I’m going to try and sum this up because this has not gone the way I would’ve like it to. If I’ve missed something, please add to it constructively.
There are other alternative methods out there, but just be careful. It may be possible to void the manufacturer’s warranty on shingles depending on the method used. It is unlikely that homeowners know who manufactured their shingles, so it’s probably safest to use a soft wash cleaning procedure using the recommended methods by the ARMA. They do recommend rinsing, but most don’t because they either don’t want to risk damaging shingles by using too much pressure or it would cost the client more because of the time spent, when you could let mother nature do the job. It seems to be a personal preference thing in that area. Although a pressure washer can be dialed down and used for rinsing purposes, it could be misconstrued by onlookers or if a shingle manufacture wanted to, they could simply void the warranty since you used a pressure washer, regardless of the pressure - or lack thereof - used in the rinsing process.
