Why Do Roof Stains Come Back After Cleaning? Lasting Fixes
Roof stains come back after cleaning when algae, moss, lichen, or organic debris remains in shingle pores, or when airborne growth reseeds the roof after treatment. Black streaks commonly involve the cyanobacterium Gloeocapsa magma, but recurring discoloration can also result from moisture retention, rust, tannins, soot, or a cleaning method that removed appearance without addressing […]