There is a lot more to it than that.

Span, live & dead loads, placement, species, wet or dry, horizontal or verical, point loads, ... plus many many many more.

http://www.altereagle.com/

http://decks-ca.com

http://kingofcrown.com

Alter Eagle Construction & Design

Walls, cieling, porch, dog house, roof???????

Excellence is its own reward!