Whenever it is hot and humid and I have the A/C on, I have runoff dripping from the rear gutter standoffs. As you can see from the picture in my signature, my roof slopes to the rear and to each side. It is not flat anywhere.
2013 Silverado 2500HD LTZ CC 6.6L Duramax Diesel
2014 Sunset Trail SF270BH
Holly & Buster, mini Dachshunds
2016: 1 trip, 3 nights in 1 state, 316 miles
2015: 5 trips, 18 nights in 3 states, 2707 miles
2014: 5 trips, 14 nights in 3 states, 2426 miles