How to Understand the Parts of a Deck

Constructing a deck will be much easier once you are familiar with the correct terms for the various elements of a deck. Though there are some differences between attached decks and freestanding decks, for the most part the following elements remain the same.

Difficulty:

Moderately Easy

Instructions

Things You'll Need

• Pre-made Concrete Footings W/straps
• Lumber

1. Concrete support footings: These provide the base for the pier blocks and the posts. Building codes determine the exact size and spacing. Footings are cast in place in undisturbed soil. In some areas you may need to add gravel for drainage.

2. Concrete pier blocks: These attach to the footings and provide support for the posts. Pre-made concrete pier blocks come with cast-in-place straps or post anchors. If you cast your own blocks, attach post anchors to them.

3. Posts: These are generally made from 4x4s. Anchor them to the concrete piers in order to provide support for the beams and joists.

4. Ledgers: These large 2 by 8 boards attach to the house or an adjoining solid structure. They provide support for the beams or joists.

5. Beams: These provide support for the joists. When you build an attached deck, one beam will sit opposite the ledger. For a freestanding deck, this beam will take the place of a ledger. Beams can sit directly on a post or can fit into the post. They are usually built of solid lumber - 4x6s or 4x8s.

6. Joists: These provide support for the decking and allow you to lay decking that wouldn't span from beam to beam. Joists can be attached directly to the ledger and beam (or beams) or they can sit on top of them.

7. Rim joists: These provide a finishing touch to the edges of a deck's substructure by covering the ends of the joists.

8. Bracing: These provide added support for tall posts and deck substructures. Blocking (lumber nailed between joists) helps reinforce joists and prevents them from twisting or buckling. Check building codes for bracing and blocking requirements.

9. Decking: This is the finished top of a deck, generally made with 2x6s. The pattern you choose for decking will affect the substructure and the overall look of the deck. Redwood, cedar, and pressure-treated pine are traditionally used for decking; newer synthetic materials that resemble these products are also available.