Solar Panel L Brackets

Just found out from Newmar that they do indeed use 3/8" plywood in the roof.

Salvo wrote:
I had no problems finding rafters with a stud finder. You'll locate rafter edges when you slide stud finder from both directions towards a rafer. It's extremely simple and accurate! The rubber skin doesn't effect finding studs.

Get on the roof and check it out. No need to call anybody. The rafters on the toyhauler are 24" apart.

I had a lot of problems locating my rafters with a stud finder. When sliding back and forth, the error was more than 1" on each edge, which is not even remotely enough because my rafters are only 1.3/4" wide and 1.1/4" thick. The spacing was 18" on most rafters, and less than 16" on some spots.

Salvo wrote:
I had no problems finding rafters with a stud finder. You'll locate rafter edges when you slide stud finder from both directions towards a rafer. It's extremely simple and accurate! The rubber skin doesn't effect finding studs.

Get on the roof and check it out. No need to call anybody. The rafters on the toyhauler are 24" apart.

I'll borrow a stud finder and check it out. Thanks much.

I had no problems finding rafters with a stud finder. You'll locate rafter edges when you slide stud finder from both directions towards a rafer. It's extremely simple and accurate! The rubber skin doesn't effect finding studs.

Get on the roof and check it out. No need to call anybody. The rafters on the toyhauler are 24" apart.

Sal

Almot wrote:

Good luck locating the rafters. Stud finders, even the best and most expensive, don't see it under the rubber and 3/8" plywood, or give 1"-1.5" accuracy which is not good enough.

pianotuna wrote:
Hi mena,

Ask them where the rafters are located?

I'm going to see if they'll send me a drawing of the frame.

Hi mena,

Ask them where the rafters are located?

mena661 wrote:
Thanks all. I sent an email to Newmar and see what size plywood they use. It's probably 3/8" I'm betting.

Thanks all. I sent an email to Newmar and see what size plywood they use. It's probably 3/8" I'm betting.

If (IF) you will hit the rafters on all the brackets, then with small panels and low brackets a single screw per bracket will do.

Good luck locating the rafters. Stud finders, even the best and most expensive, don't see it under the rubber and 3/8" plywood, or give 1"-1.5" accuracy which is not good enough.

I tried to hit the rafters, but on some I missed them on purpose because there were already 3 or 4 closely spaced deck screws in that location, holding the plywood to rafter. With less than 1.5" between the screws sometimes. Talk about not driving more than 2 screws in rafter :)...

For locating those factory screws in plywood, you may use either rare earth magnet or any stud finder. Or just look closely and run your finger over it.

So you might have eventually to drive screws into the plywood near rafter. Now, to hold well in plywood, even with flat install and low bracket, you need more than one screw per bracket. Which should not be a problem if you space them 2.5"-3.0" apart. That's why you might need 6" long bracket 3" or 4" wide. And plenty of roof sealant under the bracket - it will both prevent the leakage and will help to hold the bracket. I also lubricated every screw with sealant before driving it in, and covered the screw heads with sealant.

Yes, 1/4" plywood (usually on aluminum top roofs, fiberglass or when block foam insulation is used) is different from EPDM over 3/8" plywood. The OP has EPDM over (probably) 3/8" ply. Which he'd better check before drilling.

Hi mena,

I would not use more than 3 screws per mount. Every hole is one more potential leak. My "mounts" are angle aluminum for the entire long side of each panel. I used rails so I have 6 screws per panel and four panels, for a total of 24.

My roof was only about 1/4" material in most places so I went with well nuts because I didn't feel deck screws would hold in such thin material. I did use stainless bolts and the well nut inserts were brass however all was covered with Dicor anyway which I felt should seal out the water. I also put VHB acrylic foam tape under all the brackets.