How Big a Problem is Moss on Roof Tiles?

If your roof is consistently exposed to moisture, it may soon be covered in moss. And while a light layer of moss on the roof may give it a charming, rustic look, it is actually a matter of serious concern.

The “moss” that grows on a roof is likely a combination of three organisms: moss, algae, and lichen. Moss is a flowerless organism that grows in clumps on nearly all surfaces, except underwater. Algae is similar, with the distinction that it can grow underwater. Lichen, meanwhile, grows from a combination of fungus and algae.

These three organisms thrive in nature by absorbing water, which helps prevent soil erosion. However, moss growing on roof tiles can cause severe damage to the structure and leave you with high repair costs.

Here’s everything you need to know about moss on the roof.

What Causes Moss To Grow on a Roof?

Moss propagates through spores that spread by wind. This is why it can grow almost anywhere.

The organism grows best in damp and cool areas. When roof shingles are shaded by trees or do not receive sufficient sunlight for any reason, leftover moisture cannot evaporate. This leads to moss growing on roof tiles.

Debris that has been left unchecked could also be a cause. In some cases, moss can grow under roof tiles and shingles, making it difficult to detect until it’s too late.

What Causes Moss To Grow on a Roof

How Moss Damages Roofs

Moss on roof tiles is dangerous for the same reason it is beneficial in forests: it’s very absorbent.

When moisture collects due to moss growing on roof shingles, the sturdy material will begin to soften. Left unchecked, tiles will eventually rot and become more vulnerable to the elements. They will also become more susceptible to leaks.

Once water begins to trickle into the base of your ceiling, it can cause discoloration and, in some cases, mold. This is alarming because while moss on the roof is mostly harmless to humans, mold can lead to a host of respiratory issues.

Moss on shingles can also lead them to rise and get bent out of shape. This allows more water to seep in, leaving all types of roofing materials at risk and significantly reducing your roof lifespan.

In the worst case, unchecked moss on roof tiles can lead to your roof collapsing.

If you notice large patches of moss, it may be the best time to replace a roof entirely.

How To Get Rid of Moss on Roofs

When detected early, there are some easy ways to get rid of moss growing on your roof:

Manually Scrub or Wash it Off

If only a thin layer of moss is on the roof, it can be washed off with a hose or gently scraped off with a long-handled brush.

However, moss grows back quickly, so you must make sure to remove every bit of it.

Manually Scrub or Wash it Off

Invest in a Moss Cleaning Solution

If the moss growing on roof tiles is too thick to be washed off, you can use a moss cleaning solution. Available at most DIY shops, these detergents are an efficient way to get rid of moss on roof shingles. These fast-acting solutions also ensure that moss doesn’t grow back.

Note that moss detergent can damage plants and lead to discoloration on the roof. Put down a protective sheet before you start spraying.

Some solutions should be washed off quickly, while others should be left to evaporate. Read the manufacturer’s instructions carefully and follow them closely.

Install Moss-Resistant Roofing Materials

Companies that offer roof installation services suggest adding a thin copper or zinc sheet on the roof. Both materials are toxic to moss and can prevent its growth.

Copper is a more effective deterrent, but zinc is a more cost-effective solution.

What You Shouldn’t Do

If moss on the roof is starting to cause serious structural damage, it is best to contact a professional. But if you’re committed to doing it yourself, there are some things you should avoid for the sake of your roof.

  • Excessive scrubbing can cause more damage to the structure, so take great care when manually removing moss on roof tiles.
  • Using too much water pressure could also damage a roof. It may remove moss on the roof but cause much of the same issues that the organism causes in the first place.
  • Avoid using excessive bleach or detergents with harsh chemicals. They may lead to discoloration on your roof and damage to shingles and tiles.

If you carefully remove moss on roof tiles, you may not need the aid of a professional roofer.

What to Avoid While Cleaning Moss from the Roof

Prevention Is Better Than Cure

The best way to avoid the damage caused by moss on the roof is to prevent its growth.

Regularly trim tree branches and remove other structures that block sunlight from your roof. With no lingering moisture, it’s unlikely that moss will grow.

Regular maintenance is another way to avoid moss growing on roof tiles. Keeping your roof and gutter system clean, especially after heavy rainfall, could go a long way in preventing damage.

How AMECO Can Help

If you need professional assistance to deal with moss on shingles, or are interested in learning more about the residential roof installation process, look no further than AMECO.

With our reliable service, years of experience, and additional features like a roofing cost calculator, we’re happy to assist you with all your roofing-related needs.