ROOF WASHING
Those Black Streaks Are Not Just Ugly. They Are Eating Your Roof.
Most homeowners assume the dark staining on their roof is dirt or weathering.
It is not. Those black streaks are a living organism called Gloeocapsa Magma, a hardy strain of algae that feeds on the limestone filler in your asphalt shingles. Left untreated, it spreads across your roof, dislodges granules from your shingles, and can reduce the life of a 30-year roof by half or more.
HydroPower’s professional roof washing service uses a certified soft wash process recommended by the Asphalt Roofing Manufacturers Association (ARMA). We apply a professional-grade, biodegradable algaecide at low pressure, which penetrates and kills the algae at the root rather than simply masking the stain with water. Your roof comes out looking like new, and the results are guaranteed to last.
What Is Soft Wash Roof Cleaning?
Soft wash roof cleaning is the only method recommended by major roofing manufacturers and the ARMA for removing algae, moss, and lichen from asphalt shingles. Unlike pressure washing, which uses high-force water that strips granules and voids manufacturer warranties, soft washing relies on a specialized cleaning solution applied at low pressure. The solution does the work, not the water.
The algaecide breaks down and kills the biological growth at its source. Once the solution has done its work, the roof is gently rinsed clean. The process is safe for asphalt shingles, metal roofing, tile, and cedar shake, and it delivers results that last far longer than any pressure washing approach ever could.
Why Soft Washing Works
The cleaning solution eliminates algae, mold, and lichen at the cellular level. The growth does not return for years because the root cause has been eliminated, not temporarily masked.
Why Pressure Washing Hurts
High-pressure water strips the protective granules from your shingles, accelerates granule loss, voids manufacturer warranties, and forces water under shingles where it can cause leaks and structural damage.
Signs Your Roof Needs Professional Cleaning
Your roof is one of the most important investments in your home, and it will tell you when it needs attention. Here is what to look for:
- Black or gray streaks running down your siding, especially on the north-facing side of your home, are a sign of algae and mildew growth that will continue to spread if not treated.
- Green or yellow moss patches indicate active moss colonies that hold moisture against your shingles and accelerate granule loss and shingle curling.
- White or gray crusty patches are typically lichen, a particularly stubborn organism that bonds directly to shingle granules and is the hardest to remove once established.
- Shingles that look faded, thin, or patchy may indicate granule loss driven by algae damage that has been progressing for longer than it was visible.
- Dark staining along your roofline or soffits often signals that algae or mold has begun spreading from the roof surface to adjacent areas.
The ARMA recommends having your roof professionally cleaned as soon as algae staining becomes visible. Waiting allows the growth to spread and the damage to compound. A professional cleaning costs a fraction of what a premature roof replacement will.
The HydroPower Roof Washing Process
Every roof washing job follows a proven process designed to protect your property and deliver lasting results.
Step 1
Property Preparation
Before we begin, we protect your landscaping, close any open vents, and confirm all windows and doors are sealed. We wet down surrounding plants and shrubs and cover any sensitive areas near the roofline to prevent runoff exposure.
Step 2
Algaecide Application
Our technicians apply a professional-grade, biodegradable algaecide to your roof at low pressure. The solution is applied evenly across all affected surfaces and allowed to dwell, penetrating and breaking down the algae, moss, and lichen at the source.
Step 3
Rinse and Inspection
Once the solution has done its work, we perform a thorough, low-pressure rinse to flush away the dead biological growth. We inspect the entire roof to confirm the clean is complete and that no areas were missed.
Step 4
Post-Job Walkthrough
Once the cleaning solution has done its work, we rinse each surface completely from top to bottom. We pay close attention to corners, trim lines, window sills, shutters, and any areas that tend to trap moisture or buildup. If any section needs additional attention, we address it before moving on.
Why Homeowners Across The Philadelphia Region Choose Hydropower
Your roof is too important to hand to a company that treats every surface the same way. Here is what separates HydroPower from a general pressure washing crew.
The Right Method for Every Surface
Not every surface cleans the same way. Our technicians are trained to identify what each job requires and apply the appropriate technique, pressure, and solution, every time.
Trained, Insured, and Background-Checked
Every HydroPower technician is fully trained, background-checked, and covered under our commercial liability policy. You will never wonder about your liability when we are on your property.
Biodegradable Cleaning Solutions
Our cleaning agents are professional-grade and biodegradable, tough on buildup and safe for your landscaping, your family, and the environment when applied correctly.
A 5-Star Experience, Every Time
From your first call to the final walkthrough, you will deal with a team that communicates clearly, shows up on time, and does not leave until the job is done right.
Fast, Reliable Scheduling
Our booking process is simple and most jobs are on the schedule within a few days of your call. We show up when we say we will, and we finish on time.
Locally Owned and Community-Focused
HydroPower is a family-owned business proud to serve the communities where we live. When you hire us, you are supporting a local team that takes genuine pride in its reputation.
Frequently Asked Questions About Roof Washing
What are those black streaks on my roof?
The black streaks are caused by a type of algae called Gloeocapsa Magma. It is extremely common in the mid-Atlantic region, where humidity and warm summers create ideal conditions for it to spread. Left untreated, it feeds on the limestone filler in your shingles and accelerates roof deterioration.
Will soft washing damage my shingles or void my warranty?
No. Soft washing is the cleaning method recommended by the ARMA and most major shingle manufacturers. Pressure washing, on the other hand, is specifically discouraged because it strips granules and can void your warranty. Our process is safe, manufacturer-approved, and carries no risk of shingle damage when performed correctly.
How long will the results last?
Most soft wash roof cleanings remain effective for two to five years, depending on the amount of tree coverage, shade, and humidity around your home. Homes in heavily shaded or wooded areas may see re-growth sooner. We will give you an honest assessment of what to expect based on your specific property.
How long does a roof washing take?
Most residential roof cleanings are completed in one to three hours depending on the size and pitch of the roof and the severity of the buildup. You do not need to be home for the work to be completed.
Do I need to be home during the cleaning?
You do not need to be present, though we ask that windows and doors are closed and that pets are kept indoors. If you would like to be home for the final walkthrough, let us know when scheduling and we will plan accordingly.
See The HydroPower Difference
See what professional roof washing looks like in the real world. Browse before-and-after photos from homes across the Philadelphia region and read what our customers have to say.
Ready To Protect Your Roof?
Getting a quote is fast and free. Tell us about your home and we will get back to you with a clear, honest price. No pressure, no surprises.
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Serving residential and commercial customers throughout Montgomery, Chester, Bucks, Delaware, and Berks County, as well as Philadelphia, PA.
Proudly Serving Homeowners Across Southeast Pennsylvania
HydroPower provides professional house washing and soft wash services throughout Montgomery, Chester, Bucks, Delaware, and Berks County, as well as the greater Philadelphia area. If you do not see your town listed below, give us a call. If you are in the region, chances are we cover it.
Collegeville
Eagleville
Phoenixville
Royersford
Limerick
King of Prussia
Skippack
Schwenksville
Audubon
Worcester
East Norriton
Linfield
Spring City
Trappe
Oaks
Trooper
West Norriton
Plymouth Meeting
Norristown
Blue Bell
Collegeville
Eagleville
Phoenixville
Royersford
Limerick
King of Prussia
Skippack
Schwenksville
Audubon
Worcester
East Norriton
Linfield
Spring City
Trappe
Oaks
Trooper
West Norriton
Plymouth Meeting
Norristown
Blue Bell