Since you're laying the joists on their face @nvelaga, which already is not something that is recommended, you would have to at least go for the 90 x ...

Titan 5 x 72 x 100mm 4 Piece Yellow Packing Shims can be used to establish that 5mm gap @nvelaga. The joists will then be placed on top of them and Dy ...

Hi @nvelaga, Joist-size timbers such as 90 x 45mm are only available in H3-treatment for above and not on-ground use. Theoretically, you could use 90 ...

Hi @nvelaga, Thank you for your question. If the side of the concrete slab is not perfectly plumb and the bottom of your trench is not perfectly l ...

Hi @nvelaga, Yes, I would go to 125mm screws. The extra length will have more holding power. Mitchell

Hi @nvelaga, You're on the right track with option 1 being the best approach. By fixing the posts first with concrete, you establish a solid base an ...

That sounds like it would work, @nvelaga. Mitchell