Horizontal and Vertical Roof Drain Sizing using 2006 UPC

Horizontal and Vertical Roof Drain Sizing using 2006 Uniform Plumbing Code. Contractor License Center specializes in training Contractors to pass the state contractor licensing exams through our exam preparation services. Our top contractor schools will show you the ins and outs of each subject matter of the contractor testing.

[@chandler2927]

Shouldn’t the vertical leader be 6” since you can’t downsize drain pipe?

[@gregbowman9646]

Each section of the roof only needs a 3 inch leader, after multiple sections of the roof are connected (under the roofing) you would have to increase the pipe size to handle the combined surface area.