Keeping rust at bay when you're near the ocean

One thing I’ve wondered: has anyone tried using aluminum for the framing under composite decks? Seems like it would hold up better than wood or steel, but maybe there are downsides I’m not seeing.

Aluminum framing is definitely gaining traction, but I’d be careful about calling it a silver bullet. It resists corrosion way better than galvanized steel, especially near salt water, but it’s not totally maintenance-free either. The main issue I’ve seen is with fasteners—if you mix metals (like stainless screws into aluminum), you can get galvanic corrosion over time. Also, aluminum can flex more than wood or steel, so if your joist spacing isn’t spot-on, you might notice some bounce in the deck. Still, for coastal spots, it’s probably the lowest-hassle option out there right now. Just budget for the right hardware and double-check your spans.