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.