Footings

Post Attached To Concrete Pier

This commonly used deck foundation uses reinforcing bar (rebar) to firmly connect the footing at the base to the concrete pier. At the top, a metal post base connects the concrete pier to a wooden post. Given that the footing is well attached to the pier, the uplift resistance of this footing and pier combination is equal to the weight of the concrete plus the amount of soil that would need to be displaced by pulling the footing out of the ground.

Check Point - Wind design speeds are 70 mph or higher across the United States. Do you know how to determine the amount of uplifting force on the structure and design your deck or gazebo accordingly? Under high winds, improperly secured decks can take off like a flying saucer. For a nominal fee, consider getting a password and have instant access to uplifting wind loads and use our footing calculator to see just how strong your foundation is.

The concrete pier is poured a few inches above grade to keep the metal base and post end away from ground contact and too much moisture. A heavily galvanized metal post base attaches the wood post to the top of the concrete pier. This type of foundation does not offer any side-to-side (lateral) resistance like other options such as posts embedded into the ground resting directly on a concrete footing.

Tip: Always use nails and bolts made out of the same metal as the metal connector. If you're using double hot dipped steel post bases, then use double hot dipped nails/bolts. If you use stainless connectors, then use stainless steel nails/bolts.

Check Point - In the Password Area of BestDeckSite, we examine six different foundation types and the effects of using different types of backfill. If your deck or gazebo is being built in a high-wind area, is tall in height, supports a hot tub, and/or has a sizeable depth to it, you'll want to learn about what you can do to increase the side-to-side strength of your structure. For less than the cost of a 12-foot 2x6 board, get a password and learn how to make sure your deck or gazebo won't tip over under the worst of conditions.

Although this type of foundation is commonly used, in my experience, it is somewhat more prone to decay. The shorter lengths of 4x4 posts often used in this type of foundation tend to split and twist more than larger posts and don't usually have as high of a treatment level. Given that 4x4 and larger posts have a central core that is not penetrated by the wood preservatives, make sure to soak all cut post ends in a Copper Naphthenate wood preservative containing at least 2% copper. A few brands of copper naphthenate wood preservatives include "CuNap", "Wolmanized End Cut Preservative" and "Copper Brown".

The content under the "How-To" menu is a small sampling of all the material covered on BestDeckSite. For immediate access to in-depth information on the different types of footings, an on-line Footing Calculator, the use of rebar, and mixing strong concrete, as well as, comprehensive coverage of all aspects of gazebo and deck building, get a password and log-in now.

     Footings

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