I just bought an early Bungalow style home. The rafter supports are failing and I need to replace them. I will be refinishing the attic sometime in the future. I would like to do as little duplication of effort as possible. I have two questions for the project. 1. Can the rafters be supported with a (K)nee wall or do I need to but in new supports at right angles to the rafters. 2. If I can put the wall in do I have to put it on a the subflooring or can I put it directly on the joists. I will have to have someone rewire the house in the future so I do not want to put in a permanent subfloor in the attic yet.