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No pressure VS high pressure


Pressure-free vs. high pressure roof cleaning

The vast majority of homeowners aren’t sure what causes roof stains, or that there is a safe, and proper method to remove this cyanobacteria, aka blue-green algae.  The fact that you’re reading this indicates that you’re likely resourceful and/or inquisitive.

Much scientific research went in to this unique roof cleaning process before American-ProTech even went in to business.   Interestingly, the shingle manufacturers had already devised a pressure-free method of roof stain removal.  And since the largest shingle manufacturers have approved it and have endorsed it, we adopted it as our only roof cleaning process.   That was an obvious decision.

Simple stated, we remove stains from shingles as per the manufacturer’s directive, which is a pressure-free process.   This is important to note, as there are some unscrupulous people that will gladly use a pressure washer on your shingles, causing excessive damage via instant granule loss, while pocketing your hard earned money at the same time.

GAF-Elk, a leading shingle company in North American has published a technical document pertaining to roof stains, part of which states ver batim:  “Do not power wash the shingles to clean the shingles [sic]. Some roof cleaning companies offer this service.  However, it is not recommended as it may dislodge granules which can lead to premature shingle failure.

The Asphalt Roofing Manufacturers Association has a similar statement in their technical bulletin pertaining to algae discoloration on roofs:  “Caution!  High pressure washing systems for algae removal should not be used.”

Having these facts straight from the most credible sources (the manufacturers) takes any gray areas out of the equation.  Simply stated, high pressure should not be used to remove roof stains from shingles.

This begs yet another question, where does low pressure end and high pressure begin?  This is a very relative topic, and research by American-ProTech has not been able ascertain any formal demarcation between low pressure and high pressure where shingles are concerned.  We can, however; take the most basic approach to this topic using common sense:

Most pressure washers operate at a PSI (pounds per square inch) measured in thousands.  3000 PSI and 4000 PSI pressure washer are quite common.  4000 PSI!  Imagine that on your shingles.  Hail the size of a nickel can damage your roof – imagine what 4000 PSI would do to it.  This is what it looks like in progress – do NOT allow this on your shingles:

Don't allow this on your roof!

And this is what is in your gutters afterwards – the granules that USED to protect your roof from the sun’s UV rays.

After power washing shingles

Other outfits will tell you that their high powered pressure washer has been ‘specially calibrated’ for a ‘gentle rinse’.  Begin to peel back the layers of the onion and ask about the PSI.   Are they hesitant to answer?  A bit allusive on this topic?  STOP and hire a professional roof cleaning company that prides themselves on cleaning roofs the proper way – using no high pressure.

Perhaps you’ll get a straight answer, as there are some good people who have simply adopted the wrong process without knowing any better.  If pressed, you’ll find that the ‘calibrated machines’ are running at 800 PSI!.   800 pounds of pressure in one square inch of a flimsy fiberglass and asphalt product.  Let’s take tongue and cheek look at what 800 PSI might look like:

800 PSI?  Not on my roof!


Not on my roof.  Imagine 800 PSI on your foot.  Low pressure?  Hardly.

At American-ProTech, the pumps that move the cleaning solution to the roof top run on batteries, literally.  The maximum pressure that they’re capable of is about the same as you see from your kitchen faucet.   The only reason the pumps are used is so that the cleaning solution doesn’t have to be carried to the roof top.  Our pressure-free cleaning process, the only PROPER roof cleaning process, relies solely on science and chemistry to get the job done and done right.

Our consultations are free, and there’s never an obligation.  Nor will we use sales tactics or try to pressure anyone, ever.  We simply present facts, hard facts, answer any and all questions that you may have and if you’d like, we’ll provide a quote to make your home look great again.

We’re American-ProTech LLC, the region’s leading roof cleaning company.

  • Professional Staff
  • Professional Equipment
  • Professional Results – EVERY time

Roof Cleaning Northern Virginia