If your ledger board will continue around the corner of your house, you will also have to remove the house siding corner post in addition to the siding. The intersection of the two ledger boards at the corner should be level and firmly nailed or bolted in an overlapping joint. Do not use a miter cut. Use proper flashing techniques and apply special care for using silicone caulking for the vertical seam located at the corner.
Sometimes, you may want to extend your ledger board beyond the house to function as a beam with a post connection at the opposite end. In this case, you will probably have to double up the ledger board for at least half the distance to the post for adequate strength. Use longer fasteners to penetrate a two-ply ledger board. Take advantage of the house mass for carrying deck loads. It can reduce the number of frost footings you will need to include for your plan.
