Building Rain Screen System Fasteners with Dissimilar Materials

[RFreund]

I'd really enjoy a good reference on fasteners used in building enclosures which addresses dissimilar materials. Most of my information comes from the fastener supplier/manufacturer which I guess is good and bad. However, here is my specific question:
What type of fastener would you specify for fastening aluminum rain screen system component to either a steel or concrete substrate?
I typically use a stainless-steel (SS) fastener with a coating. The coating is to prevent the galvanic reaction between the SS and the AL. I want it to be stainless steel because if something happens to the coating then the AL will be sacrificial and there is much more AL material than fastener material.
Would you feel comfortable using a fastener that is not stainless steel or that is stainless steel but does not have a coating?
If fastening to concrete and using an epoxy system, is there a SS threaded rod than can be coated?

 

[SWComposites]

Would you feel comfortable using a fastener that is not stainless steel or that is stainless steel but does not have a coating? - depends where the building is located; in the desert far from the ocean, maybe; anywhere within 10+ miles of an ocean or in a tropical environment, no.

 

[RFreund]

How about somewhere in between? Say Midwest USA - rain, freeze/thaw, but not necessarily any salt water.

 

[jjl317]

Not sure if you have seen this, but one document that might be worth reviewing is AAMA TIR-A9 "Design Guide for Metal Cladding Fasteners", from the American Architectural Manufacturers Association, which does include some information on this topic.

Personally, I generally use a minimum of 304 stainless, preferably (though not always) coated.

Will be interested to see what else is out there.

 

[RFreund]

Here is another document MCA Tech Guide "Fastener Compatibility with Profiled Metal Roof and Wall Panels". It seems to allow some combinations that I'm not really "thrilled with", but maybe I'm being overly concerned.

 

[EdStainless]

And is this well removed from any surfaces that will be salted in the winter?
Can the rain freely wash all of these surfaces?
I am with JJ on this, overkill is the best kill.

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P.E. Metallurgy, consulting work welcomed