Living in beautiful Donegal means we deal with plenty of Atlantic moisture. While great for our landscape, it’s the perfect breeding ground for red, green, and black algae to take over your home’s exterior.
At BioWash, we specialize in safely removing these stubborn stains, restoring your home to its original beauty without the need for aggressive, high-pressure washing that can damage your render.
The Transformation: Real Results in Donegal
Take a look at this recent project. You can see how the damp climate allowed heavy red algae to streak across the render and moss to colonize the guttering.
1. The Render Rescue
Red algae (often seen as those rusty-looking streaks) is a living organism, not just dirt. Using our specialized soft-wash treatment, we don’t just “blast” it off—we treat it at the root.

2. Gutter & Fascia Refresh
Gutters are often the most neglected part of a home’s exterior. Over time, “tiger stripes” and moss buildup can make even a clean house look weathered. Our process leaves plastics looking brand new.
Why choose BioWash? Unlike traditional power washing, our BioWash system uses low pressure combined with biodegradable cleaners. This ensures your render stays intact and the algae stays away longer.
Why is Algae a Problem for Donegal Homes?
-
Curb Appeal: It’s the first thing people notice when they pull into your driveway.
-
Property Value: A clean exterior suggests a well-maintained home.
-
Damage Prevention: If left untreated, certain organic growths can hold moisture against your walls, leading to long-term issues.
Ready to see your home look like this again?
We cover all of Donegal, from Letterkenny and Donegal Town to Inishowen and the West. Don’t spend thousands on a painter when a professional BioWash is often all you need to bring that “new build” shine back.
Click here to get a free, no-obligation quote today!
Frequently Asked Questions about Algae Removal in Donegal
Why does my house have red streaks on the walls?
The red streaks/staining you see are actually a type of algae called Trentepohlia. It thrives in the damp, mild climate of Donegal. It isn’t just “dirt”; it’s a living organism that feeds on the minerals in your render and moisture from the Atlantic air.
Is power washing safe for my home’s render?
We generally advise against high-pressure power washing on modern monocouche renders (like K-Rend, Sika etc.). High pressure is way too aggressive for these types of finished plasters, often leading to “wand marks,” scarring, or even water being forced into the structure of your home. At BioWash, we use a Soft-Wash approach that uses chemistry rather than brute force to kill the algae at the root.
How long does the cleaning last?
Because our process treats the algae biologically rather than just blasting the surface, the results typically last much longer than traditional washing—often up to 3-4 years longer. The biocidal treatment kills the root spores leaveing a residual protection on the surface that inhibits new growth.
Do I need to paint my house after the algae is removed?
In most cases, no! If you’re looking to change the colour of your property anyway, then your walls would still need to be cleaned to prevent flaking and bubbling.
Often we find that many of our Donegal clients think they need a full exterior paint job, which can cost thousands. Once we remove the red and green staining, the original color of the render is restored, saving you a significant amount of money and maintenance.
Is the BioWash process safe for my garden and pets?
Yes. We use professional-grade, biodegradable solutions. We take great care to protect surrounding vegetation and rinse everything thoroughly after the treatment to ensure your plants and pets remain safe.
Click here to get a free, no-obligation quote today!