I emailed Jayco this weekend about our ALUMINUM Sided 28BHBE, explaining that the Jayco dealer said "no problem, we will install it for you" and received this...
"Awning toppers are not an option on this model so there will not be backing in the wall construction to attach the topper too."
In a prior email about this same thing they said only a Jayco Authorized dealer could install one, and they would not provide me drawings, after I explained whether it was the Dealer or Myself installing it I would like to know what was back there, they then sent me the drawings, which I appreciated, albeit not the right one for my slide.
I am sure there is not true backing in there for Slide Toppers but enough and along with the right sealant should be enough as there is minimal stress on the topper. With that said why would they NOT put an extra piece of wood across the top for this, I still believe the people who design these campers don't actually use them.
SouthCo... Like you I am torn as well. Is your 28BHBE going to be Aluminum Side or Fiberglass. If it is fiberglass I would not worry about it and get ahold of BigJohnD here on the JOF, he installed one to his FGS 28BHBE.
If I do it I will install it myself... I am going to poke around that area of the Slide before making a final decision.
'16 28BHBE / Elite / Thermal / Dual AC / 50 Amp / 12K Equalizer
'15 F250 Lariat CC FX4 6.2 w/ 3.73 / Air Lift 5000's / ARE Z Cap
'12 X19H Hybrid (Sold)