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

Bergman Roof Cleaning Port Charlotte FL 941-698-1959 wrote:

---

plainpainter wrote:

---

I am at 30% strength with bleach. Chris recommended this to me years ago - lots of other guys were saying 40%, 50%, and I always just did 30% and have cleaned every roof I have come across. I also deal with lots of painted homes, painted dormers sticking out of roofs - and I have never ruined the paint using this strength.

---

30% for shingles is right.

It's far too weak for tile though.

I doubt Chris suggested 30% for tile.

I'm sure he uses 45-50% + surfactants and TSP and Alcohol to make it work even better!

I don't use alcohol, but I use 45-50% SH + 1/2-3/4 gal of Ammonyx Lo + 5-10 lbs of TSP

on tough tile roofs. On easier tile roofs, I leave out the TSP.

---

 I am in the northeast, and shingle roofs don't exist.  Having said that - there are three buildings/homes in my hometown with clay tile roofs - and apart from another one in another town - never seen it anywhere else around here.