Many of the guys are using the 1/2×1 mesh, 14 gage wire cage traps for roofs when dealing with raccoons with very good results.  The reason for the tight mesh is to keep raccoons from getting ahold of shingles and doing damage.  Coon are notorious when it comes to wrecking anything they can get their mitts on.  The 9×11 cages were made with a bit of an intentional gap under the door so that debris would not clog the door as it closed, no jamming.  Though we have not heard of roof damage with the standard cages, while the opening is very small, it might be possible for a raccoon to reach out under a door a short distance.  

By attaching a flush mount extension ring or rings to single or double door Comstock cage traps the traps should be pretty much “roof proof.”  The ring extends 6 inches beyond the door to prevent reaching out and turns the traps into flush mount units for positive den setting.  Also, we do make traps in extra heavy duty 12 gage wire, not only incredibly strong, “bullet proof,” the gaps between the wires are smaller yet.
The rings can be quickly attached and can be just as easily removed depending on situation or what is required, one more option.