As spring rolls into Georgia, people are spending more time outside. Inside their homes, people are motivated to do some spring cleaning. Outside your home, you may be finding the time and motivation to clean up your garden or yard. But what about on top of your house? If you look up, you may notice that your roof does not look as good as it once did. There may be black streaks along the north or west sides. If it’s been a while since you attended to your roof, you may even notice some moss building up. But there are some ways you can clean roof stains. Cleaning roof stains will make your home look fresh and new this springs.


How to Clean Roof Stains [infographic]

What Causes Roof Stains

Roof stains can make your home look shabby and worn. It doesn’t matter how much work you do to the outside of your house and property. So if you plan to spend the time manicuring your garden, don’t forget to look up too. A dirty roof is an eyesore, but you can clean your roof and quickly bring back that new look to your home.

You may notice that the roof is stained more on the north or west sides. These sides of your roof tend to get less sunlight and are more exposed to the elements. As a result, those sides of your roof are more prone to damage, including stains.

Black streaks on your roof may look like dripping water. Some homeowners assume those streaks are caused by mold. In fact, they are the result of algae colonies that live in your roof shingles. If your new roof was treated with algicide, the algicide may be effective for up to 10 years. But once the algicide washes off, your roof becomes vulnerable to algae growth. If you have asphalt shingles, you may develop algae that feeds off moisture in the air and the limestone elements in your shingles.

Eventually the algae will start to break down the asphalt, loosening the gravel on top. Once that gravel comes off, the shingles are no longer protected from UV light. This can greatly accelerate damage to your roof that may require repair or even a full roof replacement. So dealing with this algae when you first notice it doesn’t just spruce up your roof. It can actually protect your roof from future damage.

Gather Your Tools

Before you clean your roof you will need to do a little bit of preparation. First, you will need to assemble the necessary tools and materials. Second, you will need to prepare your roof and the surrounding property. This can avoid damage to your roof, your yard, and any furniture or other objects in your yard.

The tools you will need include a simple garden hose, garden spray nozzle, and a supplemental water pump. It’s also important that anytime you are working on your roof you use a full body harness. This will limit the risk from falls and is probably the most important tool you will use. Finally, you will need the roof cleaning solution.

Cleaning Solutions

A simple internet search will turn up dozens of different roof cleaners. However, there are certain cleaners you should avoid. Many cleaners use bleach as a main ingredient. But using a bleach cleaner is not recommended. The bleach can lighten your roof and damage flashing, gutters, and downspouts. In addition, no matter how you clean your roof, some roof cleaning solution will reach the ground. Some will simply be oversprayed from the roof and some will drip down or flow down gutters and downspouts. If you are using a bleach based cleaning product, the bleach can damage plants or grass in your garden below. Any other items it hits, like lawn furniture, toys, or grills, can be stained by the bleach, leaving white spots. Furthermore, the bleach will kill the top layer of algae, but it will not penetrate to kill all of the algae, so your stains will be back before too long.

Another option is lye based cleaners. These cleaners will get deeper into your shingles and kill more algae. They are also less damaging to the vegetation below. However, these solutions are still highly corrosive. This can damage flashing, gutters, and downspouts. It also requires full body protective gear. For this reason, lye based solutions are also not your best option.

Instead of bleach or lye based solutions, look for non-toxic and environmentally friendly cleaning solutions. Many of these solutions work very well without the danger of bleach or lye.

Finally, you may see some information online that suggests power washers. Avoid those sites. You should never use a power washer on your roof. Even at low pressure, a power washer can damage your roof, knocking bits of shingle loose and causing more damage than they prevent. Instead, use a regular garden hose with a spray nozzle.

Preparing the Roof

Wait for the right kind of day. You will want a day that is cool and overcast, so the cleaning solution doesn’t evaporate too quickly. This will let the solution soak into the shingles and completely kill the algae. Once the weather is right, it’s time to get started.

The first thing you need to do it fix any loose shingles or flashing. After that, check your gutters and downspouts to make sure they are not clogged and water is flowing freely. This will allow your roof to drain properly after applying the solution.

Once the roof is ready, take a moment to prepare the area below. Throw a tarp over any bushes immediately below the roof to protect them from overspray. Move lawn furniture and other objects away from the roof.

Cleaning the Roof

Finally, you are ready to climb up onto the roof. Put on your full body harness and tie it down. Make sure to follow all the directions carefully. This is the most important part of the whole process, since it affects your personal safety.

Once you are on the roof, the first step is to spray down the roof with plain water. This will cool the roof so the cleaning solution doesn’t evaporate too quickly. Next, use a pump sprayer attachment to apply the cleaning solution to your roof. Work slowly using even strokes. If you don’t, you risk splotchy areas of clean and less clean shingles, based on which areas got a better dose of solution. Let the solution soak in for about 20 minutes, then spray down the roof with water again to rinse it off.

If the staining is not too bad, that is all it will take. If the staining is deeper, you may need to use a tool specially made for cleaning roofs. This is an attachment to your hose that directs the spray down onto the roof at a slightly higher pressure and at just the right angle. You get the advantage of more pressure without the potential damaging effects of an actual pressure washer.

Prevent Algae Regrowth

Once your roof is clean, you will want to keep it that way. There are two methods you can use alone or together. The first method is to install a strip of zinc of copper along the ridge of your roof. These specially made stips infuse rainwater with ionized particles that flow down the roof and inhibit algae growth. Another method is to apply a stain prevention solution. A good stain blocking solution can last 2 or 3 years before it needs to be reapplied.

Professional Roof Cleaning

If you want to make sure that your roof is cleaned properly, one option is to turn to the professionals at Eagle Watch Roofing. This is especially useful if you’re not comfortable using a harness and getting up on your roof, or if you want to avoid exposure to cleaning chemicals. A professional from Eagle Watch Roofing has all the tools and expertise to get your roof sparkling clean. They can also use the opportunity to inspect your roof for any other damage. Just that quick inspection could save you thousands of dollars by identifying issues that could cause serious damage if left untreated. So if you are ready for your roof to look brand new this spring, contact Eagle Watch Roofing today!