Expanded metal flooring?

I would not use metal grating, any metal will corrode, it is costly and as pointed out has many sharp edges.

Have you considered the fiberglass grating now used in a lot of industrial applications. It will not corrode, it is tough and durable, and cheap.

Just google "fiberglass floor grating"

 

Or PolyMax kennel and brooder flooring

Steve

 

pvc fence extrusions filled wit spray foam?..lightweight ,strong , available in a large selection of sizes from 1 x 1 & up to 4 x 4 , easy to work with.rot & uv proof, & theres trim strips for a finished look too....just an idea

 

We put diamond plate in aluminum boats frequently it works great. Expanded metal, or F/G grate ( I used to make the stuff) doesn't work well, everything you drop goes right through into any bilge water under it and needs to be retrieved later.