Natural contaminants aren’t just an eyesore to look at; they also take a toll on the life of your roof’s shingles. If not cleaned periodically, they’ll irreparably damage roofing materials. That damage could have you replacing the roof prematurely. Even repairing small sections of a damaged roof is more costly than a roof cleaning, making prevention the best cure.


The black streaking pattern seen on dirty roofs is algae. Algae is most apparent on asphalt shingles of any color. Algae typically appears on the shady side of the roof or the North Face, though can be present on all sides.


The same moss that grows on the ground also can grow on your roof. Moss looks soft and fluffy, but it is firmly anchored into the roof shingles by roots that dig deep into the shingle. In the process, the roots destroy the asphalt granules that are designed to thermal insulate the roof.


These organisms co-exist in a symbiotic relationship with algae. Lichen are usually bright green and colorful, and rooted deep into surfaces. This is the toughest natural contaminant of the bunch. Lichen is the most diverse of the group, with more than 10,000 different species. Though beautiful on rocks, it can cause extreme damage to paint, gutters, asphalt shingles, and metal roofs.


Beware of anyone mentioning or claiming mold on the roof, or cleaning Mold from your roof. It is highly unlikely that mold will exist in the conditions on a roof. Generally, new inexperienced washer use this term and/or any washer that sells using fear tactics.


  • You do not have to be home; however, we will need access to your backyard and an outdoor water spigot.
  • If you have outdoor pets, please let them out prior to our arrival, then keep them inside until the ground is dry.
  • Please remove cars from the driveway.
  • Expect it to take some time. Roof cleaning is a process that sometimes takes A FULL day or longer to complete. Beware of anyone who promises an “in and out” approach.
  • Be flexible with scheduling. Allow for rain delays. Soaps and chemicals used for proper roof cleaning are diluted by water. If it rains, the chemicals are not as effective, and the result will suffer. Chemical application placement is critical, and even sometimes, wind can delay appointments as well.


  • Contact a licensed professional that is insured for ROOF CLEANING. Pressure washing does NOT fully cover roof cleaning, meaning that if they damage your roof, you are not covered.
  • Hire someone with roofing experience. Experienced roof cleaners with roofing backgrounds know how to appropriately and safely walk on the roof if needed. Walking around without knowing where to step can cause more physical damage to shingles. In addition, an experienced roofer can check for maintenance needs, spot troublesome areas such as potential leak hazards or other unseen damage, and provide a general overall inspection of the roof while it’s being cleaned.
  • Avoid Pressure Washing Companies. Asphalt shingles are relatively fragile, and high-pressure water can and will damage them. A soft wash method is the only APPROVED METHOD and requires different equipment, skills, and experience.
  • Ask about their methods. Look up your shingle manufacturer’s required cleaning procedures and practices, and make sure this is what you are getting. A soap/chemical application and thorough rinsing is the only allowable process for this exterior cleaning. Not rinsing, or skipping any other step, can and will void your manufacturer’s warranty costing you significant financial loss.

Common Questions and Answers

  • How long does roof cleaning last?

Typically 3-5 years

  • Is roof washing a good idea?

Absolutely! It almost doubles the life span of your roof

  • Does cleaning your roof cause damage?

Cleaning stops the damage caused by biofilms(Algae, etc..) It adds life to your roof.

  • What makes Clean Roof LLC different from pressure washing companies?

First, We are an actual Roof Cleaning company. We are trained, structured, and coded (State, Local, insurance coding) as a roof cleaning company. If you are looking for roofing professionals that also have more than four years of Roof Cleaning Experience, Clean Roof LLC is your choice. Don’t just let anyone on your roof!