gap between ridge beam and ridge board
You deal with it by TAKING THE SAG OUT.
Make certain the ends of the BOARD are fastened down securely so they will not move upward when you do the following....
Put the BEAM into position, then place a jack under each end... far enough out from the ends so you can insert a support without having to take a jack out. Start jacking... slowly and evenly
The center... BOARD and rafters, both... WILL start moving upward. When the BOARD gets level all the way across, put in hefty supports for each end under the BEAM, and remove the jacks.
I'm assuming you have already made provisions for 'seats' in the top ends of the rafters for them to sit down on top of the BEAM? And how are you going to get the BOARD out of the way? (assuming it hangs down below the bottoms of the rafters)
You are aware that you will accomplish nothing (or very, very little) if the rafters do not sit down on level 'bird's mouth' cuts on the top surface of the BEAM? To get around this, you would need to install fairly heavy metal brackets bolted through both the BEAM and the tops of each rafter.... that is, IF you had in mind to be fastening these rafters to the SIDES of the BEAM.... which is usually not cool on an engineered beam.
"True eloquence consists in saying all that is necessary, and only that which is."
François Duc de La Rochefoucauld
Last edited by Willie T; 05-06-2010 at 10:36 PM.