I have an agricultural pole building that needs a lean to roof put on the side. Poles are spaced on 8 ft. centers but customer wants 16 ft. clear span on one bay. What size microlam will I need to carry that section of roof. The span is 10 ft., 4/12 pitch, purlins spaced on 2 ft. centers with joist at 8 ft. centers. Central Wisconsin so snow load needs to be considered. Galvanized metal roofing. Floor to ceiling clearance somewhat of issue, so would rather go 2ply than deeper on microlam if possible.