Seneca Roof Structure 2014

[James AO]

I am about to mount four 190 watt solar panels to the roof of my 2014 Seneca FS. My preferred method is rubber covered well-nuts. To pick the correct well-nut grip range I need to know now the roof is constructed, like what is behind the fiberglass and how thick it is. I asked Jayco to send me the roof drawings, and I thought they did, but I just looked at all of the drawings they sent and none of them show the roof construction, cross-section, and materials. Does anyone have the drawing or know the roof make-up? Thanks

 

[Grumpy]

Should be 1/4 or 3/8 luan under the fiberglass. Pull the trim ring on your bathroom skylight or the bathroom fan and you can see it.

 

[James AO]

Should be 1/4 or 3/8 luan under the fiberglass. Pull the trim ring on your bathroom skylight or the bathroom fan and you can see it.

Thanks, unfortunately it's back at the storage yard already. So it's the fiberglass roof, next 1/4-3/8" luan, and then what's next? Is the luan simply plywood, or something different? How far down from the fiberglass before you hit anything metal? How much distance between the top of the roof metal tubular frame cross members? Thanks again!

 

[Grumpy]

That's it. Fiberglass, plywood, cross members.

 

[Grumpy]

Here's the link to a 2012 brochure, info is pictured. Page before floorplans.

https://www.jayco.com/files/downloads/prod_brochure_filename_183.pdf

9 ¼" plywood decking on 5"
arched welded aluminum trusses:
More moisture resistant, plywood
holds up to the elements
10 Seamless fiberglass shield:
Features one-piece construction,
ensuring better leak protection

 

[Rustynuts]

When I was installing my solar, I emailed Jayco asking for roof structure and layout drawings for our 2018.5 RB. They send me several drawings and there isn’t really anything to hit up there when mounting panels. According the the drawings they sent, which are dated 2013, it just says for roof materials, FIBERGLASS, PW #8156 COIL PEB and LAUAN,3.4 X 93 5/8 X 48 over the foam panels and aluminum structure. The Fiberglass panel isn’t much over 1/16” thick and 3.4 Lauan (yes it’s plywood) is only .1388” thick, so basically you have 3/16” material bonded to solid foam. I chose to use large footprint mounting brackets and added a 3rd hole for 3 screws each, then piloted the roof with a 3/16” bit and set them in Dicor and secured with #14x3/4” stainless hex head screws, covered with Dicor. The key thing is to run the screws in by hand until they are snug and stop and not using power tools that usually either end up pulling the threads a little or strip the hole. The panels are rock solid and I have drove in some pretty strong winds in NV and everything is still solid. I went back and forth between screws and wellnuts but decided if done right, the screws are plenty good IMO.

 

[James AO]

That's it. Fiberglass, plywood, cross members.

Thanks!

 

[James AO]

Here's the link to a 2012 brochure, info is pictured. Page before floorplans.

https://www.jayco.com/files/downloads/prod_brochure_filename_183.pdf

9 ¼" plywood decking on 5"
arched welded aluminum trusses:
More moisture resistant, plywood
holds up to the elements
10 Seamless fiberglass shield:
Features one-piece construction,
ensuring better leak protection

Thanks again!

 

[James AO]

When I was installing my solar, I emailed Jayco asking for roof structure and layout drawings for our 2018.5 RB. They send me several drawings and there isn’t really anything to hit up there when mounting panels. According the the drawings they sent, which are dated 2013, it just says for roof materials, FIBERGLASS, PW #8156 COIL PEB and LAUAN,3.4 X 93 5/8 X 48 over the foam panels and aluminum structure. The Fiberglass panel isn’t much over 1/16” thick and 3.4 Lauan (yes it’s plywood) is only .1388” thick, so basically you have 3/16” material bonded to solid foam. I chose to use large footprint mounting brackets and added a 3rd hole for 3 screws each, then piloted the roof with a 3/16” bit and set them in Dicor and secured with #14x3/4” stainless hex head screws, covered with Dicor. The key thing is to run the screws in by hand until they are snug and stop and not using power tools that usually either end up pulling the threads a little or strip the hole. The panels are rock solid and I have drove in some pretty strong winds in NV and everything is still solid. I went back and forth between screws and wellnuts but decided if done right, the screws are plenty good IMO.

Thank you! I just went to the storage yard and pulled off the the shower skylight inside cover as Grumpy suggested. I didn't see any plywood that was 1/4" or thicker. What I saw was the backside of the fiberglass roof, and then very thin plywood looked to be around 1/8", that must be the 3.4mm luan, and then thick styrofoam. Unfortunately I could not see any of the 5" metal trusses so I don't know how far they are below the underside of the 3.4mm luan. I used well-nuts on my last rig and it was super easy, and super secure. I want to do the same on my FS37, but I don't want to drill the 3/8" dia by 7/8" deep hole for the well-nuts only to maybe sometimes having it hit a metal cross member. Do you know how close the metal cross members are to the backside of the 3.4mm luan?

 

[Rustynuts]

I would assume that the Fiberglas/Lauan lays right on the rafters with are 1x1 Aluminum tubing, then there are foam panels that fit between the rafters. In the drawings they sent me for my 2018.5 RB there are not many rafters in there and there is also wiring in the roof but the main harness runs down the center and branches out, I have attaches the other drawings they sent in case they might help give you an idea how the roof is constructed.

 

[James AO]

I would assume that the Fiberglas/Lauan lays right on the rafters with are 1x1 Aluminum tubing, then there are foam panels that fit between the rafters. In the drawings they sent me for my 2018.5 RB there are not many rafters in there and there is also wiring in the roof but the main harness runs down the center and branches out, I have attaches the other drawings they sent in case they might help give you an idea how the roof is constructed.

Thank you for the drawings! They are helpful. Tomorrow I'll ask Jayco for the same ones for my rig. When you mounted your panels did you take the trouble of measuring to find the metal beams and cross members so you were certain to miss them? Or possibly use a scanner to locate them prior to drilling? Same question for the wire harnesses.

 

[Rustynuts]

I didnt even try to hit any of the rafters as there was so few and spacing was off. I just did some rough measurements and one set of panels was straddling the center of the roof where the main wire loom was. When it came time to drill the pilot holes I was real careful to not just let the bit drop through but drilled slow until it penetrated. Then I took a fine piece of wire and probed the foam to make sure the screw would not contact anything. Everything still worked after the install so I think I did good.

 

[James AO]

I didnt even try to hit any of the rafters as there was so few and spacing was off. I just did some rough measurements and one set of panels was straddling the center of the roof where the main wire loom was. When it came time to drill the pilot holes I was real careful to not just let the bit drop through but drilled slow until it penetrated. Then I took a fine piece of wire and probed the foam to make sure the screw would not contact anything. Everything still worked after the install so I think I did good.

I’m glad it all worked out! With the well-nut approach NOT hitting any of the metal roof structural members is important (and wire harnesses too of course!). When you probed your pilot holes with a fine piece of wire, was that a spark test with the power on? . Regarding the metal rafters, isn’t there one every 15” is so? Or am I misreading the roof drawings?

 

[Rustynuts]

When you probed your pilot holes with a fine piece of wire, was that a spark test with the power on? ��. Regarding the metal rafters, isn’t there one every 15” is so? Or am I misreading the roof drawings? ��

Yes, it was the ISO Smoke test....I probed and no magic smoke was released.

Well by my reading of the print ending in 072117 there are metal rafters on each end, on each side of the vents and one in the center length wise. Also if you look at the Parts List on that drawing, it only lists 7 rafters total. I am reading the channels in the other drawing as being the channels in the foam panels for running wiring and such...I may be wrong but that’s how I see it. This is the only picture I have ever seen of Seneca roof panels.

 

[SloPoke-TC]

I would assume that the Fiberglas/Lauan lays right on the rafters with are 1x1 Aluminum tubing, then there are foam panels that fit between the rafters. In the drawings they sent me for my 2018.5 RB there are not many rafters in there and there is also wiring in the roof but the main harness runs down the center and branches out, I have attaches the other drawings they sent in case they might help give you an idea how the roof is constructed.

Thanks for sharing these... give me a better understanding of how that our roof is put together. Jayco has sent us a number of design documents for our FK and I highly recommend anyone who is planning on piercing the inner or outer walls to get the drawing before they do...

 

[James AO]

Yes, it was the ISO Smoke test....I probed and no magic smoke was released.

Well by my reading of the print ending in 072117 there are metal rafters on each end, on each side of the vents and one in the center length wise. Also if you look at the Parts List on that drawing, it only lists 7 rafters total. I am reading the channels in the other drawing as being the channels in the foam panels for running wiring and such...I may be wrong but that’s how I see it. This is the only picture I have ever seen of Seneca roof panels.

I called Jayco yesterday morning and they sent me several drawings that were helpful. It looks like you are right regarding the limited number of metal rafters (7). The wiring harness drawing they sent should help me avoid drilling into wires (resorting in my own spark test) when I drill for the well nuts. In your ceiling panel photo from the factory, do each of the modular interior ceiling panels have their own metal structure on each of their ends? It kind of looks like it in the photo, but I cannot be sure.

Another question, for fiberglass roofs did you use Dicor 501 or 502, or something else? Thanks!

 

[Rustynuts]

I emailed Dicor with that question and got this response. They must get this question a lot and I found this same wording on several sites when searching it.


""The 501LSW was developed to be used at the consumer level. The 502LSW was developed to be used in a pumping system at the manufacturing level. Very little difference with the exception of case quantity.

Any or all of Dicor’s lap sealants will work for your application depending on whether you need a self leveling or non-leveling lap sealant."

 

[James AO]

I emailed Dicor with that question and got this response. They must get this question a lot and I found this same wording on several sites when searching it.


""The 501LSW was developed to be used at the consumer level. The 502LSW was developed to be used in a pumping system at the manufacturing level. Very little difference with the exception of case quantity.

Any or all of Dicor’s lap sealants will work for your application depending on whether you need a self leveling or non-leveling lap sealant."

I ordered the 502 a few minutes ago. How many tubes did you need for your solar project?

Regarding my question about your factory photo of the ceiling panels, I tried to blow up the pic large enough to determine if those are metal reinforcements at the end of the foam but still couldn't make it out, do you know? NOTE: forget the question about the roof panel ends. I see now that what i see is the metal structure that occurs only at the end of the entire roof, not each foam panel.