How to Clean and Finish a Wood Deck

Wood deck after cleaning and finishing

Since wood sun decks receive constant abuse from the elements, they require periodic cleaning and refinishing to protect them and keep them looking their best.

Start by applying deck cleaner to all the surfaces of the deck and railing using a pump up sprayer. Cleaners often contain strong chemicals, so be sure to read the warning on the container and protect your eyes and skin from contact.

After allowing the cleaner to work for the recommended period of time, a pressure washer is used to clean the deck. Pressure washers deliver a concentrated blast of water at anywhere from 1,000 to 3,500 pounds per square inch and may be purchased or rented at home improvement centers or rental stores.

Use care when pressure washing your deck and don’t overdo it. Pausing for too long in one spot or holding the nozzle too close to the surface can actually damage the wood. For large open areas, a deck scrubber attachment can make pressure washing even easier.

After the deck has been cleaned, it’s time to perform any necessary repairs. Wood movement caused by exposure to the sun and rain can cause nails to work their way out of the board, so drive any protruding nails flush with the surface or replace them with deck screws. Repair or replace any badly deteriorated boards and use a sander to smooth rough spots—especially railings—to prevent splinters.

Once the deck has dried thoroughly, refinish it with a tinted deck stain or clear sealer. Deck stains come in solid colors to hide the grain of the wood and semitransparent shades that allow the wood grain to show through. Since stains and sealers are much thinner than paint, they can be applied using a pump up sprayer as well.

After spraying an area, go back over it with a paintbrush while the sealer is still wet to work it into the cracks and spread the finish out evenly.

If you maintain your wood deck regularly, you’ll be rewarded with many years of service and enjoyment.


  1. This is pretty general information I would like to know more is sealing options. I have used Thompsons water seal in the past but it was oily and left residue on your shoes that tracked into the house. Is there any sealers on the market that are not oily or offer a better solution?

  2. I am looking to find out if you can get cooking oil off 5/4 pressure treated flooring for deck. We have added a deck out from the back porch and i hope we can make the porch decking pretty well match the new but it has that great big cooking oil stain.
    Thank you,

  3. Hi i have just laid a timber deck the timber is a hardwood(spotted gum). I have been told to leave it for 6 months wetting it down 1 or 2 times a month before oiling it. Should i just clean it and then seal and oil it.

  4. Hi Brett,
    The wood for your deck must have been green when it was put down, since the only reason to wait to finish it would be to allow the wood to dry out and equalize with the air around it. After cleaning it, allow it to dry for a few days to a week or two (depending on the weather) before sealing.

  5. I live in central Pennsylvania. I didn’t get a chance to wash and seal my deck this spring and want to do it now. Is it too late to do it now?

  6. I don’t agree that homeowners can’t use pressure washers; some people are reasonably competent and like to do it themselves. The nice thing is, the best one to buy is the cheapest. With two minutes of cautionary reading, the little electric power washers with @ 1000 psi output are a big timesaver and not nearly as hazardous as a big pro setup.

    You can get these for $100 and although they are cheap and don’t last, they are such a time saver for so many spring cleaning projects that you can just throw it away and get another one next year. Or let it break, claim the warranty, and put the new one in storage for next year 🙂

  7. I am a regular homeowner and I have a 3000 psi power washer and don’t have a problem using it correctly. If in doubt re: the proper pressure I would advise practicing on a scrap piece of wood first or perhaps in a spot that isn’t so visible. Good luck.

  8. I am looking for a semi-transparent possibly cedar tone product that will last on my red cedar deck more that 1 1/2 or 2 years. In the last 15 years, I’ve tried a CWD product, several Beare products, and others. They all start wearing or peeling before the end of the 2nd year. The deck has always been properly prepared to like new wood (brightened, conditioned, power washed. etc), but red cedar just does not like any penetrants, and the smooth areas won’t hold long the oil or alcaloyd finishes I’ve tried. All the product claims that you can just clean the deck and reapply the next year are bogus. The deck is on the north side, sunny in the summer, and frequently snow covered all winter. I would go back to a tinted Thompsons spray on each year after a simple deck wash (not a strip) if I could find it. It’s the preparation that is killing me. Any one use a tung or linseed oil as a penetrant? Perhaps diluted with a solvent to carry it further into the wood. I would expect to renew it every year or two, but I don’t want to strip each time. Appearance is somewhat important, since it has a lovley grain and color (gold with red) when preped, but I have to cut down on the time and cost of the prep and materials.

    • Hi Dave,
      Having used tung and linseed oil on interior furniture, I wouldn’t think it would hold up very well outdoors. Since you’re having problems with peeling, you might try stripping the deck down then spraying a clear, penetrating deck sealer, like Thompson’s Water Seal, on it every year. While it won’t last that long, it’s easy to apply with a pump-up garden sprayer.

  9. For what it’s worth, I just started pressure washing my deck with a washer with 2400 PSI and ended up damaging the wood because I didn’t know what I was doing. Also, because I didn’t realize it until later, I sprayed the lattice work at too close a range and damaged a small section as well. Thankfully, I caught on quickly and will not have to replace it. Anyway, I’m just cleaning it up to sell my house. And to those of you who think you don’t need to pretreat with a deck cleaner, well, you may be right. But for me, it was a big time saver. Hope I’ve helped someone out.

  10. I just purchased a home that has a deck.The last few days the sun has been hot and directly shinning on it.There is sap/tar leaking from knot holes that are in the wood.This is terrible and I dont want to track it in the house.How can I stop this or seal it and keep it from weeping/seeping out? Thank you

  11. Chuck,

    Gently scrape the resin off. Lightly sand the area. Seal the resinous knot using a ‘binz’ type sealer. Paint/ stain the area. Eventually the knot will bleed out and the problem will go away.

    The other option is to replace the offending board with a new knot free board.

  12. Someone powerwashed my deck so I can seal it(it was build last summer but couldn’t seal then because it was a very wet fall. There are visible areas where he started and stopped washing–it is very streaked and uneven. What can I do to correct the problems and make it look even?

  13. I am an 84 year old woman and have two 9×12 cedar decks. The south deck needs attention every year. This Oct. it took me five days to clean off mold and apply a clear wood cedar tone penetrating oil finish.. I don’t like wood to be left to turn weathered gray, so now my problem is the muddy tracks from the animals. I wonder if I put plenty of mulch all around to cover the clay soil if it would help …or TRAP and dispose of the animals !! just kidding..

    • Hi, Ron,
      Here’s “Today’s Homeowner” host Danny Lipford’s answer to your question:

      “I would suggest renting an airless sprayer from your local rental center.”

      Thanks for writing to us!

  14. We have a wood ceiling that the former owners laid over the interior ceiling of the existing porch. It has sime fine mold speckled and dirt on it but we dont want to pressure wash it bc we believe that the water will go up beyond the wood panels and into the rest of the ceiling structure and lay there and damage everything. How can we clean it and then stain it???

    • Hi, Karen! Deck stains can fail when applied on dirty decks — and even new decks can collect dirt, mildew and algae (along with nail stains and other things) that can hinder the stain’s effectiveness.
      We do recommend cleaning that deck first.
      Good luck!

    • Hi, Sadie!
      You need a dry deck to apply sealer, but cleaning is a different matter.
      You can pressure wash the deck, which would make it wet, so no, the deck doesn’t need to be dry to clean it.


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