So, you’ve just glanced at your house and done a double take. That strange reddish tint creeping across your walls wasn’t there last summer. Is it dirt? Is it paint gone wrong? Sadly not. What you’re seeing is red algae, and if it’s appeared on your home, you’re not alone in wondering how to remove red algae from house walls. Across Ireland, more and more homeowners are dealing with this stubborn invader and wondering how to remove red algae from houses. In this blog, we’ll explain what causes it, how to remove red algae from house surfaces the right way, and how to stop it from ever coming back.

The Science Behind The Stain

Red algae, known scientifically as Trentepohlia, is a type of airborne algae that thrives in humid and damp climates. Sound familiar? Ireland’s soft rain and lush greenery might be a dream for nature lovers, but it’s also a paradise for algae spores. These little blighters float through the air until they find the perfect landing spot, which usually ends up being your north-facing wall or anywhere that tends to stay in the shade. Once settled, they cling to the surface and spread quickly, leaving that tell-tale pinkish-red smear across your exterior.

Now, red algae doesn’t eat into your bricks or damage your structure directly. But it does hold moisture on the surface of your home, and where there’s moisture, there’s trouble. From crumbling render to damp patches and discolouration, red algae is more than just an eyesore.

Common Causes And Why Ireland Is A Hotspot

Red algae is particularly common here in Ireland thanks to our damp climate and long periods of overcast skies. Shade loving red algae like Trentepholia thrive in spots that rarely see direct sunlight. If your walls are bare and uncoated, they can absorb water like a sponge, giving algae exactly what it needs to grow. Even a leaky gutter or cracked downpipe can create the ideal conditions for red algae to take hold and flourish. Once it starts, it doesn’t stop unless it’s properly treated.

How To Remove Red Algae From House Surfaces

This is where things get serious. Trying to blast red algae off with a pressure washer might seem like a good idea, but it’s usually more harm than help. You could end up damaging your render or simply spreading the spores around, inviting the algae to return for round two. Bleach and off the shelf solutions are equally ineffective and often unsafe.

At UEH Ireland, we use Benz Softwash to remove red algae from house surfaces, which is fully approved for use in Ireland and considered the best product on the market for red algae removal. It doesn’t just clean the surface. It kills the spores at their root, stopping future growth before it starts. Once we’ve cleaned and rinsed the affected area, we let it dry thoroughly before moving on to the most important part of the process.

The Best Defence Is A Good Coating

Cleaning removes the red algae, but if you don’t seal and protect the surface, it will be back faster than you can say another rainy Tuesday. This is where ProPERLA comes into play. This isn’t just paint. ProPERLA coatings are super hydrophobic, which means rainwater simply runs off the surface, taking any di:30rt and potential algae spores with it. The surface stays dry, which is the last thing red algae wants. It’s also breathable, so any moisture trapped inside your walls can escape, reducing the risk of damp issues down the line. And thanks to its self cleaning properties, your home stays looking fresh without constant upkeep.

For extra peace of mind, ProPERLA comes with a 10 year warranty for all colour coatings on roofs and walls, a 10 year warranty for clear coatings on roofs, and a 20 year warranty on clear coatings for walls.

Don’t Forget The Roof

While this blog focuses on how to remove red algae from house walls, let’s not ignore what’s going on above your head. Moss, algae and lichen love roof tiles just as much. Our team also specialise in roof cleaning, roof moss removal and protective ProPERLA roof coatings to complete the job. If it’s green, red, slimy or furry, we know how to sort it. If you’re looking for a roof coating specialist in Ireland, you’ve found the right people.

Ready To Remove Red Algae From House Surfaces For Good?

If your home is showing signs of red algae, now is the time to act. At UEH Ireland, we don’t just clean your walls and remove red algae from houses. We protect them for years to come. Our expert red algae removal service, combined with industry leading ProPERLA coatings, means your home stays clean, dry and looking its best no matter what the Irish weather throws at it.

Get in touch today to arrange your free survey and no obligation quote. We cover the whole of Ireland, and as the only ProPERLA Platinum Approved Applicator in the country, you can trust us to treat your home like it’s our own.

Let’s remove red algae from house surfaces and bring your home back to being brilliant.