How to Clean Decking Safely and Naturally

A clean deck isn't just about tidying the area or setting up for your next barbecue. Cleaning your deck helps it last as long as possible while also making it look beautiful on those idyllic summer days. You'll need a few common household items and cleaning supplies—or you can spring for a pressure washer. Learn how to clean decking, whether you have a wood or composite deck, in this handy DIY guide. 

Why Clean Your Decking? 

You should clean your decking to help prolong its lifespan, durability, and beauty. Cleaning your deck at least once a year helps it stay free of mold, mildew, and debris. If you plan to refinish your deck, you’ll need to give it a thorough cleaning (and sanding) first. 

How Much Does It Cost to Clean Your Decking?

If you clean your deck yourself, supplies cost less than $20. If you want to use a pressure washer, rentals cost anywhere from $70 to $300 per day. Hiring a local deck cleaning service costs about $30 to $60 an hour, depending on where you live and the condition of your deck. 

When to Clean Your Decking

You should clean your deck at least once per year, ideally in the spring, or when you notice mildew, mold, or excess dirt. Aim to clean the deck when the temperature will be between 50 and 85 degrees Fahrenheit and dry for at least a 48-hour period afterward. 

Allow your deck to dry fully after a cleaning, especially if you're planning to seal, stain, or paint the deck. If your deck gets too wet or isn't able to dry out, it can damage the wood or lead to rot.

Gather your tools and supplies beforehand to ensure a smooth cleaning process. You can use a pressure washer or a long-handled brush, bucket of water, and garden hose. Choose a deck cleaning solution or make a homemade deck cleaner (instructions below). Avoid mixing ammonia-based products with bleach, as it can create a toxic gas.

How to Clean Your Wood Decking

Clean your wood deck to give it a refreshed look and remove dirt and mildew. If you’re refinishing your deck with stain or paint, you’ll want to clean and sand the deck beforehand. 

1. Remove your furniture, grill, potted plants, and other items from the deck.

2. With a putty knife or screwdriver, clear out the debris and dirt from the gaps between your deck boards. The gaps in your deck are essential for water drainage and allowing small debris to fall through.

3. Sweep the deck of all dirt, debris, leaves, grass, and salt.

4. Rinse the deck with a pressure washer, garden hose with a sprayer attachment, or bucket of water and broom. Only use a low setting on the pressure washer along with a sprayer or wide fin. Hold your pressure washer or hose about two feet from the surface to prevent gouging the wood. Move your nozzle continually to avoid spraying too hard in one location. Rinsing is important as it allows your cleaner to disperse better.

5. Apply a gentle deck cleaner or homemade solution to the deck's surface with a long-handled brush or broom. You can clean your wood deck naturally with a mixture of two gallons of warm water and a 1/2 cup of distilled white vinegar or apple cider vinegar. 

6. Scrub areas that are especially dirty or have mildew, mold, or stains. Brush in the direction of the wood grain to prevent damaging the timber.

7. Rinse the deck thoroughly of any cleaner to avoid a dirty film being left on the surface.

8. Let the wood dry out fully, which can take up to 48 hours.

As you clean your deck, look for any broken or loose boards. Repair the parts or retighten them with galvanized screws or nails. If you plan to seal, stain, or paint your deck, ensure you sand and apply the finish before the next rain. 

How to Clean Your Composite Decking

Giving a good clean to your composite decking helps maintain the longevity and durability of your deck. It also makes the surface look fresh and ready for that next outdoor hangout. 

1. Remove your grill, furniture, potted plants, and other accessories from the deck.

2. With a putty knife or screwdriver, clear out the debris and dirt from the gaps between your deck boards. The gaps are important for water drainage and allowing small debris to fall through.

3. Sweep the deck of dirt, debris, leaves, grass, and salt.

4. With a pressure washer, garden hose with a spray nozzle, or a long-handled brush and bucket of water, rinse the deck. Use a pressure washer only on a low setting and hold the nozzle about two feet from the decking to prevent damaging the surface. A solid rinse allows your cleaner to disperse better.

5. Apply a gentle deck cleaner or homemade solution of two gallons warm water and a 1/2 cup of distilled white vinegar or apple cider vinegar. With a long-handled brush or broom, scrub areas that are especially dirty or have mildew, mold, or stains.

6. Rinse the deck thoroughly to avoid a dirty film from drying to the deck. 

7. Let your deck dry fully, up to 24 hours.

As you clean your deck, look for any discolored, broken, or loose boards. Repair the parts or retighten with new screws or fasteners. Because you have a composite deck, you won't need to seal, stain, or paint the surface.

How to Clean Mold Off a Deck

If you spot mold or mildew on your deck, have no fear. With the right products and tools, you can remove mold from your decking.

1. In a bucket, mix your homemade decking cleaner of two gallons of warm water with a 1/2 cup of distilled white vinegar or apple cider vinegar.

2. Rinse the area with a garden hose, a pressure washer on a low setting, or a bucket of water and a long-handled brush.

3. Apply your homemade cleaner to the area and scrub with a long-handled brush or stiff-bristle broom.

4. If the mold remains, sprinkle a 1/4 cup of baking soda on the area and let it sit for 15 minutes.

5. Scrub the area with your brush or broom.

6. Rinse the area thoroughly.

How to Clean a Deck With a Pressure Washer

Cleaning a deck with a pressure washer is a speedy way to get great results, but you'll need to use the right technique so you don’t damage your deck. 

Whether you have a composite or wood deck, here’s how to clean your deck with a pressure washer.

1. Turn your power washer to a low setting. It should be 3000 psi or lower.

2. Attach a sprayer or wide fin.

3. Hold your pressure washer about two feet from the surface. Move the nozzle at all times to avoid spraying too hard in one location and gouging the surface. If you have a wood deck, spray in the direction of the wood grain to avoid damaging the timber.

4. Apply a deck cleaner or homemade deck cleaner if there's still dirt, debris, or mold on your deck. Scrub with a long-handled brush or stiff-bristled broom.

5. Rinse again with the pressure washer.

6. Allow your deck to dry completely, 24 hours for composite and up to 48 hours for wood.

How to Make Homemade Deck Cleaner

With a few simple products you likely already have at home, you'll be ready to refresh your deck for the season. You can make a homemade deck cleaner with vinegar, dish soap, or a combination of dish soap and oxygen bleach. 

Here are three ways to make homemade deck cleaner. 

Homemade Deck Cleaner With Vinegar (for Composite or Wood Decking)

Safe for both wood decking and composite decking, create this solution in a large bucket. 

Mix two gallons of warm water with 1/2 cup of distilled white vinegar or apple cider vinegar. If your deck has spots with mold or mildew, sprinkle baking soda to that area after your vinegar cleaning solution and let it set for 15 minutes before scrubbing with a brush or broom. 

Homemade Wood Deck Cleaner

In a bucket, mix two gallons of warm water with two cups of oxygen bleach. Add 1/4 cup of ammonia-free liquid dish soap and stir again. If you have spots with mold or mildew, add one cup of borax to your solution and scrub the area.

Rinse your deck completely to remove all the cleaning solutions. Avoid using chlorine bleach, which is not safe to mix with dish soap and can also damage your timber. When you’re buying bleach, be sure to double check that it’s the oxygen type.

Homemade Composite Deck Cleaner With Soap and Water 

In a bucket, mix 1/4 cup of ammonia-free liquid dish soap with two gallons of warm water. For spots with mildew, mold, and stains, stir in 1/2 cup of oxygen bleach then scrub the area. Fully rinse after using the cleaner.

Tips for Maintaining Your Decking

Keep your deck in great shape for every barbecue and summer soirée. Here are the best tips for maintaining your deck. 

• Inspect your deck at least once a year. Look for broken or loose deck boards, loose or missing fasteners, and excessive wobbling. Repair and replace boards and fasteners. 

• Sweep your deck a few times a season to remove dirt, leaves, and debris. 

• Rearrange furniture and your grill every couple of months to avoid fading in certain areas.

• Trim nearby plants to be at least one foot from your deck to avoid moisture damage.

• Clean grease, food and drink spills, and mildew as soon as you can to avoid permanent staining. Use a grease catcher with a grill. 

• Redirect downspouts away from the deck to avoid moisture damage and rot.

• Use woven rugs instead of rubber mats to allow your deck to breathe. 

• If you have a nearby fire pit, use a spark screen to keep embers from flying on windy days. 

• Apply a deck brightener every few years to revitalize the surface and remove tannins.

• Avoid using harsh cleaners and using a pressure washer on anything but a low setting, as these can damage your wood.

• Turn to a professional for deck repairs, rather than get in over your head.

DIY vs. Hire a Pro

You can clean your deck on a Saturday morning with a few basic supplies. You can also hire a local deck cleaner or local deck refinisher to cross deck maintenance off your to-do list. Cleaning costs anywhere from $30 to $60 an hour depending on where you live and the condition of your deck.

Refinishing a deck, such as sanding and staining a wood deck, involves more time and some specialty tools. You can do it yourself or hire a pro. Expect to pay anywhere from $600 to $1,360 on average for deck refinishing.