I am adding a roof above a concrete patio in my backyard. The roof will be approximately 50' wide and extend out from the house 20'. The joists will be 2"x12"s attached to a ledger board on the house and then other ends sitting on a 6"x6" framing. The 2"x12"s will be 24" on center. Covering will be corragated PVC panels, so this will be rain-proof.
I am attaching the ledger board to a wood frame house that has 1" blue styrofoam insulation on the outside, which is then covered with stucco. What is the best method to attach it? Again, to make sure I maintain a water-tight seal too, so that any rain coming down the side of the house will go onto the patio roof. Obviously I will be bolting the ledger board into the vertical framing of the house using lag bolts. But, can I attach the ledger board on top of the stucco which might crush the insulation, or do I have to remove the stucco and the foam insulation underneath to attach the ledger board more securely to the frame of the house. Also what size lag bolts should I use, how deep should I go into the vertical studs and how far apart should they be (assuming the vertical studs in the house or 16" on center). Again I'm putting a 2"x12" ledger board up which I will attaching the 2"x12"-20' joists too with a corrugated PVC covering.