| My idea is, it matters what you are using for wall covering. If you use 1/2 inch plywood on both sides of the 15 foot wall you should not need any more bracing. But if you plan to use drywall to cover the wall, then I would use diagonal let-in bracing on both sides of the wall that goes past the ducting at least 1 stud. Two studs past would be better. I would also tie the wall to the floor joist above it at least every stud. |