What is asphaltic oil staining? Asphaltic oil staining refers to small amounts of dark colored oils that temporarily appear on granules causing some shingles to have a darker visual appearance.
What causes it? Asphaltic oils are naturally present in all asphalts. Staining does not occur during the manufacturing process but can occur in storage. The possibility of asphaltic oil staining increases when shingles are stored in hot conditions and/or for extended periods of time.
What NOT to do:
- Do not rinse the roof from the ground with a hose because this can drive water under the shingles. Wet roofs are slippery, so rinsing from the roof top is also not recommended. It is best to allow the asphaltic oil staining to rinse off naturally.
- Do not use high pressure sprays or sprayers to clean the shingles. This can damage the
- Do not use chemical washes as you may loosen the granule surfacing or damage the asphaltic coating.
Oil staining is not permanent and will weather-out with exposure to sunlight and rain. Weathering generally takes approximately 90-days but may take longer depending on local weather conditions. This is an exclusively a cosmetic issue and will not affect the performance or long term appearance of the shingles. Once the asphaltic oil staining has weathered-out, the shingles’ original color will be