— posts | size — | anchor size —
Complete Hardware List
- Post bases—
- Anchors—
- Structural screws—
- Coating—
- Estimated cost—
Post Base Type Comparison
| Base | Best for |
|---|---|
| Standoff | Decks, porches; lifts post 1 in off concrete to shed water |
| Adjustable | Fine height/position tuning after concrete is poured |
| Retrofit | Anchoring a post to existing cured concrete |
| Embedded | Set in wet concrete; no separate anchor |
| Saddle | Beam and heavy post pockets; bolts through the post |
| Heavy-duty column | Carports, pavilions, large columns and high loads |
Post Size Compatibility
| Post | Typical anchor | Screws per base |
|---|---|---|
| 4×4 | 1/2 in | ~6 |
| 4×6 | 1/2 in | ~6 |
| 6×6 | 5/8 in | ~8 |
| 8×8 | 3/4 in | ~10 |
How Many Post Bases and How Much Hardware Do I Need?
Every post that lands on concrete or a beam needs its own base, and every base needs its own little kit of hardware: an anchor into the substrate and a set of structural screws or bolts up into the post. So eight 6×6 posts on piers means eight standoff bases, eight concrete anchors, and roughly sixty-four structural screws, plus matching coating. This calculator builds the complete list from your post count, size, base type, and substrate, so you buy the brackets and all the hardware in one trip instead of discovering each base is its own scavenger hunt.
Choosing the Right Post Base
The base type follows the job. Standoff bases are the deck and porch default because they raise the post off the slab to shed water. Adjustable and retrofit bases attach to concrete that is already poured, embedded bases get set in wet concrete for maximum strength, and saddle or heavy-duty column bases carry big posts and high loads with through-bolts. Match the base to the exact post size, since a 6×6 will not seat in a 4×4 bracket, and size the anchor to the post and load.
Anchors, Screws, and Coating
On concrete, bases attach with a wedge or screw anchor sized to the post, commonly half inch for a 4×4 up to three-quarter inch for an 8×8. The post itself fastens to the bracket with structural screws or through-bolts in every hole, never drywall screws or nails. Coating matters as much as the bracket: use ZMAX or hot-dip galvanized with treated lumber and stainless near salt water, and always match the fastener coating to the base so the connection does not corrode from a dissimilar-metal reaction.
Frequently Asked Questions
How many anchors per post base? Usually one for standard standoff bases, two or more for heavy-duty column bases.
What anchor size for a 6×6 post? Commonly a 5/8 inch concrete anchor; 1/2 inch for 4×4 and 3/4 inch for 8×8.
Standoff or embedded base? Standoff for decks and moisture protection; embedded for maximum strength in fresh concrete.
What screws go into the post? Manufacturer structural screws or bolts in every bracket hole, matched to the coating.