DIY Floating Deck in a Sloped Backyard

Cristina Garay

Article Posted By: Cristina Garay

of Remodelando La Casa

DIY Floating Deck in a Sloped Backyard

The centerpiece, quite literally, of Cristina Garay’s recent backyard makeover was her amazing DIY floating deck. The intrepid DIYer and author of Remodelando La Casa built the deck to compensate for her steeply sloped backyard, giving her a comfortable and level space for enjoying her backyard.

Here’s how she built the DIY floating deck– including facing some unexpected obstacles.

Neglected backyard

It’s so embarrassing to show the entire world the ugly condition in which we had kept our backyard for the past few years. That’s right, I don’t even remember for how long we kept this space in that kind of disarray.

There was trouble from the very beginning… Nothing sat level on our slanted yard. That’s why we leveled off a square section for our kids’ playground. Fast forward 12 years, and the once beautiful playground turned into the junk yard you saw at the beginning of this post.

Our simple plan was to build a floating deck right there on the square leveled area, adding a privacy screen on one side and railings on the most elevated parts.

At first, we wanted to cover the entire leveled area, wood and everything, but after taking measurements and trying to keep the cost down, we decided to go with a 16 x 16 ft. floating deck.

The Home Depot was definitely our best friend for this project. I went to the store with my plan in hand and Cesar, one friendly and knowledgeable associate at my closest Home Depot store, gave me the list, and placed the order for all the materials I needed for this project. Two days later the materials arrived home.

Initially, I thought about building this floating deck all by myself, but after looking at all the lumber in our front yard, I knew that handling those 2 x 10 x 16’s and 4 x 4 x 8’s was way more than what my petite 5 ft. 3 in. frame could handle! My brother-in-law was the person who helped me the most all throughout this project, I couldn’t have done it without him.

Up next, I’m going to give you the details of how this project went for me, in hopes that it can be of help if you ever decide to build your own floating deck.

How I Built My DIY Floating Deck


Step 1

DIY Floating Deck in a Sloped Backyard

Our first step was to clean the area and level it some more.

DIY Floating Deck in a Sloped Backyard

Step 2

Then, following the plan, we set the concrete deck blocks in their designated spaces, 12 of them.

The entire area was then covered with landscape fabric, because the last thing I wanted to deal with were those pesky weeds.

DIY Floating Deck in a Sloped Backyard

We then added a 2-in. layer of gravel to be sure nothing would grow there.

Step 3

On the second day of work and after inspection, we were told that the back and main wooden retaining wall was not very strong.

DIY Floating Deck in a Sloped Backyard

It was not safe for us to use deck blocks on that back line. Instead, we had to set concrete buried post footings. We didn’t escape from digging, and it had to be done way down into the ground, below the retaining wall.

The exterior frame was done with 2 x 8 x 16 pressure treated lumber, attached to the 4 x 4’s in each concrete deck block.

DIY Floating Deck in a Sloped Backyard

We used galvanized ½ in. x 8 in. carriage bolts.

DIY Floating Deck in a Sloped Backyard

We used longer 4 x 4’s on the exterior back parts of the deck, since they’d become the railing posts.

Step 4

DIY Floating Deck in a Sloped Backyard

We created a strong center support, perpendicular to the joists, with a set of 2 x 10’s mounted onto the buried concrete blocks, in order to maintain the level line.

DIY Floating Deck in a Sloped Backyard

Once the exterior frame was done, we made sure to square it off by measuring it from corner to corner, pushing or pulling the frame until both measurements were the same.

Step 5

DIY Floating Deck in a Sloped Backyard

The next step was to measure and install the joists. We did it every 16 inches on center.

We drove two- 2 ½ in. Deckmate screws from the outside of the exterior frame and into each end of the joists.

DIY Floating Deck in a Sloped Backyard

In order to keep the joists solid and well secure, we installed the joist hangers. It was one of my favorite jobs because I used a palm nailer. There’s nothing like using the proper tools to speed up a job!

Step 6

DIY Floating Deck in a Sloped Backyard

Installing the decking material was next. I went for a composite decking material: Trex.

DIY Floating Deck in a Sloped Backyard

It wasn’t cheap, but I’m going to see its value throughout the years with the minimum or no maintenance required. I settled for the Beach Dune color one of the colors my local Home Depot store had in stock.

DIY Floating Deck in a Sloped Backyard

I love the Trex Hideaway hidden fasteners for attaching the boards onto the joists. No visible screws and perfectly spaced boards.

Step 7

DIY Floating Deck in a Sloped Backyard

My initial plan to install a privacy screen on that back-left side of the deck was canceled after one of my neighbors filed a complaint for the height of our structure.

Construction was put on hold until this issue, and some unwelcome snow was out of the way.

DIY Floating Deck in a Sloped Backyard

Two weeks later, I got news from the home owners association denying me the building of a structure that could pass the top line of the fence, which meant no wall. So, all the wooden posts were cut off and we went to Plan B: installing a simple railing around the highest parts of the deck.

DIY Floating Deck in a Sloped Backyard

Pressure treated 2 x 4’s, and balusters were the main components of these railings. I used my Ryobi Air Strike nailer  and spacers for an easy install.

DIY Floating Deck in a Sloped Backyard

Then, I reinforced the connections with screws.

Step 8

DIY Floating Deck in a Sloped Backyard

The final details were to add post caps and completing the railing around each post.

DIY Floating Deck in a Sloped Backyard

We also added Trex fascia boards around the perimeter of the deck, and installed a flower box on the side of the deck to cover up the gap the elevation created.

The Completed Deck

DIY Floating Deck in a Sloped Backyard

There is that little area on the right hand side that is still a bit too high for a comfortable step, that’s why I placed those planters right there.

The old wooden retaining wall was stained, trying to match the color of the decking.

DIY Floating Deck in a Sloped Backyard

All in all, we spent three full weekends working on this project.

Without a doubt it was time and money well spent, because this space has become the favorite spot in the house to hang out now that the weather is so nice.

Cristina Garay loves changing things around her house, creating something new, getting busy trying to make the place more livable. Her blog Remodel la Casa features DIY projects, crafts, decorating ideas and more. She lives in Germantown, Maryland with her husband and two children.

Find the materials you need to build your backyard deck in The Home Depot’s Decking Materials section.

Learn how to maintain your deck with our YouTube video.