i'm building a garage that will have a 7x18 structural ridge beam holding up the roof. the rafters are 2x12. What's the best way to connect the rafters to the ridge beam.... use birds mouth cuts at the top to bear directly on the beam, or use rafter hangers... see attached pic...

 

I'm not a carpenter but I've never seen the rafters notched to sit on the ridge beam.
I'm used to seeing the rafters toenailed to the ridge beam or hangers used.

 

The lower picture is correct, with sloped hangers.

 

Hi Sky,
I agree with Pj and X, but have to ask (I'm curious) why the massive beam attempting to support the entire roof?

Load bearing exterior walls and walk through trusses are simple to assemble and hold up nicely over time. With the second option shown you will not be able to use a ridge beam thus gable vents or roof vents.

Are you intending to use that space up there as finished insulated space?

Bud

 

the garage is 35x27 with clear spans and no intermediate support columns on either the ground level or in the attic. also the attic is open ceiling for maximum height and unobstructed space. the attic will be used for athetic training (rope, rings, high bar, etc) and also to store a pole vault landing pit in winter time. hence the need for maximum open space and ceiling height.

the roof has a large shed dormer out the back spanning the majority of the garage. also dog house dormers on the front. the shed dormer (and open ceiling) means there will be no connection between the top of the dormer wall and the opposing rafters to keep them together... hence the need for a structural ridge beam that clear spans 35ft....

a picture might help....

 

There could be more discussion but I'll stay focused on your question. I see from your drawing you have included the notched rafter top to rest on the beam. That choice allows space for the ridge vent.

Being Chicago are you including insulation, heat, and ac?

Minimum ceiling insulation depth in Chicago in the 2009 Energy codes was R-38, might have increased.

Bud

 

https://www.finehomebuilding.com/201...l-a-ridge-vent Few choices,this is what I have.

 

here's how I ended up building it. my brother and I did this in a little over a week.

 

Hope the rafters are strapped together over the ridge and that the load path from the ridge is solid.