The Perfectly Clean™ Pressure-Washing FAQ
By now, you've learned a lot about exterior cleaning.
But homeowners don't always want to read an entire chapter to answer one simple question.
So we've put some of the most common questions we hear about pressure washing, soft washing, house washing, concrete cleaning, and roof cleaning all in one place.
Think of this chapter as your quick-reference guide.
Can Pressure Washing Damage My House?
Yes, if it is done incorrectly.
A pressure washer is powerful enough to damage many surfaces around a home.
Too much pressure can potentially damage:
Vinyl siding
Wood
Paint
Screens
Window seals
Roofing materials
Newer concrete
Other delicate surfaces
That's why professional exterior cleaning isn't about using the highest pressure possible.
For house washing, Pro Wash uses a low-pressure soft-washing process rather than high-pressure tips on siding, soffits, and gutters.
The right pressure depends on the surface you're cleaning.
What Is Soft Washing?
Soft washing uses cleaning solution and low-pressure water instead of relying on high pressure to blast organic growth from a surface.
The cleaning solution does much of the work.
The basic process is:
Apply → Dwell → Rinse
At Pro Wash, house-wash solution is applied from the top down, allowed time to work, and then thoroughly rinsed using low pressure.
Soft washing is commonly used for house siding and other surfaces where high pressure isn't appropriate.
Is Soft Washing the Same as Pressure Washing?
Not exactly.
A pressure washer may still be used as part of a soft-washing system.
The difference is how the surface is being cleaned.
Traditional pressure washing relies more heavily on the physical force of water.
Soft washing relies more heavily on:
Cleaning solution + dwell time + low-pressure rinsing
That's why seeing a pressure washer in someone's truck doesn't tell you how they're going to clean your house.
Ask about the process.
Can I Pressure Wash Vinyl Siding?
A pressure washer can be used as part of the cleaning process, but we don't recommend blasting vinyl siding with high pressure.
Vinyl siding is not concrete.
At Pro Wash, we use a low-pressure application for house washing.
Remember:
More pressure does not mean more clean.
What Is the Green Stuff on My House?
Green buildup on siding is often organic growth, such as algae or similar biological material.
It tends to become more noticeable in areas with:
Shade
Moisture
Trees
Limited sunlight
High humidity
That's one reason homes in Eastern North Carolina can develop green siding relatively quickly.
Why Is Only One Side of My House Green?
Usually, the conditions around that side of the house are different.
Look for:
More shade
Large trees
Less direct sunlight
Heavy vegetation
Moisture
Poor airflow
A shaded side of the house may stay damp longer than a sunny side.
That can create better conditions for organic growth.
Will House Washing Remove All Black Stains?
Not necessarily.
This is an important expectation.
A normal house wash can be very effective against organic growth.
But a dark stain could also be:
Gutter tiger striping
Oxidation
Rust
Failed paint
Another specialty stain
Permanent discoloration
If something doesn't disappear during a normal wash, that doesn't automatically mean you need more pressure.
Identify the stain first.
Will a House Wash Remove Gutter Tiger Stripes?
Not always.
The dark vertical streaks that sometimes appear on the outside of gutters can require a separate gutter-brightening process.
A normal house wash may clean organic growth from the gutter without completely removing bonded tiger stripes.
That's why it's important to understand what is included in a quote.
House washing and gutter brightening may be separate services.
Is Gutter Cleaning Included With House Washing?
That depends on what you mean by gutter cleaning.
There are two different things homeowners commonly call “gutter cleaning.”
Exterior gutter washing
Cleaning the visible outside face of the gutter.
Interior gutter cleaning
Removing leaves, pine straw, and debris from inside the gutter.
Those are different services.
Always ask your contractor what is included.
Will Pressure Washing Remove Oxidation?
A normal house wash is not the same thing as oxidation removal.
Oxidation can appear as a faded or chalky surface.
If you rub your hand across certain oxidized surfaces, you may notice a chalk-like residue.
That condition can require a different restoration process.
Don't keep increasing pressure because an oxidized surface doesn't look new after washing.
You may not be looking at dirt.
Will Pressure Washing Remove Oil From Concrete?
It may improve an oil stain, but complete removal isn't always possible.
Concrete is porous.
Oil can soak into it.
The longer and deeper the contamination has penetrated, the harder it may be to remove.
Specialty degreasers or treatments may help, but homeowners should be cautious of anyone who guarantees that every old oil stain will completely disappear.
Will Pressure Washing Remove Rust?
Rust usually requires a specialty treatment.
More pressure isn't necessarily the answer.
Rust, fertilizer stains, irrigation stains, and other mineral-related discoloration may require specific cleaning products.
This is another example of:
Identify first. Clean second.
Can You Pressure Wash New Concrete?
You need to be careful.
At Pro Wash, our standard is:
We do not use high pressure on concrete less than three years old.
That's intentionally conservative because newer concrete can be damaged or permanently marked by aggressive pressure.
If you don't know the age or condition of your concrete, don't guess.
Should I Pressure Wash My Roof?
We recommend that homeowners do not DIY their roof cleaning.
Roof cleaning can involve:
Heights
Slippery surfaces
Cleaning chemicals
Landscaping protection
Runoff
Expensive roofing materials
A professional roof-cleaning process should use a method appropriate for the roofing material.
For asphalt shingles, aggressive high-pressure blasting should not be treated as the solution.
Will Black Roof Streaks Disappear?
Professional treatment can address biological roof growth, but the exact result depends on what is on the roof.
Some growth may respond quickly.
Moss and lichen can take longer to release after treatment.
A professional should inspect the roof and explain what you should expect before the work begins.
Can Pressure Washing Damage Wood?
Absolutely.
Too much pressure can:
Cut into wood fibers
Raise the grain
Leave lines
Create a fuzzy appearance
Damage soft or weathered wood
Wood cleaning requires controlled technique and the correct cleaning process.
Remember:
You're trying to remove the dirt—not the wood.
Should I Pressure Wash My Deck Before Staining It?
Cleaning may be part of preparing a deck for stain, but washing alone doesn't automatically mean the wood is ready.
Depending on the condition of the deck, preparation may also involve:
Cleaning
Stripping old finishes
Brightening
Drying
Sanding
Other surface preparation
If you're having the deck professionally stained, ask the person applying the finish what preparation they require.
Will Pressure Washing Hurt My Plants?
Cleaning chemicals can affect vegetation if they're not properly managed.
That's why plant protection is such an important part of the Perfectly Clean™ process.
At Pro Wash, vegetation is watered before chemical application, monitored and watered as needed during the dwell period, and rinsed again after each side is finished.
Remember:
BEFORE → DURING → AFTER
Should I Move My Outdoor Furniture?
Yes, when practical.
Before a house wash, move things such as:
Chairs
Cushions
Doormats
Decorations
Toys
Potted plants
Small furniture
At Pro Wash, moving these loose items away from the cleaning area is part of preparing the property.
This protects the items and allows the area behind them to be cleaned.
Do I Need to Remove My Ring Doorbell?
Not necessarily.
Sensitive items such as doorbells and electrical outlets can be protected when necessary.
At Pro Wash, these areas are identified during the property inspection and protected as needed.
But remember:
The door still needs to be cleaned.
The goal is to protect the electrical component while carefully cleaning the surrounding surface.
Should My Windows Be Closed?
Yes.
Before exterior cleaning begins, make sure windows and exterior doors are properly closed.
A professional should also inspect for open windows and other potential concerns before starting.
If you know a particular window leaks, tell your cleaning company before work begins.
Does House Washing Include Window Cleaning?
Not necessarily.
During a house wash, the windows should be extremely well rinsed so that house-wash solution isn't left on the glass, frames, or surrounding vinyl.
But detailed professional window cleaning can be a separate service.
Ask your contractor exactly what is included.
Do I Need to Be Home During Pressure Washing?
Usually, you don't necessarily need to be home for the entire service, depending on the company and property.
But the contractor needs access to everything required to complete the work.
That can include:
Water
Gates
Areas being cleaned
Any information about existing property concerns
If you're going to leave, make sure the company can access everything it needs before you go.
What Should I Do Before the Pressure-Washing Company Arrives?
A little preparation can make the job easier.
Consider:
✓ Close windows and doors
✓ Move vehicles away from the cleaning area
✓ Secure pets
✓ Make sure gates can be accessed
✓ Let the company know about known leaks or damaged areas
✓ Remove anything especially fragile or valuable from the work area
A professional company may move normal loose items as part of its process, but it's always smart to ask beforehand what they want you to prepare.
How Long Does It Take to Pressure Wash a House?
There isn't one answer.
It depends on:
Size of the home
Height
Amount of organic growth
Landscaping
Access
Weather
Surface condition
Additional services
Property layout
A small, simple home and a large multi-story property are completely different jobs.
A good company should focus on completing the process correctly rather than racing against an arbitrary time.
How Often Should I Wash My House?
There isn't one schedule for every property.
Instead, inspect your home regularly.
Look for:
Green siding
Organic growth
Dirty soffits
Gutter buildup
Pollen
Dirty concrete
Other visible contamination
Homes with more shade, moisture, and tree coverage may show buildup faster.
Clean based on condition—not just the calendar.
Is It Better to Pressure Wash in Spring or Fall?
Both can work.
The condition of the property and the weather on the day of cleaning matter more than choosing one perfect season.
Spring may bring heavy pollen.
Fall may bring leaves and pine straw.
Summer may bring heat and fast drying.
Different seasons simply create different considerations.
Can You Pressure Wash in the Rain?
Light weather conditions don't always prevent exterior cleaning, but rain, wind, storms, temperature, and safety conditions can affect whether a job should continue.
A professional should evaluate the conditions.
If weather prevents the work from being performed safely or correctly, the job should wait.
Is the Strongest Pressure Washer the Best One?
No.
This is one of the biggest lessons in this entire guide.
A more powerful pressure washer doesn't automatically create a cleaner house.
Professional exterior cleaning depends on understanding:
Water flow + Pressure + Chemistry + Dwell time + Technique + Surface
The machine is only one piece of the system.
What's the Most Important Thing to Remember?
If you forget everything else in this guide, remember this:
Identify the surface.
Identify the problem.
Choose the safest effective process.
That's the foundation of Perfectly Clean™.
Have a Question We Didn't Answer?
Exterior cleaning can become surprisingly complicated.
If you see something around your property and aren't sure what it is, don't experiment with more pressure.
Take a picture.
Research the surface.
Check the manufacturer's recommendations.
Or ask an experienced exterior-cleaning professional.
Sometimes the smartest thing you can do is ask:
“What am I looking at?”
before asking: