There's no reason to power wash your house unless you're intending to paint it. There's also no reason to use any sort of cleaning agent. A pressure washer will do more damage than good! Just hose it down with a good quality spray nozzle and garden hose and be done. If that's not good enough, grab the car wash brush and use that to gently loosen any surface dirt and knock down any cobwebs.
As for cleaning agents, Clorox and TSP are definitely not good for vegetation, not too good for paint either. If you absolutely must use something, choose something that is biodegradable. The only time you would want to use something like TSP is if you plan to repaint, but on an exterior it is completely unnecessary.
As for cleaning agents, Clorox and TSP are definitely not good for vegetation, not too good for paint either. If you absolutely must use something, choose something that is biodegradable. The only time you would want to use something like TSP is if you plan to repaint, but on an exterior it is completely unnecessary.