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How to Easily Remove Lichen on Outdoor Surfaces

By Wet & Forget
Remove lichen on your wood deck

Lichen grows on many exterior surfaces including sidewalks, decking, pavers, siding, and even outdoor furniture. Lichen can be especially damaging to roofs, so it’s important that it’s treated properly to avoid any costly damage.

Keep reading to learn more about how lichen grows on outdoor surfaces, and what you can do to easily remove lichen!

What is lichen and how does it grow?

Lichen is an invasive organism, formed by a partnership of fungus and algae that live together. Fungus is the main component of lichen, and the fungus relies on algae to produce nutrients that allow it to spread and develop.

Lichen requires sunlight, water, air, and nutrients in order to grow.

How can I tell if lichen is growing on a surface and what does it look like?

Learn how to remove lichen on stone

Lichen can appear in a variety of shapes and sizes. They can be seen in a wide array of colors including; blue, green, yellow, orange, red, brown, black, gray, and white.

The three main types of lichen are foliose, fruticose, and crustose. Foliose lichens have two distinct, top and bottom sides. They can be flat, leafy, or ridged.

Fruticose lichens can be shaped like coral or shrubs, with round or flat branches. Some fruticose lichen structures are hollow at the center, while others grow out from their core.

Crustose lichens are patches that form a type of crust over a surface.

Click here to learn more about the different types of lichen and where it grows.

How does lichen harm surfaces?

When left untreated, lichen can cause permanent damage to outdoor surfaces over time. In addition to the unsightly growth, it can cause pitting on exterior surfaces, which often leads to leaks and expensive repairs.

Roofs are especially susceptible to the growth and can be significantly damaged by lichen.

Lichen holds moisture in place against surfaces, which speeds up normal wear and tear. When this surface moisture freezes in cold temperatures, it can lead to frost damage to roof shingles and other exterior surfaces.

This can cause your roof shingles to bend, warp, and even separate from each other over time. If the lichen causes damage to your roof, it may cause the expected life of your roof to be dramatically shortened, and your roof might need to be replaced sooner.

Another good reason to remove lichen is because your homeowner’s insurance rates could increase if it’s left untreated. Your insurance company can send out inspectors to drive by your home and note if there are any changes.

If the inspector sees that your roof is covered in lichen, it could give them a reason to raise your rates or even cancel your policy. Your insurance agency might ask you to clean the lichen because it can cause serious damage to your home over time.

How can I remove lichen safely?

Remove lichen on your roof

Lichen and green moss growth on a slate roof.

Lichen can be a tough growth to remove due to the symbiotic relationship between the fungus and algae. Many people try to remove lichen by brushing and scraping it off with abrasive tools.

While this is a popular approach, a great deal of time and work must be put in to remove lichen this way. Removing lichen fully using this method is nearly impossible, not to mention time-consuming, especially if you are dealing with a large surface like a roof.

You also risk the potential of accidentally damaging the protective top layer of your roof shingles while trying to remove it with this method.

Lichen is a hardy growth known to firmly attach to surfaces with a tough grip. Lichen has a crusty almost concrete-like texture, making it hard to remove from outdoor surfaces.

Even if you successfully remove most of it by hand, there may still be leftover growth on the surface that is not visible to the eye. The remaining growth can cause the lichen to grow back easily.

The good news is, lichen can be easily removed with Wet & Forget Outdoor. It’s a gentle outdoor cleaner that is formulated without harsh chemicals. Wet & Forget is a safe roof cleaner that will remove lichen without any scrubbing or scraping.

Wet & Forget Outdoor can also be used to remove lichen from the trunks of trees. We advise applying the Wet & Forget when the tree is in its dormant state, which is late fall.

You can even extend the life of your outdoor surfaces by properly removing lichen with Wet & Forget. Typically customers don’t see lichen regrowth for up to a year.

In the Midwest, many customers won’t see regrowth for up to 3 years!

Two applications of Wet & Forget Outdoor are needed to treat and eliminate lichen adequately. Once applied, the Wet & Forget starts to work on the surface and then over time will remove the dead lichen with exposure to the wind and rain.

To apply, thoroughly saturate the surface with the Wet & Forget Outdoor Cleaner. Wait 15 minutes and then repeat the application a second time.

The lichen’s outer shell will soften after the first application so the Wet & Forget can go through the inner layer during the second application. Ensure complete saturation each time, as this will allow the product to deeply penetrate the lichen growth.

If you have lichen growing on your roof, siding, or decking clean it easily with Wet & Forget Hose End. You can apply Wet & Forget with your feet firmly planted on the ground.

The jet tip nozzle allows you to reach surfaces up to 30′, so you don’t need to use a ladder to climb up onto your roof. The new Wet & Forget Rapid Application Hose End bottle makes it easy to apply to hard-to-reach areas and high elevations.

If you’re starting to see lichen growing on your fencing or walkways, we recommend using the Wet & Forget Concentrate for a precise application. For smaller surfaces with lichen growth, such as steps, a mailbox, or the trunk of a tree, we recommend using Wet & Forget Ready-To-Use.

Click here to check out one of our customer’s testimonials about how he used Wet & Forget to remove lichen that was growing on his roof.

Application Tips

Apply Wet & Forget on a cool, overcast day to avoid any chance of the product drying too quickly on the surface. When using Wet & Forget Hose End, outdoor temperatures should be above 55°F during the application and for the next 4 to 5 hours while the product dries.

When applying Wet & Forget Concentrate or Wet & Forget Ready-To-Use, temperatures need to be above 32°F.  It’s best to spray lichen on a day that’s not too sunny, to prevent the product from evaporating.

Cooler temperatures ensure that the surface remains wet, and this gives the product optimum time to do its job.  It’s important to allow Wet & Forget to have enough time to work on the surface to effectively remove the lichen.

For more helpful hints on applying Wet & Forget Outdoor, watch the video below.

After the lichen has disappeared, you can use Wet & Forget as maintenance to keep your outdoor surfaces clean and lichen-free. Reapply the product on a yearly basis or at the first sign of new growth.

Don’t waste any more time trying to get rid of lichen! Wet & Forget does the hard work for you, so you can and get back to doing the things you love!

Click here to read more about lichen and how to remove it from your outdoor surfaces with Wet & Forget Outdoor.

Click here to buy Wet & Forget today, or click here to find it at a store near you.

Trying to remove the lichen from your roof or outdoor surface? Well, look no further! Check out this article on how to do just that.