DIY Ground Level Deck

DIY Ground Level Deck

After we cleared out trailer loads of overgrown hedges and trees from the backyard, we finally had some space in the corner to add something of our own. We designed and built a ground level deck that provides a much needed focal point and makes the backyard seem so much more spacious. It ended up being one of our quickest projects only taking two and a half weeks from unleveled dirt to finished deck. The timeline was kept short by having everything fully planned out and by getting all the necessary materials in just a few trips.

Scroll down for in progress photos, a description of how we built it, and some tips for future deck builders!

We started by determining the dimensions and researching various building options. We wanted the deck to be very low to the ground so that your eye level would remain below the fence height if possible. So we knew the supports would need to be partially (or fully) buried and that some dirt would need to be moved in order to make space for the support beams. We decided to go with precast concrete piers for the foundation and build a simple structure of pressure treated 2×6 beams on top of the piers.

Digging holes for the blocks took a few days and was certainly much easier when the sun wasn’t beating down directly. A few inches of rock was compacted into the bottom of each hole before placing the precast pier blocks. Then the blocks were leveled to each other in order to provide a flat and secure base. It was pretty easy to get each pier perfect by adding, removing, or shifting the rock beneath.

Leveling a pier to adjacent ones

For future deck builders out there, try to determine the exact finished height you want for the deck at the start. We ended up setting the piers a little too low and added 1.5″ shims to every pier. While that will work fine, it means we did more digging than necessary. Knowing the finished height can certainly save you some digging.

Piers set

The second mistake was assuming that only dirt for the support beams needed to be removed. In reality, the whole ground needed to be roughly level to the height of the bottom of the deck beams because we wanted to put down landscape fabric and metal mesh under the whole area. Although we could have tried to leave the dirt a bit higher between the beams, it would have caused problems later on if the dirt was too high. Trying to excavate the dirt beneath the mesh and landscape fabric wasn’t a task I wanted to be faced with.

After the ground was low enough, we staked down a layer of metal mesh and a layer of landscape fabric. It was covered by a few bags of gravel to keep it from moving or blowing away. (We had a bad experience with landscape fabric being torn up after we prepped the ground for the playhouse. The shipment was delayed and after weeks of sun, wind, and rain, the landscape fabric had become a destroyed mess. So we weren’t taking any chances here, even if it wouldn’t be more than a few days of exposure.)

Installing the beams

Next, we built the primary frame with the center support. Angle brackets hold together the corners and anchor it down to the buried piers. For the center beam, joist hangers were used. For this design, the center support must be running the same way as the top deck boards so that there are place to screw the deck boards down. (There are different styles of joist hangers and these ones are a “concealed” version which has the screws inside the hanger where the beam rests. These were chosen because it was what the store had on hand in a large enough quantity, but they take some additional effort to ensure the top of the beam is flush. The joist hangers with a top flange would definitely be easier to line up, although the deck board resting on top of the hangers might not sit perfectly flat. Also, not all of our 2×6 beams were exactly the same height, so that variance could cause high or low points if using hangers with a flange.) Before securing the frame to the piers, we measured diagonally to check for square.

Detail of attaching a joist hanger

Supporting beams were added with joist hangers in the opposite direction of the center beam. Outdoor rated lag screws specifically made for this hardware were used on all the brackets.

More gravel was added to cover all the landscape fabric. The combination of mesh, landscape fabric and gravel is in hopes that plants won’t grow beneath the deck and to promote drainage away from the wood. (We’ll let you know how it works out!)

Jig, screws, and drill for top board attachment

There are just about a million ways to attach a deck board to the framing of a deck. I preferred the idea of concealed fasteners for the look of consistency. I didn’t mind seeing the screw heads but if one screw was slightly out of line, it would bother me much more than it ever should. And if we ever needed to sand the deck down to refinish it, exposed fasteners would be damaged in the sanding process.

Attaching a deck board

We found the Camo fastening system which had reasonable reviews and looked easy to use. We bought the jig and a single large box of screws. The jig holds the screws at the correct angle to allow for the heads to be hidden in the side of the board while still holding the board down securely. I liked that it was simple to use and provided consistent board spacing. (Or as consistent as was possible with a natural material like wood.) Overall I’m happy with the purchase and it definitely made attaching the boards much quicker than it would have been screwing them down directly. I didn’t have to worry about the screws being exactly lined up since they are hidden and only had to make sure the screws hit the beams below.

Detail of attached top board

This is a close up of an attached deck board where you can see the hole formed by the screw. If you are standing at just the right angle you can just see the holes from the screws but it is not very visible and doesn’t bother us.

Deck complete and ready for furnishings!

After the deck boards were installed, a final trim piece was added to the front edges. There are similar pieces against the fence on both the rear sides which were secured directly to the fence before the top boards were installed.

Deck corner detail

Deck construction complete! We didn’t have time before our initial party deadline to apply a finish, but we do plan to do so once the wood dries out enough. (We’ll be sure to post an update once we do.)

Furnished, ready for relaxing!