If your roof is covered with spots of green fuzz, it's time to take action. Roof moss is bad news, and the longer it stays in place, the worse the problems will be in the long term.
So, how do you clean moss from your roof?
There are several methods, and we'll explore some of these in detail. The main point to remember is that your safety is paramount. Whether you're working on a bungalow or a three-storey building, any falls can cause serious injury and can even be fatal, according to the working-at-height regulations.
With this in mind, here are some DIY solutions for removing moss from your roof...
Manual Removal
Manual removal involves physically scraping or brushing the moss off your roof.
Materials Needed
Stiff brush or scraper
Broom
Ladder
Safety harness or roof ladder (if necessary)
Protective gloves
Tarp or plastic sheeting
Steps
Safety First - Use a stable ladder and, if needed, a safety harness or roof ladder. Working on a roof can be dangerous, so take all necessary precautions.
Inspect the Roof - Before starting, check the condition of your roof tiles. Avoid areas that appear damaged or fragile.
Start Scraping - Begin at the top of the roof and work your way down. Brush off any loose moss with a broom. Next, use a stiff brush or scraper to gently remove the moss. Scrape in a downward motion to avoid lifting the tiles.
Collect the Debris - As you remove the moss, collect it in a bucket or let it fall to a tarpaulin or plastic sheet on the ground. This makes clean-up easier and prevents the moss from clogging your gutters.
Check for Damage - After removing the moss, inspect the roof for any signs of damage. If you notice any cracked or missing tiles, consider repairing them promptly.
Rinse the Roof (optional) – You may want to run a garden hose over the surface to remove any debris, but do this with care!
Clean the Gutters - After you’ve finished, check your gutters for any loose moss and remove it to ensure proper drainage.
Pressure washing can quickly and effectively remove moss from your roof, but it requires care to avoid damaging the tiles.
Materials Needed
Pressure washer (with a suitable spray nozzle)
Ladder
Safety harness or roof ladder
Protective gear: rubber gloves and eyewear
Steps
Prepare the Area - Ensure your pressure washer is set up safely. Remove any obstacles around your roof, and cover nearby plants or outdoor furniture that could be affected by the spray.
Safety Check - As with manual removal, ensure you have a stable ladder and safety rope/ harness if needed. Wear protective gloves and safety glasses to shield yourself from debris.
Set the Pressure - Adjust the pressure to a low to medium setting. Too much pressure can damage your roof tiles, especially if they are old or brittle.
Test a Small Area - Start by testing a small, inconspicuous area of the roof to ensure the pressure setting isn’t too strong.
Start Washing - Begin at the top of the roof and work your way downwards. Hold the nozzle at a 45-degree angle to avoid lifting the tiles. Move the spray in even strokes, making sure to cover all areas affected by moss.
Rinse and Clean Up - After removing the moss, rinse the roof with clean water to remove any remaining debris. Once finished, check and clean your gutters to prevent blockages.
Chemical Treatment
Chemical treatments involve applying a moss-killing solution to your roof, which gradually kills the moss over time.
Materials Needed
Moss killer or biocide
Large spray bottle or applicator
Ladder
Safety harness or roof ladder
Protective gloves, eyewear, and mask
Steps
Safety First - As always, ensure your ladder is stable, and use a safety harness if necessary. Wear protective gloves, eyewear, and a mask to protect yourself from the chemicals.
Choose the Right Product - Select a moss remover or biocide specifically designed for roof use. Read the manufacturer’s instructions carefully before applying.
Prepare the Solution - If required, mix the moss killer with water in a garden sprayer according to the product’s instructions.
Apply the Treatment - Starting from the top of the roof, spray the chemical solution evenly over the mossy areas. Be sure to cover all affected sections. Avoid applying too much, as this can lead to runoff.
Wait for Results - Most chemical treatments take a few weeks to work. The dead moss will gradually turn brown and die, eventually washing away with rain or being easily brushed off.
Rinse and Repeat (if necessary) - After the moss has died, you can rinse the roof with clean water or wait for the next rain to wash it away. For heavily infested areas, a second treatment may be needed to remove any remaining moss.
Check and Clean Gutters - After treatment, check your gutters for any moss that may have washed down and clean them out to prevent blockages.
Final Tips
Regular Maintenance - To keep your roof moss-free, consider a regular maintenance schedule, such as yearly inspections and professional cleaning. Organic debris will encourage moss growth, so it's important to keep the roof and gutters clean.
Metal Strips - Installing copper or zinc strips can help prevent future moss growth from returning after cleaning.
Professional Help - If your roof is large, steep, or in poor condition, it may be safer and more effective to hire a professional moss removal service.
Don't use Chlorine Bleach - This can create toxic fumes, especially if mixed with other cleaning solutions that contain ammonia. It's also harmful to the local environment and may damage shingles and tiles.
We've looked at a few DIY moss removal solutions, so now let's look at why this is necessary.
Moisture Retention
Moss thrives in damp, shaded environments, and it tends to retain moisture. When moss grows on your roof, it holds water against the roof's surface, preventing the roof tiles or shingles from drying out properly. Over time, this constant exposure to moisture can lead to the deterioration of roofing materials. In particular, it can cause tiles to crack, warp, or become dislodged, compromising the integrity of your roof.
This is worsened by the freeze-thaw cycle, where the moisture freezes and expands, then thaws again, forcing the cracks ever wider.
Damage To Roof Tiles
As moss grows, its roots can work their way into the small gaps and crevices in roofing materials. This not only weakens the tiles or shingles but also makes them more prone to being lifted or displaced by wind. Once the protective layer of your roof is breached, water can seep underneath, leading to leaks and further damage.
Structural Damage
If moss is allowed to grow unchecked, it can eventually damage your roof structure. The prolonged moisture exposure can lead to rot in wooden structures, such as rafters and beams, weakening the overall stability of your roof. In extreme cases, this can result in costly repairs or even the need for a complete roof replacement.
Blocked Gutters And Drainage
Moss can break away from the roof and accumulate in gutters and drainage systems, leading to blockages. Blocked gutters prevent rainwater from draining away properly, causing it to overflow and potentially damage the exterior walls, foundations, and even the interior of your home. Additionally, water that is unable to drain away can pool on the roof, exacerbating the moisture problems and increasing the risk of leaks.
Encouraging The Growth Of Other Plants
Moss on your roof can create a fertile environment for other plants, such as algae, lichen, and even small weeds. These can further damage your roof by growing into the tiles and causing them to crack or shift. The presence of other plants can also accelerate the spread of moss, creating a cycle of damage that becomes increasingly difficult to control.
Reduced Roof Lifespan
The combination of moisture retention, physical damage, and structural weakening all contribute to a reduced lifespan for your roof. What might start as a small patch of moss can, over time, lead to the need for significant repairs or even an entire roof replacement far sooner than would otherwise be necessary.
In summary, while moss growth might seem harmless at first glance, its presence on your roof can lead to a host of problems that compromise the safety, durability, and appearance of your home. Regular maintenance and timely removal of moss are essential to protect your roof and extend its lifespan.
Certain types of roofs are more susceptible to moss growth due to their materials, location, and environmental conditions. Here are the roofs most likely to be affected by moss:
Asphalt Shingles - The rough surface of asphalt roof shingles can easily trap moisture and dirt, creating a perfect breeding ground for moss.
Clay or Concrete Tiles - These materials are porous, allowing them to absorb moisture more readily, which can lead to moss growth.
Wood Shingles - Wood naturally retains moisture and provides a textured surface where moss can easily take hold.
Is A Moss-Covered Roof Really That Bad?
As professional cleaners with many years of experience, the WM Wash team has witnessed first-hand the damage that moss can do to a roof!
Surprisingly, some people dismiss the seriousness of the problem. They claim that roof moss removal is, essentially, a scam targeting vulnerable or unsuspecting clients, and that moss removal is not necessary. They also imply that applying protective coatings (roof spraying) is ineffective and unnecessary.
In our professional opinion, this is both irresponsible and untrue.
The fact is that the problems mentioned above are very real. If you do not remove moss from your roof tiles, they will eventually succumb to damage and require repairs or replacement. While all roofs have a limited lifespan, roof moss speeds up the process by attacking the surface and causing a great deal of damage.
However, killing roof moss for good is near impossible, and often requires professional help.
While it's possible to follow the methods above, when you need a helping hand with your moss problem, the WM Wash team is happy to step in! We'll use our roof cleaning expertise to eradicate moss from your roof, then apply measures to prevent moss from growing in the future.
It's the perfect way to prolong the lifespan of your roof and keep it looking fresh.
