If a fellow NACHI member could further guide me…I know what the books say about notching a floor joist. What are the concerns for notching a 2 x 10 floor joist to accommodate a 3 in drain pipe to pass through. My thoughts are; that almost 1/3 of the board would be missing since the board is not exactly 10 in wide.
I’d install some additional additional support in the form of one or more metal bars, boards, or the like extending at least 2 feet (or to the end) on each side of the notch, and attach it at no less than 6 points (3 each side of the notch), David.
I don’t know the specific codes for such reinforcements, but since you’re making about a 3.5-4" notch it stands to reason that a well-attached 2x6 or metal bar of equivalent strength should be more than sufficient. When in doubt, overbuild.