Imagine this. You are sitting in your backyard with coffee in your hands, and you look up at your roof. It is covered in layers of mud, moss, and dark stripes. You wish it were gone, and quickly. When you Google, what is the first solution that pops up? Pressure washing a roof.

It is a shortcut solution, is it? But does this make pressure cleaning of roofs safe? Or might it do more harm than good?

Let us jump into it in this blog.

What Is Pressure Washing

Pressure washing is a cleaning system that involves spraying the area with water jets at high pressure to remove dust, molds, mildew, and dirt, among others. It is good for driveways, sidewalks, and siding. But roofs? That is where it becomes tough.

Your roof is not as hard as your concrete driveway. Shingles, tiles, and underlayment may be at risk when handled with excessive abnormality.

The Damage to Roofing Materials: The Main Concern

When the discussion is all about pressure washing the roof, the obvious concern is likely to be damage, and rightly so.

Under pressure, water can:

  • Remove protective granules from asphalt shingles.
  • Breakup or crumble of dainty clay or concrete tiles.
  • Blast water under the shingles, resulting in leakages.
  • Invalidate roof warranties due to improper cleaning.

The Asphalt Roofing Manufacturers Association (ARMA) suggests that using a pressure washer with asphalt shingles can cut years off the life of a roof.

Real-Life Roof Damage from Pressure Washing

One Reddit user posted a tale of an HOA that utilized pressure-washing firms to clean tile roofs throughout their complex. The result?

“Our HOA had our roofs pressure cleaned today, and they broke tiles on almost every single person’s house, with no compensation, of course.” 

This was not a one-off situation. One more reply in this thread observed:

“As someone who’s pressure-washed tile roofs before … roofs shouldn’t be pressure-washed.”

Real-World Costs

These are not mere tales; in fact, these invariably give rise to high repair expenses:

Contractors who specialize in roofing talk over and over again about the need to fix several hundred broken tiles after pressure washing. 

In Sarasota, a single insurance claim was worth more than $11,000 due to the damage to the attic and roofing surfaces, which was the result of a water intrusion during improper cleaning of the roof.

Is Pressure Washing a Roof a Bad Idea

Not necessarily, it depends.

There are two broad varieties of cleaning methods that are easily mixed up:

  • Hot-pressurized washing (not suitable for most roofs).
  • Soft washing (a less risky option of roof cleaning).

Soft washing is a type of cleaning that involves low-pressure and cleaning chemicals, which are applied to wash out algae, moss, and debris. Most roofing specialists advise this procedure.

Chemical roof treatment is another option, which is mostly used to remove moss and algae.

Roof Type Matters

Different roofing material responds in diverse ways to pressure washing:

  • Asphalt Shingles: Granules can be washed off, and the roof’s lifespan will decrease due to the use of high-pressure washing. They are recommended for soft washing. 
  • Clay or Concrete Tiles: They can break or crack when under high pressure. Go with a lot of caution.
  • Metal Roofs: They can withstand greater pressure, yet they should be soft-washed too.
  • Wood Shingles: Prone to damage. The moisture may result in warping or rot as long as it is not dried.

When is Pressure Washing a Roof Justified

In very limited cases, there are reasons that one may want to pressure wash a roof, say an old, greasy metal roof or a flat commercial roof.

However, this task must be performed by experts who possess knowledge of roof mechanisms and pressurizing systems.

These approaches are more secure and effective in the long term.

The Mold and Algae Myth

Homeowners engage in pressure washing to get rid of black streaks, thinking those are made of dirt. The streaks, as it turns out, are usually Gloeocapsa Magma, a kind of blue-green algae.

It grows well in warm temperatures and high moisture and feeds on limestone in the asphalt shingles.

The most appropriate procedure is soft washing, as it is the safest form to kill and eliminate the algae without necessarily destroying your roof.

What do the Experts have to Say?

Experts suggest soft washing as a way of roof maintenance and not pressure washing asphalt roofs.

It is not only our opinion, but it is the industry standard.

Red Flags when Roof Cleaning has Gone Wrong

When you employ a roof cleaner, you need to be on the lookout for the following red flags:

  • They apply high-pressure hoses without inquiring about your kind of roof.
  • No inspection before cleaning.
  • Nothing about the way of cleaning.
  • No insurance or guarantee cover.

Key Takeaways

  • Cleaning the roof by pressure washing may be a speedy process, but it could end up spoiling the roof in no time.
  • A much safer yet longer-lasting alternative is soft washing.
  • When choosing a cleaning method, it is always important to take into consideration the roof material that you are dealing with.

Consult with certified experts who understand the distinction.

Summing up: Is Pressure Washing the Roof Safe

No, in most situations, pressure washing of roofs is unsafe, especially concerning asphalt/tile roofs. It may cause expensive repairs, warranty withdrawals, and reduce roofing life.

If you’re serious about your roof’s care, consider soft washing. It works, it is not dangerous, and roofing specialists widely suggest it.

At Elite Inspections, we are convinced that your home should be cleaned and protected. Our certified roof inspectors adopt the secure, industry-accepted strategies to take care of the health and appearance of your roof.

Pressure washing is not worth gambling. Have your roof handled by the experts in Elite Inspections.

Call us today for a home inspection of your roof and expert recommendations on what is needed for your home.