So, you’ve decided to take on that deck project your wife has been hassling you about for what feels like forever, and you’re ready to get started. You want to build a ground level deck, but you’re not quite sure how to get started. What ground level deck footing options are out there, and which one is right for your deck plan?
In this article, we’ll present all of the deck footing options that are available for ground-level decks and provide you with the pros and cons for each to help you decide which is best for your deck plan, budget, and skill level.
- What Are Ground Level Decks?
- General Rules for Grade-Level (Floating) Decks
- Ground Level Deck Footing Options
- Other Footing Options
What Are Ground Level Decks?
A ground-level deck, sometimes referred to as a floating deck or platform deck, is so-called because, unlike conventional decks, a ground-level deck is not attached to a home or building. While a floating deck might be next to a building, it may also be a standalone structure in the middle of your yard.
Floating decks are also called ground-level decks because they typically hug the ground. Often, the posts supporting them are not visible, giving the deck its “floating” appearance.
General Rules for Grade-Level (Floating) Decks
No Permit Required
One of the nice advantages of building a ground-level deck is that you won’t need to apply for a permit or wait for inspections.
According to the International Residential Code (IRC), no permit is needed if you’re building a deck that does not exceed 200 square feet in area, is not more than 30 inches above the ground at any point, is not attached to a dwelling and does not serve an exit door to a building.
That said, make sure to check with your local building code before getting started to make sure they haven’t amended this IRC guideline.
No Shallow Footings Required
According to the main code provision for footings, the only requirement for building a deck that is freestanding is that it must have a minimum footing depth of 12 inches below the undisturbed ground surface. There is no need to extend a footing below the frost line, as is required for standard decks.
This almost goes without saying, but you need to use pressure-treated lumber when you build a deck. Why? As with standard decks, your ground level deck will be exposed to the elements, so pressure-treated lumber is required to prevent your deck from rotting.
This is even more crucial with ground level decks as they will likely make ground contact due to their nature. This means the deck frame will be more exposed to moisture, making them more susceptible to rot.
Easy to Build
One of the advantages of a ground-level deck is that they’re easier to build. Why? Due to their proximity to the ground, they don’t require beams, stairs or railings. As such, your build time for a ground-level deck should be markedly faster than it is for a standard deck.
Ground Level Deck Footing Options
Because ground level decks in most cases don’t require you to go deeper than the frost line, you have more options when considering what type of footing to use. These relaxed restrictions allow for footings that are sometimes cheaper or significantly easier to install than footings for standard decks. Below is a comprehensive list of the options you have to choose from.
1. Deck Blocks
Deck blocks are cheap and easy to install. Simply position them in the right places, level them and you’re good to go. For these reasons, deck blocks are one of the most popular options out there.
That said, they do have their limitations. Due to their small footprint, you need to distribute the weight over a large number of deck blocks to prevent the blocks from sinking into the ground. This means more footings than other options require.
Also, deck blocks will only fit 4×4 posts, so if you plan on using 6×6’s you’ll have to use an alternate foundation.
Just keep in mind that due to the height of the blocks, you’ll need to partially bury the blocks into the earth by digging footing holes if you’re trying to create a floating deck that hides the deck framing. By burying the blocks, you can build a minimum deck height that’s the width of the joists plus the thickness of your decking.
Deck blocks are one of the more inexpensive footing options as they only require the purchase of the deck blocks themselves, which are about $8 apiece at Home Depot. For a 10×8’ floating deck that requires 12 footings, you’re looking at spending only about $96 for your foundation.
- Easy to install
- Blocks can be a little cumbersome to work with
- Blocks are not attractive if they aren’t hidden
2. Concrete Blocks on Gravel
Like deck blocks, concrete blocks also represent a cheap yet effective alternative for footing your ground level deck. This method functions by taking concrete blocks and laying them on a bed of gravel. The footings are leveled using a string line. Beams can then be rested directly on the block footings.
This method requires very little site preparation and also works well for sites that are not evenly graded as the deck can be leveled by adding additional blocks for low area footings or by sinking the blocks into the ground for high area footings.
Materials are quite cheap for this method. Concrete blocks can be purchased for $1.80 a piece at Home Depot while a 50-lb. bag of gravel runs about $4.60 apiece. For a 10x8ft floating deck, you would need 12 blocks, one block every four feet, and four bags of gravel, bringing the total price of your deck’s foundation to about $40.
- Very Cheap
- Easy to install
- Blocks and gravel can be cumbersome to work with
- Blocks are not attractive if they are not hidden
3. Anchor Ground Spikes
Don’t want to fool around with concrete, cement blocks, and heavy bags of gravel. Ground spikes don’t involve any of those things. In fact, there is no heavy lifting at all, just a fair amount of hammering.
What are ground spikes? They are 24” spiked anchors that are driven into the ground with a large mallet. A squared bracket attached to the top of the anchors, which is where you secure 4×4 posts. Anchor ground spikes are typically used for fence posts.
And while these would never pass muster for a standard deck, they offer plenty of support for a ground-level deck. While won’t require you to perform any heavy lifting, this method does require some brute strength as you’ll be pounding each 24” long spike into the ground with a hammer.
This can be quite a task, especially if the earth around your property is particularly hard. Anchor spikes also require some precision as you’ll want to make sure the spikes go in square to the ground when you’re hammering them in to ensure that each post is plumb when installed.
Price, of course, depends on the size of your deck and how many posts you plan on using. These are one of the more expensive options. A 10×8 floating deck with 12 footings would run you about $180.
No heavy lifting required
A lot of hammering
More expensive than other options
Requires some precision to ensure proper installation
4. Adjustable Helical Posts
Most people think of helical posts as something the pros use. And, for the most part, this is true. Helical posts are typically used to shore up failing foundations on homes and usually require heavy machinery for installation.
As such, they are typically cost-prohibitive for use on a small freestanding deck.
There are, however, some manufacturers who make helical posts that DIYers can install. These posts typically incorporate the use of 1/2” rebar lengths. The rebar is hammered into the ground, where it serves as a guide and added lateral support for each post.
Helical posts are fitted with screw-shaped auger ends, which are threaded around the rebar and manually driven into the ground. This is where the labor-intensive part comes in. The post must be manually augered into the earth.
This is accomplished by threading a 2×4 through the top of the post, then turning it to auger the post into the ground.
As if that’s not enough, once the post has been driven into the earth, a sled hammer is used to make sure the pier is compacted into the earth, preventing sinking once the weight of the deck is added.
Phew! After all this, you might begin to wonder if the helical post got its name from the laborious installation process. Once installed, the height of the bracket can be adjusted to suit the desired height of your deck and to level your footings.
Helical piers aren’t cheap. They run about $50 a pier, making them not just a difficult option, but also an expensive one. A deck with 12 helical piers would cost you about $600.
Extremely strong. Each pier is rated up to 5,000 lbs.
Laborious to install. Rebar must be hammered into the earth. The posts must be manually driven into the ground then pounded with a sled hammer.
More expensive than more conventional options
5. Deck Footing Pads
It’s hard to imagine an easier deck footing option than deck footing pads. The idea is simple. Instead of digging footing holes than hauling, mixing and pouring hundreds of pounds of concrete, you simply use a pad. No hauling cement bags, no mixing, no messy pouring, no waiting for cement footings to dry.
Skeptical? Don’t be. Deck footing pads are tested and certified by NTA Testing Laboratories and are ICC Code compliant. You can also feel good about buying them as they’re made in America with recycled materials.
To install footpads, begin by digging a hole that is two inches wider than the pad, making sure to reach a depth below the frost line. If you want to make the job easier, rent an auger.
Level the bottom with your shovel or some pea gravel. Place the pad in smooth side down and add your post. Then backfill with soil.
Deck footings come in a variety of sizes for various sizes of posts ranging from 10” pads to 24” pads.
Pads run $80 for six 10” pads. For a 10×8’ deck with 12 footings, expect to spend about $160 on footings. Larger pads are more expensive.
Easy to install
You still have to dig footing holes.
A little more expensive than other more conventional options
Other Footing Options
If you’re not satisfied with some of the easier and cheaper options out there, and you’re willing to take on something more involved and more expensive, you might consider the ground level deck footing options below:
6. Deck Foot Anchors
Deck foot anchors offer perhaps the easiest installation process of any footing. They are comprised of an auger attached to a metal plate. They are installed by using an impact driver to drive the auger into the earth, securing the footing to the ground.
Once in place, 4×4 posts are secured to the metal plate with galvanized deck nails. The bracket is adjustable, allowing you to slide it left or right three inches, so you don’t need to be completely precise when installing the auger.
With deck anchors, your deck can be built as low as 2” from the underside of the beams to surface grade or as high as 6’ from the top of the deck to grade. If your deck is higher than 18”, you will need to brace the posts to the beams and joists.
Sold on deck foot anchors? Not so fast. You’ll pay for all that convenience. Each footing costs about $56, meaning you’ll spend upwards of $670 for a 10×8’ floating deck with 12 footings. This makes deck foot anchors one of the more expensive options out there.
Easy and fast installation
No heavy lifting required
Considerably more expensive than other options.
Not an option if your building your deck on uneven ground or a slope.
Anchors do move with the soil as it expands and settles.
7. Concrete Form Tube
Sturdy and very durable. What’s not to like about concrete form tubes for free standing deck footings? How about the installation process? This footing option involves creating a concrete column that runs four feet deep into the ground and measures at least 8” in diameter. Concrete form tubes are the footings of choice if you are looking for maximum strength and durability.
That said, this is one of the more laborious options on this list. Why? Well, for each hole, you’ll need to dig a hole 4’ deep and 8” wide. For an 8×10’ freestanding deck, you’ll need six footings. Unless you have access to a power auger, that’s a lot of digging.
After digging each hole, you will need to install tube forms into each. Each tube form then needs to be filled with one 60 lb. bag of concrete. It’s a lot of back-breaking labor. But, if you’re looking for strong footings, you can’t beat concrete form tubes.
Concrete peers aren’t the most expensive option out there, but they aren’t the least expensive either. A 60 lb.-bag of concrete runs $5.99 per bag while 8” diameter concrete form tubes are about $10 apiece. For an 8’x10’ deck with 12 footings, you’ll spend about $200.
Extremely strong and durable footings
Very laborious installation procedure
8. Diamond Piers
One of the newer footing technologies on the market are Diamond piers. What are they? Diamond piers are based on the concept of tree roots. Huh? Ever notice how large trees stay firmly supported in the earth through their root system?
Diamond piers use the same concept. Only instead of roots, Diamond piers use large pins, which it calls pin pilings. Using a breaker hammer, four four-foot pin pilings are driven through the diamond-shaped pier at an angle into the earth. Like roots holding the trunk of a tree to the ground, the piling holds the pier firmly in place.
Diamond piers are generally better left to the pros. Why? For one thing, they’re quite expensive. Diamond piers require some specialized equipment, namely a demo/breaker hammer and a special driving bit for the pin pilings. Assuming you don’t own a breaker hammer, you’ll have to spend money to rent one. As for the bit, you’ll have to buy one for $200. That’s quite an expense for a tool you may only use for one project. Then there’s the cost of the piers of themselves, which run $140 apiece.
These numbers quickly add up. Even a small 8’x10’ deck that uses 12 piers will cost you $1,680 for the piers and another $200 for the driving bit. And that’s before you’ve rented the breaker hammer. Plan on another $75 to $100 in rental fees for that piece of equipment. In total, you’re looking at around $2,000 for floating deck footings.
Installation is easy with no digging or cement mixing required.
This is a very sturdy method. Once locked in, that pier isn’t going anywhere.
Very expensive compared to other options. Expect to spend well over $1,000 for even a small deck.
With so many footing options to consider for a ground level deck, it’s important to consider what works best for your budget, deck plan, and skill level.
My preferred deck footing option is deck blocks due to their low price and easy installation process. Choose an option that you feel comfortable you can handle, fits your budget, and will safely support your floating deck.