In 30 years, I have seen lots of methods for attaching ledgers to homes, some of which make me think there are a lot of idiots in our business. I came up with my method for flashing the ledger and keeping water away from the house about 20 years ago and have never seen any problems with it years down the road.
I use a ledger that’s one size larger than the joists and set the joists 1 inch lower than the ledger’s top. This puts the top of the decking at the same height as the top of the ledger, which means the ledger flashing is visible and I know that it hasn’t been crushed by the decking boards. It looks good too.
I leave at least a 1/4-inch gap between the last decking board and the flashing to keep debris from collecting there. I also keep the siding above the deck at least 1/4 inch clear of the flashing so the siding doesn’t wick water.
Then at the bottom of the ledger, I bevel-cut the ledger to at least a 30-degree angle, and tuck the siding up tight to it. The point of the bevel creates a drip edge at the face of the ledger, and any water dripping off will always be beyond the siding. I step-flash at the ends of the ledger to deflect water.
Jeff Howe owns Jeff Howe & Co. in Pembroke, N.H.
This Tip wins a DeWalt DCF885L2 20-volt impact driver kit.