I'm a little confused with the description of what you're doing.Im buildinga porch 12 x40 with 8 post 6x6 6 header 4x10 rafters 2x8 aand 1" plywood and shingles, i like to know what is better to put simpsom metals for the 6x6 post or put the post in concrete 3' my concern is the weight of the porch and the winds here in texas
Is this a porch on the side of a house?
I see no mention of floor joists, just roof rafters.
Do you mean 3/4" plywood?
Setting sonotubes and using Simpson stand off brackets would be my choice.