Metal Roof Cleaning Help! - Certified SoftWash Roof Cleaning

Mike Wedge · SoftWash Systems Master Certified Applicator

Metal Roof Cleaning Help!

Tim Teed · SoftWash Systems 5-Star Professional

I'm guessing that it might be erosion/abrasion of the surface from the constant force of water when it rains. This may be a restoration vs cleaning. I see this more in shingles where a downspout discharges on a lower roof. That is not a good roofing detail for shingles because it causes premature wearing of the granules so probably the same for other materials.

AC Lockyer · Administrator

Those roofs are made from galvanized steel. The streak you are seeing is from the zinc oxidizing. Try some F9.

AC

Ray Burke · Community Member

I have seen the coatings wear off at gutter downspouts. If that's the case there is no color left to clean, you're down to bare metal. But try F9, if that doesn't work then it's most likely that the color is gone.

Mike Wedge · SoftWash Systems Master Certified Applicator

Thanks AC,

Do You know why it's happening only in the gutter line?

Mike Wedge · SoftWash Systems Master Certified Applicator

Thanks Tim,

I kinda feel the same way at this point. I am going to try the F9 though just as a last resort.

Mike Wedge · SoftWash Systems Master Certified Applicator

Thanks Ray,

I think the color has been eliminated as well. The strange part is that the metal is not exposed and the granules are still very prominent. The roof is less than ten years old, so I don't know how to explain the color loss. The customer is extremely happy with all the efforts I have gone to to figure it out, but I would like to explain why this might be happening and weather it will be covered by their warranty.

AC Lockyer · Administrator

Mike Wedge wrote:
Thanks AC,
Do You know why it's happening only in the gutter line?

Concentration of the zinc and aluminum oxide coming from one outlet at the gutter downspout. I have seen this condition before. However without pictures I can not say for sure this is the case with your situation.

AC

AC Lockyer · Administrator

Mike Wedge wrote:
Thanks Ray,
I think the color has been eliminated as well. The strange part is that the metal is not exposed and the granules are still very prominent. The roof is less than ten years old, so I don't know how to explain the color loss. The customer is extremely happy with all the efforts I have gone to to figure it out, but I would like to explain why this might be happening and weather it will be covered by their warranty.

Based on this comment I really believe you have an oxidation issue.

AC