In a timber frame house, the ideal way to build the second floor structure is in the reverse order of standard construction. First, put the drywall on top of the timber beams, then add some joists to allow space for plumbing and heating ducts and, finally, attach the plywood deck. I’ve received a virtually anonymous suggestion for a deck that is based on this technique. It consists of 2×6 joists resting on neoprene pads to isolating them from the timber beams and drywall for the reduction of sound transmission. However, the design doesn’t explain how to support the ceiling drywall or isolate it from the joists. I suspect some type of metal channel will work, although I’ve not been able to locate specifications providing the information needed about brand, gauge, spacing or availability. I’d appreciate information about a product that will provide adequate support for ½” drywall resting on top of 6″ beams on 4’ centers, considering that it is essential to find a product with the lowest height possible. And, it is especially desirable that the drywall not attach to the joists at all to allow for prefinishing the drywall unit before installation. Thank you for any help you provide.