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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 absolutely 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 made from Polywood or composite decking
  • Outdoor side table
  • Coffee Table
  • Outdoor Adirondack chair
  • Shelves
  • Wall Art
  • Step stool
  • Cornhole game
  • Birdhouse or birdfeeder
  • Raised garden bed (you can see our cedar raised garden boxes here)
  • Outdoor dining table
  • Outdoor playset or platform for a playhouse

As you can see, there are many different project ideas that 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!

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

DIY Outdoor Composite Decking Table

Learn how to build a DIY outdoor table with leftover composite decking.
4.50 from 2 votes
Print Pin Rate
Prep Time: 25 minutes
Active Time: 5 hours
Dry Time: 1 day
Total Time: 1 day 5 hours 25 minutes
Author: Erin
Cost: $100

Equipment

  • Miter saw
  • Cordless Drill

Recommended Supplies

Instructions

  • 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
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Tutorial Rating




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Michael

Friday 2nd of June 2023

You can run a middle 2x4 to help even out the decking. The extra 2x4 you added around perimeter and the middle stiffener 2x4 stay much straighter with the 3-1/2 inch upright instead of flat. A 2x4 upright stays straighter whereas a flat layered treated 2x4 can get kinda squirrelly as it dries.

Erin

Friday 2nd of June 2023

Hi Michael. Great ideas! We appreciate it.

Erin

Sunday 2nd of April 2023

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

Erin

Monday 3rd of April 2023

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

Joyce

Sunday 17th of July 2022

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.

Thanks

Erin

Monday 18th of July 2022

Hi Joyce. Good luck with your outdoor table!

Sarah

Friday 27th of May 2022

How much composite decking did you use for this project?

Erin

Monday 30th of May 2022

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.

Kevin Crimi

Monday 27th of September 2021

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!

Erin

Tuesday 28th of September 2021

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.

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