I can help.
You're not sure if I can help?
What future load on the roof?
I will assume it's supporting a deck then. What is the joist length supported by the beam?
Do you want wood or steel?
I can provide the size as this question. If you need detailed calculations, I can provide that as a premium service.
The beam spans 16.5' and the joists span 16'?
What length are the joists?
They are on one side of the beam only, correct?
16' x 12'?
You will need four 2x12 doug-fir no. 1 or five 2x12 doug-fir no. 2.
What is the city and state so I can look at snow loading?
three 2x12 doug-fir no. 2.
7" x 9.5" 2.0E LVL, but you will need to be VERY careful to keep it protected. LVL are not for exterior use.
Great. Just to be clear, this beam will support nothing more than the 12' joists, correct?
12', not 12", correct?
12 feet, not 12 inches, correct?
Do you still need help with this?