Ground Level Decking: How To Do It

Building decks directly on the ground are a favorite of many. They are easier during the building process due to being able to work directly off the ground, eliminating the pesky need to climb ladders. They are also less expensive to build.

These types of decks are a way to add an excellent, well-defined outdoor living space to enjoy while providing a convenient bridge between your house and yard. For a DIY person to build the deck they want, the grand hugging variety is easily within reach.

No Stairs Or Railings Required If Less Than 8″ High

They don’t require stairs or railings and are at a convenient height to facilitate access between your house and the yard. It may not require a permit, as it would if a deck is elevated.

Generally, a ground-level deck is allowed if it is no higher than 30 inches above the ground, while in Canada, it must be no higher than 24″ above grade. So 30 inches high in the USA and 24 inches in Canada. Check your local code to be sure.

The ground is a good place for building a deck, but some conditions must be met. The substructure of a deck built on the ground must be adapted for minimal height, and the deck must be made out of ground-contact wood.

In spite of the fact that based on building codes, a ground-level deck can be elevated to a height of 24″, in this article we will be discussing decks that are less than 8″ high because at this height there isn’t a need to build any stairs.

Ground Level Deck Substructure Inevitable Ground Contact

It doesn’t take long for a deck to degrade to the point of being a liability if it has the wrong material for the joists and beams in contact with the ground.  Unless they’re high enough to allow adequate free air ventilation, you should treat your deck’s joists sufficiently so that they can make contact with the ground.

This is true even if you don’t bury your joists underground. Using 2*8 joists on a deck with less than 8″ height will definitely result in them being in contact with the ground.

For treated lumber, copper azole (CA) and alkaline copper quaternary (ACQ) are the most common treatments. For wood that makes contact with the ground, the level of treatment is crucial. A majority of treated wood sold by home improvement stores, such as Home Depot, Timber Town or Lowes, is not intended for ground contact.

The level of treatment needed for wood that will be in contact with the ground needs to be increased. Wood decays more rapidly when dirt holds water, acting like a natural sponge, especially where there is inadequate drainage below your deck. Incisions on the wood are often required to achieve a higher saturation level of the treatment chemicals to be adequately absorbed.

You can check the incisions on treated timber you intend to use for ground contact by visually inspecting it. Ground contact is likely to be feasible for treated timber that has been incised. In any case, it is always a good idea to inspect the stamp that indicates the level of treatment that is displayed on the timber.

Ground Contact Issues

When wood is within 6″ (150mm) of the ground, they are determined to be in contact with each other. The ground comes into contact with almost any deck that’s less than 8 inches high. In all but the most extreme cases, ground contact wood is required unless you intend to dig 6″ below your deck.

Limited Ventilation For Low Deck Joists

Due to its proximity to the ground, a deck will have little air movement underneath it where the joists are located. Water trapped under your deck joists will cause them to become saturated and decay prematurely. This is another reason why ground contact joists need the correct treatment to prevent this from occurring.

Ground contact is not recommended for most decking, which should have a minimum distance of 6″. While some use pressure-treated wood decking in this situation, it is particularly unsuitable for ground contact since it is not sufficiently treated. 

For a ground-level deck, 2*8 joists should provide sufficient clearance for the decking. Mold and fungi can grow on decking if it’s any lower, especially on the underside. If not permitted to dry out regularly, fungi and mold can still grow on composite decking.

Beam Height For Ground Hugging Decks

It will be necessary to dig trenches for the drop beam if the deck needs to be close to the ground. If the beam is flush with the joist, joist hangers will be required, which will be an additional cost. However, the beam will be kept off the ground and out of the water.

It will also be easier to install joists if you dig a trench for the beam. A wider beam will result in increasing its strength. As a result of the increased clearance under the joist, joists won’t rock on the ground, reducing frustration.

Make sure the trench is wide enough to allow the beam to dry. Keep the trenches dry so that water doesn’t pool there and destroy the beam.

Ground Hugging Deck Support Options

Support is another factor to consider when building a low deck. Do you plan to build a floating freestanding deck or one that has footings? In case of freezing and thawing, a floating free-standing deck will move, but it will be much easier to build.

Even with a low deck, deck builders know that It is stronger to build footings below the frost line, but it will require more dirt to be removed.

Floating Deck Substructure Design

Decks that float are similar to thick blankets on the ground. A direct ground-based deck can be built with minimal leveling adjustments. You can expect your deck to move up and down with the ground. The same as your blanket at night. There are flush beams in the design to reduce the likelihood of the deck buckling, but the deck will still move as the ground moves. Although it may appear stable, the ground isn’t.

Footings Increase Deck Stability

The decks will be more stable if footings are added under the beams. A deeper foundation is required, but the deck will be more stable.

In the case of flush beams on concrete piles, a few inches above the ground will prevent the beam from coming into contact with water. You will have little space to adjust heights after pouring concrete, so check all heights before pouring.

The trench for a dropped beam should be dug at least two inches deeper than the beam dimension, and the pile holes should be dug deep enough to reach past the frost line. You can find the frost depth in your area by searching Google.

Make sure the sonotube installed at the top is level with the beam’s bottom. Airflow will be increased in a deeper trench, allowing the underside of the beam to dry and water to not pool beside it. The beam should be installed once the concrete has been cured. Another option is to use concrete blocks to raise the deck frame slightly above the ground.

Protect Against Freeze Thaw Cycles

You can protect a deck from being affected by the freeze and thaw cycles of the seasons by making deck footings for your deck that go deeper than the frost depth.

Treated 6×6 Posts For Dropped Beams

Drop beams made from 6×6 posts are safe for contact with the ground. Fence posts are intended to be buried underground. If post 6×6 posts are used with a concrete pile every 5 feet, ten feet of deck can be supported safely.

Permits And Codes Provide A Template For Sound Ground Level Decks

Quality structures are built according to building codes. If you want your deck to stand up over time, you should build it according to the code. The span limits of joists are the reason there are codes. There is a limit to how much weight a 2*8 can support.

Building a quality deck requires a reference point, which is provided by the code. Build it right, whether you need a permit or not.

Finishing Touches

With a circular saw, trim any overhangs on your decking once it has been installed to make the deck just right.

Ground Level Deck Ideas

If you need some deck design inspiration to get you going on your deck plans, here is something to get you started.

Best 25+ Ground level deck ideas on Pinterest

Ground Level Decks Frequently Asked Questions

Do ground level decks need beams?

No, ground level decks do not necessarily need beams. However, depending on the size and weight of the deck, as well as the soil conditions, beams may be necessary to provide support.

Do i need posts for a ground level deck?

No, you do not necessarily  need posts for a ground level deck. However, depending on the size and weight of your deck, you may need posts for support.

Does a ground level deck need a permit?

A ground level deck may not require a permit, but it is always best to check with your local building department to be sure.

Will ground level deck rot?

A ground level deck may rot if it is not well-ventilated or does not have a waterproofing sealant or correctly treated timber. Waterproofing sealant will help to prevent water damage and rot. Use correctly rated treated timber if it is making contact with the ground.

Can you build a deck ground level?

Yes, you can build a ground level deck. You will need to clear the area where you want to build the deck, and level it out. You will also need to make sure that the ground is firm and level before you start building.

Does a ground level deck need to be attached to the house?

No, a ground level deck does not need to be attached to the house.

Common Decking Terms

Deck frame: The deck frame is the basic structure of your deck. It includes the joists, beams, and ledger board.

Decking: This is the material that makes up the floor of your deck. It can be made from wood, plastic, or composite material.

Deck Joists: Deck joists are the horizontal beams that support the decking boards. They are typically made of pressure-treated lumber and spaced 16 inches apart.

Deck safety railing: The railing is the border around your deck that provides safety and style. A deck safety railing is a railing designed to keep people safe from falling off of a deck. The beam needs to be fine-tuned to ensure it is level by using heavy-duty metal strapping hardware or composite shims.

Deck Beams: A deck beam is a horizontal member of a deck’s frame that supports the decking. The deck beam transfers the load of the deck and its contents to the posts or concrete blocks of a floating ground-level deck.

Deck beam faces: The deck beam faces are the top and bottom surfaces of a deck beam.

Pressure-treated decking: Pressure-treated decking is a type of wood that has been treated with a chemical to protect it from rot, insects, and weather.

Sonotubes: A Sonotube is a large, hollow, paper cylinder used to form concrete columns and pillars.

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