DIY Outdoor Sofa (With Free Printable Plans!)

An easy weekend build, this DIY Outdoor Sofa (with free printable plans) is perfect for the homeowner looking to add some comfort to the backyard!

I have a gorgeous screened-in porch in my backyard. For the last year, it’s sat empty and sad, serving only as a temporary dumping ground for building materials that I didn’t feel like lugging into the house.

Back in April, though, we had some nice weather that made me realize my life would be better if I could actually use my porch as intended. So I started the “remodel” process. First, I painted the carpet gray. Then I stuck a rug on one side of the porch, and decided some furniture was needed.

First up? An DIY outdoor sofa. I know myself. If I’m actually going to use the space, I’ll need furniture that I can actually lie down on.

Planning Considerations

I spent some amount of time deciding what wood to use to build the outdoor sofa. Cedar is rot and weather resistant, however it’s significantly more expensive than both whitewood boards and pressure treated lumber.

Pressure treated lumber is cheap wood that is treated to withstand exterior conditions, but the treatment process introduces chemicals that make slivers and other abrasions caused from the wood more likely to become infected.

Whitewood boards are much safer, however they cannot easily withstand the outdoors without a weather-friendly finish.

Since I wanted my sofa to have a wood finish, not a painted finish, I ended up going with cedar except in a couple places that were unexposed and therefore unlikely to touch people using the couch. In those places, I used pressure treated lumber to save money.

The plan is written as I built it, with cedar and pressure treated boards. That said, If you’re okay with painting your sofa with exterior paint, consider using cheaper whitewood boards to save money. 

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Materials

• (7) Cedar 2x4s
• (2) Pressure Treated 2x4s
• (20) 48″ Cedar Fence Pickets
• (1) Cedar 1×2
• 2 1/2″ Exterior Pocket Hole Screws

For the complete cutlist and sofa dimensions, grab the free downloadable plans below!

DIY Outdoor Sofa

Step 1: Cut and Prep Pieces

Make all cuts and add pocket holes accordingly to the printable plans with the Kreg Jig set to 1 1/2″.

Then, sand down any visible pieces. The cedar fence pickets I purchased were quite rough; if yours are similar, take a look at my “How to Make Cheap Wood Pretty” post, which walks you through the process of making them more presentable.

Here’s what most of my fence pickets looked like when I brought them home:

See how rough they were? You can barely see the pretty cedar underneath. After sanding, though, the pieces were gorgeous.

Step Two: Assemble Arms

Each arm should consist of five different cedar 2×4 pieces. 

From left to right: Top piece, two middle supports, two main sofa legs.

Note how on the sofa legs, the pocket holes are on opposing sides of the pieces. This is so that when assembled, the holes will be hidden by the top support piece.

Start by attaching the two main legs to the top piece, keeping the middle pieces between the legs to act as spacers. Then attach the two middle pieces to the legs. Make sure to repeat this for both arms!

Step 3: Make Frame

Attach the two long front and back cedar pieces to the arms. I accomplished this by arranging the arms as if the sofa was lying on its side, that way, the new pieces were flat against the ground. Unfortunately, I did not take a picture of this, but here’s what your completed frame should look like:

Step 4: Add Center Frame Supports

This is where the two pressure treated boards come in. Since they’ll be entirely hidden by the final cedar fence pickets, they’re difficult to reach and I was therefore comfortable using them.

To add them to the frame, I propped them into place with a crate and some scrap wood, then screwed them in.

Step 5: Add Center Legs

I didn’t quite trust the four 2x4s to hold the weight across that long stretch, so I added some middle legs to the sofa.

Note that since the front and back 2x4s are perpendicular to the middle 2x4s, the front and back leg supports will be shorter than the middle supports. 

Additionally, the front and back 2x4s will be attached with pocket hole screws, since adding a top-down screw would require at least a 4″ screw. The middle leg supports, on the other hand, can be attached using a simple top-down screw, since the board is only 1 1/2 inches thick.

Step 6: Attach Seat Planks

Using brad nails and wood glue, attach the sanded cedar planks to the seat portion of the bench. 

(Note: This brad nailer is my absolute favorite tool. I would never complete a project that required significant nailing without it. It’s lightweight, easy to use, and doesn’t require an air compressor, which is pretty much everything I want in a nailer.)

The last piece will likely be too wide to fit onto the sofa. Rip it to the measured width using a circular or table saw.

Step 7: Attach Back Supports

The internet told me that the ideal angle between the seat and the back of a couch is 110 degrees.

This is kind of difficult to implement in practice, but some high school level geometry (two parallel lines cut by a transversal) tells us that the triangle formed by the top support and the arm of the couch is a 20-70-90 triangle. 

Using trigonometry, we can determine the legs of this triangle are around .5″ and 1.4.” I used that information to place the piece at an appropriate angle.

And my students say you never use math in real life.

Once the main back support was secured, I rested some cedar pieces against it, and marked where the cedar pieces met the seat. Then, at that mark, I placed the second back support, the 1×2, with wood glue and brad nails.

Step 8: Attach Back Cedar Pieces

Using wood glue and brad nails, I secured the cedar pieces to both back supports. 

Once again, the last piece is unlikely to fit perfectly, and will need to be cut to fit your remaining width.

Step 9: Attach Cedar Side Pieces

To cover up the pocket holes on the outside of the arms of the couch and prevent pillows from falling through the sides, I added a few more cedar fence pickets. Once again, they were secured with wood glue and brad nails.

Finally, the DIY Outdoor Sofa was done!

Final Thoughts

I absolutely love sitting out on the porch now, even though there is no other furniture.

The past week has been beautiful, and I’ve loved relaxing on the DIY outdoor sofa and getting some work done!

If you love the cushions, check out how I made them for $8.75. It was definitely a budget project, and I’m super proud of how it turned out!

If you think you might make this, go ahead and download the printable plans so you know exactly what cuts to make! And if you found this plan useful, go ahead and save it to Pinterest so others can find it too!