Photo: Deckorators
In a video from Glenn Mathewson posted on ProTradeCraft.com about deck ledger code requirements, Glenn looks at a couple of good details, one from the EPA, the other from Building Science Corp. Glenn preferred the BSC detail, so I put it into an animation. This article uses stills from that animation.
The peel-and-stick membrane protects the wall, and the flared drip edge protects the ledger by directing water away from it. Don’t cut the flashing at each joist—it takes extra work and can cause wicking. Instead, hold the joists ¼ inch or so off the ledger, supported by the joist hanger. Choose a hanger with base support of 1½ inches, plus the gap.
![1 ] Apply peel-and-stick membrane over the base of the wall](http://www.proremodeler.com/sites/pr/files/styles/pr_main_image/public/1-Deck%20Ledger_0.jpg?itok=DFi0dHyZ "1 ] Apply peel-and-stick membrane over the base of the wall where the deck ledger will be. This will protect the sheathing from water and will help to seal fastener holes, too. Install the deck ledger—spaced off sheathing or not—with the appropriate fasteners (through-bolts are better than lag screws; nails and deck screws are unacceptable).")
![2 ] Install Z-style ledger flashing with a hemmed drip edge](http://www.proremodeler.com/sites/pr/files/styles/pr_main_image/public/2-Deck%20Ledger%20flashing_0.jpg?itok=Sd4BsvrE "2 ] Install Z-style ledger flashing with a hemmed drip edge that extends over the face of the ledger and pushes water away from it.")
![3 ] Select joist hangers one size down from the joist depth](http://www.proremodeler.com/sites/pr/files/styles/pr_main_image/public/3-Deck-Ledger-joist-hangers_0.jpg?itok=xP_1fCjs "3 ] Select joist hangers one size down from the joist depth (such as 2x6 hangers for 2x8 joists) so that they fit below the ledger flashing. Consult a joist hanger sizing chart for exact choices.")
![4A ] Layer the housewrap over the ledger flashing](http://www.proremodeler.com/sites/pr/files/styles/pr_main_image/public/4A-Deck-Ledger-WRB-Joists_0.jpg?itok=ZIL0tfIM "4A ] Layer the housewrap over the ledger flashing, and the siding over the housewrap.")
![4B ] Install the joists, but don’t mash them against the ledger](http://www.proremodeler.com/sites/pr/files/styles/pr_main_image/public/4B-Deck-Ledger-tight-flashing-view_0.jpg?itok=BrU7_2Hk "4B ] Install the joists, but don’t mash them against the ledger and compress the flashing—let them breathe. Treat the joist ends to reduce water absorption.")
![5 ] The decking goes on top](http://www.proremodeler.com/sites/pr/files/styles/pr_main_image/public/5-Deck-Ledger-deking_0.jpg?itok=cFZ3ZNrL "5] The decking goes on top. Be careful to avoid screwing through the flashing.")
Comments
Blanchard
Looks water tight. However there is a problem when it comes to decking edge nailing where nails penetrate the flashing on the top of the ledger.
I should have made a note there ...
Thanks for the comment, Dan. I agree that it does look water tight and that there could be a problem, if people drive nails through the flashing.
I guess I figured that most folks could figure that out, but just to make sure, here's the addendum:
"Don't drive nails or screws through the edge of the first decking board to avoid making holes in your flashing (and injection channels into your deck joists)."
—Dan
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