By the Mr. Suds team, Cory & Brooke Cooper, Kingwood, TX
Here is something we have learned in over twenty years around Kingwood. Most of the damage we get called out to fix did not happen during the wash. It happened because of what nobody did before it started.
A rushed start is how siding gets water behind it and how concrete gets streaked. So before a drop of water flies, we run the same routine every single time.
Here is exactly what we do, plus the mistakes we see homeowners make every season.
What should you do before pressure washing?
Before you pressure washing, inspect the surface and figure out the material first. Move and protect your furniture and décor. Close every window and door. Cover your plants and outdoor outlets. Pre-treat tough stains with the right cleaner, then match your pressure to the surface and work top to bottom.
That is the short version. Skipping prep is the number one cause of damage we see. Here is the full process, step by step.
The 10 things we always do before we pull the trigger
1. Walk the property and inspect for damage
The very first thing we do is walk the whole house. No water, no machine, just our eyes.
We are looking for loose boards, cracked mortar, lifted siding, and chipped paint. If you spray water at a loose board, you can punch a hole right through it.
Fix the small stuff first. It saves you a much bigger repair later.
2. Identify the surface and material (this sets everything)
Every surface has its own limit. Knowing the material decides the pressure, the tip, and the cleaner.
Vinyl, brick, wood, stucco, and James Hardie
Vinyl and old wood are soft. Aged brick and lime mortar crumble under force. And fiber cement, like James Hardie siding, has its own rules (more on that below).
We never guess on this. The material tells us how to clean it.
3. Move and protect everything (what to move before power washing)
Walk your yard and clear the work zone. Anything that can get soaked, knocked over, or sprayed with cleaner needs to move.
Here is our quick move-it checklist:
- Patio furniture, cushions, and grills
- Potted plants, planters, and yard décor
- Kids’ toys, pet bowls, and door mats
- Vehicles, bikes, and anything parked near the work area
Five minutes of moving things saves you a ruined cushion or a dinged planter.
4. Close and latch every window and door
This one sounds obvious, and it is the easiest step to skip.
Even our professional gear can push water through a cracked window seal. A latched window and a closed door keep that water outside where it belongs.
5. Cover plants and pre-wet your landscaping
Your landscaping is part of your curb appeal, so we protect it.
We wet down the plants and beds first, then cover the delicate ones. Soaking the soil before any cleaner touches it dilutes the runoff and keeps your greenery safe.
6. Cover or cut power to outdoor outlets and fixtures
Water and electricity do not mix. This is a safety step we never shortcut.
We cover exterior outlets, light fixtures, and anything housing power. Doorbells, cameras, and landscape lighting all get protected before we start.
7. Pre-treat the surface (what to spray on a driveway or sidewalk first)
Water alone rarely lifts a real stain. The right pre-treatment does the heavy lifting so the pressure does not have to.
Degreaser for oil, a mildew solution for the green stuff
Here is how we match the spray to the stain:
- Oil and grease: a degreaser, also called an alkaline cleaner, breaks down the oil so it rinses away
- Mold, mildew, and algae: a sodium hypochlorite solution with a surfactant, which kills the growth at the root
- Rust: an oxalic acid cleaner made for concrete
We let the solution sit and work for about 10 to 15 minutes before we rinse. That dwell time is the difference between clean concrete and a streaky mess.
8. Match the pressure to the surface (soft wash vs. pressure wash)
Not everything should be blasted. This is where most damage starts.
Hard surfaces like concrete can take real pressure. But siding, wood, and anything fragile usually need a soft wash. That means low pressure, often under 1,500 PSI, paired with a cleaner that does the work for us.
Think of it this way. Pressure cleans concrete. Chemistry cleans your house.
9. Mix the right detergent (and skip the dish soap)
People ask us about soap all the time, so we will be direct.
We use detergents made for pressure washing. They include surfactants that grab dirt, and in our humid climate, a mildewcide to stop mold from growing right back. Plain water just pushes the grime around.
10. Plan the order, the angle, and the runoff
The last thing we do before starting is plan our path.
We always clean top to bottom, so dirty water never runs over a clean spot. We spray at a slight downward angle, never straight on and never up under the siding. And we make sure pets and kids are safely inside before the trigger gets pulled.
The most common pressure washing mistakes we see every season
We get called to fix these jobs more often than you would think. Avoid these and you are ahead of most weekend warriors.
Spraying up under the siding
This is the big one. Spraying upward forces water behind the panels, into your walls and insulation.
We once got a call from a homeowner whose “quick wash” left a damp, musty smell inside a week later. Water had been driven straight up under the siding. That is a repair, not a cleaning.
Getting too close or using too narrow a tip
A narrow tip held close acts like a blade. It can carve lines into wood, etch concrete, and strip paint.
We keep the wand at least a foot off the surface and let the cleaner do the work.
Washing bottom to top
If you clean the siding before the roofline, dirty water runs down over your finished work. Always go top down.
Using water with no cleaning solution
Plenty of folks think water alone will do it. For mold, mildew, or grease, it will not. You will just spread the stain around.
Working off a ladder
The kickback from a pressure washer can knock you right off a ladder. We use extension equipment from the ground instead. It is faster and far safer.
What detergent and soap are safe in a pressure washer?
The safest choice is a detergent made specifically for pressure washers. It cleans well and protects your machine.
Can I run Dawn dish soap through my pressure washer?
We would not, and here is the honest reason.
Dish soap suds up far too much. That heavy foam can stress the pump, and dish soap leaves a thin film that actually attracts dirt later.
The foam-cannon workaround
If you really want to use Dawn, run it through a foam cannon that attaches to the end of your wand. That bypasses the pump entirely. For real cleaning power, though, a proper pressure-washer detergent wins every time.
What the pros actually use (and why it matters here)
Our Gulf Coast humidity grows mold and algae fast. So we use detergents with surfactants to lift dirt and a mildewcide to slow regrowth.
That is why a professional wash stays clean longer than a quick rinse. The chemistry is doing the real work.
Material questions homeowners ask us most
Can you power wash James Hardie (fiber cement) siding?
Not with high pressure. The maker of James Hardie siding actually warns against it, and blasting it can void your warranty.
High pressure can erode the finish and expose the raw cement underneath. We see a lot of newer homes around Spring and The Woodlands with this siding, and the owners often do not know. The right method is a gentle soft wash, low pressure plus a cleaner and a soft brush.
How do you safely clean an old house?
Older homes need a gentle hand. They were not sealed as tightly as new builds, so water sneaks in easily.
We soft wash them at low pressure, keep our distance, and give the home plenty of time to dry. If the plan is to repaint, we wait a full 48 hours for it to dry out completely.
Should you power wash a concrete driveway?
Yes, concrete handles pressure well, and it is one of our most popular jobs. Pre-treat any oil stains first, then wash.
The one caution: do not overdo it on older concrete. Too much force, too often, can wear down the surface over the years.
Frequently Asked Questions
What should I move before power washing? Move anything that can get soaked or sprayed with cleaner. That means patio furniture, cushions, grills, potted plants, kids’ toys, door mats, and nearby vehicles. Clearing the area also gives us safe, open access to every surface we need to reach.
What do you spray on a driveway before pressure washing? It depends on the stain. Use a degreaser for oil and grease, a sodium hypochlorite solution with surfactant for mold and algae, and an oxalic acid cleaner for rust. Let it dwell about 10 to 15 minutes before rinsing.
Can I run Dawn dish soap through my pressure washer? We do not recommend it. Dish soap over-suds, which stresses the pump, and it leaves a film that attracts dirt. If you must use it, run it through a foam cannon that bypasses the pump. A real pressure-washer detergent works far better.
Can you power wash James Hardie siding? Not at high pressure. James Hardie warns against it, and it can void your warranty and expose the raw cement. Fiber cement should be soft washed with low pressure, a gentle cleaner, and a soft brush instead.
What not to do when pressure washing siding? Never spray upward under the panels, since that forces water inside your walls. Do not hold the tip too close, do not skip the cleaning solution, and do not use high pressure on soft or older siding.
Should you power wash a concrete driveway? Yes. Concrete takes pressure well, so it is a great candidate. Just pre-treat oil stains first and avoid over-washing older concrete, which can wear down the surface over time.
Not sure where to start? Let Mr. Suds handle it
Now you know the routine. If it sounds like a lot, that is because doing it right is.
If you have James Hardie siding, stubborn oil stains, or a two-story home, that is exactly the kind of job we set up carefully every day. We are happy to take the prep, the chemistry, and the wash off your plate, and we can clean your windows on the same visit.
Call or text us at (281) 635-4507 or request your free estimate online. You will get the same two owners every time, fully insured, who treat your home like our own.