Possible shower pan leak in sunken tub/shower

Discussion in 'Shower & Bathtub Forum & Blog' started by Estelle, Jan 2, 2011.

  1. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    Our tiled master shower has orange discoloration (rust from hard water stain?) on the grout join between the back wall of our Roman sunken shower/tub (we swapped out the drain when we moved in and use it exclusively as a shower now), and the floor of the shower. We have tried drying out the tub, but that area of grout never dries. It is always oozing water. We have had three plumber visits over the past two years where they had to do some minor fixes to the hot and cold faucet handles on that wall, and in pulling the handles off were able to look into the wall. Everything appeared dry there. They suggested that the problem is most likely a leak in the shower pan. We plan to remodel this bathroom in a year or two, but this discoloration has been going on for probably a few years, and now I'm noticing traces of mold on the grout in various spots. Are we risking huge problems if we wait on this remodel? Since it's a sunken tub, do we still risk rotting, mold and termite damage below it and in the walls? I can post pictures if you want.
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    Long-term moisture exposure can rot out all sorts of things, so yes, it could be a problem if you wait. Then again, maybe not, too. If you can view the underside somehow (either from the basement, crawl space, or taking out some ceiling), you'd have a much better idea. A good place for help on tiling and shower building is www.johnbridge.com.
  3. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

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    Post(s) deleted by John Whipple
    Last edited: Mar 18, 2014
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
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    John's site has helped thousands of people build a traditional shower, and their 'Liberry' has extensive info, diagrams, and references to the TCNA handbook's many methods. There are numerous ways to build a good performing shower, and many more ways to mess it up. Personally, I prefer a surface membrane, the particular one you choose is your choice, as to price, local availability, and your skill level. Many of the pros there started with traditional shower construction, and have 'seen the light' to the benefits of surface membranes, be it from Schluter, or others. the more the shower is used, and the higher the local humidity levels, the bigger the benefit of a surface membrane. there's something to be said for a waterproof enclosure verses a water resistant one.
  5. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    I'm afraid there is no "underside" to view. This house was built on a cement slab -- no basement, no crawl space. On the other side of the wall containing the hot and cold knobs and the shower head is the wall to a separate small enclosure space containing the toilet. So we could break through that wall close to the floor where the commode is and look at what's going on inside the shared wall, I guess. But that floor isn't sunken. The back wall of the large sunken shower is an exterior wall containing a window. I can go outside and see what it looks like out there -- whether or not the soil is wet next to the foundation -- but again that's at ground level, not at the 'sunken' level.
  6. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    Thanks for your reply. The shower does seem to dry out. And the floor appears to have a clear slope to the drain. It's just an area around the drain, and mostly at the grout join line behind the drain that connects the tile wall of the shower with the tile floor that seems to be wet all the time. I have no idea how this shower was built as we are not the original owners of the house, and it was built about 20 years ago. HOW DO I ATTACH IMAGES HERE? DO I NEED TO POST THEM TO A SITE FIRST, LIKE MOBILE ME?

    Another point -- I was just watching HGTV and discovered (duh!!) that an easy way to test a bathroom exhaustt to see if it is working is to put a tissue up at the vent and it should stick to it if it is taking in air. We have a large ceiling exhaust fan over the commode next door to the shower and always have it on after showering to try and reduce moisture. I just tested it, and it's not drawing in any air at all!!! I'm sure that isn't helping our potential mold and mildew problem on the tiles. Does a plumber install exhaust fans? Who do I call for this, as this is the first thing I need to do to have decent exhaust in the bathroom without having to open the window all the time and let cold air in the house.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,048
    Location:
    Cave Creek, Arizona
    The typical "garden tub" did NOT have a "shower pan", because it was below floor level and they did not worry about a leak causing damage to the floors or walls of the building, but they also felt that since it was "cast in place, that it would NOT crack and develop leaks in the first place. I cannot tell you why the joint is ALWAYS damp, unless you also have a problem with a water leak, (but not likely a drain leak), under the floor.
  8. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

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    Location:
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    Fixing a leaky sunken tub

    Post(s) deleted by John Whipple
    Last edited: Mar 18, 2014
  9. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    Well, unforunately neither I nor my husband are handy at all -- so I doubt we will be doing any repairs on our own. We have tried not using the shower for a week, and it was still wet in that one area by the drain. Didn't run a fan, though. Are you saying that there is some kind of a clear liquid membrane that can be painted over the tile floor of the shower? What we don't want to do is tear the shower apart for a fix BEFORE we remodel, as that would be a wasted effort. I can live with the discoloration, but am mostly concerned about serious damage to the foundation of the house. If the shower is below ground level and there is a crack in the waterproofing system, or no waterproofing system allowing groundwater to enter, why is it just coming in at that one spot? And can that condition cause major damage to the house if left for another year or two? I loaded photos on Photobucket and will try to post them now. Here's the link to photos on Photobucket: http://s1093.photobucket.com/albums/i430/safarigirl20/
    Last edited: Jan 3, 2011
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    If there's no organic material (wood, primarily) underneath that can rot out, a leak there probably won't do much other than promote mildew on the surface. You can probably leave well enough alone until you decide to remodel. Then, building it right should resolve the problem. Any clue where the water table is?
  11. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,711
    Location:
    North Vancouver, BC
    Post(s) deleted by John Whipple
    Last edited: Mar 18, 2014
  12. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    As to the water table -- how does one determine that? I have no idea what the water table is for this area, or who would even know that. And what would knowing the water table level tell me about our problem? Our remodel plans are just for this master bath, not the whole house. The white tile in the shower was a poor choice and is dangerously slippery, the wide grout a pain to keep clean, and the whole sunken shower/tub is an outdated concept and something we would like to get rid of entirely. So what we really want to do is bring in a designer to reconfigure the entire bathroom, use new materials throughout, and make the best possible use of the space available. High on our priority list will be a leak-proof walk-in shower! But again, the economy being what it is, we weren't prepared to launch into this project for another year or two. As for your other questions -- I think we first noticed the discoloration about three years ago. It started with a small discolored spot in the grout that wouldn't come clean. And now the discoloration is about one tile length long as you see in the picture, but still seems confined to that area. I don't see signs of tiles loosening or anything like that. No bugs. But I do get mildew. We recently had the grout in the shower cleaned and sealed and that got rid of the mildew, but now it's coming back in little spots here and there, and of course when they sealed the grout they told us there was nothing they could do with that discolored area because of the fact that they couldn't get it to stay dry. I am planning to replace the non-functioning exhaust fan immediately. Have a guy coming out to bid the job on Monday. He's recommending we spend about three or four hundred dollars on a really good industrial-strength exhaust fan (or I can opt for a cheaper one for about one or two hundred dollars) to help keep the moisture level in the bathroom down. And he said even if we remodel, they can reuse the fan -- even if they have to relocate it.
  13. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    Sorry, no clue about the water table level, and I wouldn't know who to ask. I guess my dilemma is, not knowing how sunken tubs are built, I don't know if there is wood underneath there or not. Do you?
  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    Does anyone around you have a well? Any idea how deep they had to drill? Are there ponds, streams, lakes nearby? Any springs around you know of? My mother's house sits about 1/4-mile from the town's spring fed water supply, and her basement has nearly constant water seeping in to the sump, that needs to be pumped out. If the water table is high, it could be ground water seeping in, and not anything from the shower's supply lines, or drain system. I've heard really good things about Panasonic bathroom exhaust fans...very quiet and reliable. Come in all sorts of sizes. Fantec also makes some nice ones. The thing to keep in mind is the sone (or sound) level...the lower the number, the quieter it is.
  15. Estelle

    Estelle New Member

    Messages:
    7
    Location:
    California
    Thanks for the advice on exhaust fans. I'll ask the electrician about those. I guess the quieter, the better. As for the water table thing -- I doubt the water table is high. We live in an urban area, in a nice neighborhood of custom homes on 1/4 acre each, and our house is nearly at the top of a hill with our street ending in a cul de sac. Noone has their own wells. We all have city water. No ponds or lakes or streams nearby either.
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