STUD Grade vs No. 2 Prime
In the middle of a DIY kitchen remodel in my older house. The engineer asked for a short bearing wall to be built under three floor joists that we agreed are not being adequately supported.
My local home depots only had No. 2 “Prime” 2x4x10s, and after using them I am second guessing and wondering if I should find some STUD grade 2x4x10s and redo the wall. I can’t find any definitive information about lumber grading and engineer is unreachable at the moment. Anyone have some advice? Can No.2 Prime lumber be used in short bearing wall? Could I double up the studs to avoid any issues?
see pics for more details. Second picture shows top plate under 2nd floor joists.
Edit: after talking to every local lumber supplier no one has any 2x4x10s that are better than #2 so I am assuming that everyone uses #2 for everything?
Your edit above is correct, No. 2 Prime is better than stud grade lumber. What "everyone" is using will depend on location, lumber species, and local availability (and may vary significantly around the US). Most areas of the country will carry stud grade lumber, especially for "precut studs"
Substituting No. 2 for stud grade should be no problem as long as Southern Pine or Douglas Fir was not specified by your engineer (SPF is generally going to be a weaker species - regardless of grade).
Double check the plans from your engineer, especially any notes. The engineer I use typically specifies "#2 or Better Douglas Fir" for any structural studs. I believe this is pretty standard but maybe just in my location (Utah). If you have #2 lumber as it looks like from the photos and description I can't see an issue.
As for a pretty thorough guide to lumber grades check out this article... it is helpful.
Here’s a tip you can file away for the next time.
Position your framing lumber on top of each other. And no, I’m not suggesting you change your current framing.