DIY Outdoor Sectional Sofa Plans


Many people have backyards and don’t know what to do with them. Some people start landscaping their backyards to make some grand designs. Others like to keep their backyards minimalistic and use them for sitting down and relaxing. And what better way is there to make a sitting arrangement in your backyard than an outdoor sectional sofa?

Undoubtedly, you will be concerned with any outdoor seating arrangement, worrying about the weather and how it will fit your backyard look. A sectional sofa is great because it can fill the corner of your patio where you can sit, relax, have a cup of coffee, or read a book while enjoying the outdoors. And if you are someone who likes to have DIY outdoor sectional sofa plans, then I have the perfect outdoor sectional sofa project for you to try out!

Key Takeaways

  • Planning for your sofa is important, as you need to take the measurements and buy the materials and equipment needed for your project.
  • There are 8 steps to make the sofa, where you will be making two sofas and joining them together towards the end.
  • You can decorate your sofa by painting and using 24-inch cushions.

DIY Outdoor Sectional Sofa Plans

Before you get started on building your sofa, it is obvious some planning needs to be done. So here are some materials, measurements, and equipment you need to set up before getting started! The project will be done with wood, so these are the materials and equipment you need for a wood sectional sofa.

Measuring out the area for your sectional sofa

Measuring out the area for your sectional sofa

As with anything, first measure out the area for your sectional sofa. It will be quite embarrassing to make the whole sofa out of 2x4s but it does not fit in the area you wanted to place it in. So get your measuring tape out and start figuring out how much space you need for your sofa.

Buying the equipment

With any DIY project, you will need both lightweight and heavy-duty equipment to cut the wood, set it, hold it still, etc. So for equipment, you need:

Buying the equipment
  • Circular and miter saw (to cut the lumber that you will purchase)
  • Rafter angle square and leveler (to make sure everything is aligned properly)
  • Cordless drill (to drill holes and screws)
  • Drill bits (for different types of drilling needs)
  • Wood chisel (to make fine adjustments to the wood)
  • Hammer (to hammer place a piece of wood)
  • Sander or sandpaper (to prepare for polyurethane application and wood stains)
  • Jig pieces (to set the screws in place before drilling them)
  • Clamps (lots of them, the bigger the better because you will need them)

Buying materials

To add to your shopping list, you will need to buy all the materials that are required for your sectional sofa. This will include the lumber, screws, glues, etc.

Buying materials
  • (6) 2×4 @ 12 feet long – cut the 70½ and 72-inches long pieces from these boards
  • (6) 2×4 @ 8 feet long – cut the rest of the boards from these boards
  • (30 to 50) 2½ inches self-tapping exterior deck screws, (get more to be safe)
  • Wood glue, stain, and filler
  • Exterior spar polyurethane

Cutting the wood

If you have all the equipment and materials ready, it is time to start the final prep you need before getting started on your outdoor sectional sofa. Cut the pieces of wood accordingly:

Cutting the wood
  • (6) 2×4 @ 70½ -inches
  • (22) 2×4 @ 25½-inches (includes back support)
  • (1) 2×4 @ 12½-inches
  • (12) 2×4 @ 72-inches
  • (3) 2×4 28½-inches
  • (4) 2×4 @ 70¾-inches (back support – cut to fit)

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Building the Outdoor Sectional Sofa

With all the preparation done, you can finally start on your sofa! For sectional sofas, you need to make two different sofas! One which is a full sofa and another with an arm missing so it can be joined together in an L-shape. Let’s go step by step on how to get your sectional sofa done

Step 1: Make the seating frames

Make the seating frames

For a seating frame that would seat 3 people, you’ll need 4 2×4 @ 25½-inches and 2 2×4 @ 70½ -inches pieces for both sections of the sofa. Then, clamp two of the 25½-inches pieces on the ends of the 70½ -inches. For the middle section, measure the out 22 inches from each end and place the 25½-inches pieces. Attach the end pieces with wood glue and have them clamped up to secure them. For the middle pieces, use the 2 2½ inches screws using jig pieces to safely drill the screws in.

Step 2: Make the sofa arms

Make the sofa arms

The legs of the sofa are pretty easy compared to the rest of it, but it also has to be the that is carefully made because they will hold the weight of the sofa and the people sitting on them.

Take 2 25½-inches pieces and add a 28½-inches on top of them, securing them with glue and clamps to make sure they stick. For the middle part, hammer into place another 25½-inches at about 14 inches from the bottom. You can at this point add another 25½-inches underneath this middle section and screw it together. For one of the sofas, you make 2, and for the other, you make only one as this will be the sectional part that you will attach to the other sofa. 

Step 3: Adding the arms to the seating frame

Adding the arms to the seating frame

Now attach the sofa arms to the seating frame. Drill the 2 screws at an angle using a jig piece for maximum stability of the seating frame. For the main sofa frame, you will do this for both arms, using raft angle square and leveler to make sure that the two ends are aligned perfectly. Make sure that they are aligned perfectly before screwing them together. While for the sectional part, you will be doing it on only one side.

Step 4: Make the legs and back for the sectional piece

Make the legs and back for the sectional piece.

Take a 25½-inches piece on the armless end and attach it to the other end of the seating frame. Use 4 screws to secure this piece tightly. This will also be part of the back support of the sofa. For the smaller leg that will be in the front, you take a 12½-inches and attach it using screws at an angle. Make sure to use a rafter angle square and leveler so that the sofa is leveled. If they are off by a few inches, you can use the wood filler to make up for any gaps.

After the legs are all settled, add a 72-inch piece to the 25½-inches, from one end of the sofa to the other. Use screws and clamps to secure them into place at both ends. Do this for the main sofa frame as well.

With this, you will be done with the main frame of the sofa. So the next few steps will focus on the sectional part, attaching it to the main frame of the sofa, adding the slats for seating on both sofas, and adding any supports to the back or arms.

Step 5: Adding the supports for the back and arms

Adding the supports for the back and arms

Finally, for back support you can add 2 70¾-inches spaced at 1½-inches between them, screwing each support in place. You can also add support for the arm using a 25½-inches piece and screwing from the sides and top of the arm.

Step 6: Connecting the two sections together

Connecting the two sections together

Now for the moment you have been waiting for, attaching the two sofa frames together. Before everything, you will have to make they are perfectly aligned. Otherwise, all your work will be ruined! For each of the previous 4 steps, make sure you are constantly using a leveler and raft angle square to make sure of all the alignments.

For this, take the main sofa frame and align it with the armless side of the sectional frame in an L-shape. Once you are happy with the alignment, it is time to screw in the two seating frames together. You will be doing this at the support you added for the arms, screwing them in place, and also the seating frame.

Step 7: Adding the slats to your seating frames

Adding the slats to your seating frames

The slats will be the main support for your seating. Add 5 72-inch pieces for each sofa, with a gap of 1½-inches between the slats. For the furthest back slats (which will be underneath the back support and in between the arms), use a 70½-inches piece to securely fit it into place. Screw the slat to the legs, two screws at each side of one slat.

Step 8: Sanding and finishing

Sanding and finishing

For any holes in the sofa, add a wood filler and let it dry for an hour or two. After drying, use 180-220 grit-paper sand the whole frame in the direction of the wood grain and clean the sofa using a damp cloth. Then you can add the polyurethane and wood stain to style the sofa however you want while the exterior spar polyurethane will help protect the wood from the environment.

Additional step: decorating

Additional step decorating

Your sofa might be sat on, but it is better to decorate it using cushions and wood paint to really give a feel that you have made it. For the seat cushions on this sofa plan, 23 to 25-inch cushions will fit the seating area, whereas 24-inch would be the perfect fit size. With that, you are finished with your DIY outdoor sectional sofa!


1. How long will a DIY sectional sofa plan take to make?

If you have all the materials and equipment prepared, then this plan can be finished over the weekend.

2. What is the best wood to use for outdoor furniture?

The best wood would be cedar as it is very resistant to the weather and the environment. A good alternative to that will be fir or pine wood.

3. How much will a DIY project cost?

The cost will depend on what you will need to buy. If you have the pre-existing equipment and all you need are the materials, then the project will cost around $300 to $400.

Final Thoughts

There you have it, a DIY outdoor sectional sofa plan. The problem with a ready-made sofa is that you have to search a lot before finding one that will be perfect for you. If you are already a fan of DIY projects, then a sectional sofa for your backyard will be a perfect weekend job that you can do alone or with the help of your family. It might seem difficult at first, but starting with an easy job is how you will gain interest in DIY projects. Hope with this plan you are able to make your own outdoor sectional sofa.

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I am Donald M. Beyer and I am backyard enthusiasts. I am a homeowner who has been doing DIY projects in and out of my house for many years. From simple backyard lunches to making an old-school pizza oven in my own backyard, I have a lot of experience in turning my backyard into my and my family’s personal playground.

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