We are quoting vinyl siding breezeways.  There is no mildew, just dirt on the vinyl siding.  Since there is no mildew in past we just use terrawash and water, no SH.  This job has stains from garbage sitting in front of residents doors.  We are including cleaning the wood floor and vacuuming water from 1st floor.  Here is demo I did comparing wood wash and terra wash.  Terra Wash worked good.  light scrub with bristle brush.  We will pre treat spots with pump sprayer and then spray floor while we spray walls, then rinse with booster pump