Stucco House Wash in Newtown, PA: Erasing Black Streaks and Window Algae from a 7,000 Sq Ft Home

Get Pressure Pros  ·  Newtown, Bucks County, PA

Some houses need a quick rinse. This one needed a full soft wash strategy. We recently took on a 7,000+ square foot stucco home in Newtown, PA that had gone years without a proper cleaning, and it showed: heavy black streaking across the walls and thick algae growth running down from below every window. Here is what we found, why it happens on stucco homes like this one, and how we brought the exterior back to a like-new finish without damaging the stucco.

The Challenge: A Large Stucco Home Covered in Algae and Black Streaking

At over 7,000 square feet of exterior surface, this Newtown property is one of the larger stucco homes we service in Bucks County. Stucco’s textured, porous surface is great for curb appeal when it is clean, but that same texture is exactly what gives algae spores and airborne grime something to grab onto. On this home, the black streaking had spread across large sections of the walls, and every window had a distinct band of green-black algae growth trailing down the stucco beneath it.

Why Black Streaks and Algae Form Below Windows on Stucco

This is one of the most common questions we get from Bucks County homeowners, and it is not random. Black streaking on exterior surfaces is typically caused by Gloeocapsa magma, an airborne algae that thrives in humid, shaded conditions and feeds on the minerals in building materials. Bucks County’s humid summers and tree-heavy neighborhoods make it a near-perfect environment for this growth.

Over time, what starts as a faint discoloration under one or two windows becomes the kind of heavy streaking we saw on this home, running the full height of the wall below almost every window.

Our Soft Wash Process for Stucco Exteriors

Stucco is not a surface you blast with a pressure washer wand and call it a day. High pressure can crack, pit, or strip the finish coat, especially on a home this size where consistency matters across every elevation. Instead, we used a soft wash approach built specifically for stucco:

On a home this large, the process took a full, methodical pass across every wall to make sure the result was even from corner to corner, not just clean in the spots that were easiest to reach.

Watch the Transformation

We caught this job on video so you can see the black streaking and window algae lift right off the stucco in real time.

The Results

By the time we finished, the black streaking was gone, the algae bands below every window were gone, and the stucco was back to a uniform, bright finish across all 7,000+ square feet. No pressure damage, no streaking left behind, just a clean, protected exterior that matches the rest of the upkeep on this Newtown home.

Why Bucks County Homeowners Trust Get Pressure Pros

Stucco homes are common throughout Newtown, Doylestown, Yardley, and the surrounding Bucks County communities, and so is the algae and black streaking that comes with our humid summers and shaded lots. We know how to clean stucco the right way: low pressure, the right solution, and the patience to do a home this size properly instead of rushing it. We are locally owned, fully insured, and every quote is free.