1. Waterproofing and Nailing Waterproof the roof deck with peel-and-stick membrane such as Grace Ice and Water Shield, lapped up onto the wall. Apply a 1x6 wood ledger to the wall base.
2. Membrane at the Joint Cap the end of the ledger board with site-bent copper flashing, soldered at the seams, forming a “kickout” to direct water out from the wall. Apply peel-and-stick flashing membrane to the roof and ledger board joint. Apply another strip of membrane to the wall, lapping it down over the ledger board. To protect the roof deck during stucco work, apply underlayment fabric over the waterproofing.
3. Integrated Flashing Lay a pre-formed “pan flashing” on the roof deck, with its vertical leg against the ledger. Fasten the flashing to the ledger, high up on the vertical leg. Apply a site-bent copper Z flashing to the house wall, lapping down over the pan flashing. Again, place fasteners high up on the wall.