Washing roofs: A guide to a clean and sustainable roof
Keeping your roof clean is an important part of roof maintenance to prevent damage from moss, algae and dirt. In this guide, we look at why roof cleaning is important, when it should be done, how to prepare and what steps are needed to do the job right.
Why should you wash your roof?
Above all, it's nice to have a clean façade, but roof cleaning is not just a matter of aesthetics - it plays a key role in keeping the roof in good condition. If dirt and various coatings get a foothold, they can contribute to moisture problems, frost cracking and, in the worst case, costly repairs.
Extend the life of your roof
Roofing materials such as tiles or tin roofs are designed to last for many years, but if they are not maintained and cleaned from time to time, their lifespan will be significantly shortened. Moss and algae growth retains moisture which can lead to frost cracking or corrosion.
Avoid moss, algae and dirt
A clean roof is a healthy roof. As you probably know, moss and algae thrive on damp surfaces and can quickly spread on the roof if not dealt with in time. In addition, organisms can block water run-off, increasing the risk of leaks and damage to the roof surface.
When is the best time to wash the roof?
It is best to wash the roof during spring, summer and late summer when the weather is milder, i.e. between April and September. Choose a sunny, windless day when the air temperature is around 15°C. On the other hand, if you have a plastered façade, it is an advantage to wash the roof on rainy days. Dirt will run down and stick to the façade, and in warm and sunny weather the dirt may dry and become more difficult to remove.
Checklist: Preparing before you start
- Repairing any damage: Inspect the surface to see if there is any damage that needs to be repaired before you start washing the roof.
- Clear the gutters: If the gutters are filled with leaves, dirt and other debris when you wash the roof, they can become blocked, causing water build-up and possible damage.
- Think about safety: When you are going to wash the roof, it is important to consider whether you need to use a harness with a safety line, non-slip shoes or other safety measures. Don't forget to inform someone close to you that you are going up on the roof, so they can keep an eye out.
- Gather the right equipment: You will need a soft brush, a pressurised sprayer or hose and the right cleaning agent. Never use a pressure washer as it can damage the roof surface.
How to do it: Customise your roof wash by roof type
As different materials are differently sensitive to wear, different roof types naturally require different cleaning methods. That's why we're going to walk you through the process of cleaning roof tiles, tin roofs and felt roofs.
How to wash roof tiles
- Remove loose dirt: Start by gently sweeping away leaves, twigs and loose moss with a soft broom.
- Applying cleaning products: There are different methods of applying roof cleaning to roof tiles. Some agents can be applied directly through the garden hose with an ejector, while others require mixing and application with a pressurised sprayer.
- Leave the product to work: From here, all you have to do is wait. Let the cleaner work and break down the algae and moss, then rinse it off the next time it rains.
How to wash tin roofs
- Clean gently: Use a soft brush or sponge and a mild detergent to clean. Avoid pressure washing as the high pressure can damage the surface.
- Rinse thoroughly: Use a garden hose or low-pressure sprayer to rinse away dirt and detergent residues.
- Treating fouling: If there is moss or algae, you can treat the roof surface with a special roof cleaner according to the manufacturer's instructions.
How to wash cardboard roofs
- Remove surface dirt: Use a soft brush to gently remove leaves and other loose dirt.
- Applying specialised products: Cardboard roofs require extra careful handling, as the surface can be easily damaged. Spray a mild anti-algae agent evenly over the roof surface using a low pressure sprayer.
- Let nature do the work: You don't need to rinse off after you've finished washing - it's enough to let the agent work and then be washed away by the rain.
Common mistakes to avoid
Pressure washing on sensitive roofs
Many people think that pressure washing is a time-efficient way to clean the roof, but the powerful jet of water can cause serious damage. The protective coating can be worn away, leaving the roof more vulnerable to moisture ingress, cracking and the growth of moss and algae. In the worst case, water can penetrate under the roof tiles and lead to moisture damage in the suspended ceiling.
Washing the roof too often
Washing your roof too often can do more harm than good. It can wear down the roof's surface and shorten the life of the roofing material. However, how often you need to clean varies. For example, a roof close to the forest or water may need to be cleaned more often than a roof in a more open environment, but generally every two to three years is sufficient.
Lack of safety in work at height
One of the most common mistakes is not working safely. Many accidents occur due to relying on unstable ladders or climbing on the roof without adequate support. Therefore, you should always wear non-slip shoes, make sure the ladder is stable and avoid working alone if possible. In some cases, you may also need a harness and safety line.
Eco-friendly product ranges for roof washing
Do you want to offer your customers a range of roof cleaning products? In addition to our wide range of existing cleaning products, we offer a private label-This is the perfect solution for those who want to sell roof washing products under their own brand - perfect if you want a range of sustainable alternatives. Get in touch to start your journey with us today.