Carpet in the bedroom that backs up to the 2nd floor shower gets wet. There is no water leaking below the shower or in any other direction.
I removed the drywall and there is a liner which was filled to the rim with water. In the picture below, the water has been removed. I removed caulk which had water behind it.
My plan is to let everything dry out, re-caulk, and seal the grout. I was also thinking about pouring some liquid rubber into the bulging liner in the hope that it will find its way underneath.
Any thoughts? Thanks so much!

Shower drain back of shower

liner, back of shower caulk removal

  • Why don't you unclog the shower drain? I'm assuming that's why the pan/liner overflowed. Jul 29 at 4:50

3 Answers 3


I'd be careful about how you add more waterproofing here.

Sealing the grout should help, and makes your shower surface less porous. However, depending on the water proofing system used, throwing in liquid rubber could halt water from exiting the shower and lead you back to mold or worse.

If your pan liner has water backed up, there may be an issue with the drain, such as with its weep holes, which are under the drain a bit and allow water at your water proofing level to drain. If these get clogged, any water that passes through the surface, which is by design, will get trapped by the waterproofing system.

Water has the nasty ability of affecting other parts of your shower, and home that are far from where the actual issue is. Its possible issues at the drain are leading to overflows onto your carpet.

Alternatively, within the picture of the liner there seems to be a hole in the backerboard? If that's the case, and there is no waterproofing at that spot. It could be an issue of water/moister leaking onto the liner behind the rest of the water proofing and thus creating the issue.

I'm unsure how to fix the backerboard's hole in this scenario though.

Most would suggest redoing the entire thing from scratch and do it right, but that still costs a good amount of money and time. Waterproofing the surface might give you a little longer. Just keep an eye on everything in the meantime.


Caulk and grout are not going to keep water out. This is a complete tearout job with a liner replacement. Do you know what was used to waterproof the walls behind the tile itself?

  • I think that it was a waterproof plasterboard, and that there is a liner on the outside of that around the bottom.
    – Shelly Lee
    Jul 28 at 21:01

I let everything dry out thoroughly, and then caulked and sealed the grout. So far everything remains dry. I think that the problem began with a degradation of the caulk at the joint between the wall and floor of the shower. The liner slowly filled up with water and then eventually spilled out as the water seeped through that failed joint. Re-caulking at that point failed as the liner served as a reservoir of water to keep the caulk from setting properly. Once I removed the drywall and dried out the liner, I was able to get a good caulk seal. Thanks to everyone for their help!

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