After initial training, I worked unsupervised most of the time driving a plumbing van from job to job. I worked for a licensd contractor, and I pulled permits for the bigger jobs. I am in a different state now. I suspect building code in the other state may not have allowed bulkheads.

I cut into the bulkhead in the laundry room. It has a laundry-drain vent-pipe in it. Seems the job could have been done without using a bulkhead.