On Jan 12, 12:04 pm, HerHusband wrote:
I have a 14-foot by 6-foot almost flat porch roof, and the porch roof
is held up by one column one each of the two front corners. Right
now, across the front there are two 2"x6" beams sistered together.
Can anyone tell me if that is considered sufficient under current
building codes, or where I can find some kind of info or load span
table saying what is needed for this situation?
I am in New Jersey.

Here in WA state, I would probably use 40psf for that roof, but I'll assume
you get more snow for longer periods than us and will go with 60 psf.

I assume this roof is supported by the house on one side?

14' x 6' x 60psf = 5040 lbs total

Half of that is supported by the house, leaving the beam to support the
other 2520 pounds.

According to the charts I have, you would need three 2x12's to support that
weight over 14' (using a 1/360 deflection, typical for floors).

If you can tolerate a little more deflection (shouldn't be a problem for a
roof), you could get by with three 2x10's.

If you want an easier option than replacing the beam, you could add a third
post in the middle of the span. This would reduce the span to 7', and the
total load to 1260 pounds. Your existing 2x6 sistered beam would easily
support that weight over 7'.

The OP could also install knee brackets running from the corner posts
to points more interior on the beam to reduce the span. I didn't do a
calculation as I haven't had lunch yet and I learned my lesson from my
first post in this thread, but the OP might be able to get away with
sistering on a single 2x10 if the knee brackets reduce the span
enough.

R