There’s nothing else like the fresh, clean look of a new roof! Even if it’s the first step in an exterior home renovation, a new roof immediately improves the appearance of any house – regardless of how much other work remains to be done. However, new roofs don’t remain in pristine condition for long. Cleaning your roof on a regular basis is essential to not only keeping it looking its best for that all-important curb appeal, but to prolong its useful life.
Keeping Your Roof Clean is About More Than Curb Appeal
It’s common for a roof to be overlooked until it becomes heavily stained or discolored. By then, damage may already be occurring. Rain will wash away surface dirt, but you can’t depend upon nature alone to do the job. Central Florida’s hot, humid climate promotes the growth of algae, moss, mold, mildew, fungus and lichens that can thrive on roofing material – especially if your roof is shaded under tree limbs.
Our blog post – “The Best Methods for Cleaning a Roof” – covers the difference between algae and moss, courtesy of the Asphalt Roofing Manufacturers Association.
“Often mistaken as mold or mildew, the black discoloration and streaks visible on many roofs across the United States and Canada are actually algae. The algae can form where moisture tends to dwell on roof surfaces. Coastal or humid climates create the most conducive conditions for algae growth. The most common type, gloeocapsa magma or blue green algae, protects itself from damaging ultraviolet rays by producing a dark pigmented sheath. The algae discoloration typically begins as small spots then quickly transforms into streaks on the roof plane. By the time the algae is visible, it likely has been present for several months or longer.
“Moss is a non-vascular plant that obtains water through its leaves, unlike most plants that gather water through its root system. Moss must therefore have a moist environment to survive. In North America, moss tends to grow on north facing roof planes that receive less direct sunlight and stay damp longer than south facing planes. Overhanging tree branches provide additional shade and drop debris on the roof that further holds in moisture and acts as a food source for moss.”
Where there is algae and mold, it is most likely that lichen is present – which, over time, can cause separation of roof materials and eventually roof leaks.
Add to this twigs, leaves and other debris that doesn’t wash away in the rain, and your roof has the ideal environment for cultivating conditions that are both unsightly and damaging over the long term. This situation is even more problematic for flat roofs, popular for classic Florida concrete block homes built in the 1950s through ‘60s, as stains aren’t easily seen.
How Dirt Can Damage a Roof
Again, the dark stains typically mistaken for dirt are actually some kind of organism. According to Long Roofing, the stains and growth patches they cause can damage your roof through shingle deterioration and wood rot – which occurs in the case of moss, which holds in moisture and diverts water to the roof deck. It also causes the edges of asphalt shingles to lift and curl, which also is the first sign indicating that the roof needs to be replaced.
“Moss tends to grow in the slots between shingles, which is the last place water evaporates from a roof,” says Yanni Avramidis, vice president of production for Long Roofing. Noting that the signs of wood rot are not obvious to the average homeowner, Avramidis says, “You don’t know how much damage is done to your house. You may have a leak and you don’t even know it. This will cause even more wood damage.”
In addition to shortening the life of your roof, wood rot can cause mold growth – which is a hazard to household members and pets. Wood rot also makes it easier for such animals as squirrels to chew through areas of the roof and supporting beams, further undermining its structural integrity.
As for blue green algae, it feeds off of asphalt shingles located on moist, cool and shaded areas of the roof. Roofs with algae growth absorb heat, which results in extremely high heat in the attic. This eventually reduces the lifespan of shingles by baking them from the inside out.
Barrel tile and painted metal roofs are also susceptible to algae and mold growth. Metal roofs have an additional element to watch out for. Although this type of roof is becoming increasingly popular in Florida as a low-maintenance alternative to shingle when it’s time to replace the roof, low-maintenance doesn’t mean maintenance-free. According to Sheffield Metals International, “One of the easiest ways to determine if your roof is degrading is by inspecting if the paint is chalking. Chalking is the whitish residue that can become visible on a painted or coated metal surface over time.
“As a panel is exposed to sunlight and UV rays, the paint system’s resin begins to break down and degrade. Once the resin starts to break down and continues to be exposed to the sun, oxygen, and pollutants, it loses its adhesion to the surface and those degraded particles begin to turn white. These particles will eventually become visible to the naked eye on the metal’s surface. Often times, the difference can be subtle; however, if you swipe the panel with your finger, you can notice the chalky residue on your skin.
“Keep in mind, most metal roofing paint warranties don’t cover excessive chalking in the presence of pollutants, which is why it’s important to regularly clean your roof.”
DIY or Hire a Pro?
Every cleaning method for every type of roof requires using a pressure washer. Standard high-pressure washers can damage asphalt shingles and crack barrel tiles. For this reason – in addition to the safety factor – we at The Paint Manager highly recommend hiring a professional. Pressure washing pros have special equipment that doesn’t harm roofing material, as well as the appropriate equipment and protective clothing to do the job safely.
Our blog post – “What to Look for When Hiring a Professional Roof Cleaner” – includes a checklist of how to find a reputable professional. While our post goes into greater detail, here are the basics to investigate on your favorite search engine. Enter a simple search, such as “roof cleaners near me” or a similar search, and take it from there. Visit company websites and look for the following:
- Length of time in business
- Licensed and insured
- Has the appropriate equipment and protective clothing for the job
- Scope of work – make sure the company cleans your type of roof – for example, tile roofing
- Physical location or permanent address
- Reliable means of contact
- Better Business Bureau membership – preferably with an Accredited Business A or A+ rating.
The Take-Home Message
Your home is your most important investment. Keeping its roof clean is a critical part of maintenance that is too often neglected. Fortunately, it’s easy to be proactive when you have a reliable professional to perform this service. Our team at The Paint Manager is ready to help! We have years of experience in cleaning every type of roofing material for both residential and commercial properties to provide the best possible results. Contact us today for your free estimate!