Hi all
just finished building my deck outside and now its time to put the roof up...

Was wondering if anyone knew much about the timber spans of river red gum.

I have provided a rough drawing of the set up that im intending to use, but im unsure if the timbers that i have will cope with the spans.
The roof is flat with a 10 degree slope, just going to be using colour bond as a cover.

I am using 300x50 as my main beams and 200x50 as my rafters....





Due to height restrictions, I will have to make the beams and rafters but join to each other as opposed to the rafters ontop of the beams.
If the spans will not work for timbers sizes, then would anybody know how i could brace it so the rafters could span the 4m?

thanks heaps
Daniel