im building a cover over a slab of concrete out back. its a 15x25
piece. what size of wood do i need for the rafters?

im thinking 4 by 4's in the corners and one in the middle of the 25'
sections. 4x14 around ancoring to the 4x4s and 2x6 spaning the 15 feet
from 4x14 to 4x14. will this work or is it an overkill?

im using plain wavy sheet metal roofing.

thank you