Deck posts carry real structural loads, so the concrete you use matters. You need adequate compressive strength to support the deck weight, sufficient pour volume to resist frost heave, and workability that lets you position the post accurately before the mix stiffens. These five products represent the best balance of strength, convenience, and availability for deck post applications.
| Product | Best For | Rating |
|---|---|---|
| Quikrete Fast-Setting Concrete Mix | No-mix post installation | 4.8/5 |
| Sakrete Fast-Setting Concrete Mix | Budget fast-set | 4.6/5 |
| Quikrete 5000 High Strength Mix | Maximum strength | 4.7/5 |
| Simpson Strong-Tie Post Fix | Foam expansion post anchor | 4.4/5 |
| Quikrete All-Purpose Concrete | Standard structural posts | 4.5/5 |
Quikrete Fast-Setting Concrete Mix — Best Overall for Deck Posts
Quikrete’s fast-setting formula is the standard recommendation for post installations because it eliminates the need for mixing. You pour dry mix into the hole around the post, then add water. The mix absorbs the water and begins setting immediately, reaching a working strength of 4,000 PSI within 20 to 40 minutes. This holds posts plumb while you move to the next one without waiting for a full cure. One 50-pound bag handles an average 10-inch post hole.
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Sakrete Fast-Setting Concrete Mix — Best Budget Fast-Set
Sakrete’s version of fast-setting post concrete performs comparably to Quikrete at a similar or slightly lower price depending on the retailer. It reaches 4,000 PSI compressive strength and uses the same dry-pour installation method. For large deck projects requiring many bags, the small per-bag savings add up noticeably. It is widely available at home improvement retailers.
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Quikrete 5000 High Strength Mix — Best for Maximum Load Capacity
When a deck will carry heavy loads, a hot tub, or a pergola structure, upgrading to Quikrete 5000 is worthwhile. This mix reaches 5,000 PSI compressive strength at 28 days, which exceeds the performance of standard post mixes. It requires conventional wet mixing but delivers significantly more strength for critical structural applications. Cure it for at least 24 hours before loading the posts.
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Simpson Strong-Tie Post Fix — Best Foam Expansion Anchor
Post Fix is a two-component expanding foam system, not traditional concrete. It expands to fill the post hole and anchors the post firmly. The main advantage is weight — a single cartridge is far lighter than a bag of concrete. Installation is fast and clean, with no mixing or water. The hold strength is adequate for most residential deck posts, though it is not rated as a structural concrete replacement in all jurisdictions. Check local building codes before using.
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Quikrete All-Purpose Concrete — Best Standard Structural Option
For builders who prefer conventional mixed concrete with the longest pot life and lowest cost per pound, Quikrete all-purpose 80-pound bags work well for deck post footings. The mix reaches 4,000 PSI and is widely available. It requires mixing with water in a wheelbarrow or bucket, which gives more working time to adjust post position. This is the economical choice when you are comfortable with wet mixing.
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How to Choose Concrete for Deck Posts
Match the product to your installation method. Dry-pour fast-setting mixes speed up the job dramatically and suit most residential decks. If structural loads are high or local codes require minimum PSI values, choose a high-strength mix. Consider frost line depth in your region — footings must extend below it to prevent seasonal movement. Always verify with local building codes and, when in doubt, consult a licensed contractor for load-bearing structures.
Related guides worth reading include /articles/best-concrete-for-foundation-repair and /articles/best-concrete-for-diy-projects. Learn more about how we test on the /methodology page.
Frequently asked questions
How much concrete do I need per deck post hole?+
A typical 10-inch diameter hole that is 48 inches deep requires roughly 1.5 cubic feet of concrete, which equals about one 80-pound bag. Wider holes or deeper footings need more material. Use an online concrete calculator by entering hole diameter and depth to get an accurate bag count before purchasing.
Should deck post concrete be above or below grade?+
The concrete footing should extend slightly above grade -- about 1 to 2 inches -- and be sloped away from the post to shed water. This prevents water from pooling at the wood-concrete interface and slowing rot. In cold climates, the bottom of the footing must sit below the local frost depth to prevent heaving.