9 1/2 hours is a long time, doing a good job is important but that length of time should not be needed for a 1500 square foot house. I can do that size home with 1 hour, that includes pulling up, pulling out hose from my reel and starting up my blackknight pressure washer. Using the right chems, plus having heat will seriously cut your time down. Bleach at 12% mixed with power house plus heat works great on vinyl, with hardly no pressure needed.