small deck with 90x45 bearers

hello, I am building a small deck out side a friends place and was wondering if I could use 2x 90x45 nailled together as the bearers spacing 1500mm apart, with 90x45 as the joists, I am limited to space from the top of concrete slabis only 200mm from the ground. I reckon I could dig some ground out, but would this be needed? does anyone know the spans for 90x45 as bearers, thanks alot

You can go lower by using 140 x 45 Tpine as bearer and fixing your joists to the sides of the bearers again in 140's with either ledger batten or joist hangers...
140 x 45 f5 joists will go 2300 mm single span so you wont need as many bearers and 140's will do 1500mm as bearers to

cheers utemad