Which adhesive caulk for solar panel mounts??
My CW has Sikaflex in 221, 505 and 715. Which one is best to mount solar mounts to thin fiberglass roof along with screws?
Forum Discussion
mrdon2 wrote:
I have been reading these post with regards to adhesive/securing of solar panels to roofs on motor homes. I presently own a Class C 08 Access that has Thermo-Panels Material on the roof. My question is what should I use to adhere these panels to the roof with this type of roofing material. All comments and suggestions will be appreciated.
Do you mean a TPO membrane?
TPO = "Thermoplastic polyolefin" according to google
If so, it's just like a rubber (EPDM) roof; there's a plywood under-layment that you can screw into. Or, even better, if you can find wooden joists, you can screw into those. When using screws, some don't even use an adhesive sealant between the bracket and roof material, but I did, using 3M 4200.
I have a rubber roof not TPO. Can't really say how well the 3M Polyurethane or Hybrid products will adhere to TPO. And then there's the question of how strong the glue between the TPO and the roof is. Prolly best to make sure your screws can do the job. I use 3 #10 screws per 6" bracket, 4 brackets per panel, into what seems to be 3/8" plywood, not chipboard.
On top of the bracket, covering the screws and edges of the bracket, any good non-adhesive sealant will do; but I used 3M 4200 there too just because it was already opened and available.
EDIT: Just noticed Almot has already said the same thing.
