Parts of a Deck – 16 Labeled Parts, Footing to Top Rail

All 16 parts on the diagram

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Deck from the side 15

Decking (deck boards) The walking surface, laid across the joists.
Top rail (rail cap) The horizontal top of the railing, also the handrail.
Baluster (spindle) Fills the railing so children and pets cannot slip through.
Railing post (guard post) Fixed to the frame; carries the rails.
Bottom rail Holds the bottoms of the balusters.
Ledger board Carries the house end of the joists.
Flashing Sheds water away from the ledger and the wall.
Joist hanger A metal bracket that holds a joist end.
Joist Carries the decking; they run out from the house.
Rim joist (band joist) Closes off the joist ends at the outer edge.
Beam Carries the joists over to the posts.
Support post Carries the beam down to the footing.
Footing Spreads the post's load into the soil.
Stair stringer Carries the treads; cut in a sawtooth.
Tread The part of a step you stand on.

Framing from above 1

Blocking Stiffens the joists and keeps them upright.

How this list was compiled: Read 2026-09-26. (1) A decking maker's deck-parts guide, https://www.trex.com/deck-ideas/deck-parts/ : footings, support posts, beams, ledger, joists, blocking, decking, fascia, flashing, railing, top rail (railing cap or handrail), bottom rail, balusters (spindles) and infill, stairs and stair treads, joist hangers and post anchors. (2) A second decking maker's anatomy of a deck, https://www.timbertech.com/ideas/anatomy-of-a-deck/ : footings, support posts, beams, ledger board, joists, blocking and bridging, flashing, joist hangers, decking boards, railing posts, top rail, bottom rail and infill, stairs. (3) The American Wood Council's Prescriptive Residential Wood Deck Construction Guide (DCA 6), https://awc.org/wp-content/uploads/2021/12/AWC-DCA62015-DeckGuide-1804.pdf : ledger, flashing, joists, rim joists, blocking, joist hangers, beams, posts, footings, guard posts, balusters, stair stringers and treads. (4) Wikipedia, Deck (building), https://en.wikipedia.org/wiki/Deck_(building) : decking, joists, beams, posts, railings. Licence: own work

The drawing: Drawn for this site by script, 2026-09-26. Licence: own work

How it works

What are the parts of a deck called? From the ground up: footing, support post and beam, then the frame of ledger board, joists and rim joist, the decking you walk on, and the railing round the edge.

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Parts of a deck frame

The ledger board is fixed to the house, with flashing over it to shed water. Joists run out from it in joist hangers, rest on the beam, and end at the rim joist. Blocking between the joists keeps them upright.

Railing and stairs

Railing posts are fixed to the frame, and the top rail and bottom rail run between them with balusters filling the gap. Steps hang from the frame on notched stringers that carry the treads.

Questions and answers

What is a ledger board on a deck?

The board fixed flat to the house wall that carries the house end of the joists. Flashing over its top keeps water from getting behind it.

What is the difference between a joist and a beam?

Joists are the many parallel boards under the decking. The beam is the heavier member they rest on, and it carries their load across to the support posts and footings.

What is a rim joist?

The board fastened across the outer ends of the joists, also called a band joist. It closes the frame and gives the railing posts something to fix to.