Rotten joist ends - solutions without affecting below ceiling?

[aks7]

Hi - newbie here - first post so please bear with me

Doing a renovation on my apt and have lifted all floorboards as levels are all over, I've discovered that a few of my joist ends are rotten - pic attached. I believe this was due to a historic leak but the water ingress has been stopped.

I'd like to repair ideally without affecting the ceiling of the downstairs apartment - what are my options?

I wanted to sister all the joists (as a way to level them), and have seen I could do this to strengthen the rotten joists, but I'm not sure (1) how I'd cut the rotten sections away above without being able to support from underneath? and (2) I also have herringbone struts which prevents me from sistering end to end - are these removable / should I replace with noggins?

Would love some advice, Cheers

 

[Why Not Indeed]

I would check what your lease says about how much of this structure you can work on without interacting with the freeholder.

I'd like to repair

To be clear, other than looking a bit tired, do you actually have a problem here? Ie, is the floor bouncing when you walk in the area, large cracks in the ceiling below, etc? If the answer to that is "no" then I would leave this can of worms closed, IIWY.

 

[stevie888]

To me that looks like dry rot which will not stop just because the leak has. You need to get this confirmed and you need to talk to the freeholder becasue I don't think it can be addresssed purely from above

I finished relaying a bedroom floor in our recently reposssed rental place only yesterday where 3 joists had (dry) rotted clear through. I have stripped the floor, dropped the ceiling (lath & plaster) and cut back a couple of feet beyond any indication of rot on the affected joists. I opted to add a trimmer between the first clear joists, (which I then sistered) and support existing and new infill joists off that trimmer.

Probably it woiuld have been better to replace the lot but I settled for several sprayings of chemical treatment including onto the walls where spores can lurk

 

[aks7]

Thanks for your replies.
Floor is uneven all over which I'd like to fix and so thought I may as well get this properly addressed while floors are all up etc.
Noted re dry rot - just did a quick google and I will try to get someone in to confirm.
Luckily downstairs neighbour is very reasonable and will probably be fine as long as we make good of course

 

[ree]

OP,
You definitely have dry rot.
You most definitely have to remove all signs of the infection. No short cuts.
You do this by lifting the floor cover & replacing all affected joists with treated material.
You will also have to hack off 1m high of plaster, clean out the joist pockets, and spray the brickwork.
It might be possible to do some of the work from above - but the ceiling below will need re-attaching to the FF joists.?
The pipes and cables might need a plumber & a sparkie?

Dry rot can lie dormant but it can also be "activated" again - dont take the chance.
Why not lift more flooring & post pics?

 

[aks7]

Thank you. Luckily at early stages of reno so will definitely get it addressed properly. I will contact a few professionals to get some opinions on the best course of action too.

Floors are all up, have attached another pic and will try and take better ones, yet only these 3/4 ends look rotted. Video here for those who have 2 mins! https://drive.google.com/file/d/1tcRpv1Un8uhgzYdO_k87cUg_Slr8OB4m/view?usp=sharing

If there is a way to replace the joists without completely cutting downstairs ceilings out would be great, but naturally want to minimise their disruption so am remaining hopeful for a splice/ sistering solution. Has anyone used "Bower Beams"?

I've been living in the property since June 23 however and no leaks while I've been there, hence makes me wonder what it was when I moved in and whether this is a normal rate of spreading, or whether this would be considered "slow" for two years and therefore may have stopped?