Old shifty crack at tub/tile wall interface (front side) has become intolerable

Discussion in 'Shower & Bathtub Forum & Blog' started by RCraig, Feb 24, 2014.

  1. RCraig

    RCraig New Member

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    126
    Location:
    New Hampshire
    I received help from a brilliant plumber on this forum quite some years ago. The problem in brief was as follows:

    Water comes down into basement whenever someone takes a shower. However, no leaks occur when I pour water (a lot) everywhere trying to figure out what the problem is.

    What the brilliant guy figured out over the internet was that the weight of the person in the tub was creating the problem. The solution was to fill the tub with water (weight!) and then caulk the interface between the tub and the tile wall. This solution worked for quite some time.

    I have had to recaulk many times. I think this may be because people taking showers every day creates stress on the caulk joint - it eventually develops a bit of looseness.

    In any case, the problem has now become incurable. Water comes down into basement when someone takes a shower, but it is very difficult to recreate the situation from outside the tub. My tile floor is rotting away because the flooring gets wet every time someone takes a shower. I don't want to replace the flooring until the water problem is solved.

    PROPOSED SOLUTION BY LOCAL PLUMBER: Take out old cast iron tub. Have carpenter replace rotten wood flooring. Put in new acrylic tub.
    The old tub may be "giving" when a body steps in the shower-in other words, the tub sinks a bit. This could be due to too much pressure on whatever is holding the tub up. It could be due to the fact that those old tubs are on 4 little legs, and the legs could be digging into the floor after so many years of people taking showers.

    I am interested in getting the advice of anyone who might have any thoughts about this. The proposed solution -- Is it likely to work??? It is costly, and will mean taking out some of the fairly new tiling (put in before diagnosis by brilliant internet plumber). Any thoughts on any aspect of this would be very much appreciated.

    Ruth
  2. cacher_chick

    cacher_chick Test, Don't Guess!

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    The cast iron tub could be reused if it is in otherwise good condition.

    The proper repair will be to remove the tub to replace the underlaying floor and surrounding walls anywhere it is not in good condition. This is the only right way to do the job.
  3. RCraig

    RCraig New Member

    Messages:
    126
    Location:
    New Hampshire
    Thanks so much for your response. One thing I forgot to mention, before the problem was properly diagnosed, the tile was taken down, cement board was put up all around the shower, and the whole thing was retiled. Unfortunately, that did not solve the problem. All new pipes were also put in, but that did not solve the problem.
    My fear is that we will again redo things, and the problem will recur, that is water leaking down into basement when someone takes a shower.

    About the cast iron tub, they tell me that they have to break it up to get it out. The other thing is that I am wondering whether, if I just reset the cast iron tub, will the problem eventually recur. The local plumber is advocating for acrylic tub, but that is one reason I put it on this forum, to get thoughts from others as well.
    Thanks so much, Ruth
  4. cacher_chick

    cacher_chick Test, Don't Guess!

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    If I were going through all the trouble to replace the floor, I would prefer to remodel the entire bathroom.
    A new cast iron tub would be good for another 50 years, but some plumbers don't like to install them because they are very heavy and often require extra help to bring in and install.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    CI is still the most durable tub out there...a plumber may not want to try to carry a new one up to the bathroom, an acrylic tub is MUCH lighter! If the tub is in good condition, it can probably stay, but may need to be reset.

    If the tub moves when someone is in it, that needs to be fixed. That flexing (of the subfloor, CI tubs for the most part do not bend) could be causing the drain to leak and any time the thing is not level, that can cause leaks as well.

    Does this tub have a tiling flange around the edges (other than the side to the room)? If it does not, trying to waterproof it as a shower becomes much more involved...can be done, but things have to be done properly for it to work.

    If you take a level and measure on the rim of the tub along both the long and sort sides, does it sit level? If the tub does not sit level, that can allow water to pool along an edge(s), and when that seal is not perfect, leak out. If it tilts towards the room, it can leak out into the room, down to the floor, and then who knows where.

    Plumbers are good at fixing plumbing leaks, but may not be the best at tiling and shower applications.

    You might also want to check out www.johnbridge.com and the tiling forum there for some ideas.
  6. RCraig

    RCraig New Member

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    126
    Location:
    New Hampshire
    These are very excellent points. I am not exactly sure what a tiling flange is, but I don't think I have one. That could be the problem. There is tiling on the 3 side walls, but it is just tiling, nothing special. So where I have been caulking and caulking is at the interface, where the tiling comes down to the tub.

    Here are my results from checking with a level: If I put the level on the upper rim of the tub, seems pretty level. So, like if I put the level on either long side or either short side of the tub, seems pretty level (a bit hard to tell 100% because of all the caulk I have on there). If I put the level inside on the bottom of the tub, the tub leans towards the drain.

    That is my fear about plumbers and fixing leaks. Actually, I had tiling guys, plumbers, all of them in here. Nobody figured it out until I put it out on this forum and someone figured it out over the internet.

    I suspect that the setting of the tub is not holding properly, and that this could be the cause of the flexing. The tub has been there a long time. The plumber here tells me that there is a 1 inch board on the long side. I can imaging that that board could easily flex a bit when one goes to take a shower. I just want to be able to get at the problem whatever it is, so that I can not worry about water leaking for at least a couple of years.
    Thanks so much, I will check out the johnbridge.com website.
    Ruth
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Location:
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    Well, the bottom of the tub needs to be sloped to the drain so it can do just that, drain.

    A tiling flange is a lip at the edge of the tub. On a CI tub, it may not be very big, which makes level even more important, but on something like an acrylic tub, it could be several inches tall. When installing the tile, you'd run them over that. Because of that lip, water cannot flow over it, and is directed back into the tub to drain, if any gets there. But, a concentrated spray, and bad caulking, could allow water to flow underneath.

    So, it may be just that the subflooring is now rotten, and the tub is sinking into it when weight is applied. That board on the wall is called a ledger and, because the tub is so stiff, and there are at least a few nails or screws holding it on...it should be okay.

    Depending on the tile's thickness, caulking often works best if you first fill the gap with a foam backer rod, then fill the rest up with caulk. This forces the caulk into an hour-glass shape, so the middle of it can flex better. When it is one solid, rectangular block of caulk, it is stronger, and it can split an pull away from one side or the other if the flex is too great. This also means, you use less caulk. Foam backer rod is available in lots of different diameters to accommodate different gap sizes, and is a good thing to use outside the house as well.
  8. cacher_chick

    cacher_chick Test, Don't Guess!

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    If the tub moves even a tiny bit when people are in it, that is the problem. A tub must be solid enough that it cannot flex, and be installed on a solid surface so that it cannot move.

    Any movement can cause the caulk seams to fail and/or the drain fittings to leak.

    When a tub to tile seam is done properly, only a small bead of caulk is needed to finish it. Adding more caulk over existing caulk does not and will never work to seal the joint.
  9. RCraig

    RCraig New Member

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    126
    Location:
    New Hampshire

    Yes, it is true that the movement is undetectable. Nothing is noticeable, you really don't see anything at all as far as in the tub/bathroom. It is just that water will start coming down into the basement if a person is taking a shower. No water if you are just running the shower without a person in there. Weirdly enough, if you fill the tub with water (weight) and then turn on the shower and spray directly on seams or places where you think it might leak, it is Still very difficult to get much in the way of a leak.

    One thing that I perhaps didn't make clear about this cast iron tub, the bottom of the tub does not come down to the floor. One can examine things from the basement below (there is a small opening), and there is about an inch or two between the bottom of the underside of the tub and the floor. The local plumber told me that there are 4 small legs on the tub, and that and the 1 inch board on the long side hold the tub up. Apparently a new acrylic tub would sit on the floor, which he thinks will help prevent the problem I have with the current situation.

    About flange, I understand better now what it is. I think there probably is flange back there, but since it is behind the tiling (the tiling comes down in front of it), I don't see it. Here is a question: On normal tubs (those that unlike mine do NOT leak), does water get behind the tile into the flange? In other words, is it normal for small amounts of water to go there, and then it somehow drains back to someplace appropriate (i.e., not the basement)? My thinking is that the cement board or tiling may be backed right up against the flange in my case. But I need feedback if possible on this hypothesis.

    One final question that I could use help on. My understanding so far is that I have to figure out why there is movement. If I can figure that out, then I can take steps to prevent this with the new rebuilt stuff. Why is there movement? That I don't know. I agree that the rotting flooring is contributing, but the thing is that the floor was replaced as one of the first things done, at the time that the whole thing was retiled. Unfortunately, the leaking still occurred just less noticeable and has now rotted out the flooring again.

    I really fear that everything will be redone again, but that the problem will recur. Thanks again for all the great ideas and advice. I have more questions and hypotheses, but I have to think a bit more about them.

    Ruth
  10. Reach4

    Reach4 Well-Known Member

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    Suppose you tape some paper/cardboard sheets to the wall, and let the sheets dangle into the tub. You mark where the paper bottoms hit the tub. You add weight, perhaps some people, to the tub, and see if the marks are at the very bottom of the paper.
  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Location:
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    The tiling flange is a last ditch protection for any standing water that may be on the tub rim from seeping in, and running down behind it. It doesn't need to be particularly big, but to work, the tub must be level. A CI tub does normally just sit on feet...the whole thing is very stiff, so it does not deflect IF the feet are sitting on the floor and it can't tip. The ledger on one side and the apron on the other keep it from tipping sideways. The tub does NOT hang on the ledger board, but it should be up against it snugly so it can't move.

    If there has been enough leaking that the floor is now punky (soft and maybe rotten), the thing needs to come out. To do that, if you want to save it, you'll likely need to take a fair amount of the tile off. If the tub is in good shape, there's no reason to change it unless you want to for a style issue...properly installed with no leaks, it can last many decades without issues.
  12. RCraig

    RCraig New Member

    Messages:
    126
    Location:
    New Hampshire
    I am all for keeping the tub. The thing is though, it has leaked since the beginning. So how to properly install without leaks is what I am unsure about. How to effect the "No leaks" part. What was causing the leaks at the beginning? Why did it continue to leak when the subflooring was redone. Maybe not a good job on the subflooring (It was installed by the retiling guy, because at the time we thought that it was the tiling that was leaking)? Maybe the tub needs to be "reset" which is what the local plumber says, but he want to install a new acrylic tub.
    Thanks so much again for all you thoughts! This tub is my nemesis.
    Ruth
  13. hj

    hj Moderator & Master Plumber Staff Member

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    I have NEVER found a cast iron tub that "shifts" when it is filled with water or someone is in it, IF the building structure is 'intact'. For that to happen the floor itself would have to be sagging, which would be a structural defect. I also question any plumber who recommends removing a cast iron tub and installing an acrylic one.
  14. cacher_chick

    cacher_chick Test, Don't Guess!

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    I suspect that the cement board was not properly installed and/or waterproofed so that the water is running down behind the tiles and grout. Tiles and grout are not damaged by water, but they do not stop water from seeping in behind them. The wall should have been waterproofed and sealed to the tubs tiling flange before any tile is installed.

    It should be pointed out that without being there to see what is happening, we can only speculate as to what the facts of the situation might be.
  15. BillTheEngineer

    BillTheEngineer Member

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    Location:
    Hauppauge, NY
    If you can figure out where it is leaking from then you can come up with a plan on fixing it.

    If it's leaking from the caulk seam be the tub flange and tile, it could be a poorly supported tub, the flooring up the tun might need to be fixed and/or the tub just needs to be reset. If you have access from below you might be able to do it from there.

    Other spots to look for leaks is where two walls meet, around the faucet, could be the grout joints. If concrete board (concrete board is not water proof, it's just not effected by water like wood is) was put up and tile on that, then if could be that. Not all tile is waterproof, same goes for grout. If the tub surround was not properly waterproofed, then no amount of resetting the tub will solve your issues.
  16. RCraig

    RCraig New Member

    Messages:
    126
    Location:
    New Hampshire
    This is a very good point. I agree that it is not the tub itself. It is something about the building structure. Definitely, the flooring under the tub is now rotted. However, the leaking wasn't stopped when the new flooring was initially installed. The plumber did suggest that the carpenter could install new crossbeams or joists or something like that when he re-redoes the floor. He also suggested that the legs on the cast iron tub may have been digging into the flooring with the last 50+ years of use, such that that would be contributing.

    About the ledger, what I envision is a board nailed or screwed into the other side. If the subflooring is rotting, and if the legs have dug little holes, a person getting into the tub might put a lot of weight/pressure onto the nails or screws that are holding the ledger in. Perhaps this ledger board is not perfectly stable. Maybe it eases down because nails have come slightly out of the wall over the last many years. Maybe the ledger board itself is not good, splitting or such. Although the tub itself is stiff, I am envisioning the ledger board as a possible slightly weak link. THe shifting is not noticeable except that it results in water leaking down into the basement. It is possible that this could be why it leaks when a person takes a shower (weight is at a central point, possibly putting weight on the central part of the ledger), but it is hard to make it leak when one fills the tub with water as weight. In the latter case, the weight is more evenly distributed.

    I really really appreciate all of your experience, expertise, and thoughts. I know it is very hard to get a grip on this over the internet. The thing is, the guys who can come see it really can't figure it out, and I can hardly make it leak for them because it really mostly leaks when a person is taking a shower. With your help, I will get to the bottom of this. I just don't want to find out after a lot of work and expense is "down the drain" so to speak.

    When you think about it, life is miserable when you have a plumbing problem, and very wonderful when you do not. Therefore, plumbers should be making at least as much money as psychiatrists, right?

    Ruth
    Last edited: Feb 25, 2014
  17. RCraig

    RCraig New Member

    Messages:
    126
    Location:
    New Hampshire
    This is a very good idea, I will do this. I suspect that the shifting will not be detectable. It is not at all apparent in other ways. I wouldn't even have thought of it as a potential problem, except that the internet plumber was right in that, when I put weight in the tub and then caulked the tub/tile wall interface, it will take care of the leaking for a while. Until too much stress on the caulk reignites the problem. I will test this idea with paper strips and get back to you!
    Ruth
    Last edited: Feb 25, 2014
  18. RCraig

    RCraig New Member

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    126
    Location:
    New Hampshire
    Smithtown, NY!!!! Anyway, one of the weird things about this leak is that it only occurs when there is a body in the tub taking a shower. If you turn the shower on, aim it onto the tile wall, it can run for as long as you want, but it won't leak into the basement. I will test it again, but my thought is that the cement board must be holding up ok, otherwise it would leak when I turn the spray onto it and leave it on.

    I am very confused about my leak, and really cannot determine whether it is something about the way the tub is set, or whether it is the surround. I suspect that it is the interface, where the tile meets the tub, and that this interface holds up when there is not a body in the shower, but every so very very very slightly cracks open a tiny sliver when a body gets into the tub and takes a shower.

    Very good thought about the surround, I will do more testing in this arena.

    Ruth
    Last edited: Feb 25, 2014
  19. RCraig

    RCraig New Member

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    126
    Location:
    New Hampshire
    Ok, I taped a fairly stiff paper about the size of a yardstick onto the tile wall. Where it ended near the bottom of the wall of the tub, I put a piece of masking tape. From the outside of the tub, I used a black pen to mark on the masking tape where the paper strip came down to. Then I got into the empty dry tub, and used a green pen to mark on the masking tape the end of the paper strip. The black pen line and the green pen line -- there really wasn't a difference. So one really cannot detect shifting.

    I really don't understand why it leaks when a body is in the tub and the shower is on. I suspect the tiniest crack opens up, but I really am mystified.
  20. cacher_chick

    cacher_chick Test, Don't Guess!

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    I think you are wasting your time unless you intend to make all of the repairs yourself. Knowing that there is a repeat problem there, any contractor worth his salt is going to gut the tub area, repair the structural issues, and replace the existing plumbing. What is leaking now will be in the garbage unless you insist on only doing only part of the job.
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