Moss on Asphalt Shingles: Prevention and Treatment Options

Moss on asphalt shingles can be a real eyesore, but fortunately, it's a problem that can be prevented and treated. Moss thrives in damp environments, which is why it's common on north-facing roofs.

Regular roof cleaning can help prevent moss growth by removing debris and dirt that can trap moisture. In areas with heavy tree coverage, regular gutter cleaning is also crucial to prevent leaves and branches from clogging the gutters and downspouts.

If you already have moss on your asphalt shingles, there are treatment options available. A solution of bleach and water can be applied to the affected areas to kill the moss, but be careful not to apply it to the shingles themselves.

Moss growth on asphalt shingles is typically caused by moisture accumulation and lack of sunlight.

The shady environment created by overhanging trees is ideal for moss growth.

Nearby buildings or a north-facing slope can also contribute to the perfect conditions for moss to thrive.

Once moss takes hold, it can quickly spread and damage your shingles.

Removing moss from asphalt shingles can be a delicate process. It's essential to understand that using the wrong method can cause significant damage to your roof.

In the Seattle area, where moss is a common issue, it's common to see homeowners and contractors using brushes or pressure washers to remove moss. However, this can lead to rapid granular loss and shorten the expected lifetime of the roof system.

Using a brush or pressure washing the moss will only remove the visible moss, but not the spores, which can cause the moss to return rapidly. On the other hand, using a bleach and water solution, also known as soft washing, is a more effective and safe method.

Here are the tools and materials you'll need to remove moss from your asphalt shingles:

By using the correct method, you can help extend the life of your roof and prevent costly repairs.

To remove moss from your asphalt shingles, you'll need some essential tools and materials.

Safety goggles are a must-have to protect your eyes from any potential debris or chemicals.

A stiff bristle brush is necessary for scrubbing away the moss and its roots.

A garden hose with spray nozzle will come in handy for rinsing away the moss killer solution and any remaining debris.

Moss killer solution is a crucial ingredient for effectively removing moss from your asphalt shingles.

Plastic sheeting can be used to protect surrounding surfaces from any overspray or spills.

A ladder is necessary for safely accessing the areas of your roof where moss has accumulated.

Here's a list of the tools and materials you'll need:

You can make a bleach solution at home using sodium hypochlorite (also known as bleach) at a rate of 50% bleach and 50% water. Wear protective equipment and be careful when using bleach.

To use this solution, spray it onto the roof surface thoroughly using a pump sprayer, allowing the bleach to come into contact with the moss for 20 minutes or more. Adding Dawn dish soap to the mix can help slow down the bleach's flow and keep it in contact with the moss longer.

The bleach solution is a safe and effective way to kill moss on asphalt shingles, and it's even recommended by leading roof manufacturers. In fact, one expert has used this method on thousands of roofs with great success, only seeing new moss return after 5 years.

If you're considering using bleach to remove moss from your roof, be sure to rinse it off thoroughly with a garden hose after 20 minutes or more. You may need to repeat the process several times to completely remove all the moss.

Here are some key tips for using bleach safely:

Removing shingles can have a significant impact on your roof and home value. By removing moss-covered shingles before a new roof installation, you can reduce long-term costs.

You can keep the opportunity to double-up roof layers during your next roof replacement, which is a great way to save money in the long run. Most building codes allow for a maximum of two layers of shingles on a roof, so removing the old roof will give you a chance to add a new layer when you replace it.

A properly replaced roof is more likely to appeal to potential buyers, which can increase your home's value. On the other hand, a poorly replaced roof can negatively affect your home's value, making it harder to sell.

Removing all of the moss-covered shingles can also help you avoid the risks associated with not doing so. This includes avoiding damage to your roof and home, which can be costly to repair.

Here's a breakdown of the benefits of removing shingles:

Trim back overhanging tree branches to increase sunlight exposure on the roof, which can help prevent moss growth.

Keeping your roof clean is crucial to prevent moss from growing back. Remove debris, such as leaves and twigs, that can trap moisture and create an ideal environment for moss to thrive.

Installing zinc or copper strips near the peak of the roof can help prevent moss growth over time. This is a proactive measure that can save you time and effort in the long run.

Having your roof professionally cleaned regularly is essential to remove any buildup of moss or debris. This will help prevent moss from growing back and reduce the risk of water damage.

If you're not sure how to clean your roof or if you're not comfortable doing it yourself, consider hiring a professional to do the job for you.

Here are some tips to keep in mind when preventing moss growth and return:

You can remove moss from asphalt shingles using a bleach solution, which is recommended by leading roof manufacturers.

Mix one part bleach with one part water to create a solution that's 50% bleach and 50% water. This will help kill the moss at the roots.

Adding Dawn dish soap to the mix will slow down the bleach and water's run-off, allowing it to stay in contact with the moss for longer.

Be sure to wear protective equipment and spray the solution thoroughly using a pump sprayer, then leave it on the surface for 20 minutes or more before rinsing off with a garden hose.

Alternatively, you can use a professional-grade moss removal solution specifically designed for asphalt shingles.

To remove moss from your asphalt shingles, start by wearing protective gear such as safety goggles and rubber gloves to protect yourself from the moss-killer solution and any debris falling from the roof.

Before you begin, cover any plants or bushes near the roof with plastic sheeting to protect them from the moss-killer solution.

Mix a moss-killer solution by combining sodium hypochlorite (also known as bleach) at a rate of 50% bleach and 50% water, or follow the manufacturer's instructions for mixing and application.

Avoid using a pressure washer, as this can damage the shingles, and instead use a pump sprayer to apply the solution directly onto the moss-covered areas of the roof.

Allow the moss-killer solution to sit on the roof for 15-30 minutes, or up to 20 minutes if using the bleach solution, to give it time to penetrate and kill the moss at the roots.

Using a stiff bristle brush, scrub the moss-covered areas of the roof, applying gentle pressure to avoid damaging the shingles, and start at the top of the roof and work your way down.

Rinse the roof thoroughly to remove any remaining moss and debris using a garden hose with a spray nozzle, and rinse the roof from top to bottom to avoid pushing water under the shingles.

Inspect the roof after rinsing to see if there are still areas of moss, and if so, repeat the process until it is completely removed.

In the Seattle area, where moss is literally our state plant, homeowners often want to remove moss from their roofs instantly. This is why some companies use brushes to remove moss, but trust me, the damage up close is noticeable.

Soft asphalt shingled roofs can hardly stand one improper cleaning, and using a brush can lead to rapid granular loss and a shortened roof system lifetime.

Living in the Seattle area, I've seen firsthand the devastating damage that using brushes or pressure washers can cause. These methods may make the roof look nice and clean from the ground, but they can shorten the roof's lifetime.

Using a brush or pressure washing the moss will remove the moss but not the spores, making the moss return rapidly. Instead, kill the moss using bleach and water, which really makes sense once you know your options.

Here are some areas in the Seattle area where you may need roof cleaning services:

If you see anyone brushing a roof, please stop them and take their brush away! It's essential to understand that using the correct method can make your roof last as long as its expected lifetime.