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DIY Outdoor Table: What to do with Leftover Composite Decking?

Did you just build a composite deck? Learn how to build a large DIY outdoor patio dining table out of Trex decking. We love that this outdoor DIY project used some materials we already had.

gray composite decking pile on top of deck being built with arrow pointing to gray composite decking outdoor table.

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We recently put a brand new screened-in porch and deck onto our house. We are all about DIY projects, but this big deck and porch we left to professionals. They left us with a bunch of leftover composite decking that we just couldn’t waste.

We absolutely LOVE this outdoor space, but we needed ideas for what to build with our leftover composite decking. Here is our step-by-step DIY outdoor table tutorial.

Reasons To Use Composite Decking Material

  • More rot resistant than wood
  • Is more bug resistant
  • Less maintenance
  • No need to buy gallons and gallons of stains and sealers like wood decking
  • Some companies use recycled materials to create composite decking
  • Nails are not as visible (decking technology is always improving)

Why build a deck out of composite decking?

If you are building a deck that you want to last composite decking is the way to go. While the price is more expensive at the beginning you will have less maintenance (like our DIY composite deck cleaner) and it will last for at least 25 years or more as it says in this HGTV article.

gray composite deck being built

Save Money By Using Leftover Cut Pieces

In the image above you can see the in-progress composite deck being built. We had a lot of leftover pieces of composite decking since you buy it by the board.

Why not use leftover composite decking pieces when building outdoor composite furniture?

Composite decking will not rot like even pressure-treated wood and bugs don’t seem to like the product. Not to mention you can get Trex or composite decking in a variety of colors without having to stain it.

What can you build out of leftover composite decking?

  • Composite decking benches
  • Flower boxes made out of Trex
  • Outdoor bar
  • Outdoor side or coffee table
  • Adriondack chair
  • Raised garden bed (you can see our cedar raised garden boxes here)
  • Outdoor playset or platform for a playhouse

As you can see, many different project ideas can be made with leftover composite decking.

To buy or not to buy an outdoor table?

If you shop around for different outdoor tables, they can be quite pricey. The idea that we could reuse a material we already had for an outdoor table was a way more budget-friendly and eco-friendly solution.

I just couldn’t bring myself to buy a new table when we could make one. The gray decking boards would be a great DIY outdoor tabletop.

Gray timbertech decking board

Decking Table Design

One of these projects was to create a DIY outdoor table that would be able to sit with more than 10 people. We decided on making two smaller and skinnier composite decking outdoor tables instead of one large one.

Having two outdoor tables allowed flexibility in seating options and they would not be too heavy for moving around.

If you are looking for another DIY table, we also recently just made our own DIY folding tables out of plywood. This cheap folding table is to be used in our basement for my husband’s poker and game nights. If we end up needing to sit more people outside, we plan on using these as well!

Gray DIY Outdoor Table

How to determine the height of your outdoor table?

Tip: If you already have chairs, make sure that you are building the height of the table to accommodate those chairs (like ours) or any standard outdoor chair or stool. We also made composite decking benches that you can see at the end of the post.

Here you can see the end height of our table and my husband sitting at our DIY bench. This may help you see the leg clearance and if you need to adjust the original height of the table due to your seating choice.

man holding tape measurer show height of bench, him sitting and outdoor table

What is the normal average height of a table?

An average table is normally anywhere from 28-30″ with chairs ranging in height in the 18″ range. Our bench is actually 17″ tall with a table that is 30 1/2″ which fits my husband well, but maybe I would have liked the table to be maybe a 1/2 inch shorter due to the fact that I am shorter.

Recommended Supplies

Outdoor Table Tutorial

Step 1: Design Your Table

Figure out the dimensions you want to have for your outdoor dining table. Each outdoor table is 70 1/2 ” long x 32 1/4″ wide x 29 1/2″ tall.

Here is an article about how to help determine the right size table for your indoor or outdoor space.

We made two of these tables so that we could put them together and really fit our extended family!

Step 2: Miter Cut Outside Composite Decking Boards

Miter outside composite decking edges of the outdoor table. We decided to create a picture frame on the outside and fill it in with the other pieces.

Mitered gray composite decking used to create DIY outdoor table

You will have to do some math to decide the length of your table and how many full pieces of composite decking you will fit in the inside frame.

Step 3: Cut composite decking to fill the inside.

We cut our small pieces to 21 1/4″. It took 11 pieces to fill our “picture frame”. We put our inside table pieces going horizontal to use the smaller leftover pieces of composite decking.

Our Mistake: I wish we would have changed this design and made the inside slates to be vertical. It was very difficult to have all the composite decking lay flat and we have some spots that stick up a little. It is nothing a little placemat won’t be able to fix. But you can learn from our mistakes.

Step 4: Dry Fit Pieces Of Tabletop Together

Layout all pieces of your outdoor tabletop to see how it all fits together. For each table, we made 71 1/2″ long and 32″ wide. We wanted a longer and skinnier table for our space.

Composite Decking Table top planed out

Step 5: Start To Build Base Out Of Pressure Treated Wood

Gather pressure-treated posts. We used sturdy posts because my husband liked the look of a thicker base. I am pretty sure this table could have been built with cheaper pressure-treated 2 x 4s.

Pressure treated wood used for the base of DIY outdoor table

Step 6: Cut Posts To Height

Use the saw to cut the posts. We cut our posts to 29 1/2″ tall.

Using a saw to cut pressure treated wood for posts for DIY outdoor table

Step 7: Build Frame For Composite To Rest On

Build the frame that supports your DIY outdoor tabletop. We used pressure-treated 2 x 4s to create a rectangular base at the size of 27″ x 66 3/4″.

Create the beginning frame out of pressure treated wood and place on top of composite decking

Step 8: Attach Frame To Table Legs

Drill pilot holes and 3″ screws to attach the frame together and then attach posts. Make sure you do not use just any steel 3″ screws because the metal will corrode over time.

Long galvanize screw used to attach pressure treated wood post to outdoor wood table

Tip: Use clamps to secure the post to the table frame. (See picture below)

Attaching wood frame to post to create a base for composite table top to go on.

Step 9: Flip Table Frame Over

This is a simple step: Flip the frame over (don’t mind our trash can overflowing).

Table Frame for DIY Outdoor Furniture before composite decking top goes on.

Step 10: Add Extra Wood Supports

Add 2x4s inside the table frame so that the composite tabletop can be attached there. Our 2x4s were 7″ less than the frame. Ours were cut to 20 1/2″ x 59 3/4″.

Add an extra 2' x 4' to the inside edge of outdoor table frame

Step 11: Attach Composite Deck Boards To Frame

Use the drill and screws to attach the composite decking picture frame to the pressure-treated wood frame. You could also attach from the bottom if you do not want to see the screws.

Add mitered composite decking top to pressure treated wood outdoor table base

Step 12: Attach Horizontal Boards

Use construction adhesive to attach the inside pieces of composite decking.

Smaller gray composite decking placed inside mitered table top frame on pressure treated wood base

Step 13: Prep For Exterior Stain

Flip the outdoor patio table over and use painter’s tape to frame out the composite decking tabletop and pressure-treated wood.

Blue painter's tape used to separate pressure treated wood outdoor table base and composite decking table top

Step 14: Stain Wood Legs & Frame

Use a paintbrush and use an exterior stain in the color of your choice.

We just ended up going with an outdoor stain (one that you would even use on decking).

Dark brown exterior stain being applied to pressure treated outdoor table base

Step 15: Let Table Dry

Let the DIY outdoor table dry and then flip it over and set it up in your outdoor space. We also made DIY outdoor benches using the same steps listed above but on a smaller scale.

Related Reading>>>Check out 50 More Weekend Home DIY Projects

Composite Decking Outdoor Benches

You can also make composite deck benches that follow a similar design plan. Use 3 pieces of composite decking on top. Create a base out of matching pressure-treated lumber.

Our benches are 48″ long and 16 1/2″ tall.

Gray DIY outdoor dining table and composite benches made with leftover composite decking.

How-To FAQs

Can you screw the table top on from the bottom?

Yes, for some reason my husband said he liked the industrial look of seeing the screws on the tabletop.

How has the table held up over time?

Composite decking becomes flexible. We have had a few boards that we have had to reglue with construction adhesive. However, since they rest on the wood frame this isn’t that big of a problem.

How heavy are these tables?

They are pretty heavy due to the posts being used. You probably could use 2x4s for the legs instead of the posts. For the size of our table, it takes two people to lift and move around.

What stain is best to use?

I did a lot of research to see if I could use interior stain because I LOVE the look of this color (we have used it on numerous projects in our house).
However, you would need to do another coat of special polyurethane. We decided we only wanted to paint the exterior stain on the outdoor table post once and that we wanted as much protection as possible with the least amount of maintenance.

Finished DIY Outdoor Dining Idea

Our two DIY outdoor dining tables were so awesome to use the other night! We were able to sit with our whole immediate family and friends. The kids loved the benches and being able to eat outdoors.

DIY outdoor table made with gray composite decking top with metal chairs.

What is your favorite outdoor dining space project? If you like this project, you may also like seeing some of the amazing painted flower pots we made to plant things that would help repel mosquitos while we dine.

Large gray and DIY composite decking table with brown exterior stained legs with outdoor dining chairs.

Follow us on Pinterest, Youtube or Facebook for more DIY inspiration!

We absolutely love our DIY outdoor dining space and hope we inspired you in your next DIY project!

DIY Outdoor Composite Decking Table

4.34 from 3 votes
Learn how to build a DIY outdoor table with leftover composite decking.
Print Tutorial
gray composite decking pile on top of deck being built with arrow pointing to gray composite decking outdoor table.
Prep:25 minutes
Active Time:5 hours
Dry Time:1 day
Total Time:1 day 5 hours 25 minutes


  • Miter saw
  • Cordless Drill


  • Design table. Each outdoor table is 70 1/2 ” long x 32 1/4″ wide x 29 1/2″ tall.
  • Miter outside composite decking edges of the outdoor table to create a picture frame look.
    Mitered gray composite decking used to create DIY outdoor table
  • Cut your small pieces of composite decking to 21 1/4″. It took 11 pieces to fill our “picture frame”. We put our inside table pieces going horizontal to use the smaller leftover pieces of composite decking.
  • Dry fit table together.
    Composite Decking Table top planed out
  • Start to build base. Cut pressure treated posts to 29 1/2".
    Using a saw to cut pressure treated wood for posts for DIY outdoor table
  • Build frame out of 2 x 4s.
    Create the beginning frame out of pressure treated wood and place on top of composite decking
  • Attach frame to the legs using 3" deck screws.
    Long galvanize screw used to attach pressure treated wood post to outdoor wood table
  • Flip table frame over.
    Table Frame for DIY Outdoor Furniture
  • Add extra 2 x 4 supports inside frame.
    Add an extra 2' x 4' to the inside edge of outdoor table frame
  • Attach the ouside composite decking boards to the frame. You can screw in the top of from the bottom.
    Add mitered composite decking top to pressure treated wood outdoor table base
  • Attach horizontal decking boards with construction adhesive.
    Smaller gray composite decking placed inside mitered table top frame on pressure treated wood base
  • Flip over and prep for exterior stain.
    DIY Tables and bench being built
  • Use a brush to apply exterior stain to pressure-treated wood.
    Dark brown exterior stain being applied to pressure treated outdoor table base
  • Let dry and enjoy your new outdoor table.
    Gray DIY outdoor dining table and benches made with leftover composite decking
Author: Erin Nutter
Cost: $100

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  1. This look so durable. What a great idea to make with decking.

    1. Hi Trina! Theses outdoor tables are very durable. We love having an outdoor table that will last!

      1. Wow. That is absolutely beautiful. What an excellent idea to use the scraps of decking.

        1. Hi Ashley! Thanks for the kind words. We loved using the extra composite decking to create our own DIY outdoor table!

  2. That came out just as nice as any store bought table and for a fraction of the cost. And it will match your deck and age with it. Really nice work.

    1. Hi Laura! We loved that we were able to only buy pressure treated wood and could use material we already had for our DIY outdoor dining table! Thanks for the nice comment.

  3. Louise O'Boyle says:

    This is amazing, you make it look so easy! I really wish I was skilled like you. It’s a fab idea for leftover materials.

    1. Thanks! This DIY outdoor table was really a good project for my husband! He loves building things with leftover material!

  4. This is lovely! My husband is in construction and often works with composite decking. I showed this to him.

    1. Thanks Chris! I hope he liked the idea of using the extra and expensive composite decking to create your own DIY outdoor table!

  5. In 2012 I built a 96 inch long 40 inch wide patio table with Trex decking. The base is a trestle style made of cedar. I’ve had a outside year around for 8 years and it still looks as good as the day I built it. The combination of cedar and composite make it virtually maintenance free. I highly recommend composite but would recommend cedar (even though it’s more expensive) over pressure treated pine.

    1. Hi Matt. Thank you for the advice. We were trying to keep this project a little more budget-friendly as we weren’t sure how long we would actually use the tables. We are currently building raised planter beds out of cedar and know that they will hopefully last a very long time! Thanks for visiting our site.

      1. Jim Sutro says:

        Just completed construction of ab out 200 square feet of outdoor raised planting beds, (4 boards x 5 1/2 inches vertical)

        Highly recommend that you use TREX or another composition for the sidewalls. They will NEVER rot away. I used 4 x 4 ground contact pressure treat for the corners, and am starting to think that I should have invested in stainless steel angles, which also will NEVER rot away,

        It does take a stiffener about every 4 lineal feet because the compost is so bendy it will look like a pumpkin if not reinforced laterally.

    2. Greta tutorial! But, in Step 10, how do you attach those other 2x4s to the inside of the frame?

      1. Hi Youg! Thanks for the kind words. We attached those inside 2 x 4s from the outside 2 x4s using 3″ screws. We hope that helps you in your DIY outdoor dining table design!

  6. C. W. Rice says:

    I think to add a bit for finish to the project, at least on the picture frame, i would have rip sawed the tongues & groves off the edges of the boards. As well as the field boards you used for the infill of the top, square edges would have made it look nicer in my opinion. But that option is limited, without a table saw or a rip fence attachment for a circular saw.

    1. Hi. Thank you for the advice. Yes, we simply were trying to make do with the leftover supplies that we had without having to really purchase anything new. We appreciate you taking the time to give us feedback. Good luck with your DIY projects.

  7. Hi Erin,

    My wife has been wanting to replace our older metal-and-glass hexagonal table for 6 with one that would seat 8-10, but everything she found for sale was $800-$1200. She sent me the link to this article and I priced it out around $200 at Lowes. I bought the materials Saturday morning, spent a little over an hour with my buddy’s compound saw, and started assembling Saturday evening. After a little more than $220 and 5-6 hours of build time, we’re both really pleased with our 77″ long x 35″ wide version of your table! I’m not a handy man at all, but following your tutorial, my wife said I made it look really easy.

    I did have to scrap the idea of using glue because the composite decking I found locally has a scalloped bottom instead of a solid bottom, so there just isn’t enough area to glue it down. It took me 2 62ct boxes of stainless steel decking screws to put it all together.

    I also took Matt’s advice above and went with rough cedar posts and boards instead of pressure treated. The cedar color looks good with the dark grey composite top.

    1. Hey Ted! I am so glad that you were able to use our outdoor table tutorial to build your own! I love that people are posting and sharing their ideas and thoughts. Great job and I am glad that it worked out well for you.

    2. Richard Acord says:

      @Ted D., how has the table held up, and any way to send a picture thanks

      1. Hi Richard. The table has held up and we still use it. I would take my suggestion though of putting longer boards in the center and you should screw those together from the bottom with the construction adhesive on the wood frame. We had a few small boards we had to reattach, but it wasn’t a big deal. Even though we know composite decking is a little “bendy” the outside frame of the tabletop has stayed as it was when we built it. I hope that helps!

  8. Erin I love this DIY!! I do woodworking and crafts and I’m always looking for great ideas. Would it be ok to use this plan to make these and sell them?? Don’t want to steal your plan if you wouldn’t be ok with that. I’m in Ohio as well! Thanks!

    1. Hi Loren. Are you saying make these outdoor tables and sell them? I don’t see why not. I just wouldn’t want you to copy the actual plans and sell those. Thanks.

  9. I love this table. It there a reason you did not screw the boards in from the bottom? I have never worked with composite decking and not sure this is feasible but am curious to know if it would work if I built a similar table.

    1. Hi Barb. My husband chose to go for an industrial look with screwing the top that way. I am sure you could totally screw the composite decking from the bottom for a cleaner look. Good luck with building your outdoor dining table.

  10. I just got done building my deck and cross this so I built me a table using this method. I built it a little longer (76”) and wider (36”). I’m waiting for the paint to dry on the frame and then going to attach the deck boards. I did it this way because I wanted the boards underneath to be white instead of the wood color. It looks great so far and it is a little heavy.

    1. Hi Jamie. Great idea to create the look of the outdoor table that you want. Yes, these are heavy, but totally sturdy!

  11. Hi there, I have a question about step 10. How did you attach the 2”x4”s to the inside of the frame?

    1. Hi Mike. We just screwed the inside frame 2″ x 4″s from the outside 2″ x 4″. Once the tabletop is on and you have stained the pressure-treated wood, you don’t even notice the screws.

  12. Hi,
    What would you recommend as a replacement for the composite decking?

    It does not seem like any of the hardware stores in my area carry composite decking.

    1. Hi Chad. You could always use cedar if you want a nicer or more natural tabletop. However, this would be a more expensive option. Or you could make a pressure-treated wood top table as that is what normal picnic tables are made of.

      1. Thank you for the fast reply.

        Can you share with my the dimensions of the composite decking? It seems wider that 2×4″.

        1. My guess is that 2×6″ will the closest to the dimensions of the deck boards.

          1. Hi Chad. Yes, the actual width of the composite decking boards we used is 5 1/2″ which is the width of a 2″ x 6″. Our outdoor table is narrower by design to fit in the space on our deck that we wanted. Good luck building!

  13. Billie Madhok says:

    I love this, except for those exposed screws on the top of the table. I’ll be making something similar, but will be doing a bit of research to find a method that does not show the screws on top. Way to use up leftovers though!

    1. Hi Billie. Yes for some reason my husband liked the look of the exposed screws. Good luck with your outdoor table!

  14. Brian Bayer says:

    So if I understand this correctly, the leg post was 29 1/2 inches tall. The composite decking is 1 inch which puts the total height of the table at 30 1/2 inches? That also gives the clearance for chairs under the table for sitting at around 26 inches After you take away the 3 1/2 inches for the 2 x 4 frame and the 1 inch thickness for the composite deck? Did you find any difficulty finding chairs that would allow people to sit at a 30 1/2 inch table? I’m a little nervous at going near 30 inches as most outdoor patio chairs would be too low. But I’m also looking to make the clearance from the floor to the bottom of the actual table top at around 26 inches.

    Any advice would be appreciated

    1. Hi Brian. So my first piece of advice would be to find the outdoor chairs you want to add to your set before building. This way you can ensure you are comfortable using your table with the chairs you like. You could easily knock a 1/2 inch off the posts to customize this and make it a little lower, especially if you have 18″ height chairs. The average height of a table is 28-30″ and the average chairs area are normally around 18″ but it can vary.

      I will add a picture to the end of the post to show you my husband sitting at the composite bench we made that is 17″ ish high. He is very comfortable and has leg room. You will see you could make a bench or chair have an 18-19″ height and it could still work well. So I guess it just depends on the chairs you want to use, or you could always make a composite decking bench to go with your outdoor patio table. Good luck with your outdoor table project and we would love to see your finished patio table!

    2. Brian Bayer says:

      @Erin, hello and thank you for the reply! It looks like we are going for a 30 inch high table. I was a little nervous about the 4 1/2 inch barrier from the top of the table but your response about sitting on a 17 inch bench put that at rest. I appreciate the help. My theory is if a standard chair is too low I can always purchase a firm cushion to add height.

      Also I looked at the chairs from Amazon you use. They look great for outdoors. 2 questions:

      Have you had any rusting from outdoor use? If so I’ll probably need a clear coating spray.

      How hot do they get in the summer sun?

      Thanks for all the help.

      1. Hey Brian. I am glad you are figuring out your outdoor table. As for the chairs, we actually moved them inside to our regular table as my grandma’s old chairs finally bit the dust. We have older mesh ones out that have worked pretty well now even if they aren’t the prettiest. We love those chairs but mainly have had them indoors since we built that table. I would love to know what chairs you decide to go with and how they hold up.

  15. Hi Erin,
    Thinking of doing the same – would you say that table is super heavy or easy for 2 ppl to move around?

    1. Hi David. My husband and I can move the table around, however, it wasn’t easy to get up onto our deck. The weight is mainly due to the chunky legs, so you could always change the frame to make it a little lighter. Good luck with your DIY outdoor table.

    2. @Erin,
      Thank you – think I might put the frame together in the shed and then build the rest already on the deck to avoid the hassle of 7 stairs 🙂

  16. Kevin Crimi says:

    I’ve been trying to find pressure treated wood but everywhere I go, the only option is the really ugly brown stuff with incisions along the length. Is there something specific I should be looking for/asking for to find some normal looking boards like you have? Thanks!

    1. For our table, we used #2 grade pressure-treated wood. We always recommend trying your local lumber yard and they will let you pick out your individual boards. Good luck with your outdoor table.

  17. How much composite decking did you use for this project?

    1. Hi Sarah. We used the leftover pieces from when our deck was being built and did not buy new pieces for this table. If you are buying new composite decking for your outdoor table, I would make sure you get the boards meant for the edge of a deck for the edge of your table. Our table has a little groove there because we didn’t buy new. Good luck with your DIY table.

  18. Awesome idea, I used my left over deck board on top of an old picnic table. Now I will build the frame as you did.


    1. Hi Joyce. Good luck with your outdoor table!

  19. 5 stars
    This is a great tutorial! Thanks for sharing your beautiful project and for such thorough instructions.

    1. Hi Erin. Thanks for the kind words and good luck with your outdoor table.

  20. 4 stars
    You can run a middle 2×4 to help even out the decking. The extra 2×4 you added around perimeter and the middle stiffener 2×4 stay much straighter with the 3-1/2 inch upright instead of flat. A 2×4 upright stays straighter whereas a flat layered treated 2×4 can get kinda squirrelly as it dries.