patio overhang ledger board

[boyack123]

I plan on putting up a patio roof 8' out from the eave side of garage, the ledger board will be attached no more than 12" under 14" eave. My questions are about ledger attachment. Ledger will be attached to 2x4 wall studs.

would it be okay to nail in 3' studs against wall studs to bolt ledger on??
(Im worried about hitting sheathing nails installing lags to existing studs)

I plan on putting vycor under ledger board. should I do this over tyvek, then add a second piece of tyvek over flashing . or should I remove tyvek and then install membrane and flashing?

 

[GMCGarage]

whats the load you are going to try and resist with nails? How many will you need? Might not get enough capacity out of it.