To earn your Plumbing Contractor License, a great place to start is to learn the Plumbing language. For example, What is a bathroom group? How many dfus does a bathroom group have? And most important, what happens to the dfu load when two bathroom groups are located in the same house? Look at Chapter 2 and then Table 709.1. Make sure you can define all of the different types of vents – stack vent, vent stack, common vent, wet vent, circuit vent, and island fixture venting. And while you are at it, define a branch interval.
Why take the Class II Exam? Both Class I and Class II exams are just about equal in difficulty. Class II doesn’t involve dreaded Manual N but it limits you to residential work only. One day you will want to do a commercial building. The only thing good about H-3 Class II exam is that it will help you pass the H-3 Class I exam. I suggest you sign up for both exams two weeks apart. Use the same approach for the P-I and P-II plumbing exams.