Deck Piers vs. Footings: Which is Best for Your Deck?
By Dave KileYou’re considering building a deck and want the most durable and strongest supports, so your deck can last a long time. You have been thinking about the substructure of your deck and the best way to ensure a stable foundation. A good build starts at the very bottom.
I will compare deck piers versus footings, reviewing each option so that you can see the benefits and drawbacks of both. Piers can work well in certain areas, while traditional deck footings may serve you better in other situations. We will go through each of these points by point.
Why Proper Deck Support Matters
The most important thing you can do in planning your deck is to ascertain the substructure is sturdy and robust enough to support the deck’s joists, beams, and surface. If the support fails, your deck could become quite unstable. This could lead to dangerous consequences – and even a deck collapse. Deck support is paramount for both the safety and the longevity of your new deck.
What are Deck Pier Blocks?
Deck pier blocks are also called pre-formed deck foundation blocks. They are typically made out of reinforced concrete or a highly durable plastic. Some are made out of composite. They come with pre-shaped holes so that the piers can be attached. Then, the deck’s structure is built directly on top of the pier blocks.
Deck pier blocks are best used with freestanding or floating decks, often low to the ground. If you’re going to use pier blocks, think about the weight distribution on your deck. An advantage of pier blocks is that there is no digging and prepping the ground beforehand so that the deck installation will be faster.
What are Deck Footings?
Deck footings are traditional vertical posts you often see underneath a deck. A new deck connected to a structure will require deck footings. Before connecting a deck to a house, ensure it is stable so there is no damage.
Deck footings generally hold up well with heavier decks and fare better in harsh weather conditions, such as snow and wind. Deck footings are also dug into the ground and placed below the frost line, thus necessitating building permits. The majority of new deck construction uses deck footings. They’re ideal for two-story decks.
Comparing Deck Piers and Footings
While both options will support your deck, there are fundamental differences between the two. Here, I will review the various points of using deck pier blocks versus deck footings. Many homeowners can attest that before building a new deck, researching the supporting structural choices of their deck project has successfully aided their deck build.
Strength and Stability
We all know how important it is to start building something from the ground up, and decks are certainly no exception! Both footings and deck pier blocks can hold a lot of weight.
As mentioned, use pier blocks on decks low to the ground. If you are building a deck detached from your house, say next to a pool or garden in your yard, you would likely be fine with pier blocks.
In regards to footings, it’s important to consider how many deck posts and also the thickness of each of the posts. Typically, deck posts (or legs) are 4″ by 4″ – as they will support 50 pounds per square foot of deck surface space. Posts that are 6″ x 6″ are available as well. However, one thing to keep in mind is that the further apart you space the posts, the larger the posts must be.
Installation Process
Comparing deck piers and footing posts for your deck installation is something you’ll want to do when planning your deck. Both supports types work well, but you need to make sure you’re using the optimum one for your deck, your soil, and your type of climate. A few factors to consider would be:
- Location and size of your deck
- Kind of soil or ground conditions
- Climate (harsh weather)
Paying attention to safety guidelines is of utmost significance. Inspection of joists, railings, surface boards, and the deck supports (like footings or pier blocks), are a few things that make your new deck durable.
Installing deck piers, usually done with smaller decks, is quicker. With these blocks, there is no digging, therefore simplifying the first part of the deck build. On the other hand, footings take longer as they’ll need to be placed below the frost line.
A note about the frost line: this is the depth at which the ground freezes. Digging well below the frost line is tantamount to avoid any potential structural problems. Frost heave occurs when the ground thaws after a freeze. The ground surface tends to move upwards, thus causing a shift in the deck’s substructure.
Code Compliance
As for building permits and code compliance, you should make sure that whatever you choose falls within the guidelines of local ordinances. Pier blocks will need to hold the weight of your deck, but they require less adherence than footings. It’s still strongly recommended that you contact your local government’s building and zoning office to see what, if any, permits you would need to build using deck pier blocks.
Conversely, footings must comply with the local guidelines of your municipality, city, or county zoning and regulations. It’s primarily because of the digging. Calling 811 before doing any ground prep before your deck build is advisable. The IRC, or International Residential Code website, is a useful tool for guidance in planning your new deck.
Cost
Now we get to the part where we want to be thoughtful when comparing the costs. As a general rule, pier blocks cost less. Although some can be more expensive than others (depending on the material), the blocks require less installation prep.
Footings are more expensive because of the material, ground prep, construction permits, and a more complex installation. In the long term, deck footings are extremely sturdy and quite durable. Although you might think about using pier blocks for a freestanding or floating deck – which could be a temporary structure – footings are best when connecting a deck to a building, like a house or a residential building.
Footings can be cost-effective due to the possibility of future deck repairs. They are made to hold more weight and can tolerate a wider variety of temperatures, wind, and snow.
Environmental Considerations
Speaking of frost, wind, and snow, let’s compare deck piers to footings. For the most part, pier blocks work well on solid ground. Level ground is even better. Otherwise, you must adjust the blocks to the landscape’s slope. Footings, however, are frequently used when the soil is craggy, potentially loose, or if the ground soil is in danger of freezing.
Use deck footings in commercial builds, larger decks, and when the outdoor temperatures span a broad range of degrees. The rainfall amount is another consideration when assessing deck pier blocks versus footings. Footings tend to hold up better and have greater longevity than pier blocks. Because footings are installed deep in the ground, they will support more weight and keep your outdoor oasis stable for a long time.
When to Choose Deck Piers vs. Footings
We’ve covered the main differences between deck pier blocks and footings. While both are key components to start off your deck build, one is likely more suitable than the other. Factors like soil conditions, climate, and the ultimate setup of your new deck will influence which option is better.
When it comes to code compliance, do your due diligence in researching what the city or the county requires before you start. Some pier blocks may not need permits, yet we have found that others might. Footings almost always need to have a building permit. And remember to call 811 before digging!
Another important note: the more solid the soil, the stronger the deck foundation. This might make pier blocks a sound choice. However, for durability and in extreme weather conditions, a more established substructure with footings may be called for.
Conclusion
Whether you are building a deck, which will be either a permanent structure attached to your house or a floating or freestanding deck, there are plenty of ways to build a solid, secure foundation. Pier blocks are definitely a great choice for a faster build, yet footings are the tried and true base used for many decks.
Whatever you decide will be the start of something amazing. Decks will bring you joy and beautiful views and give you a new appreciation of nature. Start off with a sustainable, stable, and solid plan for your outdoor investment. It will pay off in the long run.
Sources:
https://trexprotect.com/find-an-installer/
https://trexprotect.com/blog/deck-post-size-guide-find-what-works-best-for-your-design/
https://trexprotect.com/blog/deck-safety-checklist/
https://www.groundsguys.com/blog/how-to-prevent-frost-heave/
https://codes.iccsafe.org/content/IRC2024P2
https://trexrainescape.com/resources/how-to-install-deck-footings/
https://www.decks.com/how-to/articles/deck-footing-size-chart
