In a previous post James wrote...
I plan to build a small garage, 20 feet by 30 feet. I want to be able
to span the 20 foot width, so that I don't have to use interior posts.


Use engineered lumber I-joists. 14" TJI 210 @ 16" o/c should be about
right.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com