If you’ve landed on this page, chances are you think your roof looks like something out of the Addam’s Family, but don’t worry! Much like your roof — we’ve got you covered!

Keep reading along to learn how to best clean your roof just in time for spring and summer!

Why You Should Clean Your Roof

While the task isn’t the most exciting thing you may do during a weekend or over a summer break, it is something you’d want to consider doing sooner rather than later. Especially in the south — the warmer months are upon us and being on a roof is going to be hot.

Cleaning your roof will ultimately help extend the life of it and save you money in the long run. For shingled roofs, most manufacturers develop their products with algicide, but once the algicide wears off, you can bet your bacon, algae and moss will begin to grow.

What Causes Black Streaks on Asphalt Shingles and Metal Roofs?

Gloeocapsa Magma 

This is the fancy name for the bacteria that is known as “roof algae” and commonly referred to as “blue-green algae.” Colonies of this bacteria begin to grow on shingles, typically on the north and west slopes (if you have them), as well as areas that are shaded under by tree branches or other structures.

These algae colonies feed off the moisture in the air and on your roof as well as the limestone fillers in the shingles themselves. While algae isn’t necessarily harmful to your roof, it will negatively impact its performance, especially if you have a cool or reflective (metal) roofing system.

buildpro moss on roofLichen and Moss

Lichen and moss can absolutely damage your roof and cause all sorts of problems. Just like shingle roofs, lichen and moss will show themselves by creating brown or black streaks down the length of your roof. When they team up, a thriving environment is created that only makes their potential for roof damage that much more possible.

The damage lichen and moss can cause will undoubtedly cost you hundreds and even thousands of dollars. They’ll grow under your shingles and attach directly to your roof decking, causing your shingles to curl and bend up and separate from the decking itself.

Speaking of roof leaks, we have a great article on how to find roof leaks here, just in case you need it!

How to Remove Algae, Lichen, and Moss

First, we strongly recommend you reach out to a roofing company to inspect your roof. They will be able to determine what may be growing on your roof and recommend treatments or professionals that can safely and effectively clean your roof for you. It’ll likely be a lot safer and a more efficient process than trying to handle that on your own.

However, if you’re looking to do it yourself, here are some general steps to take in order to get your roof looking spick and span!


We can’t stress this enough. If you plan on getting on your roof, please make sure you heed the following:

        Ladder Safety

             Make sure your ladder and working space are clear of any power lines

             Maintain 3 points-of-contact on the ladder at all times

             Stay near the middle as much as possible

             Make sure the surface your ladder is set upon is level and stable


             Non-slip shoes with good tread and rubber soles

            Thick gloves so you can safely handle whatever chemicals you decide to use

            Safety glasses/goggles so said chemicals don’t get in your eyes


        Wear a harness!

Make sure you have good rope or cordage to attach to either your chimney or an anchor point on your
roof. Make sure the harness fits well and is tight, because let’s face it — nobody has time to fall off the roof!

While we’re at it, make sure you tell someone you’re going up on the roof. God forbid you fall or get stuck without someone knowing you’re up there or around to hear your calls for help!

Tools of the Trade

As you stand before the task ahead, be sure you have all the right tools to get the job done. You’re going to want to have things like:

        A garden hose with a spray nozzle (No, not a power washer. Definitely NOT a power washer!)

You’ll want a gentle stream of water to soak and clean your roof. A power washer will damage both a shingled roof and a metal roof.

       A leaf blower

This will help clean off loose debris from your roof and help clean out your gutters. (Pro tip: keeping your gutters free of leaves and junk limits the possibility of water backing onto your roof’s decking and causing mold and leaks!)

      Your cleaning chemical/s of choice

There are a bounty of options out there to choose from and an equal amount of considerations as to which would be best for
your roof. Check out this great article to help you determine which may be best for your home.

      A good pair of gardening shears or snips

Having a pair of these wouldn’t hurt, especially if you have tree branches or other debris on or near your roof that you may want to cut back or remove altogether.

     A long-handled, soft-bristled brush

If you’ve got moss on your roof, a gentle spray of water and chemicals may not be enough to clear it from your roof. So, consider buying or having on-hand a brush you can use to gently remove moss and lichen from your roof without damaging your shingles or metal.

Plants, Shrubs, and Bushes, Oh My!

The chemical/s you may choose to clean your roof with could be toxic to your foliage, grass, even lawn furniture.

So, before getting up the ladder and onto your roof, you’re going to want to make sure your plants and bushes on the ground are protected. Your best bet is to soak all of them with your hose, then cover them with a plastic film or tarp.

buildpro overhanging limbTake a Look Around

Once safely atop your roof, take a look around and see what’s what. You’re not only looking for tree limbs, leaves and other debris, but you’re also wanting to find any problem areas with your roofing material (like loose or missing shingles), decking, vents and flashings.

If you find any problems with the roof itself, that’s your signal to stop whatever cleaning you may have planned and either call a roofing contractor or make plans to repair those issues yourself.

Should you choose to neglect those issues, your cleaning process may exacerbate the problem and cause your shingles to break off, your decking to crack or break even more, your metal roofing panels could become more loose — it’s just bad news all the way around.

While inconvenient, stopping and getting repairs done before cleaning your roof will save you a lot of money in the long run.

buildpro roof debris

Debris Removal

When you’ve safely arrived on top of your roof and are safe and secure, look for any branches or bunches of leaves or other debris that may be on your roof that shouldn’t be. This is where a leaf blower may come in handy! Just make sure the ground below is clear of people and pets!

You’re also going to want to take a good look in your gutters and make sure leaves and debris aren’t blocking your downspouts. Debris buildup in your gutters can force rainwater up your roof and under your shingles or metal panels, causing leaks into your attic (and foster the growth of algae and mold.)

Start Cleaningbuildpro roof cleaning

Using your low-pressure hose and the cleaning solution of your choice, you’re going to work from the top of your roof (the ridge,) down to the edge. This way, the cleaning solution will have less of a chance to get blown back into your face or onto your clothes. You’ll also not be forcing water up under or between your shingles or metal sheeting, risking leaks or damage to your roof.

Saturate large areas of your roof until you see some runoff. If there are particularly troublesome or darker areas, they may require a second soak. Let the solution soak for about 15 or 20 minutes, then rinse the roof off with plain water.

If some areas on your roof are still discolored after drying, you may have to get on your roof again for another soaking, or you could bring a soft cleaning brush or even a broom with you to scrub the problem areas individually.

Finish Up

Once you’re satisfied with the work you’ve done, give the foliage and grass around your roof a good rinse with the hose. Leaving the chemical runoff on them will only, likely, kill them off. So, unless you like brown grass and dead flowers and bushes – give them a nice bath after you get done cleaning your roof.

Roof Algae and Moss Prevention

Keeping roof algae and moss from coming back is a relatively simple fix: install copper- or zinc-coated sheet metal under the first row of shingles from the peak of each ridgeline on both sides. Just slide the metal under the shingles to the point that anywhere between 2 to 4 inches of metal are exposed to sunlight.

You can also use galvanized sheet metal to accomplish this same goal. While it may not be as toxic to algae as copper, galvanized metal is less expensive and may be more readily available than copper- or zinc-coated metal.

When it rains, molecules from the metal will run down your roof, killing algae and moss alike without risking damage to your roof or poisoning the ground below.

Should I Clean My Roof?

If you’re still reading, then chances are you already know the answer: YES! Regularly maintaining your roof not only extends the lifetime of your roof, but can provide you with multiple chances to remove debris and harmful objects from your roof’s surface and clean your gutters, thus limiting chances for leaks and damage to occur.

If you think roof algae, moss, lichen, or just time and weather have damaged your roof, give the roofing experts at Buildpro a call. We provide some of the best warranties in the industry, including partnerships and certifications with trusted brands like Sheffield Metals, Owens Corning, IKO, and CertainTeed.

So, if you’re ready to get started, fill out this form, and we’ll be in touch shortly.