failed or could there be anything else we should test for prior to the very large job of ripping out the tile and redoing the shower pan and hot mop all over again to fix it? Thanks in advance for any help/advice.

PS: I only have a couple of pictures of the construction in this area after it rained once but they show a little bit of where the water lines are running.

 

[havasu]

My hot mop specialist guarantees his job for 5 years. How long has it been? Did you use a tightly sealed test plug to determine if the hot mop failed? Is it possible the water leaked around the drain flange?

 

[TinyHouseDisaster]

My hot mop specialist guarantees his job for 5 years. How long has it been? Did you use a tightly sealed test plug to determine if the hot mop failed? Is it possible the water leaked around the drain flange?

Sadly the contractor was licensed but he has disappeared and we are left on our own to fix it. Plus we were told we are past the point of liability in California since it's been just over 5 years now. It is possible the plug test failed...I suppose we could try that again too just to be sure. Thank you.

 

[Geofd]

The area you point out is below the shower valve has anyone removed the trim to see if that ok

 

[MG70]

I won't comment on the hot mop, but based on your second pic, I'd say it would be pretty easy for water go get around that glass panel behind the spiral stairs and run down to the corner below it. Also, was the backer board properly water-
-proofed and silicone applied around the tile floor perimeter and vertical corners of the tiled walls?

Good luck with the fix.

 

[Geofd]

When you test the shower pan use water from another source to flood your shower base,

 

[TinyHouseDisaster]

The area you point out is below the shower valve has anyone removed the trim to see if that ok

No not yet, is it possible that a problem with the valve could be mistaken for a cracked shower pan?

 

[TinyHouseDisaster]

When you test the shower pan use water from another source to flood your shower base,

Oh interesting, why is that?

 

[Geofd]

Because you won't be filling with the shower valve ,I'm curious if anyone has removed the trim to see if that is leaking behind the wall, that's the 1st thing we do when checking for random leaks you haven't ruled out the water piping yet,you also haven't mentioned checking the window for water tightness