level a wooden floor

[dave12345678]

i have a lage bathroom with a dip or belly in the middle with wooden floor boards, how do i level this out without using any levelling compounds ?
do i choc under the floorboards that are lower to level them up ?

 

[^woody^]

You will have to fix a [straight] piece of timber to the side of the joists to the correct level, and fix the boards to this

 

[dave12345678]

hi woody,
oh god, of course, how obvious, but didnt think of it, many thanks dave