Soft Washing vs. Pressure Washing

soft washing gutters on a roof

It’s surprising how dirty the exterior of your house can get throughout a year. Some of the most typical stains include mud or dirt, algae, mold and mildew. These types of stains can give your house an unkempt, uncared for look, even though you invest time and care into it.

Some materials, like dirt or mud, are harmless, but algae and mildew can be damaging to your health and to your house. These contaminants produce allergens that can impact your family, and some, like algae, can grow directly underneath vinyl or roofing and enter into your house.

As a professional power washing service in Seattle, we recommend that you have your home’s exterior cleaned once every 12 months. The spring season is typically the most common time of the year to do an extreme home exterior cleaning, but you can do it any time throughout the year so long as the weather allows.


All of the following surfaces need to be cleaned from time to time:

• Vinyl siding
• Rock and stone
• Brick
• Concrete and asphalt

Power washing used to be the only way to thoroughly clean vinyl, brick and painted surfaces. Now, homeowners in Seattle have another option for exterior house cleaning: soft washing.

As the names imply, one method is much gentler than the other, but there’s a little more to it than that. Let’s cover the features of each method to help you decide which is best for your house.


The soft wash method uses much less power than a typical pressure washer, hence the name. The highest water pressure used in a soft washing system is 500 PSI. This lighter spray is generated from a nozzle with a wider spray setting, only a little more powerful than a backyard lawn hose.

Soft washing uses a mixture of soap, bleach and water in combination to eliminate organic matter and debris from your home, roof and other surfaces. The mixture used in a soft washing process can also include algaecides and residual inhibitors which will deter further growth of these types of organisms in the future.

Because chemicals, not pressure, are responsible for cleaning the exterior surfaces, no powerful water pressure is necessary. This means that soft washing should be used for delicate surfaces that might otherwise be harmed by harsher pressure washing.

The soft wash solution is sometimes washed off, but not always. This just depends on what type of solution is used, if there’s plant or animal life that can be impacted by the runoff, and if the chemicals are powerful enough to harm surfaces over time.

Soft washing provides the distinct advantage of getting down into cracks to kill unseen bacteria, meaning that its impact can last much longer than standard power washing.


Pressure washing has always been the gold standard for cleaning exterior surfaces. It is extremely effective and quick, which is why many home and business owners prefer it over soft washing.

This cleaning method uses water only, there are no chemicals, to get rid of stains and mold from exterior surfaces. The use of chemical-free water is a big advantage to home and business owners that don’t want to use chemicals, whether for the environment’s sake or to avoid zoning violations.

The pressure washing process can be used on a lot of different materials. Home and business owners often choose power washing for cleaning their driveway, porches, decks, walkways and outdoor furniture because it is quick, efficient and affordable.

Pressure washing requires somewhere from 1300 to 3100 PSI water pressure with water sprayed out from a tiny nozzle for maximum power. Both organic and inorganic stains are sprayed from your home’s exterior surface, stopping their growth and restoring the curb appeal of your house.

One drawback to power washing is that the water can sometimes be too powerful and lead to damaging the surfaces you’re attempting to clean. Pressure washing is powerful enough to put grooves into wood and plastic, and it can get into cracks, breaking off chunks of stone or brick.


The real question for homeowners is, “Is pressure washing or soft washing better?”

Both soft washing and pressure washing are good choices for your home’s exterior, including sidewalks, driveways and more. Both cleaning systems can be done by a professional company – and truthfully, are more correctly done when left to the experts.

Soft washing is perfect for outdoor toys, gardening tools, roof shingles, decks, gutters, patios and painted surfaces because it is unlikely to harm plastic and wood. It’s also a safe and smart choice for vinyl siding.

It kills organisms that are present on the exterior surface, and it stops future growth for much longer than power washing can.

A problem with soft washing is that it can kill plant life under the surface that you’re cleaning. Remember to spray them down with water right before putting the soft wash chemicals on your house or roof, and it probably won’t be a problem.

Pressure washing is considered the best choice for difficult stains, and harder surfaces like asphalt, stone and brick. Pressure washing is the preferred method for commercial properties. A professional pressure washing service in Seattle might use a mix of detergents and water pressure to eliminate problematic stains, but they should tell you if they are going to be spraying chemicals after your consultation.

It can be used on siding too (and has been for decades) so long as it is done correctly. Powerful water pressure can damage fragile or smaller pieces of vinyl. A local service that does power washing all the time are going to know how to protect these pieces, but a amateur might do a lot of harm.

Your home’s roof is definitely off limits for power washing if there are slate, tile or asphalt shingles. The high pressure of the water might damage these materials and cause you to replace your home’s roof much faster than expected.

Choosing between pressure washing or soft washing is best left for a pressure washing service. Which process is right for your house? Give Seattle Pressure Wash Plus a call at 206-385-1984 and we’ll send a trained technician over to take a look!

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