How to Remove Lichen From Roof Tiles and Outdoor Surfaces

There’s nothing to like about lichen- especially when it invades on your home’s outdoor surfaces.

This ugly growth spreads across roofs, walls, and sidewalks with strands or “fingers” holding on with a powerful grip.

Here’s the lowdown on lichen and how to kick it to the curb with Wet & Forget Outdoor.

What is lichen?

Lichen is a combination of algae and fungus.

Roofs, pavers, rock walls, gravestones, and sidewalks are popular areas where lichen can be found. Although, they can be found on virtually any outdoor surface.

Lichen is an invasive organism and may appear on surfaces as tiny, shrubby branches (fruticose) leafy structures (foliose), or in crusty patches (crustose). Lichens thrive on a combination of sunlight, carbon dioxide, water, and minerals.

What are the most common types of lichen?

One of the most common types of lichen is made up of single-celled green algae (Trebouxia). This type of lichen can be found growing worldwide in temperate, alpine, and arctic regions worldwide.

Lichen can grow in a wide range of temperatures and conditions; from the hottest desert to the coldest arctic tundra.

What does lichen look like?

Lichens come in multiple shapes, sizes, and forms including shrubby, leaf-like, or crusty. It may appear as an orange crust on a rock wall, or as mint green patches on a roof.

Lichen can be seen in a variety of colors including blue-green, gray, brown, and yellow.

Is it harmful? Should I remove it?

While lichen may appear to be harmless it can cause significant damage to outdoor surfaces over time.  This can shorten the life of your roof or other outdoor surfaces.

This surface moisture may freeze in cold weather and cause frost damage to asphalt shingles or other surfaces. Lichen holds moisture against the surface thus speeding up the wear and tear. So over time, your roof shingles may bend and warp.

The lichen can also penetrate your roof’s exterior causing the shingles to separate and spell disaster for your roof!

Another reason to remove lichen growth is your homeowner’s insurance rates may increase. Your insurance company may send out an inspector to drive by your home to observe any changes.

If the inspector sees a dirty, lichen-covered roof, this may give them a reason to raise your rates or even cancel your policy because lichen can cause serious damage over time.

Fortunately, it can easily be removed with Wet & Forget Outdoor.

How do I get rid of lichen?

The problem with scraping, sweeping, and raking

Removing lichen with a brush, broom or scraper is one common way to remove it. Unfortunately, removing lichen this way is very time and labor-intensive.

Lichen can be really tricky to remove because it grips strongly onto the surface. So if you attempt to remove it with a hand tool, you may accidentally remove the protective top layer of your roof shingles as well.

Using metal strips

Lichen avoids galvanized steel, copper, and zinc because these metals work as a natural biocide. Adding metal strips along your roof’s ridge line may inhibit lichen growth.

When rainwater moistens the strips a tiny amount of metal will run down on your roof preventing the lichen from grabbing hold. Unfortunately, copper and zinc dripping from your roof is bad for the environment.

The runoff will find its way into streams and ponds where it is toxic to fish and other wildlife. Metal-infused rainwater is also unsuitable for landscape use.

Chlorine bleach

Although it’s an inexpensive option to remove lichen from your roof, the end result may corrode downspouts, gutters, and flashings. True to its name, chlorine bleach may “bleach” your asphalt shingles, lightening or changing the color.

Bleach solution that drips from your roof during or after application can kill landscape plants and ruin outdoor fabrics. You may need to wear protective clothing when applying bleach as the solution can burn the skin.

The bottom line is bleach can be hazardous to people and the environment.

Pressure-washing

Since pressure-washing can degrade your roof’s protective coating, it is not a recommended method for removing lichen.

It can also compromise the seals around windows and doors and damage skylights and roof windows. Also, mold growth can occur underneath your home’s siding and get into the inner walls from a forced water source.

Keep in mind- some shingle manufacturers will void the warranty on their products if they discover that you have subjected your roof to high-pressure washing. So, be sure to reach out to your shingle manufacturer before treating your roof.

Why is Wet & Forget Outdoor the Best Way to Remove Lichen?

Wet & Forget Outdoor’s gentle, eco-friendly formula kills lichen without damaging your outdoor surfaces. It does so by working with the wind and rain to remove the unsightly lichen.

And Wet & Forget Outdoor keeps on working to keep outdoor surfaces clean and lichen-free for months!

Two applications of Wet & Forget are required to thoroughly treat and eliminate lichen.

How to Apply Wet & Forget Outdoor

1. Make sure no rain is in the forecast that day.
2. Dilute 1 part Wet & Forget Outdoor to 5 parts water in a pump-up garden sprayer.
3. Once diluted, thoroughly saturate the lichen or moss-covered surface.
4. Then wait 15 minutes before repeating step 2.
5. After the second application, allow the surface to dry for 4 to 5 hours.

To make one gallon of the solution:

Begin by adding 2 1/2 cups (20 oz.) of Wet & Forget Outdoor to your garden sprayer. Then, add water to your garden sprayer until the one-gallon mark.

To make two gallons of the solution:

Start by adding 5 cups (40 oz.) of Wet & Forget Outdoor to your garden sprayer. Then, add water to your garden sprayer until the two-gallon mark.

Listen to this unsolicited testimonial from Dave L. that was left on Wet & Forget’s corporate voicemail:

HINTS AND TIPS

Surface Preparation

For best results apply Wet & Forget Outdoor to a dry surface.

Before spraying the surface, remove any loose debris. Completely saturate the surface with Wet & Forget Outdoor to penetrate the growth.

Ideal Temperatures for Application

During the application process, check to make sure that the temperature is above 32°F (0°C) for the best results.

Then, allow it to dry for 4 to 5 hours after the application.

Ideal Weather

For best results apply Wet & Forget Outdoor on a cool, dry day. Early morning or later in the evening are the most ideal times to apply Wet & Forget Outdoor.

This will ensure that the surface will remain wet for an extended period of time and allow it the optimum time to do its job.

Future Maintenance

When the stains and growth have finally disappeared, use Wet & Forget Outdoor as a routine maintenance tool to keep your surfaces clean and lichen-free. In the future, apply it annually or if the growth reemerges to keep the stains away.

Cleaning Vertical or Covered Surfaces

Vertical surfaces or surfaces without exposure to natural elements like covered porches and headstones may require some assistance with a hose or a scrub brush. If the area is heavily stained, a yearly application of Wet & Forget Outdoor will keep surfaces clean.

Eliminating lichen is easy with Wet & Forget Outdoor. Plus, there is no hand raking or scaping required.

Don’t let the disgustingly dirty outdoor surface ruin your summer day.

Wet & Forget Outdoor will make your outdoor living areas shine like new!