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How To Remove Green And Red Algae From Walls

Few things are as unsightly on a wall surface as green algae and red algae staining. Whether you are concerned about the impression this appearance has on others, property value or potential health concerns, you need to manage and remove green algae quickly and effectively.

RenWash knows the cause of green and red algae staining, and more importantly, we know how to completely remove red algae stains from any wall surface. For a comprehensive walk through guide, and dependable service, rely on RenWash to cover the job.

What Causes Green And Red Algae To Grow?

There are several reasons algae may grow on buildings. Some of the main reasons include the following:

Moisture: Algae thrive in damp and humid conditions, so if walls are consistently moist or damp, red or green algae may grow. This can be due to high humidity levels, poor ventilation, or leaks that lead to water accumulating on wall render.

How To Remove Green And Red Algae From Walls

How Is Your Roof?

Roof runoffs or leaks from roof guttering can also combine with poor weather to get render wet, and this needs to be treated asap. We also offer roof cleaning service.

Weather Impacts Properties And Plants

Wind and rain make surfaces wet, and this fosters algae staining and the growth of organisms at your house or surface.

Nutrients: Algae also requires nutrients to grow, which can come from various sources. For example, if a building is located near a fertilised lawn, nutrients may be carried by the wind and deposited on the walls and render, providing a source of nutrients for the algae.

Similarly, if the building is located in an area with high levels of air pollution, the pollutants may provide nutrients for the algae to grow.

Light: Algae need light to photosynthesise and grow, so organic species may develop and form, if they receive sufficient sunlight. If your wall faces the sun, you might need treatment to manage growth and stains.

Porous Surfaces: Algae may also be more likely to grow on a porous surface, such as brick or concrete, which can retain water and nutrients. Smooth surfaces, such as metal or glass, may be less prone to algae growth because they provide fewer nutrients for the algae to thrive.

North facing walls or property in a coastal area or one which experiences a blend of rain and sunshine are susceptible to algae growth. Algae is useful in capturing carbon dioxide, but you don't want to see it on concrete walls.

Is Algae Growth A Problem?

Algae growth on the outside of buildings can be a problem for a few reasons, especially when left untreated for a few years.

Aesthetics: One of the main reasons algae growth on wall render can be a problem is that it can be unsightly. With green, red or black algae, slimy growth appears, which can be unattractive at first sight and may decrease the curb appeal and appearance of a property.

Damage To The Building: In some cases, algae leads to damage. For example, if the green or red algae grow in large enough quantities, they can retain moisture against the walls, leading to mould and rot. This can weaken properties and may lead to costly repairs.

Health Concerns: In some cases, green or red algae staining on the outside of a building raises health concerns. Certain algae can release toxins or allergens into the air, which can cause respiratory problems or allergic reactions in some people.

Green Algae On wall

How Does RenWash Remove Algae Growth?

As a professional cleaning company, we are pleased to say we offer a range of treatment solutions which tackle growth effectively, many of which use a low pressure solution, ideal for wall render or any outdoor surface.

You Can Remove Algae With A Jet Wash

While jetwash, pressure wash and power wash are often used interchangeably; some differences exist. Yes, all methods use pressurised water to clean, but the pressure level is different, and a jet wash utilises hot water.

Jet Wash

Heat Is An Effective Treatment On Spores

The higher temperature yet slightly lower pressure of the jetwash makes it the ideal solution on an exterior surface, which might be damaged by high pressure.

It would be best if you didn’t pressure wash a rendered wall, but with a jet wash, you can be confident of removing algae growth without damaging any surface.

The Doff Cleaning System Removes Organic Growth And Algae

The Doff cleaning system is steam based and primarily helpful in treating stone surfaces. This is another high-temperature solution, with water reaching 150 degrees at the nozzle end.

Again, the high temperature and lower pressure (compared to pressure wash) steam solution make the Doff system highly effective at removing biological matter and organic growth, like black algae.

Doff Cleaning

TORC Cleaning Is A Unique Way to Remove Green And Red Algae Stains

The TORC system takes a different approach to cleaning. Here, little water is used and, in relative terms, low air pressure. The use of inert fine granulate in the swirling vortex creates a process that is gentle on but harsh on unwanted substances.

TORC Cleaning

Soft Wash Approach Kills Algae On A Surface

The soft wash method is recognised as highly effective in dealing with moss and algae residue on buildings. When soft washing, you don’t use a high-pressure solution, which minimises the likelihood of damaging a surface. You can also check out our post on what is soft wash render cleaning.

Also, soft wash doesn’t just remove algae or mould; it kills it. Soft wash provides longer-term benefits, hopefully reducing the need to clean your render regularly.

Soft Wash

Get Help In Clearing Remaining Algae From Your Surface Or Property

These cleaning approaches are highly effective at removing algae from render, and we can help you decide which is most appropriate for you. At RenWash, we have skilled and experienced professionals trained in using specialist cleaning equipment.

We also have access to the best equipment, PPE clothing, and if we require additional equipment, such as scaffolding, we will arrange this.

Are There Other Methods To Remove Green Or Red Algae From Walls?

People can use several methods to remove red or green algae from a building. Some of the most common ways include:

Pressure Washing: A commonly cited cleaning method for removing algae from a building or render such as K rend is to use a pressure washer. This involves using a machine that sprays a high-pressure stream of water to blast away the algae growth.

Pressure Washing

Scraping: If the algae growth is not too thick, removing it by simply scraping it off with a scraper or a stiff-bristled brush may be possible.

Chemical Cleaners: Specialised chemical cleaners are designed to kill and clear algae from surfaces. These cleaners are typically applied and left to sit for some time before being washed off. Some common chemical cleaners include chlorine bleach and algaecides. Check out our guide on cleaning render with bleach.

Chemical Cleaners

Natural Solutions: If you prefer to use more natural methods in removing green and red algae from a building, there are several natural solutions that you can try. For example, layers of water and vinegar work, as can a mixture of water and baking soda.

Watch You Don't Damage Your Render

There are concerns with all these solutions. A pressure wash can damage your render; scraping can be very time-consuming, chemical cleaners are harsh on the environment and surrounding ground, plants, tree bark or soil while natural solutions are often ineffective against spores.

Therefore, it is best to rely on the commercial algae growth services provided by RenWash.

We Are Algae Removal Specialists From Every Surface

Whether you are blighted by deep green or red algae stains, your wall render deserves a clean finish. RenWash provides soft wash, TORC, Doff and jetwash treatment and solutions that many professionals cannot offer, so contact us today for this essential job.


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