Install Z-Flashing

What happens here

The final crucial step in waterproofing the ledger involves installing a Z-flashing, also known as ledger flashing. This pre-bent piece of aluminum flashing is custom-cut using a utility knife or tin snips to fit precisely around any deck joists that will be attached. It is designed to sit on top of the newly installed pressure-treated ledger board. One edge of the Z-flashing is tucked securely behind the upper PVC trim board (which was previously installed in Step 3), while the other edge extends out over the ledger. This creates a final, essential layer of protection, ensuring that any water that might manage to get past the siding and counter flashing will hit this Z-flashing and be positively directed away from both the ledger and the house rim joist.

Goal: Apply final waterproofing layer over the ledger board.