No, you should not pressure wash a shingle roof. Asphalt, cedar or composite shingles are susceptible to damage when placed under high pressure.
For cleaning these types of roofs, professionals prefer to use a “soft wash” which uses low pressure and cleaning solutions to safely and effectively clean your roof.
Why You Shouldn’t Pressure Wash Shingle Roofs
Shingle roofs, especially asphalt shingles, are designed with a protective layer of granules that safeguard them against UV rays, moisture, and other environmental factors. High-pressure washing can compromise this protective layer, leading to accelerated roof deterioration. Below are the key risks associated with pressure washing shingle roofs.
Damage to Protective Granules
Asphalt shingles are covered in small granules that serve as a protective barrier against the elements. These granules help prevent premature wear and shield the shingles from harmful UV rays. The force of pressure washing can strip away these granules, leaving shingles vulnerable to sun exposure, leading to cracking, brittleness, and a shortened lifespan. Without these granules, shingles will degrade faster, requiring premature replacement and increasing maintenance costs.
Shingle Dislodgement
The powerful water stream from a pressure washer can loosen or even completely remove shingles from the roof. Unlike more rigid materials like metal or tile, shingles are relatively lightweight and rely on their adhesive backing and overlapping structure for stability. When shingles become dislodged, they create gaps that expose the roof deck to rain, wind, and other external elements. This can lead to leaks, rotting, and additional roof damage over time.
Water Intrusion and Structural Damage
One of the biggest risks of pressure washing a shingle roof is water intrusion. The force of the water can push moisture underneath the shingles, leading to water seeping into the underlayment and roof deck. This trapped moisture creates the perfect environment for mold and mildew growth, which can compromise indoor air quality and pose health risks. Additionally, long-term water intrusion can weaken the structural integrity of the roof, leading to costly repairs or even the need for a full roof replacement.
4. Voiding Manufacturer Warranties
Many roofing manufacturers specifically advise against pressure washing asphalt shingles. If pressure washing is used to clean the roof, it can void the manufacturer’s warranty, leaving homeowners responsible for any future repairs or replacements. Manufacturer warranties often cover defects and durability issues, but damage caused by improper maintenance methods, such as pressure washing, is not covered. Homeowners should always check their warranty details and follow recommended cleaning guidelines to avoid unnecessary expenses.
5. Increased Risk of Personal Injury
Pressure washing a roof requires climbing onto the structure, which already presents a fall risk. The combination of high water pressure and a wet, slippery surface increases the danger of losing balance and falling. Additionally, the force of the water can cause sudden recoil, making it difficult to control the pressure washer. This makes pressure washing not only a risk to the roof but also a significant safety hazard for homeowners attempting DIY cleaning.
Safer Alternatives to Pressure Washing
Instead of pressure washing, there are safer and more effective ways to clean shingle roofs without causing damage. These methods remove dirt, moss, and algae while preserving the roof’s integrity.
1. Soft Washing
Soft washing is the preferred method for cleaning shingle roofs. This technique uses low-pressure water combined with eco-friendly cleaning solutions to break down dirt, algae, and moss. Unlike pressure washing, soft washing does not rely on force to remove buildup but instead utilizes chemical cleaning agents that kill bacteria, moss, and algae at the root. Additionally, soft washing leaves behind an inhibitor that helps prevent future growth, keeping the roof cleaner for a longer period.
2. Garden Hose and Gentle Scrubbing
For minor cleaning needs, a standard garden hose with a spray attachment can be an effective and non-damaging solution. A gentle stream of water can rinse away loose debris without the harsh effects of high-pressure water. In some cases, a soft brush or broom can be used to lightly scrub areas affected by moss or algae. This method, when done carefully, allows homeowners to clean their roof without removing protective granules or causing water infiltration.
3. Professional Roof Cleaning Services
For the safest and most thorough roof cleaning, homeowners should consider hiring professional roof cleaning services. Roofing professionals have the expertise and proper equipment to clean shingle roofs without causing damage. They use specialized techniques, such as soft washing, to ensure a deep clean while protecting the structural integrity of the roof. Additionally, professionals can inspect the roof for signs of damage or wear, allowing homeowners to address any issues before they become major problems.
4. Preventative Roof Maintenance
Regular maintenance can help reduce the need for deep cleaning and extend the life of a shingle roof. Homeowners can take the following steps to keep their roofs in good condition:
- Trim Overhanging Branches: Trees can drop leaves and debris onto the roof, which can trap moisture and promote moss growth. Keeping trees trimmed can reduce buildup and minimize roof cleaning needs.
- Keep Gutters Clean: Clogged gutters can cause water to back up onto the roof, leading to moisture damage. Regular gutter cleaning helps prevent water-related roof issues.
- Apply Algae-Resistant Treatments: Algae-resistant roof coatings and chemical treatments can help prevent moss and algae growth, reducing the need for frequent cleaning.
Final Thoughts
You should not pressure wash a shingle roof. It can damage roofing materials, lead to water intrusion, and costly roof replacement.
Instead, opt for a soft wash roof cleaning. Soft wash uses low pressure and cleaning solutions to clean roofs without damaging them.
At Vesta Property Pro we offer soft wash roof cleaning, reach out to us today and say hello to a cleaner roof!
