[Zeppelinium]

Did a total replacement last summer. To start, the "scaffold" consists of two 14' extenable ladders and an 8' long 2x10 with cleats at each end to ensure it won't walk off the ladders. This rig allows the 2x10 to be adjusted to almost any height above the trailer. The boards you can see under the ladders have 1" foam on the trailer side, which has prevented any scratches and absolutely no oil can dents.

The AC had previously been dinged and removed, leaving the old support plate and a new vent to close the hole temporarily. The old flanges on the support plate can be sawed off with moderate effort, but it is effective and easy to bend them over with a hammer. Bending them provides some additional strength to the plate.

Once the vent was removed, you can see the very simple and weak aluminum channels around the periphery. When you remove the channels, you can see that the wiring runs close and thick on the curb side of the opening. You have to enlarge the opening about 1/2" to comply with the new standard vent/AC opening. A hack saw does a good job, but you need to install short pieces of wood rib (just outside of the cut line) and clamp them in order to get a clean cut.

Putting in the 2x4 wooden ribs is amazing! Suddenly the roof is extremely strong--I felt like I could do a pullup on the edge, should I be so inclined. You have to make a decision on whether or not you want to pull the old drain through the rib and make it available as a drain for the plate. You'll also have the old 4-wire themostat connection--I coiled up the wires and stored them behind the ribs. The only connection you have to make is the 110 volt.

Photo 9 you can see the interior plate with the air divertors and the thermostat. The cover fit on perfectly and the roof in my Caravel is essentially flat at this point, so no trimming was required.

The outside view of the installation, totally normal except that the side flanges of the old installation only had to be cut down slightly, so they are still visible, but I can stand it. Taking the old support plate off would have been a real nightmare and probably would have caused major skin damage.