Tree Sap Accumulation
While metal roofing is known for its ability to resist fungus growth and subsequent streaking and staining, the sap from nearby or overhanging trees that lands on the roof can support fungus and hold dirt.
Owners of homes in wooded areas should avoid light-colored metal roofs that will show dirt accumulation more than dark roofs. Whenever possible, it is helpful to keep sap-bearing trees away from the roof as much as possible. Keep in mind that dirt and fungus accumulation are usually just an aesthetic issue and will not affect the life expectancy of a metal roof. However, if the appearance of this dirt becomes objectionable, it can usually be power-washed or cleaned by hand using a minor detergent solution. Adhere to pro-active roof safety measures if this is attempted.
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