Just cleaned my first softwash roof using Greenwash. Roof came very clean and the customer is happy. This was an easy one story walkable roof. What I'm really anxious to clean are the larger two story non-walkables, and I consider this as practice for those. This roof I cleaned was 1296 sq. ft., black algae was the eyesore. I used 30 gal. total mix at 3% solution. Based on the mixology for 3% I used a factor of .69 x 30 = 20.7 gal of water, a factor of .3 x 30 = 9 gal of SH(12.5%), and a factor of .64 x 30 = 19.2oz of GW. Because it was a walkable I went ahead and rinsed the roof with garden hose pressure and a simple brass twist spray nozzle. The mixology says to use one gal of GW per 100 gal mix but I have also saw on here where 1/2 gal GW is a good starting point.
I really want to be able to give 'instant' results like this on the large two story non-walkers. To do that I am thinking of using a 4% solution with more GW. I wanted the community's input as to whether this mixology would take care of those higher roofs, would be nice not to have to rinse, will I still need to rinse?
Was 30 gal of mix a proper amount for 1296 sq ft of roof?
I would stay with 3% and hit it with a second coat if needed. I use an ounce per gal. of greenwash with my mix with good results. I personally don't rinse roofs except for metal one's.
Yeah like Matt said, for steeper roofs keep the strength the same just use more surfactant.
Don't rinse the roofs either if there are gutters, if their aren't gutters take other precautions.
Quick tip, once you are doing steeper roofs you will be spraying off of a ladder which means that you will have more over spray when you are hitting the high spots. IE over the roof and flying towards the back yard. This is when you need to have your ground guy back there to make sure everything is diluted properly.