Outdoor Built-in Bench for My Deck

3 Materials
4 Hours

A wood working tutorial on how to build a corner built-in outdoor bench. This corner has always been a little bit of a “dead man’s land” tucked all the way back behind my home. I had considered a little seating area and even thought about building a tall pub table here but it didn’t feel like that was utilizing the space as well as it could be. A friend of mine has an outdoor bench running literally around her entire deck in place of a railing and the amount of seating offered is just amazing.

However, I have way more deck then she does and certainly don’t need that much bench! But this corner spoke to me as being the perfect place for an L-shaped outdoor bench!

I built my smaller bench first by building a rectangle out of 2x4s and adding legs where they were needed. I didn’t see any reason to add legs to my benches where the deck already had posts so I kept that in mind as I was building.

I went on to build the much longer bench (over 10 feet!) also with legs only where they were needed. Because of the distance I chose to cut my 8 foot 2x4s so the “seem” would land on one of the posts instead of requiring to add two legs in a weird spot. I flipped my benches “right-side-up” then attached them to each other before screwing them to the main posts.

Next I just needed to cut around eight million 24 inch boards for the seats… I set my miter saw up outside for this so I didn’t have to measure every board! Then I just stood there and cut and cut and cut. I used the deck as best I could for a saw horse but in the end it was kind of a pain in the butt because green treated wood is so heavy.

(I used green treated wood on this project which is made to be outdoors – it is more expensive then regular pine and considered very toxic. I live in northern MN and I know folks with cedar decks who watched them degrade within only 5 years of having put them in so, honestly, there was no choice but to use green treated wood on this project. Green treated anything requires up to a year to fully out gas and dry out which is why I built them in the late summer to give them the entire fall, winter and next spring to sit and do their thing.)

With the seat complete I moved on to the back of the bench. I wanted to create a little bit of a slant so I screwed a deck board all the way around the back of the bench pressed tight against the deck posts – with it laying down flat it was 5 1/2″ from the back of the bench to the front of the board. Then I duplicated that board where the top of the back rest would land, screwing it to the deck posts all the way around above the benches. Then it was just a case of putting another two million 24″ boards on, lining them up with the bottom seat boards.

(Because the slant was not very severe I didn’t feel the need to miter any of them.) SO, pretty much I just stood there and cut 24″ boards for most of the day…

With the majority of the outdoor bench complete I just needed to figure out what I wanted to do in the corner. Using a scrap piece of wood I created a support across the top of the corner and across the base. This gave me a place to put one more board. I considered doing something a lot more complicated in the corner but I didn’t hate this both in looks and in functionality… 

UPDATE: it has become my favorite spot to sit and read actually!

I also went ahead and screwed all of the 2×4 legs down to the deck. With the bench complete this no-man’s land has now become my favorite outdoor escape.

Eventually I plan on covering the back bottom of the bench (on the outside of the deck) with lattice like I did along the bottom.

Suggested materials:
  • 1x6 green treated deck boards   (local lumber yard)
  • 2x4 green treated   (local lumber yard)
  • 3" deck screws   (local lumber yard)
Want more details about this and other DIY projects? Check out my blog post!
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  1 question
  • Allison Newby Allison Newby on Oct 28, 2017
    Very good job....but is it really okay to not put a 2x4 post where you used the deck post and a square piece of 2x4 attached with a 3"screw. Overtime won't that part of the seat cave in or be the first to break bc it's compromised and isn't apart of the whole but added to another part with a part of board? I just worry about the future of the seat and it's stability as a whole? If a carpenter says this is okay then I'm sold but I don't know. It just seems iffy....I'm sorry. It looks wonderful but im just a worry wart I guess. Please don't mistake this as being ugly. Thanks. Sincerely, Allison Newby

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