Hi @MitchellMc I'm pressed for space. My slab is sloping out and available space is 60mm - 105mm.
You mention using 90mm x 45mm on its side (90 facing up) then using the adjustable footings to get it level. Would it make a difference if it was 70mm x 45mm? What would the spacing of the footings be on the 90mm x 45mm and if it is possible to use the 70mm x 45mm what would the spacing be? In this configuration would you stick to a 450mm joist spacing or would you go to 400mm?
Alternative is to cut the a wedge out of the one end of the joist. What do you think would be the best?