I would like to build a lean-to pergola attached to my house wall. What is the best way to attach the (sloping) rafters to the wall plate (ledger board). Common practice seems to be to use joist hangers, but I thought a prettier solution would be to notch the rafters into the wall plate. Would screwing/nailing the notched rafter from above into the (2" thick?) wall plate be secure enough or is there a better way to achieve this without using joist hangers?