Throat depth?

I’m having trouble locating a minimum throat depth requirement for interior stair stringers, although I have found a couple of references to 5" for deck stairs. Can anyone cite a reference?,d.b2I&cad=rjt;/content/Documents/File/51.pdf

Check page 17

Do you have one for dimensional lumber? I also found several tables for engineered products.

It would depend on the stringer span and on center spacing and the quality of the wood, etc… 3 1/2" to 5" or more can work…depending.

Was it loose, springy, etc?

stringer throat.jpg

stringer throat.jpg

It was springy. You can see where someone tried to secure the stringer to the column adjacent to it. I’m already calling it out due to tread depth, landing size, handrails, etc., and I felt the stringer was too small, but wanted something to refer to.

Thanks for the illustration, Bob. Perfect.