The "required" testing would be whatever the contract document specifies. I did a RSW structural aluminum project 5 years ago and the building department asked the QA agency (me) to develope a QC program specifically for this project, for this fabricator. There was not any acceptance criteria or guidelines for this application, so I put together the following recommendations:

For the PQR;
1.) 2 tensile tests [acceptance criteria was based on an engineers calculations]
2.) 2 macroetch tests to verify weld size, depth of penetration and the presence of discontinuities [accpetance criteria Mil-W-6858D, Class C welds was used to determine discontinuity compliance or noncompliance].
A deputy inspector would monitor all testing.

For WPQR;
3.) 2 peel tests to verify weld diameter and welding parameters at the start of each shift for each operator.
4.) Tensile testing of 2 welds at the start of each shift for each operator.
A deputy inspector would provide periodic inspection and review each day's operator qualifications speicimens.

The building official accepted these conditions. The project went well. Please note this is what worked for me. End of story.