can these be used with a ledger board to hang 2x12 white wood rafters,

Thank you for your interest in our product. Unfortunately we are not fully sure what you are asking, but the Ridge Rafter is designed to accommodate any rafter 2 x 6 or larger. If you have further questions about specific installations, please contact our Customer Support department at 800-328-5934 or by email at uspcustomerservice@mii.com.