TJI L65 Joists for Axial + Bending

[pdavis88]

Hi everybody,

I am working on a tenant finish to an existing building where several new mechanical units are being added to the roof. The roof is composed of 1/2" plywood sheathing over 16" deep TJI L65 joists at 16" o.c. On one side, the joists are connected to a stud wall, on the other side they are anchored to a CMU wall to transfer lateral loads. The mechanical equipment is going to require ducts that cannot fit between the 16" o.c. spacing, so we will be forced to cut some of the joists and install headers to transfer the loads out to adjacent joists. My problem arises because I cannot find any information regarding bending+axial capacity of these joists.

The original structural documents did not call out any lateral load on the joists, and I can't seem to find any information from the manufacturer regarding axial+bending stresses.

Has anyone ever come across an issue like this before? Any help would be appreciated!

 

[ishvaaag]

A 3D model, direct design, of your reformed structure including the standing bracing should be able to provide a reasonable appraisal of the members in your joists for the standing solicitations.

If you remain unconvinced of such approach, then make a more complete reform introducing new structural members, doublers or so, that will be meeting what you will be demanding of them, since your "as new" design.