I also wouldn't use 2x12 onto a 2x10 ledger already attached to the house - your joist hangers will not be properly secured and you risk a failed inspection.
I also agree you must attach your ledger with heavy coated screws or lags. Just mark your joist position first and attach the lags or heavy screws between those in a V pattern. I'd also add some flashing to the top of the ledger.
With 2x10 joists @ 16 OC you are going to require a set of piles as you can't span the full 16ft.
Now if you went 15' out on the longest joists - minus a ~20" cantilever you could get away with a span under 13'8".
I'd suggest, nevertheless, a second set of piles anyways. You span at or near the max and the deck is springy. drill and extra row of three holes and don't look back IMO.
|