To all, thanks for the advice. I have done 2 small timber frames and both used this type of roof but it sounds like it will not work for a larger building. So the principal rafter (i think this is the correct term for large 8x8 beams? that go top of each post, meet at ridge) and purlins is what I need. With this sort of span would I also need a king post or queenposts support? I plan on 3 bays 12, 8 and 12 again and the interior walls on second floor would be on same demensions so the posts will not be an obstruction as long as the tie that connects rafters and post can be set high enough for a door. Also it seems as though purlins, running parallel to the ridge would make dormers diffucult to frame since their ridge would run at right angle to the purlins. Could you place pulins down from the ridge until they would interfer with dormer, then run rafters down from the last purlin but at right angle to ridge to a plate? to frame in dormer opening? I kinda have my heart set on gable dormers and 1/1/ stories. I wanted a 3 foot knee wall and was planning on a brace from top of each beam to post extending above beam, I could sacrifice and go to a 2 foot knee wall but i know that will reduce my headspace above. Thanks for all the advice, sure learning lots. Joe
