Pressure Washing vs Soft Washing

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Pressure washing uses high-pressure water jets to blast away tough dirt and debris from hard surfaces like concrete and brick, versus soft washing, which uses a low-pressure application of water mixed with cleaning solutions to gently clean and sanitize delicate surfaces such as roofs, siding, and windows without causing

damage. 

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Have you ever heard the term Soft Washing, and wondered how it is any different than “power washing” or “pressure washing”?

Today, we will break down the differences between these types of cleanings, and how you - the homeowner, business owner, or facility manager- can know what your property needs and what to look for! 

The words “power washing” and “pressure washing” are often used interchangeably, but we like to be precise and consistent where we’re from.

Power Washing

Power washing really encompasses all types of water based washing, low-pressure and high-pressure, chemical usage or not, etc… “Power washing” is what we do as a whole. It’s exterior cleaning using a power source (electric or gas) to pull and dispense water, soaps, cleaning chemicals, etc.

The goal of any power washing project is to remove an unwanted substance such as algae, mold, dirt, oil, rust, calcium, gum, tar, paint, and more, which can all be targeted by specific power washing practices.

The First question is, “What am I removing, and which process works best for this substance?” There are so many options to choose from. High-pressure or Low-Pressure, Cold water or hot water, Chemicals or no chemicals, Soap or no soap, Algicides, Degreasers, Acids, Neutralizing agents, the list goes on and on….

The Second question is, “Is my chosen process safe for the surface type I am cleaning, and the surrounding areas?” Brick, Stone, Concrete, Wood, Hardyboard, Stucco, Steel, Aluminum, Asphalt Roof Shingles, Glass, Window Screens, Painted surfaces, and more, all require their own cleaning process, or even a combination of multiple, to be cleaned effectively without damaging the surface and the surrounding areas.

Brick, stone, and concrete can all be pressure-washed with high-pressure jets, but softer surfaces, like wood, stucco, shingles, and window screens cannot. Soft Washing with chemicals is the go-to for washing houses and commercial buildings. But some jobs do not allow for any chemicals to be used at all.

With Power Washing, one method does not fit all. There is a lot to consider, depending on what your specific needs are. And setting expectations with yourself and/or your clients is absolutely key!!!!! Not everything can be removed. Not everything can be power washed. Sometimes, damage is to be expected. It’s just the way it is. Many of these options come with risks and safety precautions, not only for the user, but for the property itself also. This is why hiring a professional wash company is often a wise choice!  

Pressure Washing

Pressure washing is what most, traditionally, imagine when we think of using a power washer/pressure washer. It is the use of HIGH-PRESSURE water jets and nozzles to blast away unwanted dirt, soiling, and debris. Pressure washing machines have been around for decades, and are often fairly simple to use as long as you follow a few safety practices.

Pump motors can be found in electric options (small jobs) up to large gas and diesel powered machines (medium to large jobs). Specifically designed water heaters can be equipped with pressure washers to provide hot water washing and even steam cleaning (very effective for oil stains and gum removal). And, the high-pressure nozzles are generally capable of jetting between 1,500 psi - 4,500(+) psi water streams! On the higher end, these water pressures are more than enough to etch, chisel, and quickly erode concrete, brick, mortar and other hard, porous materials if caution is not used. Unless that's the desired effect you are looking for. But…for most general residential and commercial cleaning needs, no more than 2,500 psi is really ever needed, even for the tougher jobs. In fact, running anything higher than 2,500 psi runs the risk of damaging your property more than helping it. Of course, there are always exceptions and certain instances where more pressure may be needed to tackle a specific stain or substance. But, most surfaces are going to be damaged to some degree when running these higher pressures. Remember what I said earlier? Not everything can be removed.

Not everything can be power washed. Sometimes, damage is to be expected. It’s just the way it is. However, when these machines are dialed in to the appropriate pressures, and correct techniques, chemicals, and equipment are used along with it, a Pressure washer is a very, very effective and versatile tool for any exterior cleaning project.

Soft Washing

Soft Washing. What is it? It is a gentle, yet highly effective wash method often used in the professional power washing world, and is the answer to many “is this safe for my project?” questions. It is a LOW-PRESSURE application of a mixture of water, soap, and/or cleaning chemical to blanket the area being cleaned. Think car wash, but for your building or your house. The soap mixture is applied to all the vertical surfaces: walls, windows, doors, etc. Even the roof can be (and should be) Soft Washed. And for almost all building materials today, the Soft Wash process is safe to use; even gentle enough for window screens!

Generally, for most the most common exterior cleaning needs, targeting algae, mold, dirt, dust, spider webs and other organic growth on buildings and concrete areas, the go-to cleaning chemical is Sodium Hypochlorite, a.k.a Bleach, or SH (we will call it SH). SH is a versatile cleaning chemical that is used in many industrial, commercial, and residential uses. It’s not just for laundry you know!

Bleach is a very controllable, stable, and effective chemical that can be used as an algaecide and sanitizer for your property. When properly mixed into the correct strength ratios, SH is one of the safest, most effective options for House Washing or Soft Washing. In fact it is so effective, that scrubbing and brushing are rarely needed. These are all reasons why ARMA (Asphalt Roofing Manufacturers Association) has listed Soft Washing with SH as the only approved method to clean an asphalt shingle roof! And in our area (Houston, TX) the majority of millions of homes have this exact type of roof. Now, most shingled roofs are designed to last roughly 25+ years in perfect conditions. However, the dense humidity and heat we have here in this area of Texas are far from perfect conditions. It is a breeding ground for mold, mildew, and algae….

Drive up and down any street in Houston. I guarantee you will see houses, driveways, office buildings, shopping centers, parking lots, and more with black stains and streaks all over them. 9/10 times, that's a form of algae. Heavy build up can usually be found near a gutter spout, or where a roof valley drops rainwater, or just algae growing from the humidity in shaded areas. North facing sides tend to grow faster due to less sun exposure.

The next time you are driving in your neighborhood, look at 10 or 20 roofs along the way. More than half will have black streaks and stains running down the slopes with small lighter spots below the vent pipes. All of these darkened streaks are a specific algae called Gleocapsa Magma, or “roof algae.” This particular damaging breed of algae feeds off the limestone used in the shingles manufacturing process. The algaes aggressive roots burrow into the shingles, loosening or dislodging the shingle granules. Its black color is a unique bio cover, which the algae has evolved to create for itself, blocking out sunlight. Meaning, it can grow in direct sunlight, under intense heat, with very little water, unlike many algae/moss species. This also means it is stubborn and difficult to kill. Roof Washing requires a much stronger algaecide mix to effectively remove it from the roof, killing the algae at the roots. Ever cleaned your gutter and noticed large amounts of granules, like coarse black sand, in the gutters? This is from the failing shingles above. There's really only 3 things that damage and decay a roof's shingles: 1. Sunlight,  2. Wind, and 3. Roof algae. There isn't much to avoid the first two; but, the 3rd can very easily be managed, helping you prolong the lifespan of that very expensive roof over your head. 

Like any Power Washing method, Soft Washing comes with its own risks. The cleaning chemicals typically used can be harmful or even deadly to plant life and aquatic animals. Fish ponds, dense flower beds, exotic trees are all high risk areas and should be protected at all costs. Choosing a different eco-friendly cleaning agent or even a different cleaning method may be best for around these areas.

Remember, the primary goal of Soft Washing a home or building is to kill and remove organic growth (algae, dirt, webs, wasp nests, etc), which means it can be harmful to all organic material in the immediate area if not addressed quickly.

This is quite easy though, in most cases. Simply watering grass, flower beds, trees, and bushes thoroughly before, during, and after the wash process is typically the best solution, and it works well protecting these plants.

“The solution, to pollution, is dilution.”

Only when absolutely needed, should plants be covered (mainly during summer months) or a bleach neutralizing agent be used for an extra layer of protection.

Water, water, and more water!!!!

Stained wood is also very subjective to damage from soft wash chemicals. Stained wood doors, garage doors, pergolas, decks, soffits, and patio ceilings must all be addressed and protected during the wash process. If your home or business have many plants or stained wood around, calling a professional company is best to ensure these are protected.

For every job we do, our #1 priority is property protection, and our #2 is the property cleaning. 

Regardless of what method is chosen, what chemical you use, or what type of machine/system is used, always remember to do your research, use safe practices, and when in doubt, call the professionals!