Rafter to ridge beam height
 

I am adding a 14x14 porch addition to my existing house. I have built and raised both side walls along with the gable balloon wall to a 4 in 12 pitch. My rafters are 2x 10's with the ridge beam measuring 11 3/4 inches in height. Even with the plumb cut on the rafters they won't reach the full hight of the beam. If I set the rafters at the bottom of the beam then I would have to trim the top of the ridge beam to meat the sheathing...not a good idea. Plus, no ventilation. If I set the rafter to the top of the beam I still have that ventilation issue...plus my beam is hanging a couple of inches into the room below. The only thing I can think of is to raise the rafters 1 inch above the beam top to provide proper ventilation and deal with the dropped beam later from the inside. By the way the ridge beam is two 1 3/4 inch x 11 3/4 lvl's sandwiched together. I have 3 roofing books and I can't find anything on this configuration.....Any thoughts would be appreciated.:eek: Thanks in advance. Dave

Usually, the ridge beam does extend below the bottom of the rafters. If you're worried about finishing the underside of the rafters, you can put a board horizontal across the bottom of the ridge at the peak, this will give you a place to mount lights, ceiling fans, etc.

As for insulation, if you're using 2X10's, use faced insulation for a 2X6 wall. The facing paper goes down, stapled to the bottom of the rafters so the un-faced insulation is still about 3" below the roof decking. This leaves room for the roof to vent above the insulation.

This is the standard around here.