How to add/repair Deck Flashing?

[Tex]

I was replacing a sliding glass door and came across a nice discovery on my 1968 house in CT, lots of rotten wood and water damage. The deck is attached to the house with a ledger, but I don't believe there is any flashing. THe bottom few inches of the sheathing under the aluminum siding is completely rotten and just falls apart. I obviously should remove the aluminum siding and add some sort of flashing, but I am not sure I can safely remove the ledger board to get behind it to install the flashing. Any ideas? Can I install the flashing over the ledger? Thanks Jeremy

[roger61611]

This will sound cantankerous, and I should preface this by saying I hate decks both aesthetically and for this sort of reason.

But anyway, if it's that big a mess you'll need to dig in and see if you have termites, carpenter ants, mold, or more extensive damage.

(I am off now to spread more cheer !)

[tbasc]

Your situation is - unfortunately - common. Look for: pan flashing below the door threshold. flashing over the ledger. It sounds like this doesn't exist. Rain splashes up from the deck and blows along the deck, putting a lot of water at the line where the deck meets the main building. It takes special care that's seldom given to manage the water. I don't know of any books or web sites that address the problem. Your best bet is a well respected contractor or an architect. TB