Typically a roof for a dog run is made up of 1.0m wide box profile panels. These are prone to damage when in transit so we do not offer them as a mail order product. You should buy sufficient length to have an overhang from front to back and normally you will raise the roof at the front for drainage. These supports are designed to hold a timber support ( typically 75mm x 50mm) to which the roof panels are attached.
You can normally attach the roof panels direct to the frame at the back of the run, although many customers will use roof supports set on a lower height instead of drilling directly into the metal.