What you want to be on the lookout for, and take pics of, is this. All that dust/dirt/mortar mix, etc makes a fine grit dust that will easily scratch painted metal. So say joe the mason has mix on his hands then leans against the metal and slips, there will be fine scratches in the metal. Very fine to fine normally unless it is some hack, then it will be much worse. Just something to think of when you tackle the mess. I would rinse first if I was doing it, sure it is an extra step, but I want to see if something is ruined before i get into it. Plus, how are you controlling for the mud mess around the foundation? Did they mulch or stone it yet? Be on the lookout for splatter marks too.
Talk to @DisplacedTexan he did a job similar to that one but much more glass and less metal. Lots of powder/dirt he had to be careful with from the masons.
