Rob,

This was done with a 30% mix ratio. We ran short by a few gallons, so I mixed up another batch and gave a real light second coat over the entire roof with the left over from the second batch. It came out great, so now, on the front of the homes I do I spend a few extra minutes spraying a second light coat using a 2520 nozzle. Most of the time it comes out like this with very little if any light brown residue. This is a good practice in key locations(entrances to a busy neighborhood, open corner lots etc.). When I first started roof cleaning I was a little hesitant in leaving a sign in the front yard with light staining left on the roof. We know it will remove itself with the first rain, but would a potential customer?

Thanks a ton for the reply Barry!  I figured it was either time or a second coat... Do you let it shed off to almost dry or anything like that before second coating?  What surfactant or additives are you using? 

We are new to asphalt roof cleaning.  We've been cleaning heavy moss laden cedar roofs for over 15 years and getting big money for them and sealing with F&P sealer.

Always shyed away from asphalt because heavy Sodium Hydroxide cleaners make them bleed and difficult to pressure wash... plus the damage to shingles.  Doing more & more roofs lately with softwash.  Just trying to perfect the mix and process.

Have you tried AC's Green Wash?  or what do you suggest?

 I appreciate your help bro!

Thanks,

Rob