PC Roof Question

I have a question for anyone that has information regarding a solar panel installation or knowledge of the Phoenix roof construction.  During the initial order specification I had  Phoenix install two 160 watt panels behind the air conditioner.  I am considering adding two more panels in front of the AC. 


Prior to the construction I was told PC would install a plywood panel between the aluminum roof supports to attach and support the solar panels.  I asked them to also add similar plywood panels in front of the AC in case I wanted to add two more solar panels in the future.  Unfortunately I did not see this to confirm exactly what was done as the fiberglass skin and the interior head liner panels were already in place on my next visit to the factory.  It appears the solar panel support brackets are screwed or bolted to the roof between the aluminum roof support members.


The PC panel installation has been without issue. If anyone has installed a solar panel or seen how the factory does this I would be very interested in how the panel is attached to the roof.  How is the standard roof constructed?


This is a photo of my factory panel installation and another photo of the planned solar panel addition.

Since you can walk on the roof, I bet there is plywood on the whole roof. One layer would be adequate, I'd assume, as the solar panel feet are lagged and gooped to the roof. Others have added panels aftermarket all of the time. The above statements are assumptions, and a quick call to PC would answer your concerns for certain.

Have you contacted the factory to inquire as to your unit's roof construction? When I wanted to add panels to mine I contacted them and they had a blueprint of the build of my specific PC that they sent me (it showed where the trusses were etc.). 

In general whenever I have had any questions about the build or particulars of my PC, the factory was extremely helpful and was able to provide very specific information about my rig.

I expect you will be able to just screw down regular solar panels, but if you can't you can use flexible panels, as they are very light and can just be attached with adhesive. I'm pretty sure there is a discussion of someone doing this exact thing somewhere here on the forum. Flexible panels however, are more expensive.

I added a Renogy flexible panel about four years ago and it has worked just fine.   I secured it with 3M tape like the kind used to attach some exterior automotive mirrors.

https://www.amazon.com/Renogy-Extremely-Flexible-Monocrystalline-Solar/dp/B07BMNGVV3/ref=sr_1_1_sspa?crid=2531I0GV18E3Z&dchild=1&keywords=renogy+flexible+solar+panel&qid=1619440974&sprefix

Earlier, I had mounted a conventional 100 watt Renogy panel and used the bracket kit you can order.   I drilled into the roof with great concern, but it worked out OK.   My concerns included hitting wiring up there.  Apparently, most of the wiring runs through the metal framing of the roof which is used as a conduit.  Also, I used a self leveling roof sealant around the edges of the brackets to also help hold it down.   I have never had a problem with either the rigid or flex panels. 

As I recall, I removed the ceiling fan facia from the inside of the PC and was able to take a look at the roof construction from the underside.  I don't recall the specifics, but I do recall I was rather surprised at how thin the roof materials were but  since I can walk on the roof, apparently they are adequate for the job. 

Here is PC's 2552 roof structure

The Green Mods are what was supposed to be added.
Here is how I attached to roof & panels, use lots to sealant.


See if you can just hit the aluminum structure if you can, it's easy to see, just crawl up there on a dewy morning and you will see where they are.

Thanks for the responses.  It has been right at 5 years ago when I was at the PC factory working out the details of the solar panel installation so that is almost ancient history.  Heck,  I struggle remembering what happened yesterday.


I vaguely remember I think Kermit mentioned that the aluminum roof supports were box type members and some of them were used to route wiring.  If this is true I would expect the roof vent and perhaps the AC being routed inside the roof supports.  John, if your panels are attached to these aluminum supports did you use self drilling self tapping stainless cap screws?  Was drilling into/shorting out the wiring a concern or did you attach to the embedded plywood roof panels shown on the drawing you provided?


I haven’t contacted the factory yet but I will do that before firing up the old drill.  I would like to have an “as built”  drawing of the roof for our unit.  My recollection of the Phoenix portion of the solar install was that solar in general was relatively new to Phoenix in 2016 and various details were being worked out on the fly.


Any other experiences or thoughts are most welcome.


Fred

Fred, I use self drilling screws. There isn't any wiring up front in the square tubes.

Just use the shortest screws needed to do the job. Any threads penetrating past the total purchase point is wasted money.