How to Build a Patio Sofa
When it came to deciding which house we wanted in Florida, a huge factor was outdoor space. Having only had a small balcony in our previous city apartments we really wanted a space where we could be outdoors and enjoy the (mostly) beautiful weather year-round. Thankfully, the house we ended up opting for had a great sized space for us. When we first moved in at the end of 2020, there were mostly sunny but chilly days and actually cold nights that surprised us - Florida is the sunshine state after all - right? Wanting to soak in the beautiful weather got us drawing up plans and budgets for the Lanai project by mid-February and here we are in March staying outdoors nearly all day, thankful we built our lanai patio furniture. The weathers been great but it also doesn’t hurt that we built our patio set for a quarter of the price of what we had been eyeing at West Elm.
Here we’ll be going in depth and detail on how we built the sofa portion of our furniture set. This is definitely an intermediate (or ambitious beginner) level project. To pull this off we watched a few videos and pulled on Cara’s previous knowledge of building while growing up in a very DIY household. If you’re worried about this being too complicated - we’ll be honest - it’s not an easy breezy project. It is a project great for learning new skills and building something that, in the grand scheme of wood working, is quite doable for even a beginner. We made mistakes and learned a lot - we invite you to join us and do the same! It turned out more than ok after all!
Before you get started on this build, the most important thing is to have clear build plans. You can find the build plan with illustrations here (or linked on the image below). For the bench (and chairs) we based our measurements off of the cushions we chose. While these are mostly standard size, we did opt for deeper set options as a personal preference for us. Before you start your build, be sure to decide what cushions you’ll be using as that serves as the foundation for your measurements going forward. We do recommend purchasing your cushions before you build to ensure whatever dimensions you build for are available for you to complete the project when you’re finished.
Additionally, the cushions do make up for 50% of the cost of patio furniture typically. They aren’t cheap but this is a good thing. You’ll want to invest in good cushions - especially if in direct sun or weather - to ensure they hold up and you don’t find yourself buying the cheapies every year ultimately spending way more than if you had just invested up front. There are lots of different options - some of our favorites you can find below.
To build this bench (and chairs) you will need the following materials:
2 x 4 Lumber (66” total + extra for mess ups)
Deck Screws (4 -6)
Wood Screws (20 - 24)
Pocket Hole Screws (48 - 50)
** For our build, it cost us $104 for the bench not including tools since we already had those. You can find the full budget breakdown of the lanai project here. Do note, lumber and supplies costs vary all across the U.S. and your build may come out to be more or less expensive. **
If you’re looking on ways to save on this project, one of our best tips is to buy lumber in larger lengths (12 ft, 14 ft, etc.) and have them cut to size (~6 or 7 ft) in store if you need. Doing this saved us about 50% of what it would have cost if we bought 2x4’s in 6ft lengths. Additionally, we opted to use pine and do additional sealant to make it more “outdoor proof”. You can opt for a “better” outdoor wood such as cedar, however this will increase the cost of the project exponentially. Ultimately, lumber is what will cost you the most in this project so finding savings there is your best bet.
Once you have all your lumber, start by marking off all the cuts. For this piece alone there will be 26 different pieces you’ll need. Your cuts can be sorted into the following lengths with how many needed per length also indicated below.
46” - 6 pieces
46” ripped in half - 1 piece (2 halves)
26” 8 pieces
25” 6 pieces
24” 4 pieces
We suggest you label each piece with painters tape or a similar means to keep track of what piece is for what. We used the following abbreviation system (you will see this on the build plans) to keep each piece in order. This is also helpful in deciding which pieces that are more visible will be used if you have any less “pretty” pieces.
Bench (B) Back Rest (BR) Bottom (Bt) Arm (A)
B BR T - B BR B - B BR Slat - B BR Side
Bench Back Rest Top - Bench Back Rest Bottom - Bench Back Rest Slat - Bench Back Rest Side
B Bt T - B Bt B - B Bt Slat - B Bt Side - B Bt Rack
Bench Bottom Top - Bench Bottom Bottom - Bench Bottom Slat - Bench Bottom Side - Bench Bottom Rack
A T/B - A S/F
Arm Top/Bottom - Arm Side/Front
Once all your pieces have been labeled, you’ll want to begin adding pocket holes to the back rest frame, bottom frame, and arms. For the size of wood being used, you will need to create two pocket holes per board. The pocket holes will be on the long side of the frames as indicated on the build plan. For the backrest we totaled 16 pocket holes - the bottom has 8 pocket holes and the arms have 6 pocket holes each.
When creating pocket holes, be sure to place them where they can be more hidden. For the arms you will want your pocket holes on the under side of the top and bottom arm pieces so they are better hidden. We wanted the back rest pocket holes showing as they would be covered by the cushions. When taking on this portion of the build you can totally change it up to your own preferences. Plus, anything that goes “wrong” can be filled in with wood filler so don’t fret any oopsies here too much.
Once your pocket holes are created, begin by assembling the outer frames of the back rest, bottom and arms. For all of these you will need to utilize the pocket hole screws. For the back rest we do recommend you add in the middle slats while putting together to ensure a snug fit.
With the frames of all four sections - back rest, bottom and two arms - put together, you’ll next want to start on adding the slats to the bottom. First, install the rack on the bottom frame using wood screws. Be sure to check that it is place on the bottom half of the four inches to ensure the slats don’t stick up past the frame when fully assembled. Once the rack is in place you can place in the 25” slats. We suggest adding the six in similarly spaced increments though exact measurements matter a bit less here. If you want to add more slats here for even more support you’re welcome to!
With the bottom now fully assembled, you can begin assembling the back rest to the bottom. We did this by matching up the back rest frame’s bottom 2x4 with the bottoms furthest 2x4. You can also stack them, however, we felt securing them by matching them up was significantly more secure. Attach by adding wood glue between pieces and drilling in deck screws evenly across (4 - 6 screws).
Once secured you can begin securing the arms to the sofa. In deciding on the height of your bench try a few different seating options you have in your home to gauge how high up you want the sofa. Generally speaking you will want to stay somewhere between 10” and 15” from the floor to the bottom of the bench seat plank. We opted for 10” off the ground for a more medium height taking into consideration the additional 5” the cushions would give us sitting getting us closer to 15” off the ground.
To install the arms, be sure to mark on the arm where it should be lining up with the top and bottom of the bench bottom. It is definitely a two person job to get these secured on so be sure to get assistance here! Add wood glue to the inside of the arm where it makes contact with the sofa frames bottom, using pocket hole screws to secure. Wash and repeat with the other side.
With your bench fully assembled, allow time for wood glue to dry.
Once dried, go ahead and get to filling in any spots needed with wood filler allowing time to dry based on filler instructions. When any filling is done, get to sanding with a smoothing grit paper - we used 120. This part is especially boring and we definitely should have spent longer sanding. Learn from our mistake and just do it!
With sanding done and a good wipe down to get rid of any dust use your preferred stain on the entire piece. We recommend using a brush to get into any nooks and crannies but a cloth works fine for the piece overall. For this project we used Minwax’s Ebony and were really happy with how it turned out. Given that this project would be outdoors, we wanted to opt for a darker color that wouldn’t yellow like much light wood stained outdoor furniture does. If you’re looking to keep your piece light and bright, we recommend opting for a white stain. We did two coats to achieve the color we wanted and let dry over night.
With the stain complete, we did one last clean and began sealing. Since we are using untreated, inexpensive pine this portion of the process was extremely important to ensure this would hold up through its time outdoors. If we were to do this project again, we would likely invest in a sprayer however you can totally do this with a brush. We didn’t have too many bad streaks and found using the brush was just fine. For ours we applied additional coats to the recommended three to ensure the piece would hold up waiting 4 - 6 hours between each coat. When applying you can sand as recommended by many sealants. We only did this on the first coat after learning this was not totally necessary from a far more experienced wood worker. For this project, sanding between each layer is really personal preference unless you’re trying to fix up any really bad streaks.
Completely dry, we added on our cushions and throw pillows and called it done! As much as we wish this project only took as long as the YouTube video does it took around 5 days to complete in full. While we built this, we were also building the two chairs which may be why this took a bit longer. If we were moving at a more comfortable pace doing just the bench it likely could be done in a weekend or two.
Overall, the build was something we really wanted and ended up saving a significant amount of money. You can see the full lanai cost break down here.
Bench Cost Breakdown -
Lumber - $80
Deck Screws - $2.50
Wood Screws - $7.50
Pocket Screws - $7.50
Stain - $4
Sealant - $9
Cushions - $180
Bench Build = $104
Bench with Cushions = $284
Believe it or not, we actually wrote up this post on said bench - it was just such a beautiful day! We hope you found this build helpful and inspiring to take on this project for your self! If you have any questions, comments or feedback, we’d love to hear from you! Be sure to check out the project page for the Lanai for additional builds as well as the accompanying video on our channel for a more visual look at this project. Until the next build - thanks for being here, we’ll see ya soon!
