Aloha Gang, I did a demo on a Gerard barrel tile look alike metal roof today. The thing cleaned up amazing with a 3% mix, except where the gutters had been running down from the second story to the first story. It has a dark streak that runs straight in line with the gutters. Tried 3%, 3% with some pixie, 3% with some pixie and TSP and light brushing and even hit it with the no no blaster at around 1500psi with no results. Am looking for any suggestions or an explanation to give the homeowner. Its only in the gutters path so not sure what it could be. Aluminum gutters so I dont think that F9 will help but I am open for suggestions.
Thanks
Tim Teed said
Dec 24, 2013
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 said
Dec 24, 2013
Those roofs are made from galvanized steel. The streak you are seeing is from the zinc oxidizing. Try some F9.
AC
Ray Burke said
Dec 24, 2013
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 said
Dec 24, 2013
Thanks AC,
Do You know why it's happening only in the gutter line?
Mike Wedge said
Dec 24, 2013
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 said
Dec 24, 2013
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 said
Dec 26, 2013
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 said
Dec 26, 2013
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.
Aloha Gang, I did a demo on a Gerard barrel tile look alike metal roof today. The thing cleaned up amazing with a 3% mix, except where the gutters had been running down from the second story to the first story. It has a dark streak that runs straight in line with the gutters. Tried 3%, 3% with some pixie, 3% with some pixie and TSP and light brushing and even hit it with the no no blaster at around 1500psi with no results. Am looking for any suggestions or an explanation to give the homeowner. Its only in the gutters path so not sure what it could be. Aluminum gutters so I dont think that F9 will help but I am open for suggestions.
Thanks
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
Thanks AC,
Do You know why it's happening only in the gutter line?
Thanks Tim,
I kinda feel the same way at this point. I am going to try the F9 though just as a last resort.
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.
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
Based on this comment I really believe you have an oxidation issue.
AC