Bouncy Floor

[KarlT1]

Good Morning all,
I'm new here, so be kind.

I own a 1890's end of terrace 3 bed house which seems to have last been decorated in 1895! Haha.

Anyway, my 3rd bedroom, which is now my home office, seems to have a very bouncy floor, it's a 1st floor room, above the kitchen.

I am a little concerned on how bouncy it is.
I do need to rip up all the old floorboards as they have seen better days, plus I want to replace the kitchen downlights and wiring, along with some old microbore heating pipes and add some addition wall sockets.

So while I have the flooring up, can I do anything to stop the bounce? It is quite unnerving when I am at my desk and someone walks up to me and the floor bounces so much.
Many thanks

 

[foxhole]

You can sister joists and add noggins.

 

[Lower]

Loads you can do, but you need to understand why it's bouncing first. It may be just undersized joists, or they may be some kind of structural problem like rotted joist ends.

 

[KarlT1]

Loads you can do, but you need to understand why it's bouncing first. It may be just undersized joists, or they may be some kind of structural problem like rotted joist ends.

Thank you for the reply.

So, i am yet to pull all of the floorboards up, i have done a few and from what i have seen are a lot of older notches and holes from previous services.
The joist are from 2" x 6" (definitely 2", all floorboards are back down but from memory the joist are 6" deep) and span just over 2.7m. the room is 2.5 x 2.7m.

So, the issues i can think of are:

Rotten joist ends
Undersized joists
Too many notches/holes

So what are my options for these?

Are they really likely to be undersized? it is not an extension so is part of the 1890's build and we don't have the issue in bedroom 1 which is nigh on double to size room and same size joists.
But hey, i am no expert, just a DIYer looking to not end up in my kitchen whilst on a work Skype call. haha.

I am happy to sister joist if that is the solution, do the sister joist need to anchor in the wall either end like the originals? Assuming the originals are not rotten of course.

Thanks again

 

[Deleted member 174758]

Could be various issues e.g.masonry pockets too big (slate packings/mortar fell out), rotted timber bearers in brickwork, racked or split joists (overloading), minimal bearing area because of shrinkage (can happen if the timber was insufficiently seasoned), etc in addition to the aforementioned problems. You need to lift a couple of boards and have a really good look around