The Roof Cleaning Institute Of America Training & Certification Forum
"Find A Certified Roof Cleaner Directory"

If possible wait for it to dry a bit and you can usually tell if it'll need a second coat. If in doubt...I always apply two coats.

-- Edited by Bob Jr on Wednesday 14th of April 2010 09:22:49 AM

Why would you rinse and remove the special cleaning solution you've applied before it's done its work 100%?

You're making it to complicated. Chances are, there are gonna be spots on every roof that needs hit at least twice. Not the whole roof,...just spots.
Spray, wait 20-30 minutes for the application to work,...then hit the troublesome looking spots again. Mostly what I've been doing opposed to rinsing the entire roof is: Just kinda' blend the noticeable brown streaking spots with the rest of the roof and let the rain take care of the rest. The roof will look 100 times better when you pull out,...and only get better with time and rain.

I like the sunny days also,...but when it warms up to Summer heat,...those cloudy days are actually better for drying time. If the solution dies to quickly due to direct sunlight it won't work properly. I actually mist it with water to reactivate sometimes.

Jeff

you can only remove a layer at a time apply, dry and re-apply if need be

I agree with Jeff that your making it too complicated. But it seems to be a common problem that people think they can one coat it leave some stains and hope for the best. A properly cleaned roof will not have any stains left when you leave. On a commercial job you will have plenty of time to see the results before leaving. When we say there might be a light brown ding here and there we mean just that, a very light hint of dirt, not half cleaned black streaks. If there are no streaks and no thick pasty spots then you are done. If there are still streaks and they are brown they need hit again.

I just recently did a job reguiring a lift and I was afraid of the same thing I found that starting on the area that had the most concentration of algae build up first, typical the north side. Do that area real well while letting your ground man do his thing and work together and go from the worst portion of the roof to the least affected area by the time you are finshed you will know if you need a second coat! Just like Bob says when in doubt its better to apply two coats then one Especially for commercial jobs really any job for that matter Nothing is worse than having another company come behind you to fix your mistake. Word of mouth travels fast!

Wow... I may have stepped away for too long.  There is NO way I would walk away from that roof to come back a week or two later to see it. If that was a commercial job they wouldn't let me... not with approving my invoice.

I always rinse... just lets me know (and them) that what I did worked.

Great looking job.. I just couldn't walk away before it looked like the third pic.

Hey who knocking my pics??? LOL!!! I got better pics of moss lifting the shingles, then brand new too?

EDIT: This may have been one of my first no rinses. This also the job the HO wanted to charge me for using some of her water!

 Hindsight, This Some Good Chit! ... A better job than this one, If the black stain aint brown, Your not guaranteed out of a call back.

 This house hasnt called me back. I got lucky on this one. Not that the roof didnt come clean, but that it did.

 I do use more now.

-- Edited by gutterdog on Tuesday 21st of December 2010 10:41:12 PM