The new guidelines by manufacturers of ACQ lumber call for heavily galvanized or stainless steel fasteners due to the corrosive nature of the ACQ treatment.
You have two basic options for using Palram products with ACQ lumber:
Use a comparable fastener made from an ACQ approved material. Make sure that such a fastener uses either a neoprene or EPDM washer, and that it is installed per Palram’s recommendations.
Use Palram’s fasteners. Initial tests with ACQ have shown no adverse effect on our fasteners. This is added to the fact that the fasteners are being used to secure a light weight plastic panel (rather than connect structural members). If you use Palram fasteners, our 10 year warranty will still apply.