Here's what you should know about targeting the most common causes of dirty shingle roofs: debris, algae, and moss.
Falling debris is a common cause of shingle damage and dirty shingles. Debris that makes its way onto your roof usually includes sticks, branches, leaves, and acorns that fall from trees, get blown onto the roof, or are brought by animals to make nests.
Debris on your roof isn't just an eyesore; it can also cause damage. This is because the debris will create a dam blocking rainfall from flowing away from the roof. This leads to a buildup of water that seeps under the shingles and causes rot of the roof deck or leaks into the interior of the building. Damp debris on the roof also encourages mold and moss growth that can easily spread to other parts of the roof. Small animals will even use debris as nesting material to move into your chimney and gutters. In some cases, dry debris like leaves can work as kindling and start a fire on your roof.
How to Remove Roof Debris
There are a few ways to remove debris from your roof. The most straightforward method is removing debris by hand. This is an option when the debris is light, but it may require you to step onto the roof. Always use extreme caution to avoid falls.
A blower is an easy way to remove sticks and leaves from your roof. An air blower can be used to safely remove debris without the risk of damaging your shingles. If you don't have a blower, a soft broom can also be used. Be careful that you don't apply much pressure to the roof or you can remove the shingle granules.
Homeowners in humid areas know the greatest bane of shingle roofs: algae. If you've ever noticed those dark, ugly streaks on your roof and wondered where it came from, it's usually caused by a blue-green algae called Gloeocapsa Magma. Spread by airborne spores, this algae grows quickly and easily on shingles, especially on the north side of your roof that gets less sun and stays damp longer. You will notice the stains are absent below metal flashing around your roof vents and chimney. That's because the zinc and copper in on the galvanized metal kill algae. When it rains, tiny amounts of metal wash down the roof and kill the algae below.
The algae itself doesn't do much harm to your roof, but it's definitely not attractive. Getting rid of algae is a double-edged sword; cleaning your roof with chemicals will get rid of the algae, but using harsh chemicals too often will damage the asphalt shingles themselves.
Removing Algae Stains
It's important to use the right cleaning solutions to get rid of algae stains. Before applying anything to your roof, check your shingle warranty an test the solution on spare shingles to make sure it doesn't cause damage.
There are two options for removing algae: you can use a DIY solution of bleach, trisodium phosphate (TSP), and hot water, or you can use a roof cleaning solution designed to remove algae stains. If you use a homemade solution, keep in mind chlorine bleach produces a faster and more dramatic effect but oxygen bleach is less harmful to the environment.
Once you've chosen your cleaning solution, you will need:
- Cleaning solution
- Pump sprayer
- Garden hose with nozzle
- Safety goggles
- Safety rope
- Rubber gloves
- Slip-resistant shoes
The best time to clean your roof is on a cloudy day so the solution won't evaporate as quickly. Pour your cleaning solution into a pump sprayer, mix, and spray. Once the roof is wet with the solution, allow it to sit for 15 minutes before rinsing.
Prevent Algae From Returning
Want to keep algae away for good? Instead of repeatedly cleaning your roof and risking damage to your shingles, consider installing zinc or copper strips. Just like the flashing around your vents and chimney kills algae below, zinc strips installed on your roof can keep algae from growing. Every time it rains, a tiny amount of the metal will wash down your roof and act as a natural algae-killer.
Unlike algae, which is mostly a cosmetic problem, moss can actually cause damage to your roof. While it may look pretty, it damages the structure of your building over time by growing under the shingles, raising them higher like a jack, and allowing water to make its way underneath.
Moss is a plant that grows quickly in moist, cool areas. Moss does not have a root system so it needs a damp environment and shade. It also grows well in acidic environments. There are three ways to kill moss on a roof:
- Remove its shade.
- Make the environment more basic or acidic.
- Remove the moisture or water.
The easiest of these methods is changing the pH of your roof with specially designed roof cleaning products. There are several household products with an acidic pH below 4 that can kill moss effectively, including lemon juice, orange juice, and white distilled vinegar. You can also make the environment a base by making a solution with baking soda, baking powder, ammonia, soap, or bleach.
Do not try to scrape off the moss or use a pressure washer. Be careful you don't spray any water upward and under your shingles as it can leak into the house or rock the wood deck.
As with algae, you can keep moss from growing on your roof by installing copper or zinc strips at the top of your roof ridges.
Before attempting to clean your own roof, remember that there are very real risks involved. Along with causing damage to your roof with improper techniques, you risk physical injury if you do not take proper precautions.
Do not attempt to pressure wash away stains or debris on your roof. If you pressure wash the roof, you will likely void your warranty. Pressure washing can also remove the granules from your shingles or force water under the shingles. Always leave this to a professional.
Take care to avoid fall injuries. Many homeowners fall from their roof while attempting to clean it. This risk extends to professionals as well. Falls account for 76% of fatalities in the roofing industry. If you do not have the proper experience and equipment to protect against falls, leave the job to professionals.
Some cleaning products can kill plant life. Some solutions will kill plant life and landscaping as it drains from the roof. Read any warnings on the cleaning solution prior to use. It can help to wet down plant life before and after applying the cleaning solution. You can cover bushes with plastic, too.
Use extreme caution when scrubbing. Scrubbing asphalt shingles with a broom or brush can tear the shingles or remove granules. We do not recommend scrubbing shingles.
Contact Pressure Washing Tampa today for a free estimate on your roof project from licensed, insured professionals or call right now 1-813-658-5893.