Build Your Own Floating Deck | Step-By-Step Guide To A More Relaxing Backyard

Build Your Own Floating Deck

So here’s my li’l back yard. While it’s a good size for a city, the problem is that it’s not level. It angles down from the house, dropping many feet in relative elevation.

My dad and I again looked at the problem and brainstormed. It makes me laugh because this was an example of ascending problem solving.

Me: “Let’s make a flat place back there by flattening out the dirt/yard.”

Dad: “Good idea. Well, you know, you have those extra 2x8s, so we could just lay them on the flattened ground to make a little platform.”

Me: “I like that…but if we’re going to build a little platform, I could pick up a few more boards and we could build a decent sized deck.”

Dad: “Sure, why not…well if we’re going to build a decent sized deck, we might as well build a frame for the boards to keep them in place.”

Me: “That’s a good idea…of course, if we’re building a framed deck, we might as well get some concrete blocks to keep it off the dirt.”

Dad: “Yes, we should…now if we’re making a decent deck, we should probably build some steps down to it.”

So what started as a simple earth-moving project ended up spiraling into a much larger, but ultimately better, deck building project. Sometimes it’s better to go “the full monty” and do the larger project and be very happy with it, rather than doing a little project and constantly feeling like you could have done more.

By the way, this is called a “floating deck” because there are no posts driven into the ground to stabilize it.  It is just “floating” on the top of the earth. These are much easier to install as you don’t need to deal with deep holes, making and pouring cement, etc.  As long as it’s not going to get banged around too much, the weight of it will keep it in place.

Tools needed/used for Floating Deck:

• Spade
• Mattock
• Long-handled prong cultivator
• Iron rake
• Sod tamper
• Circular saw
• Power drill
• ½” drill bit
• Level
• Hammer
• Large square
• String
• Garden stakes
• Metal mallet
• Metal cutting saw (hacksaw, steel cutting blade in a saws-all, or other type)
• Orbital sander.

Supplies used on Floating Deck:

• (9) 2”x8”x12’
• (10) 2”x8”x6’
• (5) 4’x’4’x8
• (3) 3 ½“x3 ½“x8’ pressure treated landscape timbers
• Steel rebar cut into (12) 1’ sections
• Landscape fabric (optional)
• 3” self-driving deck screws
• 15 concrete blocks

Step #1: Measure out the space and start moving dirt

I measured out a few different sizes (10’x6’, 14’x8’) and finally decided on 12’x8’. Next I hammered in the garden stakes at the corners and strung some string to get an idea of what it would look like. Like I said before, I always like to get a real-world, physical view of where it would be and what it would look like when I can.

As the ground sloped downward, I needed to dig into the hill on the upside, and put the dirt on the down side to start getting an even playing field. The mattock is great for ripping up the grass layer and then I used the spade to dig in more. Using the cultivator and the iron rake, we pulled out the large rocks and a lot of broken glass, rusty nails/screws, and other construction debris that they left littered all over the lawn after they renovated the house before we bought it. (Gggrrrrrr, sore spot, but moving on.)

Step #2: Level it up

After we had it relatively, eye-balled level, we used the sod tamper to pack it down.

To get the final leveling done, we took one of the 2”x6”x6’ and laid it edge-up along the dirt and put a long level on top of it. We removed dirt where needed and added where it was necessary. This was a bit time consuming but if you want it done right, take a little extra time and be sure of yourself. At the end, I also watered it with a hose to get the dirt to settle in solidly.

You don’t need to use all of these different gardening tools, but as I’ve taught my wife, if you have “the right tools for the right job,” it saves you a lot of time.

Step #3: Put down the first concrete blocks and frame

Time to lay out the frame. I put the concrete blocks down on the 4 corners and the middle. Grabbing the level again, I made some more adjustments to the dirt. I know that things will settle in the future, so all the measurements may change, but I at least wanted to start with everything plumb, level, etc. and then deal with the adjustments as they came.

My dog Hudson “helping out.”

Step #4: Finalize and attach frame, prepare base

Before I started to attach the frame and base, I wanted to prepare the dirt area. While yes, the deck itself will block most of the light, nature has a crazy way of taking over! So I wanted to make sure that we didn’t have any weeds that would get started growing and then be impossible to eradicate, like the picture below.

(not my deck, photo courtesy of bearcooks.com)

Firstly, I rolled down some landscape fabric. This will help block the light as well as giving any weeds another layer to grow through. The next step was a mix of necessity as well as desire. Remember me saying there was construction debris left here? Well, there was a large pile of rocks, tiles, busted concrete blocks, and other crap left in my yard. So I decided that under the deck 1) it would be a good place to “hide” the junk and 2) it will help prevent weeds growing as well as animals making a nest under it. I love it when things can serve two purposes!

Step #5: Affix the boards to the frame

I didn’t want seams on the outside boards, so I used two 12’ boards on each side. Then I alternated the 12’ boards with the 6’ boards working my way in. Obviously, make sure that your 4”x4” underneath is in the middle and centered so that the seam for the 6’ boards is right on it. You’ll want to leave between ¼” and ¾” between each board to allow for expansion and contraction. Also, it allows the rain to easily drain off the deck and not sit in the joints between them, possibly rotting the boards. I used 3 ½” self-driving outdoor screws. On the downhill side, I affixed another 12’ piece to give a finished look to it. Both of the sides, I left somewhat unfinished because I wasn’t sure what I was going to do on the sides.

Step #6: Make stairs down to the deck

I wanted to make the stairs easily manageable with wide steps and low rise. I went with the pressure treated landscape lumber so it will last longer and the rounded edges make it easier to walk on/down. Cut the rebar (or get it pre-cut) into 1’ pieces and cut the lumber into 4’ sections. I placed the steps about where I wanted them and temporarily pounded the rebar in to, again, visualize what we were going to do.

Step (haha, get it?!) #7: Install the steps

We looked at having the steps curve around, start right up against the house or to put them at an angle. I decided that I wanted them at an angle going down so it would be gentle and lead you to the deck. I laid down a board to get a straight line, angled down towards the deck and abutted the steps up against it. Once I was happy with the degree of the angle, it was time to affix them permanently.

The first thing was to level out each location for the step to that there was a consistent rise and fall. Basically, we just did the same thing we did for the deck but in miniature. Remove some dirt from the uphill side and add it to the downhill side, creating a flat section to step onto.

Using a ½” drill bit, I drilled two holes into the lumber, about 8” in from each edge. Then using the metal mallet, I pounded the rebar into the hole and down into the earth. I was loathe to do anything too permanent so I/we could change our minds easily down the road.  But for now it gives us a semi-permanent fixture.

Step #8: Make it look pretty

The wood needs to be protected in order to last. I went back and forth between stain and paint. With paint, you can choose any color you want, but it’s usually thicker and hides the grain of the wood. Stains have less color choices, but showcase the wood instead of hiding it. I’m a wood guy, I like to actually see the wood if there’s some nice grain to it, so I decided on staining it. Make sure you get an exterior stain as opposed to an interior. The former is to protect against mildew and fading while the latter is made to be cleaned easier and to not show stains.

Even when I knew it’d be stain, I had 2 more choices, and they are dependent on each other. I had to decide whether I wanted a semi-transparent stain or an opaque. The semi-transparent shows more grain but there is a limited amount of colors you can get.  We decided that we liked the smoky, grey-blue palette, so we needed to go with the opaque to get the tone we wanted. Before staining, I used the orbital sander to give the deck a once-over, removing any burrs, splinters and flattening out the seams. It is better to give it multiple, thin coats rather than a few thick ones. So I added a little water to the stain and gave it 3-4 coats.

Bonus steps – make the oasis a little more oasis-y

True to many projects, once I finished one thing, I said to myself, “Well, as long as I’ve gotten this far, I might as well do a little more work and really make it nice.” First pro tip: it never is a “little” more work, it’s usually a lot. But it makes me very happy when I’m finished with it all.

Since we are on a little hill, surrounded by apartment buildings, we can never truly have privacy. But we can give ourselves the illusion of privacy and make it a little less open. So I picked up some 6’ bamboo “fencing” that we could attach to the chain link fence.

This was a two person job. We needed one person on the outside and on person on the inside. As we unrolled it along the edge of the fence, we used zip ties to attach it to the fence. We put the ties about 18” apart along the top and put a few along the bottom.

While it’s not fully solid, it’s a huge difference from before. It feels like this area is now more enclosed, more private.

Final step: Add chairs, add fire pit, add whiskey and add wife.  Perfect afternoon!

What went wrong:

1. Some boards were twisted. Not warped, but more curved, almost like a crescent. We attached one edge, then used a pry bar to stretch it a little. Then attached it to the next nearest 4×4, repeat for each support. You won’t get it perfectly straight, but it’ll be much less curved. And it’ll settle into its shape and not be constantly trying to torque the screws.

2. Some of the screws got stripped, so I needed to drill some guide holes. I like to use self-driving screws because it usually removes the need for pre-drilling guide holes. However, sometimes the boards were really tight/hard and would get stuck going in and the drill would strip the screw. We had to use vise grips to unscrew some of them. So we had to drill some guide holes for a few of the boards.

3. Accidentally measured wrong but it worked out better than we could have planned. Every once in a while, you make a mistake that actually works out and makes your life easier. As we were planning the size of the deck, how many boards we’d need and the sizes, we made a little mistake. All boards are a little smaller than their “size.”  A 2”x8” is actually 1 ½”x7 ¼”.

We knew this, this is basic, but we totally missed the boat on this. We originally thought that we’d have to rip the last 12’ board to fit. However, with the spacing between the boards and the difference in actual sizes, when we laid the last board down, it fit perfectly. So perfectly that we stopped and were like, “Wait, what did we do wrong here?” Once we realized it, we facepalmed and shrugged, as it looked better than we originally planned it. Oh, happy accidents!

4. Some boards were a little longer than others. No board is EXACTLY the length advertised. Some are a little short and some a little long. I made one edge, the one closest to the outside, the flush edge. The other side, the boards were all a little different in length. At the end of affixing the boards, I just ran a circular saw down the deck, cutting off all the excess. You can see the pieces in one of the latter pictures. I just kicked them under the deck!

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