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?
Welcome to the Bunnings Workshop community. It's fantastic to have you join us, and thank you for sharing your question about building a low-level deck.
Would it be possible for you to post a picture of the area where you're planning on building the low-level deck? This will give our members a good idea of how it's laid out and where exactly the slope is. We can then make an assessment and provide you with recommendations on possible frame layouts.
Here is a link for ideas and inspiration: Inspiring low-level deck builds
Here are some amazing low-level-deck projects our Workshop members have shared:
We look forward to seeing the photos.
If you decrease the size of timber used, you need to reduce the span of its supports to compensate. So, if you were supporting 90 x 45mm every 1000mm, you'd support 70 x 45mm every 800mm or so. You'll need to check regulations and timber spans table to verify maximum timber span distances. You could reduce the joist spacing to 400mm if you wish. I can't see 50mm making much difference either way, though.
If you could go into more detail about removing this wedge, I'd be happy to advise.