Deck Post - Vertical Deck Support Guide for Homeowners
A deck post is the vertical structural member that transfers the weight of a deck down to its footing or foundation.
What It Is
Deck posts support the beams and framing that carry the load of the deck. They are a critical part of the structure because they keep the deck elevated, stable, and properly supported over time.
Most deck posts are pressure-treated wood, engineered wood, steel, or wrapped structural members. Their size, spacing, and connections matter as much as the material itself.
Where It Is Used
Deck posts are used beneath raised decks, stairs, covered porches, landings, and balcony-style exterior platforms. They are typically located at beam lines and major support points.
How to Identify One
A deck post is a vertical support under the deck, often a 4x4, 6x6, or larger member sitting on a post base or pier. Rot at the bottom, splitting, and loose connections are common warning signs.
Replacement
Replacement is needed when a post rots, twists badly, splits, settles, or loses secure connection to the beam or footing. Structural deck repairs should be designed so the load stays supported during the work.
Frequently Asked Questions
Deck Post — FAQ
- What does a deck post support?
- A deck post carries the load from the beam and framing above down to the footing or foundation below. Without sound posts, the deck can sag or become unsafe.
- How do I know if a deck post is bad?
- Common signs include rot near the base, severe cracking, leaning, insect damage, or visible movement where the post meets the beam or footing.
- Can one damaged deck post be replaced by itself?
- Often yes, but the deck has to be temporarily supported correctly during the repair. The new post also needs proper hardware and footing support.
- Do deck posts have to sit on concrete?
- They need an approved footing or foundation support sized for the load and soil conditions. In most cases that means concrete piers, footings, or another engineered support system.
Have a question about your project? Get personalized answers from our team — $9/mo.
MembershipAlso in Exterior
- Extension Ladder Access & Safety
- Concealed Hinge Cabinet Hardware
- Board and Batten Cladding
- EIFS (Exterior Insulation Finish System) Cladding
- Hardboard Siding Cladding
- Shake Siding Cladding
- Siding Cladding
- Stone Veneer Cladding