Ridge beam undersized--any ideas on how to reinforce it now that its in place? 1

[Qwikone]

Members-
I was called to look at a 2-2x12 ridge beam spanning 11'9" on a mostly finished porch roof yesterday afternoon. The rafters are 2x8, and the roof pitch is 5:12. The issue is that the inspector noticed a difference in depth of the 2x12's, one is 11-1/2" and the other about 11". He said that the Contractor needed an Engineer to determine if the ridge beam was adequate.
I ran StrucCalc on it and it is undersized by 6% for Moment. Required depth is 11.58"
I am not coming up with any solutions to alleviate the issue without replacing the existing 2x12's with an LVL set.
I know this Board has many folks who must have come across something like this in their travels-- so does anyone know of a solution that could correct the the the existing 2x12's without taking them out?
DusterMick

 

[KootK]

I wonder if the statistical calibration takes into account the inherent redundancy in light framed, wood structures? Probably not.

There is the repetitive member factor. Of course that would just be a drop in the redundancy bucket.

Back in my metal plate connected wood truss days, the hot topic was coming up with ways to account for system behavior in component design. It went nowhere because, frankly, it's just do damn hard to come up with something that is reliably quantifiable and/or easily applied.

While there is surely some low hanging redundancy fruit out there to be picked, until we can figure out what to do with it, I don't feel that we have any business relying upon it. We still don't even have a live load reduction protocol for stud walls do we?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[XR250]

I hear ya. I guess we just have to use our best judgement in each particular case.