I need to fasten a 3/4 inch PVC trim board to a poured concrete basement wall. Since this will be on the exterior of the house I want to avoid rusting of the fastener. The previous pressure treated board fell off when the concrete nails rusted and broke off. I was considering using Tapcon screws and counter sinking the heads and filling with a paintable epoxy. I know the Tapcons will rust at some point. Does anyone know of a stainless steel concrete fastener?
Tapcons and similar are available in stainless:
You have various options. The thickness of the fastener matters. Really a hot dipped galvanized fastener of sufficient thickness should last decades. Are you close to a marine environment? - that will speed oxidation of fasteners.
If you want the fastener to never rust out you could go with stainless steel and epoxy. Something like HY-150 or there is a simpson strong tie version. A lot of structural components are drilled and epoxied into concrete so certainly this will work to hold up a simple panel.
I have some pvc panels that I plan to install on concrete - I'll probably just use the strongest PL - PL Premium. Seems like PVC is listed as compatible.