Header board for deck?

Question:Can I put stainless steel washers inbetween aluminum siding and treated wood with out either corroding?

Answers:
Stainless means just that: it will Stain, less. However, it is a good choice if you choose to spend the extra $ for stainless...most builders use double coated "hot dipped galvanized" or zinc plating...becuase it's hard to find stainless steel lag bolts to secure the header/ledger to the house. Also, I would recommend removing the aluminum siding where the board is to be secured, and use flashing to channel water away from behind the board.