A pressure washer may seem like the fastest way to remove dirt, algae, and dark stains from a shingle roof, but the force of the water can damage the roof and shorten its useful life.
Asphalt shingles are covered with protective granules that help shield the roof from sunlight and weather, and high pressure water can loosen or remove those granules while also lifting shingles and pushing moisture underneath them.
The dark streaks commonly seen on shingle roofs are often caused by algae that grows in warm and humid conditions.
Leaves, branches, and debris can also trap moisture on the roof, creating an environment where algae, moss, and other organic growth can spread.
Although these stains may make the roof look old or dirty, pressure washing is usually not the safest way to remove them.
Strong water pressure can remove protective granules, loosen shingles, damage seals, and force water beneath the roofing materials.
The roof may look cleaner immediately after washing, but the cleaning process could leave it more vulnerable to leaks, sunlight, and future weather damage.
Walking on the roof while using heavy equipment can also crack shingles and create a serious safety risk.
A professional roof cleaning company can use a low pressure cleaning method and products designed for asphalt shingles.
This approach treats the stains without using the same level of force as a traditional pressure washer.
Before cleaning the roof, it is also important to inspect the shingles for damage, since cleaning an older or deteriorated roof may cause additional problems.
Not every stained roof needs to be replaced, but not every roof should be cleaned without first understanding its condition.
As a local roofing company, we recommend having the roof inspected before choosing a cleaning method, especially when shingles are loose, cracked, curling, or losing large amounts of granules.
Keeping your roof clean can improve the appearance of your home, but protecting the roofing system should always be the priority.
When it comes to shingle roofs, more pressure does not mean a better cleaning.
Get a free, no-obligation inspection from South Florida's trusted roofers. Serving all of Palm Beach, Broward, and Miami-Dade County since 1987.