After moving flat time and time again one thing is true of all rented accommodation it seems. There is very little storage. I appreciate space is at a premium these days but some places I’ve lived have been pretty ridiculous.
One thing that you’ll need in most flat is a mop and bucket, and one thing that’s not so compact is a bucket. Usually unsightly enough that you want to squirrel them away when the Jones’s come round but if you don’t have the storage space what do you do.
One solution is this:

which is definitely a space saver for the car washing amongst you, however I’d like something with some structural integrity so that I could wring out a mop on the top of it.

I’d been mulling this over on and off for a while and I was always trying to work out a way for joints and hinges that enabled the folding up of such a invention to be water/air tight. It struck me today that I’d been thinking of the problem from the wrong angle and I didn’t need water/air tight hinges I just needed a plastic bladder inside the bucket that was flexible so the hard structure could create the rigidity and the fold down method and the bladder could create the water seal.

Another application for this idea is collapsible lunch boxes.
When I was working up town I used to take a packed lunch with me most days and it was pretty much the only thing I was taking with me, and it was somewhat bulky. But carrying the empty lunch box home with me meant that I was carrying bulky nothingness with me. If I could collapse my lunch box I’d reclaim all that space again.

MikeD