Over time, algae, moss, lichen, dirt and even salt (if you’re near the ocean) can build up on your roof. These buildups can affect the look and function of your roof unless removed. The buildup of organic materials such as moss on a shingle roof can prevent water from sloughing off as it normally would. Trapped water can rot the roof or cause early deterioration of your shingles. Even if you don’t have a shingle roof, moss and lichen absorb water, and that wet material adds weight and stress to your roof — as well as providing a home for insects and other pests, and collecting dirt. For reflective, cool roofs that redirect heat away from the home, algae and moss growths can hamper their ability to deflect the sun, which can affect utility bills. Visually, moss, dirt and algae growths on a roof can have a negative effect on perceived home value and curb appeal. For example, black algae streaks on your roof may cause a potential homebuyer to assume that the roof might need repair or replacement, when it only needs to be cleaned.
Yes roofs can be cleaned, and yes, it’s a real thing. Roof cleaning may actually be a wise investment to prolong the life of your roof. Overgrowth of moss, grime, lichen or algae can all shorten the life of your roof. If you have black streaks growing on your roof, they are likely caused by gloeocapsa magma algae spores that have landed on your roof and taken up residence. Once the algae has grown into streaks, the organism has usually been growing for several months and it’s high time to have it removed. If you live in a rainy part of the country, such as the Pacific Northwest, there’s a good chance you’ll find moss growing on your roof at some point. The northern part of your roof, as well as any parts that remain shaded all day, will provide a wet, cool haven for moss to flourish. Unfortunately this water-absorbing moss can damage your shingle roof, leading to rot if not removed. Beyond roof health and function, a clean roof can boost your curb appeal and potentially boost your home’s resale value. The national average for roof cleaning costs ranges between $270 and $350, although prices can be higher depending on how large your roof is, how steep your roof is, and what type of cleaning is necessary. Typically pros use either a pressure wash or chemical wash (made with a concentrated bleach solution) to remove algae, lichen, moss and dirt.
Rain gutters, those easily-forgotten trenches that hang off the edge of your roof, protect your roof, walls and foundation from excess rainwater. When they get clogged with leaves, sticks and other wind-blown debris, they can no longer direct water away from your walls and foundation, and may become homes for pests and insects. They also become heavy enough to pull away from the house, preventing proper rainwater drainage and spoiling the appearance of your home. Experts recommend inspecting and cleaning your gutters twice a year, once in spring and once in fall, as part of your regular landscaping schedule. Gutter cleaning and maintenance is a fairly easy DIY job for some homeowners, especially on one-story homes. However, professional gutter cleaners have ladders tall enough to safely reach rain gutters, as well as the necessary tools to clean out the downspouts. Most gutter cleaning professionals can also make any necessary quick repairs.
The national average for roof cleaning costs ranges between $270 and $350. Factors that can affect the cost to clean your roof are the height of your house, the size and pitch (steepness) of your roof, and the complexity of your roof’s design and accessibility. Geographic location also plays a role in roof cleaning costs as regional labor rates and area costs to do business will vary. There are several ways to clean a roof. The most common is pressure washing. Industrial pressure washers can spray over 3,000 pounds per square inch (psi) of water — which is much too powerful for roof cleaning, and may tear off shingles and damage your roof. Confirm that the roof-cleaning pro you choose will only use a low-pressure sprayer to protect your roof investment. For large algae or moss growths, pros often recommend a combination of low-pressure washing with a bleach-based chemical solution. This is referred to soft washing and should handily remove any growths taking over your roof.
The national average cost to clean windows is $120-$170. Typically, window washing for commercial spaces costs less per window than residential window washing, but has a higher overall price because the greater number of windows. Commercial window cleaning companies may charge a standard rate per window — for example, $3 to clean the exterior only, with a higher rate of $4 or $5 to also clean the interior. There may be an additional charge, such as an extra $1 per window, for scrubbing off water stains or deep-cleaning window tracks. Double-hung windows require more labor and will therefore cost more to clean. Companies may charge a flat rate, such as $8 per double-hung window or $9 per French door, to account for the added work. Building height will play a factor in window washing costs. Standard cleaning for one- and two-story buildings will typically stay within the same range, but cleaning high-rise windows may entail special safety permits and equipment, which would increase costs. Your location will also affect window washing costs. Smaller towns and areas with a lower cost to do business will have lower window cleaning rates than large cities.