How to Pressure Wash a Deck the Right Way
Hi, I’m Scott Paul, a licensed exterior restoration contractor with over 30 years of experience and 10,000+ deck restorations. This guide to pressure washing wood decks is based on my own hands-on field experience, not manufacturer claims.
We suggest that only experienced professionals use a power washer when deck cleaning or doing exterior wood cleaning. That being said, it will obviously make your deck cleaning a lot quicker if you do use a power washer. If you use a power washer, please follow these guidelines.
- Always apply a deck cleaner or stripper before pressure washing; these products do 90% of the cleaning work.
- Use the power washer only as a high-pressure rinse, never as the sole tool for cleaning wood.
- Wash with the grain using a continuous sweeping pendulum motion; stopping mid-stroke causes visible stop marks.
- Keep pressure between 1,200 and 2,000 PSI at the wood surface; distance from the nozzle significantly affects actual pressure delivered.
Table of Contents
Power Washing Guidelines for Decks
1. Always Use a Deck Cleaner or Stripper First
Always use a deck cleaner and/or a deck stripper. The cleaners do 90% of the work.
2. Use the Power Washer as a Rinse, Not the Main Tool
Use the power washer as a high-pressure rinse off. Never use it as the only tool to remove or clean the wood.
3. Wash With the Grain in a Sweeping Motion
Wash with a motion similar to sweeping a broom (pendulum motion). Wash with the grain of the wood. Exaggerate your sweeping motion, never stop, and reverse your direction without sweeping up. Failing to do this will result in a “stop” mark on your decking.
4. Keep Pressure Between 1,200–2,000 PSI
Never use more than 1,500 to 2,000 PSI of pressure. This doesn’t mean you can’t use a 3,000 PSI machine — it’s only actually delivering 3,000 PSI if you’re washing from 1 inch away. If you’re 8 to 12 inches away, you’ll be using about half that amount of pressure.
5. Exercise Caution or Hire a Professional
Please be sure to exercise caution when using a power washer. Improper use could result in severe damage to wood. If you don’t feel qualified, consider contacting a professional in your area.
For more info on how to properly clean a deck, visit DeckStainHelp.com for all deck-related things.
Deck Pressure Washing FAQ
What PSI should I use to pressure wash a deck?
Keep pressure between 1,200 and 2,000 PSI at the wood surface. A 3,000 PSI machine can still be used safely if you hold the nozzle 8 to 12 inches away from the wood, since actual pressure at the surface drops significantly with distance — it’s only true 3,000 PSI at 1 inch away.
Can I pressure wash a deck without a cleaner first?
You can, but you shouldn’t rely on the power washer alone. A deck cleaner or stripper does about 90% of the actual cleaning work by breaking down dirt, mildew, and old finish; the power washer should only be used to rinse that loosened material off, not to clean the wood by pressure alone.
Why does pressure washing sometimes leave marks on a deck?
“Stop marks” happen when you pause or reverse direction mid-stroke instead of using a continuous, sweeping pendulum motion with the grain. Stopping in one spot concentrates pressure and can etch or discolor the wood right at that point.
Should I hire a professional to pressure wash my deck?
If you’re not experienced with a power washer, it’s worth considering. Improper technique or excessive pressure can cause real damage to wood, including gouging, splintering, or uneven cleaning that shows up once you stain. A professional already knows the right pressure, distance, and motion for your specific wood type.
Which direction should I move the power washer wand?
Wash with the grain of the wood in a continuous sweeping motion, similar to sweeping a broom. Keep the motion going without stopping, and avoid sweeping back over an area you’ve already passed, since that inconsistent pressure is what causes visible marks.
Other Related Must Reads!
- 101 Wood Deck Restoration Tips
- 10 Myths for Wood and Deck Restoration
- Stain a Deck in Two Hours
- Wood and Deck Cleaning Tips
- Wood and Deck Stripping Tips
- Wood and Deck Brightening Tips
After pressure washing. What kind of problems am I going to have if I leave it unsealed for two weeks?
I tore up my deck in the beginning of pressure washing. Didn’t do my homework and learned quickly too back off but the portion I did rip up. Should I just sand it down or can I use a filler then sand and seal?
Fillers will not work. You will have to power sand to fix.
Thank you.
Yes that could create issues with stain absorption.
Thanks again for the quick reply!
Is it problematic to sand with a belt sander? Is the problem that it might “close-up” the wood and not allow penetration or is there a different reason?
Thanks again, this has been very helpful.
Lightly hand sand slivers is okay before you clean and brighten the wood.
Thanks for the reply!
If the deck has potential for slivers, i should sand it right? and sand it before doing anything else?
You are correct but you do not need to sand the deck so you can skip that step.
No you cannot use wood filler on outside wood. It will not work.
Can poly eurathane caulking or wood filler be used in cracks? IF so, at what point should this be applied?
4 year old PT deck that has never been stained. Just treated once with a wood preservative. What steps do i follow to stain deck?
1) Level
2) Sand
3) Wet deck
4) Apply cleaner
5) Rinse with pressure washer
6) Apply wood brightener
7) Wait 48 hours or until dry
8 Apply stain
Is this right? Do I sand before applying any cleaner or brightener?
Thanks!
Surface damage.
I had to take off BM Arborcoat that was peeling badly. Other sites had said that deck strippers do not remove this product well so I did most of the job with just a PWer. The worst peeling areas came off easy with the PWer. However, other areas that were not peeling required a lot of water pressure. The wood is 5/4 cedar with tight knots. Yes I have left some marks with the PWer that I intend to sand. Yes I definitely did use more than 1200 psi. (The PWer is a 2600psi.) I used the widest (40 degree) spray attachment but I did hold it close in some areas.
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Do you tell people not to do this to avoid surface damage (ie marks) or have I irrevocably damaged the cedar decking by applying that much water directly at high pressure into the wood?
I have about 25% of the deck left to do and most of that has little to no peeling occurring so I expect it would be tough to take off with just the PWer.
The only way to fill cracks is to use a solid stain and that will look like a paint. We sell semi-transparents and since this wood is dried out and neglected, we would suggest the Armstrong Clark in one of the semi-solid colors. You can spray it on but you will need to back wipe to ensure uniformity.
Hi, I just purchased a short sale home in the northern mountains of Asheville. The deck has been up for 4 years and is showing splitting and chipping from the weather. It has never been stained or coated.We have a normal mix of Summer sun, Fall/ spring rain, Winter rain ,snow and some ice. No mold to speak of, so the deck does get the Southern sun. What is the best product for this issue. I was looking at Olympic solid color stains to fill the cracks but its a Lowes product….. I was looking at TWP or Armstrong Clark with a basic sprayer.What direction should I go? Do I need the professional sprayer? I plan on ordering these products ASAP.
Thank you.
I also have this to add; Make sure that you’re strong enough to handle it.
I’ve seen quite a few incidents where people have gotten some minor injuries from using a pressure washer they weren’t strong enough to handle. They’re very powerful machines, and even the spray can cause you a few bruises at close range.