Once the siding's cut and the ledger board's prepared, you can set it in place on the wall.

Make sure there's equal space left on the ends if there'll be skirtboards added on later.

Then tack the board in position with nails to hold it in place.

NOTE: Unless your sheathing has a moisture resistant exterior, the code may require that you cover the exposed sheathing with builders felt as a moisture barrier before installing the ledger board. Check with your local building officials.

 

Securing Lag Screws

Use lag screws to secure the ledger board permanently to the house framing, generally 1 or 2 lag screws driven in between each pair of joists.

First, pre-drill through the ledger board and the sheathing and partway into the house framing.

Squeeze enough silicone caulk into each hole to provide a moisture seal. Tap the lag screws in with a hammer to bite into the framing. Then finish driving the screws with a ratchet.

 

Installing Z-Flashing

Galvanized metal z-flashing is usually required to keep moisture from seeping down behind the ledger board.

First, seal any gaps with silicone caulk (like between the sheathing and the threshold) and run a bead along the sheathing to hold the flashing tight.

Set the flashing in, Sliding the back up under the siding first (you may need to loosen or remove a few nails to get it up there). Then push it down over the top of the ledger board.

If you use 2 or more pieces of flashing, be sure to overlap the joints by several inches and use caulk to seal the joints.

TIP: Flashing comes in a couple of sizes. Make sure the back's high enough to cover the gap between the siding and the ledger board and to ride up behind the siding about an inch.