I am doing some remodeling and want to run a 6-inch HVAC (kitchen exhaust hood) duct through the floor joists. There is one section where the path is impeded by a standard floor joist cross-brace. Can I replace that one cross-brace with two horizontal pieces of blocking between the floor joists? Should I use one at the top by the subfloor and another one at the bottom? How thick should they be? Would 2 by 10 work?
Floor joists are 2x10 on 16-inch centers.