My instinct is to replace the deck and eliminate the ledger altogether add posts near the wall and leave a big gap between the end board and new flashing tucked under the siding.
Flashing deck to siding.
For pricing and availability.
Install z flashing behind the bottom of the ledger and over the siding below.
You may need to pry out siding first.
Window and door cap 1 25 in x 120 in x 1 56 in aluminum z flashing.
Amerimax 14 in x 30 ft vinyl roll flashing.
Tearing into siding is all but inevitable if you build.
Gap between the end of the ledger and the ends of siding and fill it with high quality exterior caulk to keep water from leaking behind the ends of the ledger.
Slip the back flashing under the siding at least 3 at the top and the sides.
Flashing consists of metal which is durable enough to be exposed to sunlight and mechanical wear and tear plus peel and stick membrane like vycor grace construction products.
Pry the siding out near a nail then push the pry bar against the nail as you partially tap the siding back in.
A simple metal or plastic cap flashing is probably adequate to flash a deck ledger in a dry climate while the 3 layer system described in this video is suitable for high rainfall and damp climates.
The irc doesn t provide prescriptive measures for flashing other than the minimum thickness for metal flashing 0 019 in.
Item 3807 model 5504900120.
To prevent water from seeping behind the deck s ledger board and rotting the board and the siding the flashing must cover the top of the ledger board and bend over the edge.
Then slip flashing behind the siding covering the top edge of the ledger.
I would remove the old siding that was behind the existing ledger to about an inch above the deck surface.
Start by making an outline on the siding where you want to position the ledger board.
If nails are in the way pull them out.
This flashing needs to extend up at least 2 or 3 inches up under the siding above the deck.
This keeps water from wicking along the bottom of the ledger and getting behind the siding.
Union corrugating 14 in x 30 ft vinyl roll flashing.
