First thing you need to is find the source of the moisture and repair that. The selective demo to find the extent of the damage. Depending on how long there has been a moisture issue you may have rot but it doesn't sound like putting new flooring over whats there in my opinion.

Theres no leak, it’s just From people using the shower and not using the weight in the shower curtain. Selecfive demo?

There is significant moisture damage under all of that. That’s what the smell means. Paint isn’t going to fix the actual problems. It just masks a symptom. Put your head in the sand if you want, it won’t be for long. You need to do demo here, and rebuild the whole thing.

Do the smart thing and have an expert remove that tile. Then remove the rest of the subfloor and repair the joists. You may need to remove and replace the tub as well. Demo will tell the tale. It will need to happen sooner than later. The rot wont go away, and you may find the tub crashing through the floor into the room below.

Remove the damaged wood product. Just because the water came from somewhere other than a pipe, doesn't make it any less damaging. Decades of splashing water = decades of a slow leak. Water is water. Damage is damage.

If you have swollen wood product AND odour, it means this has been going on a LONG TIME. Like REALLY REALLY REALLY long time. And that means the amount of mold that is sitting in/under that subfloor is going to be HUGE.

It could be SO BAD that the joists underneath have been affected/infected as well. Just because you can't smell it anymore, doesn't mean you killed/cleaned the mold. The damage is still there and the mold is still growing.

Not until you rip it all out to see how bad the damage is, will you be able to assess how to correct the issue. I suggest you start demolition with the understanding that you will continue ripping things out until you can see "clean and healthy" wood underneath. Be aware this could be a Pandora's Box of issues.

Check your state's requirements for asbestos abatement. There are many states that allow homeowners to remove/remediate SMALL amounts of asbestos tile without having to hire a remediation company. You may or may not be allowed to deal with asbestos by yourself. It is better to do some research on that front before doing much more. If you are allowed (by your state/local ordnance) the same website will have detailed information as to HOW to go about removal/disposal (disposal is expensive because it has to to a special location ...which you will have to pay for).

While you are doing all this research, please reach out to your bank to find out the MAXIMUM amount of loans/credit you can access so that you can feel comfortable moving forward with your project.

Thank you for your advice, but can we skip the condescension? I am obviously in need of guidance, not “sticking my head in the sand.” Thanks.

To be clear, the wood has only recently been exposed to moisture and has only swollen/emitted an odor within the last few days. I am Also able to see under the floor through the crawl space beneath the floor and there doesn’t appear to be damage down there.

It's your call. Odour takes a LONG time to present itself. I would hazard a guess that this wood has swollen in the PAST...and then dried out (shrunk). The mold/mildew spores became DORMANT and were reactivated with moisture. It only takes a SMALL amount of moisture to reactivate mold/mildew spores (so small you can wipe it up with a dish sponge). Once wood has swollen once, it will continue to swell. And with each swelling, more and more of the glue in the plywood/OSB "lets go". That means it becomes less and less structurally sound.

Your damaged wood *might be salvageable (dried out one time only) but more often than not it is not. If this swelling has a repeating pattern (the presence of odour is the tell tale sign this has happened more than once) the chance to salvage the wood has passed. Which means removal is still the best option.

A great question to ask yourself is this: "How much can I afford (money, time, effort) to lose if I have to do this again?". Good luck.

Sorry but you are trying to stick your head in the sand and put bandaids over a gushing artery. This isn’t a paint it kludge. It isn’t a patch. It’s minor surgery of a dangerous substance and some surgical wood repair if you are very very lucky. And a complete gut of the whole room if you are not.

head in the sand · More Info

Wow, and you are obviously similar to the end sticking out. I obviously did not paint it to solve the problem, I painted it to prevent further damage while seeking out advice, because I did not know what to do. “Sticking my head in the sand” would have been tiling it over the paint with crossed fingers, not asking for advice. Stay kind, folks. <3

I'm not sure at this point what advice you want from people over the internet.

The only advice people can reasonably give you is to hire an expert asbestos abatement company to remove the tiles and then have an expert flooring person assess the damage after the subfloor has been exposed. It is only at that point that you would know the best way to proceed.

What other advice could anyone possibly give you in terms of the safest and most reasonable way to proceed? Without knowing what the problem is and how extensive it really is, how did you want to proceed?

I can only speak from my experience in terms of my recent gut remodel of a bathroom with asbestos tiles. Although no one in the household or I assume prior to that was particularly careful about wiping up from normal splashes and wet feet, there was no accumulated moisture under the tiles after 30 odds years of use.

Well actually, that’s exactly the advice that I was looking for. I’m not sure why you think I’m looking for different advice or in disagreement with that which I’ve been given. I’ve thanked everyone who gave me advice, with the exception of the person who did so in a condescending way. There is a difference between ignorance and a lack of knowledge. To imply ignorance because I sought out knowledge is illogical, inaccurate and rude. But whatever, some people just need to feel important behind their keyboard, meanwhile I’m just trying not to die in my first home...

Whoa, slow down there! Take a deep breath. Everybody's going all doom and gloom on the poor OP. Mold! Asbestos! Collapse! Disease! Famine! Pestilence!

Heck, we haven't even seen the floor yet.

Sarah, I suggest that you shoot some photos of the problem area, some close, and some more distant for an overall perspective. Post them so we can have a look. Then let's talk some more.

BTW, if you really have a plywood subfloor, consider yourself fortunate. IMO plywood isn't as good as the solid old-growth dimensional lumber found in houses from the early 20th century, but it sure beats the heck out of the splinters-and-chemical-glue "wood products" that they make floors out of these days -- and which you'll no doubt get if you gut your bathroom to the floor joists and start over.

Thanks David. I climbed up in the crawlspace above our basement and snapped this photo of the subfloor. There’s a small chance the Black stuff is mastic from the tub, but then There’s that teal stuff too... The plywood never changed colors like that, I suspect some of the other posters were correct in assuming that I awoke a previous issue more so than doing all of this damage in such a short period of time.

I believe by “selective demo” and “minor surgery” some are implying that I may just be able to deal with the boards that are damaged? I‘m not sure the whole subfloor needs to be replaced up there, but I think those tiles are going to have to come up just to let me get to these. It seems like the whole job requires different skill sets, I don’t even know who to call first! Mold guy to assess damage? Then abatement guy so I can get to it? Then Someone to actually replace subfloor? Lol, what have I gotten myself into!

It’s hard to tell anything from the top because we sealed it with kilz to keep more shower water from getting in there. About half the tile was missing and now the board beneath is even with it, maybe even sticks out from it

I'm not an expert on these matters, but I do like to avoid major projects when it's safe and reasonable to do so.

This is what I'd do in your place.

Take your showers and baths somewhere else for a few weeks. Let that mess dry out thoroughly. Then poke at it with a screwdriver, from both above and below. IF it's still solid, IF the wood isn't delaminating or lifting, hit it above and below with chlorine bleach diluted between 3:1 and 5:1. That kills mold and mildew. Let it dry thoroughly again. (Ventilate really well when using bleach.)

Then call a good flooring person and a good tile person.

If the wood IS mushy and/or delaminating, I'm afraid I see a big project in your future.

yep, that wood is done.... mushy on top and I’m afraid to see how deep. I can’t get to the wood beneath, but I did catch a picture of the other side of the joist. Looks like one particular board is damaged on this side. This angle shows a little bit of darkness on the corner of the joist as well.

So tile’s coming up first I guess. I’ll be back when I know more. Thank you all.

It may be even more, I hate to say. That water may be coming from a leaky pipe under the bathtub itself, and running that way. Please get someone in there to check everything out. I agree, stop using that tub and shower, if you have a way to shut the water totally off, please do so. It could even be a water line in the wall that is leaking. Its doubtful it is this bad, from water splashing out of a shower.

Oh I hope not. But I can see the drain pipe and the shut off valves, there doesn’t seem to be any moisture or damage to the wood around that area. No cracks in the tub or anything. I really think that board was just exposed for a long time before they sealed it up with sheet flooring, and now I’ve awoken the beast lol. The damage seems to line up perfectly with this exposed area. A water line in the wall may be possible though, I’m not sure I can see all of that down there. I’ll look again this evening.

Good for you, Sarah, climbing down there yourself and getting those pictures! I hope that the rot IS limited in area. Facing crap like this is what being a homeowner is all about. I once told a contractor that the drywall had gotten wet and moldy in a room off the kitchen that used to be a porch. I asked him to remove drywall and wood until he got to good, solid, undamaged structure. We ended up with the entire wall and ceiling drywall removed and finding rotting roof rafters. He had to replace a few. Others had good wood after being treated with bleach, though he sistered a few more because they had been weakened. I learned that this guy did thorough work and thought of safety first. He has become my contractor, and had done every project in my two homes in the past 15 years. I just waited 3 years to have him remodel my bathroom!

Update:

Hooray! We took the tile up. The subfloor in both corners by the tub was definitely shot, but the actual floor beneath that was perfectly fine. Wet, but it began to dry out to its normal color within the hour and was not at all soft. We cut out and replaced pieces of subfloor by both ends of the shower where it was soft, and covered the whole thing in cement board.

Great news!