...2X12 rafters with 2' overhang This Question is really more for a structural engeneer. 2006 I.R.CODE 43#ground snow load,30# roof snow load & 105mph Exposure C. Seismic design category B. Table R301.2(1)-climatic & Geographic Design Criteria. Elevation 5618ft. Patio roof attached to house on one end and on a beam at the other end. Almost flat roof only 1.5'/12 pitch. In the center of beam area I need to span the Posts 26 ft Apart. So what size beam will I need. Can go 5.5" wide or maybe even 7.5" wide so the beam is not so high. Its about 8'off the ground. 2X12 douglas fir @ 16"on center rafters span 19ft with 2ft overhang on one end only, because the other end is attached to a ledger bolted onto the house wall. The roofing is corrugated polycarbonate sheets. Thank You in advance. Question is from Clem .