If you’ve noticed green buildup on your siding, especially on one side of your home, you’re not alone. This is one of the most common questions homeowners in Pennsylvania have, particularly in areas like Easton, Bethlehem, and throughout the Lehigh Valley.
While it might look like simple dirt, that green discoloration is usually something more.
What Is the Green Buildup on Siding?
In most cases, the green substance on your siding is algae.
Algae thrive in environments that are:
- Shaded
- Moist
- Humid
That’s why you’ll often see it more heavily on the north-facing side of your home or areas that don’t get much sunlight.
Over time, this buildup can spread and become more noticeable, giving your home a dull or stained appearance.
Why Is It So Common in Pennsylvania?
Homes in the Lehigh Valley deal with a mix of weather conditions that make algae growth more likely:
- Humid summers
- Frequent rain
- Long winters followed by damp spring conditions
Even if your home looked clean last year, it’s completely normal for algae to develop again.
Is It Just Cosmetic, or Is It a Problem?
At first, algae might seem like just an appearance issue. But over time, it can:
- Continue spreading across your siding
- Trap moisture against surfaces
- Contribute to long-term wear if left untreated
The sooner it’s addressed, the easier it is to remove.
Can You Just Pressure Wash It Off?
This is where a lot of homeowners run into trouble.
While pressure washing might seem like the quickest solution, using high pressure on siding can:
- Force water behind the siding
- Cause damage to vinyl or other materials
- Lead to inconsistent results
In many cases, pressure alone doesn’t fully eliminate the root of the problem, so the algae comes back sooner.
What’s the Right Way to Clean It?
The safest and most effective method for cleaning siding is a process called soft washing.
This involves:
- Applying a specialized cleaning solution designed to break down algae
- Letting it dwell long enough to do the work
- Rinsing the surface gently without high pressure
This approach treats the source of the growth, not just what you see on the surface.
How Often Should This Be Done?
For most homes in Pennsylvania, siding should be cleaned approximately every 2-4 years, depending on:
- Tree coverage
- Sun exposure
- Surrounding environment
Homes with more shade or moisture may need cleaning more frequently.
A Quick Note for Local Homeowners
If you’re in Easton, Bethlehem, Allentown, or nearby areas, seeing algae on siding is completely normal. It’s something we deal with regularly across the Lehigh Valley due to our climate.
The key is knowing what it is and using the right approach to clean it safely.
Looking for an Estimate?
If you’d like help taking care of your home, you can request a quote online here:
We’re always happy to take a look and point you in the right direction.
Service Areas in the Lehigh Valley
Pressure Brothers proudly provides house washing, roof cleaning, and exterior cleaning services throughout the Lehigh Valley, including:
- Easton, PA (18045, 18040, 18042)
- Bethlehem, PA & Bethlehem Township
- Allentown, PA
- Palmer Township
- Forks Township
- Williams Township
- Wilson Borough
- Hellertown & Center Valley
If you’re located nearby and don’t see your area listed, feel free to reach out! We’re happy to let you know if you’re within our service range.