Your deck is more than just a functional addition to your home. Like most things, it attracts dirt and debris and needs semi-regular cleaning to maintain its condition and protect your investment.
In this article, we’ll teach you how to pressure wash a deck and cover a few frequently asked questions surrounding this topic.
Let’s get started!
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Hey there, I’m Cody.
A decade of residential and commercial pressure washing led me to start JCS Refresh. Now I can share my knowledge with folks like you.
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Quick Answer
Want to skip the long read?
We’ve compiled six easy steps to pressure wash a deck correctly.
- Clear the space
- Wet the area
- Apply your cleaning product of choice
- Tackle those stubborn stains
- Give your deck a final rinse
- Allow your deck to dry completely before staining or sealing
If you’re looking for a step-by-step guide, keep reading because we’ve got some more tips to ensure you don’t damage it while cleaning
Quick questions before starting
Pressure washing isn’t a simple point-and-shoot task.
Let’s review some quick questions to see if you’re up to the task and what materials you’ll need.
How difficult is this to do?
Pressure washing a deck falls into the medium category, but only because wood and other materials are sensitive to damage.
Some materials are more delicate than others, so control and precision is essential to avoid damage.
How long does it take to pressure wash a deck?
Cleaning should take around 2 hours, or longer, depending on the size and condition of the deck, but drying time can be up to 48 hours.
How to pressure wash a deck
Here’s the best way to pressure wash a deck in six easy steps:
1. Clear the area
First, remove leaves, furniture, and other items obstructing the area you plan to clean. You can also take this time to cover nearby plants, outlets, and other things that may get wet.
With this, use a putty knife to remove trapped dirt and debris lodged in cracks. Pressure washers are great, but attending to little details is sometimes necessary.
2. Wet the area
Next, wet the area with your 40-degree nozzle before applying soap in the next step.
To learn more about nozzle types, you can read our article on how to use a pressure washer.
3. Apply your cleaning product of choice
To begin, use a deck cleaner or a wood stripper and wash the railings first.
Then, apply the solution from top to bottom with the black soap nozzle and let it sit for 15 minutes, or follow the directions on your cleaning product. Remember, it’s best to work in small sections.
Next, apply a deck brightener if working with extremely dark wood.
Before the soap dries, rinse the surface in a sweeping motion to remove marks.
Choose between a 40-degree and a 25-degree nozzle, depending on the type of wood. If you’re washing other outdoor surfaces, visit our article about types of pressure washing soap.
4. Tackle stubborn stains
For mold and mildew, use a solution made up of 1 part bleach 4 parts water, and for tougher stains, use a TSP substitute.
Agitate and distribute the product with a nylon brush. Then allow the product to sit for 15 minutes before rinsing. Lastly, sand the surface with 80-grit sandpaper to remove any rust stains.
5. Give your deck a final rinse
Give your deck one last rinse with the 40-degree nozzle. When cleaning the railing, always rinse from the bottom up.
6. Allow your deck to dry completely before staining or sealing
If it rains, wait for your deck to dry for 48 hours or more.
Then apply the stain to the top rail and all surfaces of your deck, working from the top down.
Using a foam applicator pad, stain one section at a time. As you work, brush away any drips. You can cover each board with an extension pole or spray the stain in a spray bottle for areas with unique shapes and structures.
Power washing vs. Pressure washing your deck
Even though they are not the same, power washing and pressure washing are frequently used interchangeably.
The system’s water temperature determines the difference between pressure washing and power washing.
For example, power washers use hot water to dissolve tougher stains, such as grease, whereas pressure washers use cold water.
Although hot water is more effective at removing stains, wood is delicate. Therefore, stick to pressure washing and use the correct PSI setting for your deck’s material.
Items needed
If your deck doesn’t have specific problem areas, you can leave a product or two out, but it’s always best to have the essentials on hand.
Those essentials include:
Pressure washer – Prices range from $160 to $500+ depending on PSI and GPM, and if you’re using a gas or electric-powered model.
Light-duty pressure washers with 500 to 1900 PSI can clean soft and hardwood, but if you’re also washing other exterior surfaces, choose a medium- or heavy-duty pressure washer.
Don’t want to buy one? Rentals cost $40 to $100 per day.
Deck cleaner – For areas that require a little more attention, a good deck cleaner should be gentle but effective on both your machine and the surface. A good cleanser can range between $20 and $25.
Wood stripper (optional) – A wood stripper is an excellent alternative to deck cleaners for removing dirt on the outermost areas—these range from $25 to $33.
Deck brightener (optional) – Another optional cleaning product, deck brighteners are especially effective on dark decks. A brightener after cleaning allows the wood to absorb stains even better—these range between $16 and $28.
Putty knife – A reliable putty knife can dig trapped dirt out between deck boards and typically only costs between $7 and $8.
Non-chlorine laundry bleach – Removes mold, mildew, and algae that will not come off with a regular deck cleaner. You can expect to pay between $16 and $21.
Trisodium Phosphate (TSP) substitute – This chemical is an excellent cleaner for hard-to-remove stains and costs between $13 and $21.
80-grit sandpaper – sanding your deck first is your best bet if it develops rust from nails or other stubborn stains—packs of sandpaper run from $5 to $11.
Nylon brush – also known as a wire brush, this tool is used to spread chemicals on specific areas so they can break down organic growth easily. Brushes are available for $5 to $7.
Wood stain – apply this after your deck has completely dried to restore its original appearance. Stain typically costs between $8 and $20.
Foam applicator pad – this tool helps you apply an even amount of stain and ranges between $7 and $9.
Extension handle – attach this to your applicator pad to evenly apply stain to your deck—these range between $18 and $20.
Spray bottle (optional) – for areas of your deck with unusual shapes or structures, you can apply stain with a spray bottle, which costs $9 to $12.
The total cost of supplies is approximately $309 to $642.
Safety considerations
Below are some pressure washing tips and tricks to wash your deck safely.
- Always point your wand in a safe direction: Point your wand away from people, animals, and electrical outlets.
- Test the pressure and don’t get too close: Before cleaning, test the pressure on a small or hidden area to ensure that it’s at the right setting and will not damage the surface. Then, hold your wand about 6” from the surface when cleaning.
- Use the correct nozzle: We suggest using a 25-degree and 40-degree nozzle for decks.
- Choose the correct type of detergent and chemical: Wood is easily damaged, so choose a chemical solution that’s safe the environment, your wood, and the machine.
- Wear protective equipment: Dirt, debris, and cleaning solutions can easily backlash on your eyes and body while pressure washing. Wear safety goggles and other appropriate equipment to safeguard yourself from harm.
Deck types and how to pressure wash each
Deck materials come in various forms, and their cleaning process may differ slightly.
To get you started, we’ve covered five of the most common types of decks and how to wash each.
Cedar
Cedar decks are made of less dense wood and are prone to dents and dings.
When pressure washing cedar, always start with the lowest pressure possible (around 500-600 PSI). Instead of a stripping solution, use a deck cleaner to avoid damage.
We recommend using a deck brightener to restore the look too. Always apply a stain afterward; otherwise, dirt and dust will sit on its surface.
Spruce, pine, and other treated lumber
These are classified as hardwoods and can withstand 1200 to 1500 PSI.
You can use a deck cleaner or stripper on these materials too. However, they still need regular cleaning.
Trex composite decks
Composite decks are made of synthetic materials. They have the appearance of wood but are primarily made of plastic, so deck cleaners and strippers aren’t required.
Trex can withstand up to 3100 PSI, but we recommend starting with lower pressure. Additionally, we recommend using a brush to remove tough stains, mold, and mildew.
Fiberon composite decks
Fiberon is opposed to using pressure washers for cleaning.
However, if you still want to use your machine, keep your pressure low because the damage caused by pressure washing may void the warranty.
One more thing- we recommend keeping a distance of 12” from the surface.
PVC composite decks
PVC is durable, but pressure washers easily damage it. Stay under 1500 PSI because anything higher will easily etch this material. Also, keep at least 8″ from the surface when cleaning.
Frequently asked questions
Here are some of the most common questions people ask us when pressure washing their decks.
If you have a question that isn’t answered here, please contact us, and someone from our team will get back to you.
What PSI do I need for a deck?
500 to 600 PSI for softwoods like cedar or pine works best.
For harder woods, we recommend 1200 to 1500 PSI.
How much does it cost to pressure wash a deck?
On average, pressure washing a deck costs about $.30 per square foot. On average, labor costs about $.51 per square foot.
Should I pressure wash my deck?
You bet! Pressure washing is the most effective and efficient way to clean your deck or patio. Just remember to take it slow and adjust your PSI appropriately. To learn more, check out our full guide about 5 reasons to pressure wash your deck.
How often should I pressure wash my deck?
We recommend that you pressure wash your deck at least once a year.
Need some convincing? Here are some oddly satisfying deck before and after pictures that might make you think twice.
Which pressure washer nozzle is best for a deck?
Use a 25-degree nozzle for cleaning and a 40-degree nozzle for rinsing.
Can you pressure wash Trex deck?
Yes, you can pressure wash Trex, but use EXTREME caution.
Should I pressure wash my deck before staining?
Absolutely! Always wait to stain until after pressure washing. Your deck must be clean, free of dirt and debris, and completely dry before staining.
Can you pressure wash stain off a deck?
We suggest using a deck or wood stripper to remove stain and paint from a deck.
Pressure washing decks – Before and after
Pressure washing is the most effective way to clean the exterior of your home, and it can completely transform old and worn-out decks.
Here are some great pictures to show you the power of pressure washing.
Conclusion
Your deck or patio gives you extra space to entertain guests, exercise, lounge, and host parties, so keep it clean!
Always consider your deck’s material, research recommended PSI levels, and understand how to target specific problem areas on your deck with safe cleaning detergents and chemicals.
Looking for local deck cleaning services? We have you covered.
If you’re looking to pressure wash your fence next, we’ve covered that too.
Thanks for reading!
