Yes, you can pressure wash a metal roof, but it must be done with caution to avoid causing damage.
Using improper techniques or excessive pressure can strip away protective coatings, dent the metal, or force water under seams. This guide outlines the safest way to pressure wash a metal roof, including best practices, safety considerations, and alternative cleaning methods.
How To Pressure Wash a Metal Roof
Before pressure washing a metal roof, it is essential to take safety precautions. Working on a metal surface can be dangerous due to its smooth, slippery nature. Additionally, using a pressure washer incorrectly can cause damage or personal injury. Below are key safety considerations to keep in mind:
1. Use Low-Pressure Settings
Metal roofs can handle pressure washing better than shingle or tile roofs, but excessive pressure can still cause problems. It is recommended to use a pressure washer with adjustable settings and keep the pressure between 1,000 and 1,500 PSI. Using too much pressure can strip away protective coatings or damage fasteners, leading to long-term issues.
2. Choose the Right Nozzle
The type of nozzle used plays a significant role in controlling the pressure applied to the roof. A wide spray nozzle (such as a 40-degree or 25-degree tip) is ideal, as it distributes water evenly and prevents excessive force from concentrating on a single spot. This reduces the risk of denting or scratching the roof’s surface.
3. Maintain a Safe Distance
To prevent damage, maintain a safe distance between the nozzle and the roof surface. Holding the pressure washer too close can lead to unintended damage, such as stripping away paint or protective coatings. Start from a distance of at least 3 feet and adjust as needed.
4. Avoid Harsh Chemicals
Many homeowners may be tempted to use strong cleaning chemicals to remove stubborn stains. However, harsh chemicals can degrade the roof’s paint, protective coatings, and metal integrity. Instead, opt for a gentle detergent, such as car wash soap or a diluted mild detergent. This ensures effective cleaning without harming the roof’s finish.
5. Use Safety Gear
Due to the slippery nature of metal roofs and the power of pressure washers, safety gear is crucial. When cleaning a metal roof, wear:
- Non-slip shoes to maintain traction.
- Safety glasses to protect your eyes from water spray and debris.
- Gloves to maintain a good grip on equipment.
- A safety harness if working on a steep roof to prevent falls.
6. Rinse Thoroughly
After pressure washing, ensure all cleaning residues, detergents, and loosened debris are completely rinsed off. Any leftover soap or chemicals can degrade the finish over time. Use clean water to rinse the roof from top to bottom thoroughly.
Alternatives to Pressure Washing a Metal Roof
If you are concerned about using a pressure washer on your metal roof, there are alternative cleaning methods that can achieve the same results without the risks.
1. Soft Washing
Soft washing is a safer alternative to pressure washing and is ideal for cleaning metal roofs. This method uses low-pressure water combined with specialized cleaning solutions to break down dirt, mold, and mildew. Soft washing provides an effective clean without the risk of damaging the roof’s finish.
2. Garden Hose and Soap
For roofs with light dirt buildup, using a garden hose with a spray attachment and mild detergent can be sufficient. This method is gentle and prevents damage to the protective coatings on the metal. Simply spray the roof, apply a mild detergent, and rinse thoroughly.
3. Manual Cleaning with a Soft Brush
For spot cleaning, a soft-bristled brush or sponge can be used to scrub away stubborn stains. Combine this with a mild detergent solution to remove dirt and mildew without excessive force.
4. Hiring Professional Roof Cleaners
If you are unsure about cleaning your metal roof yourself, hiring a professional roof cleaning service is the safest option. Professionals have the expertise and equipment to clean a metal roof safely without causing damage. They can also inspect the roof for any signs of wear or needed repairs.
Final Thoughts
You can use a pressure washer on a metal roof, but you still need to exercise caution. Using too high of a pressure setting or harsh chemicals can damage your metal roof.
For best results, we recommend using a low pressure soft wash that safely and effectively cleans your roof.
At Vesta Property Pro we pride ourselves on providing best in class roof cleaning services. Call today for a free quote on your next roof cleaning!
