Moss, algae, and lichen thrive in moist, shady areas. It can sometimes make its way onto your roof, which is an eyesore and could lead to serious damage. If your roof is prone to roof vegetation, you can take proactive steps to prevent roof moss with zinc strips. In the video above, This Old House’s Tom Silva shows you how to apply zinc strips to your roof and what you can do to get rid of any existing moss growth.
Why Is Roof Moss Bad?
Even if you aren’t bothered by a little moss or lichen on your roof, you need to remove it before it causes damage. Moss holds moisture against the shingles, and unchecked moss growth can lead to the following:
- Decreased energy efficiency: Moss can trap moisture and create a barrier that affects your roof’s ability to reflect sunlight, leading to increased heating and cooling costs.
- Leaks: As moss grows, it can lift shingles and allow water to seep underneath, causing potential leaks and water damage.
- Mold growth: The moisture retained by moss can promote mold growth both on the roof and in the underlying structure, which can pose health risks and lead to costly repairs.
- Reduced roof lifespan: Moss can accelerate the deterioration of roofing materials, shortening the lifespan of your roof and leading to the need for premature replacement.
- Shingle damage: Moss can cause shingles to crack, curl, or dislodge, compromising the roof’s ability to protect your home from the elements.
- Wood rot: Prolonged moisture exposure from moss can lead to wood rot in the roof’s underlying structures, weakening their integrity and potentially causing structural damage.
How Zinc Strips Work To Prevent Moss
When it rains, zinc particles from the strips dissolve into the rainwater. As the zinc-infused water flows down your roof, the zinc ions disrupt moss, algae, and other vegetation from forming on the surface. Zinc strips are especially useful for homes in areas that get a lot of rain or high humidity.
Zinc strips are cost-effective and easy to install. They offer low-maintenance, long-lasting protection and are environmentally friendly.
Installing Zinc Strips on Your Roof
Most homeowners with some do-it-yourself (DIY) experience can install zinc strips onto a roof. You can find zinc strips sold in rolls or precut sections. Check the manufacturer’s recommendations to learn how much material you’ll need according to your roof’s size. Before getting started, collect all the tools you’ll need:
- Hammer or nail gun
- Pry bar
- Roofing nails
- Safety equipment
- Tri-polymer sealant
Step-by-Step Installation Process
Here’s how to install zinc strips on your roof, as demonstrated by Silva:
- Choose a suitable location near the roof’s ridge.
- Gently lift the shingles using a pry bar.
- Slide the zinc strip under the shingles, leaving about 1 inch exposed.
- Secure the strip with roofing nails, placing them in the pre-drilled holes.
- Apply tri-polymer sealant over the nail heads for added protection.
- Press the shingles back down until they’re sealed.
Tips for Safe Installation
Working on a roof is dangerous if you don’t take the proper precautions. Install the strips on a dry day without a lot of wind. Use a stable ladder and wear protective gear. You can always hire a professional to take on the job for you if you aren’t comfortable working on the roof.
How To Remove Moss That Has Already Formed
Zinc strips prevent new growth, but you’ll still have to remove any moss, lichen, or algae that’s already formed on your roof. Silva recommends using a bleach and water solution and covering any surrounding vegetation with tarps to protect them from harsh chemicals. Follow these steps:
- Mix equal parts water and bleach in a garden sprayer.
- Apply the solution to affected areas but avoid oversaturating the shingles.
- Allow the solution to sit for 15–20 minutes.
- Gently rinse the roof with a low-pressure hose.
Zinc strips don’t require much upkeep, but remember to inspect them every so often to check that they’re still securely fastened to the roof, especially after a storm. Keeping your roof clear of leaves and debris will further reduce the risk of moss growth, and making sure your gutters are clean and functional prevents water from pooling on the roof.
Alternative Solutions for Moss Prevention
You can use other measures to prevent roof moss other than zinc. We’ve covered a few below.
Copper and Lead Strips
You can install copper and lead strips, which are similar to zinc strips. They work the same ways as the zinc strips do, releasing ions that inhibit moss growth when it rains.
Some homeowners choose copper over zinc strips because they are an attractive alternative. Lead strips are a little darker in color, so they may blend in with your shingle color more. However, you must handle them carefully due to their potential health hazards.
Proper Tree Maintenance
Overhanging tree branches can contribute to moss growth because they provide shade and drop debris onto your roof. You can trim tree branches back so that your roof dries faster after rain.
Moss-Resistant Shingles
Some manufacturers offer shingles that have zinc or copper granules, so moss prevention is built right in. They’re more expensive than other shingles, but they may pay off in the long term.
Chemical Treatments
Chemical treatments that kill and prevent moss are commercially available. Roofers spray the solution onto the roof, but they’ll have to reapply it periodically for continued moss protection.
If you are unsure which method to choose, a roofing professional can help. Remember that taking preventive steps can prolong your roof’s lifespan, so consider your options and make the right choice for your home and budget.