Is this rot?

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Hi bought a house that tenants have been living in for 2 years , I noticed that the floor was coming away from the floorboard in one corner and lifted up the carpet which felt like it hadn't been lifted for years.
I came across some water stained chipboard which was bone dry to the touch but springy when stepped on as it can come loose to wherever it attached to the stud wall to the bathroom.
I speculate a leak has happened in the past as the bath is directly behind the wall where this stained chipboard was found.
There was also high damp kitchen ceiling reading directly under the bath but again this is likely historic as in 3 months I have not noticed any wetness or bubbling of plaster.

I pulled back the carpet and found this white dusty looking stuff on the chipboard. It seems to located only in this area from what I can see so far. Its brittle when touched and easily snapped off into my fingers. Also it rubbed in/away like chalk.

Wonder if its mold, wet rot or dry rot and if its dead ot dormant.

I noticed a minor smell when peeling back the carpet but nothing too bad. I also checked under the bath by taking off the panel and the floor seemed dry and there was no smell or anything no any of this white stuff from what I could see.

Any help into what this may be would be appreciated. I know the chipboard panel needs replacing at least.
 

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It certainly looks like you have or have had water leaking in that area, probably as you said from the bath next door so check pipes and waste. If the floor is flexing you may have rotten joists under the chipboard so it may turn into a bigger job but you won't know until you get the board up.
 
can't tell anything from that other than there is a potential problem in that corner - you need to lift up that bit of flooring and have a look, you also need to work out where the dampness is coming from and stop it.

you certainly should not ignore it,
 
The patch is bone dry so I am wondering if it's a historic leak, or the side of the bath wasnt sealed. I will fill the bath and drain it today and watch with the panel off to identify if there's any leaks and will try and get the board up
 
The patch is bone dry so I am wondering if it's a historic leak, or the side of the bath wasnt sealed. I will fill the bath and drain it today and watch with the panel off to identify if there's any leaks and will try and get the board up
sorry I hadn't read you earlier post properly and assumed it was all wet.
so the bath is on the other side of that wall ? and what does the floor look like there ? is it upstairs and if if so do the ceilings underneath look good ? can you poke a screwdriver through it ?

if all thats good, and its dry and no smell, I would be thinking all is ok.
 
Yes it is, the floor looked ok but it wasnt chipbaord it seems to be on a different type/style of floor but it didnt look rotten at least not from the top. I will try prodding with a screwdriver today and see.
The kitchen ceiling did read high on a damp proof meter in the survey, but was dry to the touch when I touched it. Not sure if high readings can also show from historic leaks.
I will try and poke a screwdriver there too.

There isnt a strong smell just a bit musty, but that could because im exposing flooring thats been damp before and the carpet not lifted for years.
 
That white growth does look like it could be fungal activity from past damp. Possibly early dry rot mycelium or another wood-decaying fungus that’s since dried out. The fact that it’s brittle, chalky, and snaps easily suggests it’s inactive at the moment. Active rot usually feels soft, cottony, and has a musty odor, while yours sounds more like residue from an old leak that’s now dried.

If the chipboard feels springy, it’s likely lost strength and should be replaced regardless. You’ll also want to check that the moisture source (like that old bath leak) is fully resolved. No damp pipes, condensation, or seepage.

You could take a small sample to a local timber treatment specialist or DIY store for confirmation, but from your description, it doesn’t sound like live wet or dry rot.
 
Managed to get to
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he subfloor doesnt smell damp and cavity was dry. Attached some images. The mold and mildew were on the carpet gripper, see pic as well. I poked the joist with a screwdriver and it was solid and didnt go through. It just left a little ident where I pushed hard. Is this good news?
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all looks good to me
obviously it has been wet and there has been the very beginning of a bit of fungal activity that is dead or dormant now - I would think there is nothing to worry about

- I'm no expert though !

i did have an old victorian property for 30+ years and it have quite a few issues with wet and dry rot, one very serious case of dry rot - so i have a bit of experience with both, and I wouldn't be remotely concerned with what you have there, just keep it dry like the rest of your house
 
Only question is, this is still on the chipboard tile and the base of the stud wall around the leak. This doesnt look like dry rot does it? It was chalky and rubbed off in my hands.
Also doesnt seem have seem to gone down the joist.

Cheers
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I think the chipboard under the bath has had it as it looks like the pics above. Mold and rotten.
It seems dry.
Will need a plumber to take bath up to see the other side of the joist.

Do people Think its best of just replacing, spraying any joists and making sure the stud wall is secure and replacing the bath tiles and sealant to ensure no water can get behind?

Sorry just worrying about it as its my first home and Im very inexperienced.
 
If it were me, I'd be looking to replace the floor and any compromised joists. Wood preservative on all timbers, as a precaution.
If there are isolation valves on the bath taps then taking it out is potentially a DIY job, if you are up for the challenge!
 
Im getting a new kitchen fitted by a plumber joiner so might ask him he will do it as a side hustle haha. Hopefully the joists are ok, they seem solid from the bedroom side. But yes new floor definitely.
The look of this rot and mold just worries me.

Another potentially silly question, the stud wall which separates the bathroom from.the bedroom is not supported in an area from below as the chopboard has been removed and it was nailed into that originally but rotted and came away. Will it be supported from above by the attic joists so it wont come down?
 

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