I had a guy install a whirlybird-type vent in my roof.. those non-powered turbine types. Upon cutting the hole to install the vent, he accidentally cut a notch in the rafter:
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There are two notches in the rafter (one on each side of the circle he cut, 15 inches apart). I'm looking for advice on how to reinforce it. I'm thinking of putting a nail plate like this, spanning each notch:
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Should I put nail plates on both sides of the 2×4 (sandwich the 2×4 between two nail plates.. meaning 4 nail plates in total.. two for each notch)? Or would you recommend a different approach entirely?
Edit:
If you're interested in more detail. The 2×4 is the er.. 'top chord' as defined in the attached pic. I've circled the region that was notched. It doesn't support anything other than the roof.. single story house.. about 32 foot span (i.e., the 'clear span' in the pic is 32 foot). Sounds like a nail plate is a dumb idea, I'll scrap it. I'll either sister a board to it or just leave it alone. If the added detail changes anyone's thinking on either of those tacts, please let me know.
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Best Answer
Roof trusses tend to be highly engineered and not designed to be altered, and I don't consider myself knowledgeable enough to know exactly how dangerous this is. My suspicion is that you've reduced the possible load your roof can support which would be an issue in strong windows for heavy snow.
The typical solution is to sister another board onto this one. To transfer the load, you'd want it fairly long, several feet to each side, the longer the better. Put some construction adhesive on the current rafter, clamp the sistered board on tight, and screw it with a bunch of 2.5" screws (I'd probably put one every 8" with 2 on each end). That's likely over engineered, but you're better off overdoing the solution than underdoing it and having it fail later.