AC roof mount problem

[series60man]

The weight of my AC units depresses the roof creating a shallow depression. This makes the water puddle around them and is a potential leak as the gasket under the AC ages. I lowered the ceiling mirror on my 06 Exec looking for an area to shim the roof up 1/4 inch under the AC. I was hoping to do it above the steel framework but it is not visible in that area. Nothing else that is visible is strong enough for this purpose. Any thoughts? Bad engineering.

[Diplomat Don]

How about a sheet of hardened aluminum ( 1/8") the size of the A/C unit, placed under the A/C unit on the roof. Seal the edges and cut the same 14" x 14" hole in the center. It wouldn't be visible to anyone and would probably displace the weight enough to solve the issue.

[series60man]

Since no one else had the same complaint, it appears mine was an actual manufacturing defect. I should of had it fixed while it was under warranty a few years ago. Interesting idea Diplomat Don but a lot of work. Maybe a thin layer of expanding foam (almost not visible) would seal and protect the gasket.

[TGMarrs]

Your post made me do a inspection and water test on my '03 Executive - but everything looked OK and water runs away from the a/c units. Strange they would change something in your newer model that would cause that problem...

Only thing I could think of as a quick fix would be to buy some "dicor DiSEAL" roof seal tape. It is 4 inches wide and specifically made to seal rubber or fiberglass roofs and sold a Camping World. It forms a permanent seal and has a soft grey adhesive that works great. You could use this to attach to the bottom of the a/c and ramp down to the roof. I'm sure it would seal up water tight, and perhaps form enough slope to keep the water from pooling.

I used the stuff to reseal my previous coach because I was too lazy to scrape off the old cracked dicor sealant and put the new sealant on - it worked great. I just got some for my new coach to seal up screws I'm about to put in the roof while installing some new solar panels.