>> a stick, slightly longer than 0.4m. Stick in at an angle, and tap
>> more upright with a hammer until you achieve the amount of lift
>> required.
>
Thank you, and others, for all the suggestions. I have 2 old bottle
jacks and 4 axles stands so I'll aim to use the former to provide a bit
of temporary lift and the latter with some blocks and folding wedges for
the longer term support. I've never used folding wedges so that'll be a
voyage of discovery for me: they look a really nice machine.
> That could be a lot of hammer action in a confined space!
>
> Robin has not said if the floorboards are up or if he is crawling
> under the floor to do the work:-)
Initially crawling under. But I may well end up removing skirting
boards and lifting floorboards to get a more level floor which at my
pace means "I may be some time".