A sprinkling of moss on a cottage roof can look whimsical and charming. Despite its fairytale appearance, moss can actually do some serious damage to your roof. Moss absorbs moisture and takes root in your roofing. The moisture and the root infiltration can lead to rot and roof degradation, which can affect your roof structure and be expensive to fix.
So, if you do start seeing moss on your roof, it’s important that you take care of it as soon as possible. And that means some serious roof cleaning.
What do you need?
Removing moss from your roof is a fairly straightforward job, but you will need the right tools for the job. Here’s what you need:
- Garden hose with spray nozzle
- Garden pump sprayer or spray bottle
- Scrubbing brush
- Soft-bristle brush
Since you’ll be working on the roof and with potentially harmful chemicals, you should make sure you have the appropriate safety equipment including:
- Safety glasses
- Rubber gloves
- Non-slip footwear
- Comfortable work clothes (not so tight that they restrict movement but not so loose they could catch on anything)
- Choose your moss-remover Before getting anywhere near the roof, you need to find the right moss-remover. There are plenty of chemically based commercially available moss-removers available. You could even make your own from bleach, vinegar and lemon juice or baking soda. Whatever you choose, the moss-remover should not only kill the moss but create conditions that prevent any regrowth. For example, vinegar will make your roof more acidic, while baking soda will make it more alkaline. Suitably acidic or alkaline conditions will prevent moss from regrowing. However, it’s important to consider what the chemical solution will do to your roof. Acidic solutions can eat away at your roof surfaces, while other solutions may discolour roof tiles. You should also be aware of the environmental impact of your choice. Be aware that any chemical cleaning solution you use on your roof will get rinsed off through your gutters and into stormwater or onto your garden. Some of the harsher chemical solutions can kill plants, so you may need to protect nearby plants when hosing down the roof.
- Do the job on a cloudy day once
You have all your equipment, wait for a cloudy day. You need at least 20 minutes for the moss to absorb any chemicals. A sunny day could evaporate the chemicals before they’ve properly soaked in, which will reduce their effectiveness.
- Dress appropriately and stay safe Put on your protective gear (safety glasses and rubber gloves). If you can, make use of any safety equipment like safety harnesses or roof edge guards to minimise the risk of falling off the roof. Working with another person is a great way to stay safe as you won’t need to move as much or do as much climbing on and off the roof. Ensure you can easily and safely access the roof. If you’re using a ladder, ensure that it is stable on the ground and properly secured. You could also consider hiring a scaffold or a scissor lift for the job.
- Wet the mossUsing the hose, spray the roof, focusing on any mossy spots. Work from the top of the roof down so that any dirt, debris and loose moss runs off the roof.
- Scrub the affected areas Start with the scrubbing brush and then use the soft-bristle brush to remove as much moss as possible. Work in sections and use downward motions so you don’t break any tiles or shingles.
- Spray chemicals as needed Now is the time to use the moss-remover fully remove all remaining moss, kill the roots and ensure it doesn’t regrow. Following the instructions on the packaging, add the chemical solution (diluted as necessary) to a spray bottle or garden pump sprayer. Use the moss-remover as directed. Be prepared to let the moss-remover sit for a while to properly soak into the moss and the remaining roots.
- Rinse the roof When the moss-remover has had time to soak, use a hose to rinse away the chemicals so they don’t damage your roof. Don’t use a power washer for this job as it can chip tiles and shingles. Even if you didn’t use a moss-remover, rinse your roof to wash away the moss you scrubbed off. Otherwise, you might find it growing again.
- Repeat scrubbing as needed Sometimes, there may be stubborn patches of moss that have resisted your best efforts. Scrub at them again before rinsing once more.
- Stop the moss from coming back Once you’ve removed the moss from your roof, you want to minimise the chance of it growing back. The best way to do this is to minimise the build-up of moisture and plant matter on your roof. Regular roof cleaning and gutter cleaning is vital. You should also trim back any overhanging trees to reduce the amount of plant matter falling onto your roof.
You can also add zinc-coated metal flashing to your roof. When it rains, the zinc is released and washes over your roof. Since moss doesn’t grow in zinc-heavy environments, it’s a natural and easy way to prevent moss from growing.
Moss can add a touch of the fantastical to any home, just make sure it’s not on your roof. You can instead encourage it to grow on trees or rocks, or in a dedicated garden. If you want a green-roofed cottage, use green tiles instead. Moss quickly turns a fairytale into a nightmare if left alone on your roof.