How Bad Is It?


Old 12-03-15, 04:20 PM
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Question How Bad Is It?

I turn to the experts for some help. I am dealing with a built-in shower which has been leaking. The owner waited too long to deal with it. I am helping out. I am handy with tools and with my hands, but have not done work quite like this before.

The shower leaked through the floor and into the kitchen below. After years of this, there are problems.

Below is a view of the shower. You can see I've torn out a lot of the wall. It seems the builder did not use cement board behind the tile--just drywall. I also found no hint of any other barrier/liner. So I'm suspicious that one problem was moisture seeping through the tile grout, and into (and eventually through) the drywall.
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You can see in the picture above some black wood. QUESTION #1: With joists like these, which are rotting, do I need to replace the entire joist, from top to bottom? Or can I cut out the rotting portion, and nail/secure 1 or 2 3x4's to the sides of the effected joist?

(If you happen to be a plumber, too: I see the cold water feed pipe is green. I suspect that means there is a leak, which would have added to the overall problem. Thoughts?)

Next is a picture looking up into the ceiling from the kitchen. It maybe doesn't show here very well, but about 2 sqft of flooring is rotting. Replacing this will be a major project. Probably means ripping out the shower pan above it, as well as the wall seen in the right in the first picture. QUESTION #2: Do I have to replace this flooring? Or once the leak is resolved, is there another way to deal with this flooring?
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This third picture shows a wooden beam immediately below the flooring pictured above. This definitely has some water damage, and is darker than surrounding wood. However, it is not black, and is pretty solid; I push on it with a screw driver, and it seems to be as hard as the surrounding wood which is not discolored. QUESTION #3: Can I leave this beam? Having to replace it would turn a major project into a really major project.
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I know this is a lenghty post. Thank you for reading it and offering any guidance.
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Old 12-03-15, 04:47 PM
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You don't "need to" cut out anything you dont want to. Many people are hypersensitive about mold nowadays, and if so, that's a good reason to remove it. Truth told, if the wood doesn't get wet in the future, it's not a problem. You could sister right alongside it if you want. You likely have floor joists that are probably in the same shape and I bet you won't be replacing them. Bottom line, if it's easy to remove and replace, you might want to. If removing it opens up a can of worms... like repairing drywall (and painting) on the opposite side of the wall... then leave it and just sister alongside.

Copper pipes naturally turn green. Its called oxidation. If the pipe ain't dripping, it isn't leaking.

People used to put tile over moisture resistant drywall, or even regular drywall all the time. Omaha is filled with houses from the 60's, 70's and 80's where ppl thought it was ok. Doesn't make it right... now most people know better.

Back to the floor joists. NO don't cut out ANY part of your floor joists! Sister alongside as needed. If by chance a joist is really rotten, like rotted in half, then yes you would obviously need to cut something out. (Won't go into that method here and now) But if you poke it with a screwdriver and it's solid, then it probably just looks worse than it really is. Plumbing will need to be cut... new wood sistered along side (generally it should be from bearing to bearing if it needs to be structural, but if not then it can be as long as practical)... then new holes are drilled and plumbing replaced.

Yes, replacing the plywood floor is likely a good idea. Only replace what is needed. You will need to add blocking around the edges of your replacement piece so the plywood seams are supported on all sides. Again, poke with a screwdriver. If it goes through, obviously replace. If it's solid, then maybe you can leave it. You basically just don't want any "give" under the shower pan. If it's still solid it might be okay. But if you are like most people, you won't be able to sleep at night knowing there is old rotten moldy wood under there.

As for the beam, if it's solid, it's probably fine.
Old 12-03-15, 05:26 PM
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Join Date: Apr 2014
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Thank you, @XSleeper. I'm not terribly worried about the mold, except:

1) To the extent that any framing/flooring has become a problem with regard to support and needs to be replaced,

2) To the extent that the mold might spread, even if the leak is fixed.

I think you've essentially addressed those issues for me.

With one exception. The framed wall where the shower head is (shown on the right in the first picture) rests on top of the bad underfloor. That same underfloor also goes under the shower pan a little bit. I'll inspect further, but I'm afraid replacing that rotten flooring means tearing out that wall and the shower pan. Grr.

Thank you for your help.

Old 12-03-15, 07:11 PM
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It's a common misconception that mold can continue to spread when water is not present (your leak). Dry rot is a misnomer, as things rot because of being wet, not dry. But you are right to concern yourself more with the structural integrity of the wall and floor. Hope you find that the floor isn't as bad as you think.
Old 12-04-15, 04:34 AM
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There unfortunately does not look like much salvage of the shower above and it all has to come out. Once you have removed the shower pan and subfloor, we can access to what extent we need to repair of replace. X gives some great advice here. I'm still trying to determine the source of the leak. Once you have everything out, we may want to test the plumbing by running it into a bucket. May be a leak at the shower arm that only leaks when the water is running. That would help explain the green pipe and the wet studs in that cavity and why it doesn't leak when the shower is idle. The rest of the moisture damage to the side wall is most likely from water infiltrating through cracked grout either in the corner or in the wall itself.

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