Originally Posted By: escanlan This post was automatically imported from our archived forum.
Very interesting topic!! I have not encountered a roof with staining like this before but I do see a lot of it driving around outside of the Dallas area in the countryside. I’ve always wondered when driving by what was up with the roof.
Now I have a question maybe someone can answer. The references discuss killing it with copper and zinc. One reference mentions placing copper and/or zinc strips under the shingles, leaving a small edge exposed. Over time and with rain, dew, etc. the copper or zinc strips will add the amount needed and flow down the roof killing the algae. Rolled copper for flashing use is readily available, although expensive. But due to the issues associated with lead and zinc I have not come across anyone that supplies these in a form suitable for flashing nor just as strips for this application.
In the absence of any algae stains on the roof or water penetration signs inside or out, is there any way to determine if the strips we see inserted under shingles are made of zinc? Copper is naturally easily identifiable. There was a discussion thread awhile ago about strips being found under shingles as a method of roof repair
( http://www.nachi.org/bbsystem/viewtopic.php?t=14254&highlight= ). Since I do see this type of staining around our area I would be interested in being sure what the strips are when making a call. Naturally the call would be "Consult a qualified roofer" but it would be good to know.
-- Manny (Emmanuel) Scanlan
Knowledge is power, but sharing knowledge brings peace!
Originally Posted By: lkage This post was automatically imported from our archived forum.
escanlan wrote:
Very interesting topic!!
In the absence of any algae stains on the roof or water penetration signs inside or out, is there any way to determine if the strips we see inserted under shingles are made of zinc?
Manny, thanks for the links. I agree...very interesting topic.
From what I understand it's not possible to tell if steel is coated with zinc just by looking at it. The metal can be chemically tested but that defeats the visual inspection part of the equation.
-- "I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei