If left for a long time, mold stains on roof shingles can cause discoloration on your roof and damage to the shingles. It also leads to mold growth, which in turn exposes the crawlspace or the attic’s interior to mold spores. Clean your roof shingles immediately to remove mold stains and to avoid expensive roof replacement in the long run.
Here are the steps you have to take to get rid of molds on roof shingles.
1. Create and apply the cleanser
As a safety precaution, wear a face mask and rubber gloves before you start with this step to protect your respiratory system and skin from the fumes coming from the chemical solution that you will be handling.
Make a cleaning solution by mixing three-quarter water and one-quarter chlorine bleach in a two-gallon bucket. Add one tablespoon of trisodium phosphate (TSP) to the mixture. Mix it well. Pour the solution into a pump sprayer and apply it to the areas of the shingles where molds are present.
2. Rinse the roof shingles and check them
Leave the applied solution on the shingles for about 15 minutes or longer if there are too much molds. Then rinse the shingles using a garden hose from the topmost part downward to keep water from seeping. Low-pressure water is just enough—do not use a pressure washer because it will make the mold problem worse.
Afterward, check the shingles for any slimy mold by running your gloved hand over the surface. If some molds are still present, apply the cleaning solution again, leave it for 10 minutes, and rinse the shingles again.
3. Consult a roofing professional.
If mold continues to grow on your roof shingles, it is time to contact a roofing contractor, as you might need to replace your shingles or waterproof them.