How can you tell if the subfloor beneath a shower base is in good?

Shuganne
by Shuganne

The shower had been built with 4x4 ceramic tiles. The grouting failed and tiles fell off. I want to reuse the shower base and just replace the walls, but how can I tell if the base is solid? It is on the second floor and there have never been any drips or mildew on the ceiling below it. The shower has not been used in several years, but it's time to remodel and have a guest bathroom.

Sorry about the dust. This is the worst spot. This is the left wall.

This is the back wall where the second row of tiles are bowed out and ready to fall off. The right wall seems solid.

  9 answers
  • Johnna Glover Johnna Glover on Jul 16, 2018

    I tear it all out, and start new, but u might be able the check around it when u remove the tile from the wall. If the floor has any give what so ever it's bad but if it ceramic, I'll keep my fingers crossed you can see some of it after u remove the wall tiles. If it's sunk in the middle a high on the sides u should be able the ck it.

  • Johnna Glover Johnna Glover on Jul 16, 2018

    I tear it all out, and start new, but u might be able the check around it when u remove the tile from the wall. If the floor has any give what so ever it's bad but if it ceramic, I'll keep my fingers crossed you can see some of it after u remove the wall tiles. If it's sunk in the middle a high on the sides u should be able the ck it.

  • Johnavallance82 Johnavallance82 on Jul 16, 2018

    Hi there, Best way is to remove all existing tiles and investigate! Could be that water has been seeping down and ruined the sub. floor. Wishing you good news.........

  • Jewellmartin Jewellmartin on Jul 16, 2018

    Shuganne, you have a leak somewhere or those walls wouldn’t start dropping tiles. Unless you have a plumber or licensed contractor to evaluate the situation, I don’t think you can save the current shower. Perhaps you could remove the walls whole, by cutting all the corner seams, then work on repairing each wall away from the shower. Once you cut away all the grout and caulk from around the pan, you should be able to pry the pan up enough to check the bracing and subfloor. Once the wall with the fixture is removed (all the fixtures unscrew one way or another), you are sure to be able to spot any leaks or drips. Make all the repairs and buy all the replacement parts (keep the receipts!), and have all the reconstruction supplies you will need. If you were able to save the walls and tiles, I suggest you consider flipping the walls upside down, with the repaired tiles on top, since the water should not hit above the tiles. If it does, there is your leak! Clean the drain, possibly get a new drain cover, and even a new shower head. Make sure the mounting of the walls corresponds with the studs and framing boards, and use plumber’s glue or E6000 if you can’t use nails. Grout carefully, and allow the proper amount of curing time. If you use caulk, follow those directions. Then install all the fixtures, and polish the whole shower. Other cleaning is implied. Shuganne, you have chosen a big project. Please document it all and post on Hometalk! ☺️

  • Jeanette S Jeanette S on Jul 16, 2018

    Shuganne, from the looks of this, it appears that you need to tear this out and redo the entire area. But you may want to consult a professional since it looks like there may be black mold hiding in the walls.


    You can buy a kit from the big box stores to put in the area to capture what kind of mold is growing there...some are harmless and some can kill you...so you definitely want to check this before you do anything!


  • Shuganne Shuganne on Jul 16, 2018

    Johnna, John, Jewell,and Jeanette, thank you for taking the time to look at my ugly shower and answer my questions. It sounds like I'll have a better answer once I take out the tiles. Really, that's like making a wall with a sieve, just waiting for one pin hole to fail and watch a little the tiles float down the drain! I'm not replacing the walls with tile, but I may leave the ceiling up....and shower with a helmet! Thanks so much for your thorough and thoughtful replies!!

  • Shuganne Shuganne on Jul 16, 2018

    Johnna, John, Jewell,and Jeanette, thank you for taking the time to look at my ugly shower and answer my questions. It sounds like I'll have a better answer once I take out the tiles. Really, that's like making a wall with a sieve, just waiting for one pin hole to fail and watch a little the tiles float down the drain! I'm not replacing the walls with tile, but I may leave the ceiling up....and shower with a helmet! Thanks so much for your thorough and thoughtful replies!!

  • William William on Jul 16, 2018

    Tear the wall down to the studs. From there you can look at the subfloor with a small mirror and flashlight. Replace/repair any damage to the studs/walls. Then continue the project.

  • Shuganne Shuganne on Jul 17, 2018

    Excellent idea, William, thank you! And even if it weighs 80 lb, they tell me, I am going to use cement board this time. I'm not going through this again! Thanks to the Hometalk community for your help!