What is causing my bouncy floors?

[Willdoitlater]

My kitchen floor has gradually become more bouncy during the last year, to the point where it is quite unnerving. The bounce is getting worse in other rooms too, and we can also feel the water pipes vibrating more. It's unbearable when the washing machine is going at full speed. Actually, its unbearable when someone lightweight walks across the floor. Thing is, my lovely plumber has had a look and can't find anything wrong. So, do I get a builder to wreck my kitchen looking for a problem or just ignore it and pray my washer doesn't fall through the floor next time its doing its final spin? House was built in 1984.

What type of flooring do you have down?

Floor boards, hardboard, then vinyl.

My first thought would be that some of your floor joists are rotten. This is assuming that underneath the floorboards you have a timber floor.

We have quite bouncy floors, we don’t have solid concrete floors, it’s like a cavity underneath. We think that the joists have slightly adjusted and the boards aren’t sitting quite on top of them. We don’t want to rip up all our hard flooring though to look.

Yes to first thought being rotten joists, but, as I said, someone has looked and all looks fine. Before that it was unnerving and worrying, now add spooky as well...

Does the floor just need re-fixing to the joists? I read they can become loose after a while and need re-fixing.

There's probably someone more technical than me who can confirm.

Mine has gone the same way over the last 12 months but I haven't had anyone come and look yet same as PassMeTheWotsits, as I don't really want the boards taking up.

www.familyhandyman.com/project/fixing-bouncy-floors/

There’s no easy fix to this , it’s going to be a floors up job if you want the floors solid. It could be a number of issues. Rotten joists in the walls , undersized joist when it was built, sleeper walls not supporting properly, not enough noogins/ bracing in or just something simpler like joists loose in the wall or packing slipped out under some of them.

But if you want them solid you have to support them in the middle if it’s a long span .

you're sure its floorboards (like planks) and not chipboard?

@Chumleymouse is right.

as it's the kitchen, it's possible a leak has caused rot in a joist.

Thanks for all the suggestions everyone. I'll have to find a good builder I guess. But since there's nothing to see atm, I'm hoping it will wait until 3 weeks after my second jab!

Joists can look ok but you have to poke them with a screwdriver, they can be like weetabix when you do that 😱 ( voice of experience here).
It sounds like the joist ends to me, they crumble away in the brickwork or joist hangers, which causes the bounce.