Crew jumped from 8 to 22 mid-build. When do we need a second porta potty?

You need a second portable toilet now that your crew has reached 22 people. The OSHA construction standard 1926.51 requires one toilet for 20 or fewer workers and one toilet seat and one urinal per 40 workers for 20 to 199 workers. With 22 people, you are over the 20-person threshold and must provide facilities for at least 40 workers, which means a minimum of two units. The requirement applies immediately when the crew size increases, not on the next service day.

Most rental companies can deliver a second unit mid-week if you call, but they will likely charge an extra delivery fee for the special trip. The alternative is to wait until your next scheduled service day, but that leaves you out of compliance. Since you have easy truck access, adding a unit is straightforward.

You should also consider adding a handwash station. The sanitizer packs are not a substitute for running water under OSHA rules for construction sites. A separate handwash station is required. For the second toilet, a standard unit is sufficient. If you plan to keep the larger crew long-term, you can have the rental company add both the toilet and the handwash station on your next regular service visit to avoid the extra delivery charge.

Ray is right, you must add a unit immediately. The OSHA inspector or a city code officer does not care about your service schedule. They count heads on site that day. Your rental company's driver can drop a second standard unit the same day you call if they have a truck in the area, but that special trip incurs a delivery fee separate from your weekly service. For a long-term fix, tell them to bring the second unit and a handwash station on your next regular service day to avoid the extra charge. The handwash station is not optional; OSHA 1926.51 requires it when you provide toilets.