Concrete Piers for Decks

Deck foundation planning has gotten complicated with all the pier types, depth requirements, and soil considerations flying around. As someone who has poured concrete piers for every deck configuration, I learned everything there is to know about building solid foundations. Today, I will share it all with you.

What Concrete Piers Do

Probably should have led with this section, honestly—concrete piers provide solid foundation to support deck weight and structure. They transfer loads from the deck to the ground, preventing settling and movement.

Types of Piers

That’s what makes pier selection endearing to us deck builders—each type serves different needs:

• Poured Concrete: Most common, customizable depth and diameter
• Precast: Ready-made for quick installation
• Tube Forms: Cardboard tubes filled with concrete for uniform shape

Installation Process

1. Mark pier locations according to deck plan
2. Dig holes below frost line (depth varies by region)
3. Place tube forms if using
4. Mix and pour concrete
5. Insert post anchors before concrete sets
6. Allow proper curing time

Sizing Considerations

• Diameter based on load requirements
• Depth must reach below frost line to prevent heaving
• Spacing determined by joist span and beam size

Common Mistakes

• Not digging deep enough for frost line
• Improper spacing causing structural stress
• Not allowing adequate curing time
• Poor soil compaction at bottom of hole

Code Requirements

Local codes specify minimum depth, diameter, and spacing. Always check requirements before construction. Non-compliance can result in failed inspections or structural problems.

Maintenance

Inspect piers periodically for cracks or settling. Address drainage issues that might undermine foundations. Proper initial installation minimizes future maintenance needs.