Types of Deck Footings

Strong footings lay the groundwork for a safe, solid deck. They distribute the weight of the structure into the ground, preventing shifting or settling and protecting the deck’s long-term stability. There are several footing options to choose from, and the right one depends on soil conditions, climate, deck size, and budget. As with every deck project decision, I find that understanding the options makes the choice much clearer. In this article, we’ll look at the main types of footings, how piers differ from footings, and cover the key considerations when selecting footings for your deck.

What Are Deck Footings?

Footings are the bases in the ground that support your deck framing. They work by providing a more stable foundation than a post or beam alone, spreading the deck’s weight across a wider area of soil. Without the extra surface to distribute the weight, the pressure from the deck would be concentrated on the relatively small contact area of a post end or beam edge, leading to unwanted—and potentially dangerous—sinking or shifting.

In colder climates, footings are required to extend below the frost line so expansion and contraction caused by seasonal freeze and thaw cycles don’t disturb the structure. International residential building codes set the minimum size, depth, and placement of footings.

Types of Deck Footings

Several footing options exist, each with its own advantages, limitations, and best-use scenarios.

Poured Concrete Footings

Poured concrete is the most common choice for permanent decks. A hole is dug below the frost line, a form or cardboard tube is set in place, and the hole is filled with concrete. Anchors or brackets are then installed to connect the posts.

Pros: Strong, versatile, durable, and suitable for most soil types.

Cons: Labor-intensive, requires curing time, and can get messy.

Another variation uses plastic tapered footing forms instead of traditional cardboard tubes. These flared forms are placed in the ground and filled with concrete, creating a wider base that resists uplift and settling.

Pros: Lightweight, durable, less risk of collapse due to moisture compared to cardboard forms, wider base for more stability.

Cons: Availability varies, some building departments have not yet officially approved them, and they may cost more than cardboard tubes.

Buried Post Footings

This older method sets wood posts directly into the soil. While it may be allowed in some regions, codes often discourage it due to the risk of rot. It’s usually limited to small, light-duty decks in well-drained soil.

Pros: Simple and inexpensive.

Cons: Limited lifespan, soil contact accelerates rot, and not recommended in clay or wet conditions.

Helical Piers (Screw Piles)

Helical piers are steel shafts with screw-like blades driven deep into the soil with specialized machinery. Because the blades anchor below ground and the shaft continues above, they serve as both footing and pier in a single system. At the surface, brackets are attached to support posts or beams.

Pros: Fast to install, immediately load-bearing, ideal for poor or sloped soils.

Cons: Expensive, requires professional installation.

Deck Blocks

Deck blocks are compact precast concrete or high-strength plastic blocks that sit on leveled ground. Joists or posts slot into them and the weight of the deck keeps them stable, making them popular for ground-level or floating decks.

Pros: Budget-friendly, quick to install, no digging or concrete needed. Plastic versions are light-weight and easy to handle.

Cons: Limited load capacity, not suited for all soil types, and typically not allowed for attached decks.

Larger precast concrete versions are also available, often with built-in brackets for posts and beams, which can increase load capacity.

Deck Piers vs. Footings

You’ll also hear the term pier used, and in some builds footings and piers are poured together as one continuous unit. The distinction is that a footing is the base in the ground, while a pier is a vertical extension above the footing. Piers are often concrete, though steel helical piers are another common type, and they continue above grade to provide a stable bearing point for deck posts or beams, preventing soil contact that can lead to rot and insect damage.

Choosing the Right Deck Footing

When I’m planning a deck, I always weigh a few key factors before deciding which footing is right for the project:

• Deck size and load: Larger, heavier decks need stronger foundations like poured concrete or helical piers.
• Soil type: Sandy or loamy soils may allow for blocks, while clay or shifting soils call for poured concrete or piers.
• Climate: In frost-prone regions, footings must extend below the frost line.
• Deck height: Raised decks require stronger, more secure footings than a ground-level platform.
• Water management: Footings must remain stable over time, but water collecting around them can cause erosion or shifting. A deck drainage system like Trex RainEscape diverts water away from the substructure and footings, protecting the foundation while also keeping the space below the deck dry.

Conclusion

Every deck starts from the ground up, and a solid footing system is the key to years of safe enjoyment. Whether you go with poured concrete, screw piles, deck blocks, precast options, or explore newer plastic tapered systems, the goal is the same: a foundation that will never let you down. Now that you’re familiar with the main footing types, check out my guide on how to install footings for instructions on putting the right option into place.

Sources

Decks.com. (2025). How to Install and Build Deck Footings.

Fine Homebuilding. (2024, June). Choosing a Deck Foundation.

International Code Council. (2024). IRC 2024, Chapter 5: Floors.