laterally braced stair stringer?

[structuralnerd]

Just curious, do any of you consider the top flange of a channel stair stringer braced laterally by the risers? The risers are located in the top third of the stringer.

 

[csd72]

Yes usually.

If the risers or treads are connected close enough to the top fleange then they will provide at least some lateral restraint.

I have designed stairs supported only by vertical (about 10" by 3/4") plates and the only way these work is by the lateral restraint provided by the stringers.

I would be surprised if you needed it though as I usually find that the required depth to fit the rise and run governs.

csd