I have a porch that has a 6' overhang and I would like to put soffit under it, however I would like the soffit to go up along the rafter, so that it is going from the front of the house to the end of the roof (fascia), this is my 6' length. The area is roughly 6' wide x 18' long. How do I do this? I know that I can install the soffit on one end with F channel and then J channel on the other end but how to I support the total 6' length of the soffit? Do I use furring/nailing strip and then put a nail into the soffit for support? See pic for clarification.