How To Build A Ground Level Deck

Every homeowner has dreamt of transforming their yard into the perfect outdoor oasis, and building a deck is on top of the list.

To many, this might seem like a complicated project, and rightfully so, but a ground level deck eliminates some of the hard work since you don’t need the stairs or the safety railings. How exactly can you build a ground level deck?

The exact process of building a ground deck, such as the layout and design, planning the foundation, and laying the deck, which you will learn if you read on. 

What’s the Process of Building a Ground Level Deck?

Ground level decks are one of the most straightforward outdoor structures to build but definitely not the easiest. Due to the low height, you need plenty of ventilation underneath or the deck will rot quickly.

Due to their height, many people don’t see the reason for adding stairs or safety rails, although the latter may be necessary if you have toddlers running around. 

A ground level deck is considered less than 12″ from the ground. It should be well-ventilated to allow free air movement to prevent mold and rot. Always use pressure-treated wood or better for the framing and decking. 

Additionally, a ground level deck doesn’t have to be attached to a structure, eliminating a ledger board which can be a source for wood rot to your house foundation, if not installed properly. This type of deck doesn’t cost as much to build as a regular height deck, due to no stairs or railings.

Most ground level DIY decks cost $10 per square foot for pressure treated framing and decking and 2-3 times that if you have someone build it for you. The cost can go comparatively higher depending on the materials used and the size of the deck. 

If you want to upgrade your decking, chose a composite decking for longer life and easier maintenance.

These are the DIY steps of building a ground level deck:

Lay Down The Plan And Design

The success of any project depends on the planning. If you get this right, you’re halfway through your successful project. In this stage, you need to consider the following:

• Location – You don’t need a huge space for the deck, as small and simple is always better. Make sure you choose somewhere you can have a great view of your yard. 
• Drainage – Standing water is the enemy of wood, and you should prepare the land and under the deck for better drainage.
• The size of the deck – The deck should be high enough from the ground to prevent mold and rot. The deck should not exceed 200 square feet or go above 30 inches high to avoid needing a permit. If you want a bigger deck, you can pull a permit or you can build separate frames as I did in my back yard.

Typical wood lengths are 8, 10, 12 and 16 feet long. To have the least amount of waste for framing and decking boards, you will want to use a size that incorporates the lengths above. An example would be a 12×16 deck.

Get All The Materials Needed

Pressure treated wood is the primary material for framing any deck, especially a ground level deck. No matter if you live in a wet or dry environment, building codes require ground contact pressure treated wood for any framing members that touch the ground.

Make sure your beams and joists are considered “ground contact” pressure treated wood. If you don’t use that type of wood, your framing might not last as long.

As far as decking, there’s a wide choice of materials as listed below. The lowest grade possible is pressure treated decking which will also be the cheapest. How long your wooden decking lasts will depend on many factors.

Many decks are made with pressure treated wood decking and last a long time with proper maintenance. If your deck will see a lot of sun rays, see which type of decking is best for full sun.

If you want to upgrade the look and prolong the life of your deck, consider tropical hardwoods, i.e., ipe, cumaru, tigerwood or composite wood decking. They cost 2-3 times more than pressure treated decking but will last 2-3 times as long. If you can’t decide which size decking, read our article about the difference between 5/4 decking and 2/6 decking boards.

• Pressure Treated Decking
• Cedar
• Redwood
• Tropical hardwood
• Composite wood

Account For Deck Ventilation 

Free air movement helps keep the ground under the deck dry and fresh, which should be at the top of your priority list. If you’re looking at building a ground level deck, I’m making an assumption that maybe you’re trying to go below a patio door or you want something without a big step up.

If you’re building a deck less than 6″ inches from the ground, you’ll have to remove a lot of dirt to get the required ventilation underneath. Removing dirt will be one of the biggest parts of the entire building process.

I try to dig at least 6″ or more of dirt from underneath my ground level decks, then lay 2-3 inches of gravel over weed barrier fabric, which helps with water drainage. This will also help extend the life of the deck.

Set Up Leveling And The Framing

The foundation of any structure is very critical as it determines its strength and longevity. If you’re going under a patio door, that height is key to know for your deck height. I actually go backwards when building decks by putting together my flush beams and joists first.

I build the outer layer of my framing at the height I need under my patio door, then I go around each side leveling it with concrete blocks. Having a long level helps to lay on to top of the framing boards. Once everything is level you’re ready to frame everything.

Make sure you’re outer framing is a few inches less than your longest deck board. Typically you want at least an inch overhang from your deck board to your framing underneath. If you deck boards are 16 feet or 192 inches, you will want your framing to be 190 inches or less. I usually build my framing 4-6 inches less since some decking boards will have checks or cracks on their ends that will need to be cut off.

Set Up The Beams

The flush beams will be necessary in order to allow better drainage and free airflow under the deck. “flush beams” are on the same height as your joists, not underneath like regular beams. Make sure they are supported throughout the bottom of the deck either with buried concrete forms or floating concrete blocks. Where you live may dictate which you can use.

Anywhere with high wind possibility will require you to anchor the deck framing to the ground. You would need to either bury posts in concrete or use concrete forms and use hardware to connect to the deck framing. If you’re able to use floating concrete blocks, make sure you have enough to support the framing properly.

If you need to shim a few spots, use pressure treated or composite shims under the beams to improve leveling. Another option would be to add more gravel to the ground to level it up. 

Add Inner Joists

Before connecting all the inner joists, make sure your deck is perfectly square by taking a diagonal measurement from each corner. The measurement should be the same, if not, make adjustments, until it is the same.

I connect all my outer beams and joists with structural screws and joist hangers for my inner joists. These hardware choices will give you peace of mind to know your deck framing is very secure. With ground level decks, most beams and joists will be 2×6 or less.

I try not to go below a 2×6 for deck framing unless it’s over a concrete patio with 2x4s. Joist spacing with 2x6s should be 16″ on center or less. Most building codes will showcase the beam and joist span for certain types of wood used.

To make your deck even more sturdy, add blocking between the joists, especially if they are longer than 10-12 feet. Adding blocking halfway will stiffen the joists creating a more secure deck.

Lay The Decking

By now, you should notice that the deck is beginning to take shape. Before laying the decking, inspect each one to find any that may have cracks or checks at the end and if possible cut off. I like to lay all my boards on the deck and install a few screws in each, then go back and fill in with the rest of the screws. Each joist will get two screws per decking board.

I also cut the ends of the boards off after installing rather than cut each board separately before installing. Note, if your first board will be next to a house go ahead and cut that one to length.

With a ground level deck, you’ll want a bigger gap to allow more ventilation. I use 1/4 to 3/8 inch gap between my decking boards. If you are using pressure treated decking boards, be careful of your gap as the boards will shrink as they dry.

To cut the ends of the deck boards at once, chalk a line across the board at the point of the cut or clamp a long straight board to the framing, as noted in the pic above. Take a circular saw and saw through each board at the marked line. If you don’t fill like you can screw in a straight line, chalk the joist locations perpendicular to the decking. This will keep your decking screws in a straight line and look more professional.

Conclusion

Ground-level decks are perfect for transforming your outdoor space into something that you will spend countless hours enjoying. It’s also a simple structure to build with the right instructions. Hopefully, we’ve given you the confidence to tackle this project for your backyard. Don’t forget to maintain your deck by pressure washing regularly and staining or painting to prolong the life of the decking boards.