Soft Washing vs. Pressure Washing

soft washing gutters on a roof

It is amazing how dirty the siding, wood or brick of your home can get throughout a year. Some of the most common stains include mud or dirt, algae, mold and mildew. These stains will give your home an unkempt, uncared for appearance, regardless of if you invest time, money and maintenance into it.

Some materials, like dirt or mud, are harmless, but algae and mildew can be destructive to your health and your home. These contaminants produce allergens that can affect your family, and some of them, like algae, can even grow directly underneath vinyl or roofing material and enter your home.

As a professional power washing service in Portland, we recommend that you have your home’s exterior cleaned once every 12 months. The spring season is the most common time of the year to do an intense home exterior washing, but you can really do it any time 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

Pressure washing used to be the only option to thoroughly clean vinyl siding, brick and painted surfaces. Now, homeowners have another option for exterior home 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 to help you determine which one is the right choice for your home.


The soft wash method uses less power than a typical pressure washer, hence the name. The highest water pressure used in a soft washing system is 500 PSI. This lower spray is produced from a nozzle with a wider spray option, only slightly more powerful than your standard backyard lawn hose.

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

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

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

Soft washing offers the advantage of reaching down into small cracks and crevices to eliminate even unseen organisms, meaning that its impact can last longer than traditional power washing.


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

This cleaning method uses water only, there are no chemicals, to eliminate stains and mildew from exterior surfaces. The use of plain water is a significant plus to home owners that don’t want to use cleaning chemicals, either for the environment’s sake or to avoid zoning violations.

It can be used on many different materials. Home and business owners often choose power washing for cleaning their driveway, patio, decks, walkways and patio furniture because it is fast, efficient and cost-effective.

Pressure washing needs somewhere from 1300 to 3100 PSI water pressure with water sprayed out from a small nozzle for the most power. Both organic and inorganic stains are sprayed from your home’s exterior surface, stopping their growth and restoring the appearance of your home.

One drawback to power washing is that the water can sometimes be too powerful and lead to damaging the surfaces of your home you want to clean. Pressure washing is powerful enough to cut grooves into wood and plastic, and it can push into cracks, breaking off chunks of stone or brick.


The obvious question for most homeowners is, “Which one should I choose?”

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

Soft washing is great for outdoor toys, yard equipment, shingle roofs, 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 removes organisms that are present on the exterior surface, and it stops future growth for longer than power washing can.

A disadvantage of soft washing is that it can kill plants underneath the surface that you’re cleaning. Remember to spray them down with water right before putting the soft wash solution on your home or roof, and it probably shouldn’t be an issue.

Pressure washing is the recommended method for severe stains, and harder surfaces like asphalt, stone and brick. Pressure washing is the recommended process for commercial surfaces. A professional pressure washing service in Portland might use a mixture of detergents and water pressure to clean offf problematic stains, but they should tell you if they will be spraying chemicals after your estimate.

It can be used on siding as well (and has been for several years) so long as it is done correctly. High water pressure can break fragile or smaller pieces of the vinyl. A local service that does power washing often will know how to protect these areas, but a amateur could do a lot of harm.

Your home’s roof is off limits for power washing if you have slate, tile or asphalt shingles. The high pressure of the water might ruin these materials and require you to replace your home’s roof a lot sooner than expected.

Choosing between pressure washing or soft washing is best left for a professional pressure washing service. Which process is right for your home? Give PRO Portland Pressure Washing a call at 503-382-8937 and we’ll send a trained technician over to take a look!

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