Most of this type of panel are being made waterproof by the use of glue. However we know that after one or two years of the use of glue this might corrode. Especially under the influence of UV light.
Instead, we work with a rubber and/or silicone profile sealing to protect the inside from the wet environment. For this we also use a more heavy weight aluminum frame with a thickness of 12mm. This gives us the opportunity to reinforce the closure of the outside panel onto the inside structure thus closing it without any glue.