Plywood laminated cranked stair stringers

[mr.rob]

Help please!

AHJ is asking for an engineered stair drawing for a residential stair with cranked stringers. Stair fabricator has been manufacturing stair stringers with glue-laminated CSP plywood for as long as they've been in the business...sized based on experience. Curved, cranked, and straight. First time being asked for engineering on a residential project.

Does anyone have any literature or guidance on how to put numbers to these plywood stringers? CSA O86?

Many thanks.

 

[bones206]

My first thought is to do a load test in their shop and write an engineering letter certifying the load test. It should be fairly straightforward.