Residential Pressure Washing pressure washing roof shingles

When it comes to maintaining your roof, you might wonder if pressure washing roof shingles is a suitable cleaning method. While pressure washing can be effective for various surfaces, it may not always be the best choice for roof shingles, especially asphalt and cedar varieties. Understanding the implications of pressure washing roof shingles and the safer alternatives is essential.


Is Pressure Washing Roof Shingles a Good Idea?

Pressure washing shingles can seem straightforward in removing dirt, algae, moss, and other debris. However, it is essential to consider the potential risks and downsides. Roof shingles are designed to withstand the elements but are not necessarily built to handle the force of high-pressure water streams.

Does pressure washing damage asphalt? Asphalt shingles are one of the most common roofing materials due to their durability and cost-effectiveness. Despite their robustness, pressure washing can cause significant damage to asphalt shingles, especially if they’re old. As such, if you want to pressure wash your roof shingles, it is best to hire professionals.

Here are some reasons why DIY pressure washing isn’t the best option for roof shingles.


1. Potentially Voids Manufacturer’s Warranty

Many roof shingle manufacturers explicitly state that high-pressure water can void the warranty. Pressure washing can compromise the integrity of the shingles, leading to premature failure. Manufacturers’ warranties are designed to protect homeowners from defects and premature wear, but using improper cleaning methods can cancel these protections.


2. Strips Protective Coating

Should you pressure wash asphalt shingles? Asphalt shingles are coated with granules that protect against UV rays and provide fire resistance. High-pressure washing can strip away these granules, reducing the shingles’ protective capabilities. Without this coating, shingles are more susceptible to damage from the sun and other environmental factors, leading to faster deterioration.


3. Loosens the Shingles

The force from a pressure washer can loosen shingles or even dislodge them entirely. Loose shingles can lead to gaps in your roof, making it vulnerable to leaks and other weather-related damage. Furthermore, displaced shingles can be challenging to repair, often requiring the replacement of larger roof sections.


4. Leaks Water Under the Shingles and Into Your House

High-pressure water can penetrate beneath the shingles, causing water to seep into the underlying layers of your roof. This can lead to water damage inside your home, promoting mold growth and structural issues. Once water finds its way into your roof’s underlayment, it can be a costly and time-consuming problem to resolve.


5. Reduces the Lifespan of Roof Shingles

Overall, the mounting effects of pressure washing can significantly reduce the lifespan of asphalt shingles. By stripping away protective layers, loosening shingles, and potentially causing leaks, pressure washing undermines the durability and longevity of your roof, leading to the need for more frequent repairs or replacements.


how to clean asphalt shingles Can Asphalt Roof Shingles Be Power Washed?

Power washing is similar to pressure washing as it uses high-pressure water to clean surfaces. The only difference is the water temperature. Power washing uses heated water, whereas pressure washing does not.

Given the potential damage, it is not a good idea to power wash roof shingles without the help of a professional. The risks outweigh the benefits, making it an unsuitable cleaning method for this type of roofing material. Instead, homeowners should seek alternative, gentler methods for cleaning their roof shingles.


How to Clean Asphalt Shingles

Pressure washing asphalt roof shingles is ill-advised, especially when not done by a professional. So, how do you clean dirty asphalt shingles? Here are some safe and effective methods:

  • Soft Washing. Use a low-pressure sprayer and a biodegradable cleaning solution specifically designed for roofs. This method effectively removes algae, moss, and dirt without damaging the shingles. This is also best done by professionals.
  • Manual Cleaning. Gently scrub the shingles with a soft-bristle brush and a mild cleaning solution. This is labor-intensive but minimizes the risk of damage.
  • Preventative Measures. Install zinc or copper strips along the roof ridge. Rainwater will carry metal ions down the roof, inhibiting algae and moss growth.


Can You Pressure Wash Cedar Shingles?

Cedar shingles, known for their natural beauty and durability, also require careful maintenance. While cedar is more resilient to pressure than asphalt, pressure washing is generally discouraged unless performed by a professional.

High-pressure washing can strip the natural oils and fibers from cedar shingles, leading to a loss of flexibility and increased brittleness. This can cause the shingles to crack and split over time. Moreover, excessive moisture from pressure washing can promote mold and mildew growth, especially if the wood doesn’t dry out properly.


How to Clean Cedar Shingles

Cleaning cedar shingles should be done using methods that preserve the wood’s integrity. These methods include the following:

  • Soft Washing. Use a garden hose with a spray nozzle to gently rinse off dirt and debris. This method is effective for light cleaning and prevents damage to the wood fibers.
  • Oxygen Bleach Solution. Apply an oxygen bleach solution to remove mold and mildew. Oxygen bleach is non-toxic and safe for the environment, making it an excellent choice for cleaning cedar shingles.
  • Manual Scrubbing. A soft-bristle brush and mild cleaning solution can be used for more stubborn stains. Scrub gently to avoid damaging the wood.
  • Sealing and Staining. After cleaning, consider applying a wood sealant or stain to protect the cedar from moisture and UV damage. This helps maintain the shingles’ appearance and extends their lifespan.


The Importance of Professional Pressure Washing

There are several reasons why hiring professionals to pressure wash your roof is crucial.


1. Experience and Expertise

Trained experts have the knowledge and experience to handle the equipment correctly, ensuring the pressure and technique do not damage the roof shingles. They understand the nuances of roofing materials and can adjust their methods to prevent stripping protective coatings or loosening shingles.


2. Special Solutions and Equipment

Professionals use specialized cleaning solutions and low-pressure washing systems that are safe and effective for cleaning roofs without causing harm. These methods are designed to remove algae, moss, and dirt without compromising the integrity of your shingles.


3. Safety Precautions

Professional roof cleaners have access to the necessary safety gear and training to work on roofs. This is especially important considering the risks associated with working at heights. Hiring experts minimizes the risk of accidents and injuries if you attempt to pressure wash your roof yourself.


4. Warranties

Many roofing manufacturers and insurers recommend or even require professional maintenance to keep warranties valid. Professionals can provide documented maintenance that helps ensure your roof remains covered under warranty, providing peace of mind and protecting your investment.


The Bottom Line

Pressure washing roof shingles, mainly asphalt and cedar, is generally not recommended due to the potential for significant damage. High-pressure water can strip protective coatings, loosen shingles, cause water leaks, and reduce the lifespan of your roof. Instead, opt for gentler cleaning methods such as soft washing for asphalt shingles and oxygen bleach solutions for cedar shingles.

Washh provides residential and commercial cleaning services, including roof cleaning. Call us today at 704.321.8000 or contact us online to get a free estimate!