How to Build a Backyard Deck – DIY

Hi Everyone – Ryan here!

What I enjoy most about DIY projects like this: They let you take a space you like and turn it into a space that you love. It’s either about making a space more pleasant to be in or taking a non-functional space and making it functional. Any time I can check both of those boxes, that’s what makes me the most happy!

So let me introduce you to a project that has made such a difference in how we use outdoor space: our backyard deck.

I’m writing this post not because there aren’t a million other great tutorials out there for building a deck, but because I want to show how you can build great deck for roughly $350 and highlight things that a lot of tutorials I read did not cover well. So in case you are contemplating this project for your own home, here’s everything you need to know, step by step, about our DIY wood deck. 

The Original Space:

This was a “dead” area of sorts in the back of the side yard. When I built our paver patio a few years ago I had a different plan for this space. Those plans never materialized, and over time I realized this space would be most useful as a grilling area. Rolling the grills across the paver gaps or through the pea gravel always frustrated me. With a wooden deck they would finally have a home. And the space could also double as a casual outdoor sitting area. We’ve dubbed this space “the café” and have enjoyed dozens of meals, coffees, and bottles of wine perched at our little bistro table we placed out there.

So in case you are contemplating this project for your own home, here’s everything you need to know our DIY wood deck. 

How to Build a Deck

Materials

Decks are great because there really isn’t a lot to them. There are just a handful of things you need. And while this IS NOT a sponsored post, I am a huge fan of Home Depot’s “curbside pickup”. It came especially handy during the shutdowns, but is a real time saver when you are on a schedule (I’ve used it about 4 times now with LARGE orders). If you’re worried about Home Depot staff not picking the best materials, just inspect it when they bring it out. Let them know if there’s an issue and they will make sure you leave with the right stuff – still saving you time.

Here’s everything I used:

• 2×6 Prime Ground Contact Pressure-Treated Lumber (Pressure treated was a requirement because this is a ground level deck and you don’t want teh ground contact to cause rot.)
• Concrete Deck Blocks
• 25 5/4 in. x 6 in. x 10 ft. Ground Contact Pressure-Treated Premium Pine Deck Boards
• Joist Hangars
• Angle Braces
• Deck Screws (lots of “˜em!)
• Joist Hanger Nails
• Deck joist tape
• Leveling sand
• Weed mat
• Shed Anchor

Tools:

• Circular or miter saw
• Drill
• Hammer
• Clamps (helpful for this and pretty much everything else!)
• Level

Planning

As any DIYer or contractor would tell you, planning is the most important part. Really taking the time to understand your space and “testing”out different designs on paper can save a lot of money, time and headache in the long run. So here’s where to start:

Evaluate your Space:

What are the measurements? What will you use it for? Is it in the open or are there space constraints? Do you need steps? Do you need concrete post forms or can you get away with deck blocks?

As you can see from the images, where I built this deck is enclosed on one side by the house and the other sides by our fence. So that really limited me on “how” to build this deck. At the same time, I did not feel like I needed to mix concrete and pour it to anchor the deck. Instead I used a “shed” anchor and concrete deck blocks (more on that below). That saved quite a bit of time.

Sketch it out

Once you have measurements, sketch it out. Try to think of all the little areas that can cause issues. For me, the challenge was that the fence line runs at an angle to the house, so to avoid a big gap on the back side of the deck, I had to account for that. It just took a little trial and error, but wasn’t too difficult.

Other questions:

Can I do it alone? Technically, yes, and for the most part I did, with the exception of a couple of times I needed Ashley to hold a board in place. If you can find a helper, I HIGHLY recommend it.

How long will it take? Two very efficient workers could knock this out in a day. Give it 2 days to be safe. Working alone, give yourself 3-4 days (or two weekends if you want to think about it that way).

How much will it cost? For this roughly 10’x10′ deck, material costs totaled around $350.

Building the Deck

Dig out the area Most decks are built over grass or dirt. Depending on the space and size of deck, you may need to do some additional leveling and digging. In my case, I just had to remove a few wheel barrels full of gravel, then dig out squares where the deck footings would go.

Install the deck blocks: This was a real trial and error process, but it turned out great. I dug out the square areas to my needed depth. Next I lined the holes with weed mat and added leveling sand. Paver sand is much more manageable than dirt especially damp soil – and makes it easier to have a flat area to get the deck block into place.

Level the Deck Blocks: I used a 4-foot level to get my deck blocks level with one another, allowing for a slide incline away from the house. The paver sand really helped here. If I needed to raise or lower a deck block to get it level, all I had to do was add or remove deck sand. Originally, by plans called for 9 blocks, and I ended up installing just 7. My motto is “over-buy, return later.”

Build the frame : This step will vary greatly depending on your deck area, size, and physical constraints. Because I was walled in on 3 sides, I used the joist hangars to make the connections. You may not need them if you have room to drill the boards together, which I also did where I could. I was very liberal with my use of deck tape, placing it anywhere there was wood-to-wood or wood-to-metal contact. The deck tape prevents rot that can occur between materials and really extends the life of the deck. I also added corner braces to the four outer-most corners for extra support. You’ll also notice I added additional joist beams support on the sides. This was a precaution just to ensure the far ends were well supported.

• Spacing the Joists to Support the Deck: Decks require support so you will want to make sure you have enough support for the decking, so plan to have a joist every 14″ to 16″ This way you won’t have weak spots on the deck. 
• Keep the Level Handy: You may have to “re-level” deck blocks during this stage, depending on how level the planks sit on top. Working with any kind of wood, some boards will be warped and bowed. When a leveling the block won’t fix it, you may need to sand down or use a planer to get the boards to be flush and level. This is where it’s VERY helpful to have a second set of hands.

Shed Anchor: After the frame was built I installed a shed anchor. Because my structure is on the ground and flanked on three sides, the risk of the deck blowing away is low. Still, I felt that absent underground concrete feet, some form of anchor was needed. Don’t be fooled once you get about 2 feet deep, this anchor is really tough to twist into the ground. I suggest a metal pipe or whatever you can find to get leverage on it.

Do a final check and make sure there aren’t any leveling issues. If not, take a break and have a beer, you’re half way there!

Deck Tape: This, I learned, is extremely important. As mentioned above, the tape adds life to your deck by preventing rot and decay where materials meet. I have a few engineer/contractor friends. When I told them about building the deck, they did not first congratulate me, they immediately made sure I had used deck joist tape before putting down the decking. Fortunately, I did and I got a nice pat on the back. I used about 100 feet worth and they usually come in rolls of 50 or 75 feet.

Finishing Touches – At this point I replaced the gravel I had removed previously, distributing it evenly between the joists. This would further ensure the deck and stayed in place and serves as a weed barrier (there’s actual weed barrier underneath the gravel as well). If you don’t already have weed mat installed, it’s a great idea to add it. 

Deck Board Install: This part is pretty straight forward but is where you really see progress! In my case, because of the shape of my deck area, I had to increase my board length by ½ to ¾ inches every 3 boards or so as the space widened towards the back. This created an inconsistent edge at the fence, but was easily addressed by using a circular saw at the end of the job, cutting a nice straight line. I did this, then had the idea to build a “bumper”or rail around the back and fence side of the deck. This actually prevents my grills from ever rolling over the edge. You can see it in some of the photos. It adds a nice finished touch!

Beyond the particulars of my deck, there are a few things to consider in advance and during the decking any installation. 

• Spacing the Deck Boards – remember that wood expands and contracts depending on temperature and humidity. So you’ll have to be careful to properly space the decking to avoid large gaps or compacting. Here’s how to space the board decks depending on your material:
  • Normal pressure treated wood comes pumped full of chemicals and preservatives that keep pests away and prevent decay. This is what I used. The downside is that over time the wood dries and the departing moisture causes the wood to contract. It’s always best to let pressure treated wood sit and acclimate outside for a few days (or weeks) prior to installing. If the boards are really wet when you install, opt for a 12D nail to use as a spacer (pictured). 
  • Kiln-dried pressure treated wood is an option, though for a premium price. This comes pre-dried and ready for immediate install. You won’t have nearly as much contraction. Use a 16D common nail to space the boards. 
  • If you’re using composite or other decking check the specifications from the manufacturer/supplier

• The End Board : Measure your space again to determine exactly how many whole boards you will be able to lay down. This measurement should also include the space in between boards (see below). What you are looking for is whether the final board will have to be ripped down in order to fit. A sliver of wood may not look good or may not hold up over time. What you can do, once there are 4-5 feet to go, is reduce (or increase) slightly the spacing between boards. That might get you to a better place with the final board. This can be a little tricky, but believe me, it’s manageable.  
• Working with Bowed Boards: You will likely have a few of these. I like the way Family Handy Man solves this (and by the way, this was a great resource I used there are a lot of helpful tips here). I used their chisel suggestion with moderate success. For the rest, I drilled a scrap piece of wood into a board end at the fence line, then using a clamp to force the boards closer. This only works if you have edges you’ll end up cutting off (you don’t want random holes in your decking).

Staining, Seal, or Paint: This is the last step, but DO NOT do it immediately if you used pressure treated lumber. The lumber is wet and needs time to dry out. Over time, the wood will “push” the moisture out. So much so that if you stain, seal, or paint over it too soon, the boards and paint will eventually crack and you’ll have a messy, broken looking deck. Wait 2-3 weeks, if not 2-3 months.

You’ll know when your deck is ready to stain or paint when you can sprinkle water over the decking and see the wood soak it up within a minute. If the water beads up and stays for longer, the wood has not properly dried yet. I know how torturous that can be, especially when you just want to finish the thing. But trust me, it’s worth it. I waited about 2.5 months and used Olympic Waterguard which is a clear wood sealer.

DIY DECK COMPLETE!

And that’s it! You’re done with your deck. I immediately moved the Weber and Traeger Smoker into their new home and grilled steaks later that night. I could not be more pleased with how it turned out. In highsight, I’d ask a friend for help, but that seems to be a lesson I have to keep learning. Regardless, once you’re done it’s even more fun having friends and family over to show off your work!

Materials Recap: