[kaptain]

Jack, 

How are you attaching the solar bracketry to the roof?  

I ended up using aluminum rivnuts that went through the supports under the skin of the roof then bolting unistrut mounted with 1/2" aluminum spacers.  

I ended up adding epoxy to the rivnuts so that it would prevent them possibly turning as I assembled.  I also added self leveling sealant at the spacers and on top of the unistrut bolt heads.

They seem to be holding up very well, and the spacers help keep water from pooling up under the unistrut.

What material is the roof on your coach? Mine appears to be aluminum. But I don't know how thick it is, I need to find out.