Subflooring Under Toilet Problem

The subflooring under our toilet has rotted due to a toilet leak we didn't know we had. The toilet can no longer be screwed to the flooring so that the toilet won't rock.

What is involved in repairing this problem? And, what would the approximate cost be? I know prices vary depending on region but just an estimate would help.

(We have a ceramic tile floor.)

Thanks! Ruby

Is the plumbing cast iron, PVC or ABS or copper?

Cut out the floor and replace some wood.

That's a really tough call. Are you thinking about replacing the tile floor? Do you have any spare tile if not, since they will likely break some or all of those that will need to be removed?

Where is the flange now? Is it on top of the finished floor (ceramic)? Or, did you end up using a double wax ring to try to get it to seal? If so, you are seeing one of the consequences of not updating the flange to the designed parameters - the flange is supposed to be on top of the finished floor, and anchored through it to the subfloor. This makes it (usually) more evident if it develops a leak.

Plywood isn't very strong unless you provide blocking or you can span at least two, and preferably three joist bays. If you only span the one bay where the pipe comes up, it won't be very strong unless you also install some blocking to hold up the edges of both the new piece you install and the one you cut. It is very possible that in hammering in the new stuff, you could crack some tiles or grout on what was undisturbed.

Removing the old tile from the subfloor is a very chancy situation, and they likely won't come up intact.

It also depends on whether the tile was set in a mudbed, on cement board, or what. If a mudbed, the cold joints if you were to just patch this would be alikely place for the tile to crack, and might suggest replace the entire tiled floor.

I can envision what might need to be done, and see a whole bunch of gotchas. The damage might go much further than you think.

The mechanics of tearing out enough to replace the subflooring isn't too bad. How far they'd need to go, and what you want done after that to either try to restore what is there, or remodel can really add up.

Not sure anyone that can't see it would be willing to venture a guess, sight unseen. I know I don't have enough experience to tell you how long, but I'm sure I could fix it if I had to.

We are pretty sure the plumbing is cast iron.

The flange is on top of the finished floor. It does not have a double wax ring. The toilet is pretty stable unless you purposely try and rock it.

It sounds as though you are saying the repair has to be done from above - no way to replace the subflooring from below - that's a shame. We don't want to get into tearing up the ceramic flooring.

How can we be sure that the holes that the toilet is anchored into are just enlarged by repeated repairs? That happened to some hinge screw holes on one of our cabinets - we had to use wood putty and then the screws went in fine and were sturdy and stable.

Also, is there a work-around to tearing up the floor (if the subfloor does indeed need to be replaced)? My brother mentioned something about anchoring the flange to something that crosses the joists below the house. Just thinking outloud here <g>.

Thanks for any help and all information!!

Ruby

It is highly likely that by nailing in new stuff from below, you'll crack tile and grout above. Also, the existing plywood may have delaminated, and anything you do from below won't fix that...the only way to fix it is replace it. We're not there to see what is going on, so this is just a guess.

I realize you are looking and hoping for a quick, easy, and cheap fix for this problem. I can't say I blame you for that, but it sure sounds like water has gotten to the subfloor and it is in a state of decay. The only fix for it is to open the floor and cut the bad stuff out. As previously pointed out, you have to cut far enough to expose at least 3 floor joists, maybe more if the decay goes beyond that. Unfortunately, the is virtually no chance you will save the finished floor. It's going to be major surgery and it will cost plenty. The bathroom is one of the most expensive rooms to renovate, and you are pennywise but dollar foolish to try to do a halfway job.

But this is a relatively easy, though messy job for a DIYer. once you start digging the repairs required are pretty obvious. Just hope that the floor damage doesn't extend under other fixtures, or cabinets as that will require removing a lot more stuff, though still a pretty straight forward job. It sounds like there is a crawl space under the house. From that you should be able to guage the extent of the damage.

i would recommend determining the extent of damage from below before u go tearing up tile. if i understand your problem being a rocking toilet "but u really have to try hard to get wobbling?" in my experience really bad subfloor damage will not support your tile and toilet at all! without seeing extent of damage myself its really hard to pin point your exact problem. everyone on here can only speculate or share their experiences in similar situation. it sounds to me that it could be as simple as shimming base of toilet, possibly using epoxy if it is just reemed out screwholes to seat flange. on the other hand if your leak has been going on for years your damage could extend to other rooms as toilets usually back up to a wall. i experienced worst case scenario in last fixer upper house i bought. the toilet actually fell through floor. entire subfloor was missing under toilet area, joists eaten by termites (attracted there from then plumbing leak) only tile"in bed" and waste pipe held it up at the end. tearing up any amt of tile over couple sq. ft. is a pain in the ass!! i wouldn't recommend tackling it as homeowner diyer unless you have more than one bathroom and a small familyand can finish the project at your own pace/ skillevel. when you only have a 1 bath house you will quickly discover that it is the most essential room in your house once you can no longer use it! i know i did!! if you think about it these plumbers giving advice have actually brought the most essential element to your home! without it you mind as well live in a tent! always correctly assess the problem first before jumping in. you will save an incredible amount of time and money. get somebody under that house with flashlight if possible( i have had to bring shovels in addition to flashlight to dig bigger crawl under beams to get to problem area, it not fun!! if the under approach no work. then rent borrow right tools for job if you can. most homeowners dont own the time/back saving /specialty tool like air powered tile removal tools. (i never used one, with more common tools like rock bar/sledge etc. it could take you days to just to remove the tile and one sore back! my best advice to you from simple approach/less money spent/ and quite possible the only fix really needed is to shim up that toilet well, buy those hard plastic shims from home center cost 1.50? and your problem could be solved? in general water is a homes worst enemy doing the most common/ extensive damage to a home other than fire!!!! get it fixed as soon as leak is noted