I'm adding a 4 foot addition to the front of my ranch. The roof pitch will run the opposite way and will make a 12 x 16 foot room 12 x 20. I need to run a beam across the what is now the front wall of the house and since we have short 90 inch ceilings, I want to conceal it. I'm planning on 2 2x12's maybe three, wish I could do 3 2 x 10's. The roof rafters and ceiling joists are 2 x 6's and are nailed together on top of the existing wall at the birds mouth. I've uploaded a picture of a similar idea which would work except the example is with trusses. Can I just use double 2 x 6 jois hangers to attach the rafters and joists to the beam, suggestions? The beam will rest on the corners of the existing wall headers with 4 x 6's supporting them in the wall to carry the load to the plates. Thanks

Check with your local lumber yard, they frequently stock LAM beams or LVLs. This will carry your load better than a stick built beam of 2x12s

Thanks. I'm not too concerned with the beam as it's a small ranch and the load is also held by a purlin half way up the rafter. My main question is what is the best way to secure the ceiling joists and rafters to the beam since they are an integral part of the support. Any ideas!

You'll likely need a permit for this so ask the local inspector what he will approved or not. Sometimes the best adivce comes from the guy who can shut you down.