How to revive an old deck

We have an old, worn small deck, pressure treated wood that is in rough shape. Some areas are damp and have a green slime on them. Actually, when the deck was built, they didn't leave enough space between boards - my husband is supposed to take a skill saw to it to open up the spaces. Can this green slime ever be treated/removed? What else can we do to improve this deck? (On a budget!)
q how to revive an old deck, decks, diy, home maintenance repairs
  64 answers
  • Beth Beth on Jul 10, 2014
    I'm not sure this will help...but....if you look at the end of a piece of wood, you'll see that every plank of wood has grain that goes up or down. I believe it's called a "cup". What building a deck, the cup should go down so as the wood ages and bends(warps) in a way, it won't hold water. I think that if you look at the very ends of your deck, you'll find the cups up, therefore holding water= green slimy stuff. Perhaps drilling drain holes in those planks? Or ripping it down and doing it right. Yech! Hope it helps.

    • See 1 previous
    • Shannon Wright Shannon Wright on Jul 12, 2014
      @Beth I work for a cabinet Shop and actually the cup should be alternated up and down so the bows will pull against each other to prevent bowing..

  • Diana Hendricks Diana Hendricks on Jul 10, 2014
    power wash

  • I would check the underside of the boards and see if they look new (I did this on my deck and the underboards looked new on a 25 yr old deck)-If you are on a budget and you are patient, I would clean the deck with simply bleach and water/power wash or use the hoses and then carefully take the boards off and flip them. Use screws to put them back down and you should be able to use the same holes if you mark the boards. Leaving gaps is not that important and did not make your deck look like this-age and lack of proper cleaning and maintenance. If the deck slopes/runs away from the house then having no gaps is not a problem. Also, check how much deck boards are too because 16' long deck boards are less then $10 a piece (I see them under $8 here) and it may not cost you that much money to replace. Make sure to invest in a good quality stain and watch the markdown racks in the paint dept at Lowe's and Home depot for mistints for more than 1/2 off. good luck

  • Carol Claremont Carol Claremont on Jul 10, 2014
    I would power wash first and then you might need to sand it. Home Depot (and maybe others) carry a product by Behr that is called Deckover, I think. You can buy the kind that is just a stain for the railings and then a matching product that actually fills in and changes and protects the wood. We have bought both products but it needs to be below 80 (ish) to get good results so we haven't done it yet. Go to the pain counter and they might have a sample and look at for prices.

  • Melissa Gutilla Melissa Gutilla on Jul 10, 2014
    I would sand it down and put a sealant on it. It should look new again as long as the boards haven't started to rot.

  • Virginia Nelson Virginia Nelson on Jul 11, 2014
    I agree with Carol about the Deckover by Behr. We used it on our deck and also a concrete patio with great results. It actually fills in cracks up to a quarter inch wide and also nail holes. The product is thick like pudding . Be sure to follow directions for thoroughly cleaning the boards before proceeding. Behr makes a product especially for this purpose and it does a very good job without damaging the wood.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    I am going to check out Deckover! Thanks!

  • Lyn Cady Dozier Lyn Cady Dozier on Jul 11, 2014
    Kristi please read reviews on Deckover and Restore - I was going to surprise my parents and re-do their deck while they were out of town. I pressure washed part of it and brought out a lot of splinters, THEN read the reviews. Now I'm not sure what I'm going to do with it.

  • Penny Penny on Jul 11, 2014
    Agree with Lyn Cady Dozier. Read reviews on those thick deck restoring products before using. More problems than the lucky ones like Virginia. Sounds to be labor intensive too & needing 150% good prep. Think about that option before using it. Was going to do it here in MN but have not heard much of any good in our cold climate.

  • Donna Shipley Donna Shipley on Jul 11, 2014
    I had moss (green slime) on the floor in my green house. I sprayed it with vinegar and it dried up and was removed with the "jet" setting on my hose.

  • Mary Law Mary Law on Jul 11, 2014
    I used Deckover on new wood on a ramp and old wood on some steps. So far GOOD. I've only applied 1 coat so far,but plan to hit it again. It makes wood like concrete and extends the life for a long time!

  • Sue Sue on Jul 11, 2014
    Mix Oxiclean and water to clean the deck, looks great and then you can stain, whatever.

  • Anna Erishkigal Anna Erishkigal on Jul 11, 2014
    Those boards look ROTTED, not simply stained. When you go to rip up the boards, you are probably going to damage many of them beyond repair. Suggest you power-wash the deck with a bleaching solution, sand it lightly to remove splinters, seal or paint it, and hopefully it will limp along for a couple more years while you budget to replace it. It looks like this is at a part of your house which doesn't receive enough sunlight to dry the wood out properly, so when you -do- replace it suggest you budget for one of the composite deckings. Some of the newer stuff isn't too fake looking.

  • Dawn Carr Dawn Carr on Jul 11, 2014
    I would go straight to sanding, no powerwashing since you already have moisture issues. if possible, and screws were used remove the pieces that have extensive rot. then seal!!

  • Susan E Susan E on Jul 11, 2014
    Powerwashing can damage old wood (like bringing up splinters mentioned above). I used vinegar and water on mine as we have cedars which turn the deck wood black. I also used a good deck brush and an oil stain. There were some dry rotted boards which I replaced. You can also get a wood hardner if the dry rot is only in a small area. Use for the support structure, not for the boards you walk on. Replace those.

  • Susan E Susan E on Jul 11, 2014
    Of course I am in California and my big problem is too much sunshine drying out my wood. Snow in winter, SUNSHINE in summer. :)

  • P.j. C P.j. C on Jul 11, 2014
    I disagree with the comment that you don't need to provide drainage. Decks aren't always constructed with enough slope, so rainwater may not run off. That's why common practice is to leave a small space between boards, about the width of a large nail. Even if you scrub or powerwash the surface, algae will grow back in an area that doesn't receive full sun at least a couple hours each day. But before investing too much time in powerwashing, check to see how level the surface is. For proper drainage experts recommend a minimum of 1/4" per foot drop on rough surfaces, which would be 2" drop for a 8' span. If your deck doesn't have that much slope you'll either have to address drainage (remove & reinstall the boards with space between) OR scrub/powerwash the surface every few weeks. Algae will still grow on sealed wood if there's enough moisture & shade, so I wouldn't waste time sanding & sealing the surface until the drainage issue is resolved. My DIY hubby says sawing between the boards would be easier said that done & also risky, because the blade would probably get caught & seize or hit hidden nails or screws.

  • Heather Heather on Jul 11, 2014,,20282692,00.html this video is very helpful and cleans up old decks nicely. To clean between the deck boards I use a hack saw blade (no power, just elbow greese)

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Oh! Wow! Thanks for the heads up Lyn!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks for the tip Penny!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks Donna, I will try it on a test spot and see if it makes a difference!

  • Jeane Gross Jeane Gross on Jul 11, 2014
    Kristi, lots of good suggestions here. If you find you have enough slope for proper drainage and the boards aren't rotted so you need to replace, I would highly suggest you check out before making your final choice as to how to restore your deck. I think you will be absolutely amazed at the before and after pics when using this product. AND it can be used for other purposes as well, not just cleaning decks (I also used it to remove the yellowed age stains from my mothers silk baby dress). Plus, it is plant and pet friendly. Tim Carter, contractor/builder invented this product after years of using products that don't work or harm the wood. I am in process of cleaning my deck with it right now. Pressure washing is extremely harmful to the wood if you aren't very careful. I found Stain Solver because I pressure washed my front porch and steps and damaged the wood in the process causing it to splinter, this resulted in lots of sanding and staining to get it looking good again. I did this myself as I too was on a budget and a novice at maintaining wood decking. Over the past 6 years, I have tried several different brands of stains, wood preservatives and maintenance products and many have failed within just a few months. Cleaning, sanding and staining is not easy and who wants to keep doing it over and over again when the products you are using fail. Tim also did a 3 year study using numerous Brands of deck stain to see which one stood the test of time and weather elements. After seeing these results, I chose Behr. Good luck.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Good to know Mary Law! Thank you!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Hey Sue! I have Oxiclean and will give this a try! Thank you!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Anna, you are right on both counts. Wood it pretty much rotted and this part of the house gets little sunlight. Thanks for your suggestions.

  • Pat Pat on Jul 11, 2014
    A friend living in Iowa said she and her husband used oxyclean and a scrub brush to get the mold and slime off of their desk. Lots of work, she said, but looks like new.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Good point Dawn. Thank you.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks Jeane. I will consider the stain solver. Glad you had good luck with it!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks Heather! I will check it out! :)

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks P.J. My husband realizes that the drainage issue has to come first. I picked up a blade for his saw today....He is going to give it a try, but I will definitely mention your husband's warning! Thanks!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks Susan!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Just want to thank everyone for taking the time to respond. There are a lot of great tips here. I'm actually blown away by the response. What a great community. Thank you! :)

  • Tegma Tegma on Jul 11, 2014
    Have you tried pressure washing the deck? That should clean up the green mold and everything, preparing the deck for a stain. Yes, the boards need to be separated for the water to seep down between them. But other than that, it just needs pressure washed and then go to Lowes for a proper stain (Paint).

  • Tegma Tegma on Jul 11, 2014
    (When you pressure wash, add a little bleach to the water for the mold problem.)

  • Sandy Slade Sandy Slade on Jul 11, 2014
    Hi, Have you thought about drilling holes every so often instead. It may be easier than sawing gaps.Then may be putting a waterproof light underneath for a alternative lighting effect for the evenings.

  • Sandy Slade Sandy Slade on Jul 11, 2014
    This is after it has been repaired . Then holes drilled Then jetwashed so all the water can escape then revairnished of course. I love jetwashing the smell of the sea is lovely and the satisfaction I get from doing is fantastic. If I lived in your country I would of come and done the job for you .

  • Barbara Turner Barbara Turner on Jul 11, 2014
    Hmmmm if it were me, and budget allowed, I'd tear this all out, redesign it and build it with the new Trex decking. End of story! These boards here are going to have so many splinters, damage and wood rot that I'd literally be afraid to stand on it. It wasn't installed correctly obviously because it doesn't have the proper spacing. God only knows what it looks like underneath and I'd wonder about how it's mounted to the house. There are specific codes to follow.

  • Wilma Hurley Wilma Hurley on Jul 11, 2014
    Pressure wash with bleach or awesome from dollar store then seal

  • Jo Boswell Jo Boswell on Jul 11, 2014
    My deck boards are not in great shape, spacing is good though. I've been looking into, reading about & checking reviews for Olympic Rescue It, Rustoleum Restore & some others. Olympic had the best reviews. This is what I'm going with; 10x thicker than paint, scads of colors, fills minor cracks & locks down splinters.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Thanks Patricia!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Hi Sandy, I love the under deck lighting. What a cool idea! Thank you!!

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Really? You are welcome anytime! ;)

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Funny you say that Barbara Turner! A home inspector did say that it was NOT mounted to the house properly. There are a lot of things wrong with this house. We tried to sell and long story short, it didn't work out after years of being on the market....WE moved every last thing out, only to have to move back in. Buyer was dishonest about income etc..etc....Honestly, I am not very happy here. But what can you do? What can you do.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 11, 2014
    Sounds good Jo. Thanks!!

  • Lauren Lauren on Jul 11, 2014
    Home Depot has a product called Deck Over, it's much thicker then stain or paint and with 2 coats they say it will seal all splinters and smooth out old wood. It comes in a few colors too.

  • Mikell Paulson Mikell Paulson on Jul 11, 2014
    I had the Trex Deck and it sucked. I did the Rustoleum Restore! Looks much better and has not been slippery or slimy like the Trex. I did not have to power wash it. The Trex needed it every year. I wish I had put in wood when we built the house. Good luck!

  • Before you spend any money on the deck surface, you need to check the framing under it for rot and decay. Take a long thing screwdriver and try to push it into the top of the framing near where the deck boards are attached. If the framing is in good shape, although funky looking the screw driver should only go in enough to put a dent in the wood. If it is soft and the driver pushes easily into the framing will need to be replaced so any work on the top surface would be worthless. To start off with, do not waste any time with cutting into the spaces between the boards. The smaller the gap the better. Water will drain through the boards sufficiently as it is. Making the gaps wider will only allow for heals to get stuck if they are thin enough and items such as leaves and such will get stuck making them harder to get out later on. On any steps if you have them, if the step boards are single boards that are 10 or 12 inches wide, Drill half inch holes about 12 inches apart. This will allow any standing water that could occur if the boards have cupped. This can create a slipping issue should water rest on the steps in the winter and freeze. With small holes in the center of the step will allow any water that could collect on each step to drain away. A complete power washing is in order. Using a 2500 psi unit will do nicely. You need to move along with the wand while keeping it about six inches from the deck surface. If you go to slow you will begin to remove the surface wood on the deck raising the grain of the wood and along with that splinters. You want to move just slow enough to remove the surface dirt and mildew. You can get deck cleaning soap to use with the washer. I personally suggest that you use a garden sprayer with those chemicals and wet the deck with it. Using a scrub brush on a long pole scrub the cleaner into the wood surface. Do not allow it to dry. Once the cleaner has been on the deck for a short while, then have at it with the power washer. Do not use bleach, vinegar, or anything other then deck cleaning soap. Bleach will do nothing other then empty your wallet of cash, or kill vegetation that surrounds the deck itself. . I know a lot of folks suggest that you use it, but it will do nothing for you. Once the deck is completely clean, you will want to prep it for stain or paint. Using a vibrating sander go over the deck surface removing any splinters and rough areas that were exposed using the power washer. If nails are coming up, remove them, do not nail back into place. They will only come out again. Replace these nails using a long deck screw and set them tight so the heads are sunk into the surface of the wood. Done, never will come up again. Now comes the painting/staining part. Restore or any of these deck restoration paints work well, but everything needs to be done properly. Start by doing the work on a cool day with perhaps overcast if you can. and as soon as you can once the deck dries and all the prep has been completed. If you wait for perhaps the following weekend, a patina will form on the deck surface preventing the paint from sticking as it should, so its performance will be much less later down the line. (if you read complaints about these products people claim the paint peels, this is the result of waiting to long between the cleaning and the painting) The sun simply dries everything to fast. mask the wall off around the areas where the deck comes up to the house. Even if your careful, when using the roller the paint will splatter no mater how careful you are. Use a stiff brush and work the paint into the spaces between each board and into every crack that is more then 1/16" in width. It may seem like a lot of work as the directions do not tell you to do this, but trust me, it makes a big difference if you do this step first. Then using a high quality roller and good strong pole install the manufactures recommended roller cover and being painting. Its not going to look anything like it does in the how to videos. You will be using at least twice the amount of paint then they suggest. I know as I have done several of these decks and I have never even come close to applying the paint in the quantities that are suggested on the label. The paint goes on slow and thick. Also heavy. You need a lot on the roller so simply dip it into the paint and roll, you do not need to work it off the roller pad like you would do with regular paint. You want globs of this on the pad so when your slowly painting it stays wet and ahead of the pad as its rolled down the deck. Pulling the paint is the best method. You can roll back and forth but its not suggested. Simply pull the paint towards you as you move along. Doing four or five boards at a time. Let it sit for about an hour and then do another coat. If you do not want to use the restoring type paints, you can fill gaps in the wood surface using wood hardening putty. This material is a dry powder that you mix with water to a putty thickness. Then using a stiff putty knife, push it into the gaps of the wood, filling as much as you can. let dry for a few hours then sand the deck surface. Once dry use a stain sealer so this putty that you just applied will take the stain that your planning to use, which should be a solid stain, evenly. If you do not seal the deck first the surface of the deck will be lighter and darker with the putty showing up. Stains are much better then paints as stains will allow the boards to breath, Paint creates a vapor barrier that traps moisture that comes from the other side of the deck boards causing the paint to peel Stain will allow the moisture to travel though the surface and harmlessly into the air. The railings are another issue. All done the same as far as finishing, but they do not meet any code. The boards should not be horizontal. This allows small children to climb up and fall over. Only a top and bottom board should be place with the bottom horizontal board about four inches off of the deck surface. Then nail the vertical balusters in with a space that a tennis ball can just not quite fit through. If you are tight on cash, use lattice panels between the boards. But do not keep the horizontal boards in place as they are unsafe.

    • See 1 previous
    • @Kristi Davis Maloney If your going to cut between the boards, do not do anything wider then the saw kerf width. Be sure to wear a mask when doing this, if indeed its treated lumber as the saw dust is toxic that comes off the wood as its cut.

  • Marsha Spears Marsha Spears on Jul 11, 2014
    I just finished cleaning a deck that looked almost exactly like this. It now looks close to how it looked thirty years ago when it was built. First, I put the kettle on and while it was coming to a boil, I put on my wellies and "work clothes". I put a cup of bleach and a scoop of powdered laundry detergent in a tub. Next, I added the boiling water and gave it all a good stir, then added enough tap water to fill the tub. With a broom, I literally swept on the concoction and left it very wet. Then, I let it dry for a couple of days in the heat and sunlight. Later, I used the power washer and gave all of it a good blast. That was the hard part. The power washer seemed to clean in stripes. Up close I couldn't see that when I was cleaning, but when I stepped back the stripes were very obvious, It was slow hard work, and took a couple of hours, but the results were outstanding. Even knowing how "not fun" it was, I would definitely do it again. With some plants, furniture, candles, and a rug, I have a lovely deck now. Good luck!:.

  • Mar369880 Mar369880 on Jul 12, 2014
    We use a product called. 30 seconds. Kills the slim. Brightens the wood. It is fabulous.

  • Connie Shurtz Connie Shurtz on Jul 12, 2014
    Bleach and a good household cleaner. Apply it and wait a little while then either scrub off by hand or garden hose. Power washers can be rented and come with adjustable pressures but do a fantastic job and removing the dirt. Also you could paint it afterwards and even tape off some design such as a rectangle or stripe and paint or stencil a design on it to draw attention away from the damaged areas.

  • Mary Law Mary Law on Jul 12, 2014
    So far, so good with my 1 coat of Deck Over! Hope it stays that way till I can put next coat on and do the trimming!

  • Lauren Lauren on Jul 13, 2014
    Another option is to flip the boards. I had this done to my deck last year, the underside of the wood was like new! I power washed it and sealed it as soon as it was totally dry, looks like a brand new deck. A few boards had to be replaced because of rot/splitting but it was a fraction of the cost of replacing the whole deck.

  • Penny Penny on Jul 14, 2014
    @ Lauren - just curious, were your boards screwed or nailed?

  • Penny Penny on Jul 14, 2014
    Thanks, Kristi. I hope Lauren sees my post too because I was curious about her deck when they flipped the boards over. Ours are nailed too & I'm concerned that removing nailed boards would do quite a bit of damage to them in the process. Thanks again.

    • Lauren Lauren on Jul 20, 2014
      When they pulled the boards up they cut the old nails off, flipped them and wah lah brand new boards

  • Tegma Tegma on Jul 14, 2014
    Lauren... I'm glad you mentioned "flipping the boards". I'm wanting to do that and my son told me it wouldn't work. Aha! Now I can show him your testimony to the fact that it does! I'm 72 and would do my own work, if I can just get him to take the boards out for me. Unfortunately, the people who built the deck, used nails instead of screws! Even as an old woman, I know better than that! LOL Thanks for the confirmation!

    • Lauren Lauren on Jul 20, 2014
      They used a block of wood and crow bar, the boards pulled up easily and only a few needed to be replaced due to some wood rot.

  • Cathy L. Cathy L. on Jul 18, 2014
    Believe it or not if you get the ends loose then lift the boards straight up the nails just pop! (most of the time!)

  • Sandra Whittier Sandra Whittier on Jul 18, 2014
    Lowe's and Home Depot sell a wood deck cleaner and if you use it you will cut your work down by 2/3. I have put on the kettle and all the other things mentioned here, but (I'm sorry I don't remember the name, I just know I was very impressed.

  • Its natural to flip the boards, however you need to check the grain pattern on the wood. If the deck, or any deck was correctly installed, the crown of the grain needs to be up. This causes the wood to curve with the high spot being in the middle of the board. This does a few things, 1. it allows the nails which are near the edges to hold better, but more important it allows water on the board to run off the sides of it keeping it dry. If you turn the board over, the board will have a cup shape. This shape will lift the nails right out of the joist that supports it, but again more important is the board will allow standing water to remain on the surface causing it to mildew faster, cause clear ice in those areas that freeze and will cause high spots on the deck which can result in a possible tripping issue.

  • Kristi Davis Maloney Kristi Davis Maloney on Jul 19, 2014
    See below pic. We pressure washed w/o any cleaner or household product. Not perfect but much improved.

  • Tegma Tegma on Jul 20, 2014
    Glad to see the pressure washing worked! Now, all you need to do is hit Lowes or Home depot for some deck stain, and I'm sure you will be really happy with the deck!

  • Penny Penny on Jul 20, 2014
    Thanks for your reply, Lauren.

  • Tegma Tegma on Jul 20, 2014
    Lauren When you say they used a board and crowbar to lift your deck boards, can you tell me how the board was used? My boards are nailed in with 2 1/2 - 3" nails and I can't get them out for anything. Also, my boards are 16' long. I'd sure appreciate further instructions.... I know how to use the crowbar okay, but was the board used like a lever or what?

  • Adele DuranGO Adele DuranGO on Oct 03, 2016
    Please see my post: We saved $$$$$$$ and are in love again ;) The character will blend beautifully and look artsy as all get-out.