Get To Know Your Deck Parts With Our Comprehensive Guide For Building a Deck

Building a deck can be like assembling a giant outdoor jigsaw puzzle, with each piece playing a role in the overall structure. For a lot of homeowners, though, they’d rather jump right ahead to the picture on the box rather than think about all those parts!

In our view, knowing about each of those pieces and how they all fit together not only helps you appreciate your deck more, it helps you keep your deck safe and sturdy for years to come. 

Today we’re pulling on our more than 100 years of experience to help you understand the essential parts that make up your deck and why keeping them straight is key to building a safe and beautiful outdoor space.

Deck Substructure

Before diving into the visible aspects of your deck, it’s important to understand the substructure, the unseen framework that provides essential support and stability. 

The substructure is the backbone of your deck, ensuring it remains safe and secure for years to come. 

Let’s explore the key components that make up this critical part of your deck.


Footings provide the essential foundation for your deck, ensuring it remains stable and secure. 

Typically made from concrete, footings are poured into holes dug into the ground. They distribute the deck’s load over a larger surface area, preventing sinking or shifting. 

In colder climates, it’s important that footings extend below the frost line to avoid movement caused by freeze-thaw cycles. Understanding footings is vital as they are the backbone of your deck’s stability.

Support Posts

Support posts are vertical elements that hold up the deck frame. 

Attached to footings with metal brackets, they rise above ground level to support the beams and joists. 

For decks over 8 feet tall or built on slopes, bracing may be required to prevent buckling under the weight. Knowing about support posts helps ensure your deck can handle the load and remain durable over time.


Beams, or girders, are horizontal components that support the joists. Installed alongside or below the rim joists, they provide critical strength and stability. 

For larger decks, additional beams may be necessary. Proper beam installation ensures your deck can bear the weight of use and weather conditions, making it an essential part of the construction process.


Joists are horizontal boards that run between the beams, forming the foundation for your deck flooring. 

Typically spaced 16 inches apart, they provide the necessary support for the decking above. The spacing can vary depending on the deck design and pattern. 

Joists are key for a sturdy and durable deck surface, making their proper installation and maintenance a top priority.


Hardware includes all the fasteners and connectors that hold your deck together, such as joist hangers, screws, and brackets. 

Using the correct hardware ensures the structural integrity of your deck, preventing wobbling and instability. 

Regular inspections and maintenance of these components can prolong the life of your deck.

Ledger Board

The ledger board is a key component that attaches your deck to your house. Securely fastened, it provides a stable base for the deck structure. 

Issues like rot or loose fasteners can cause the deck to pull away from the house, posing safety risks. 

Regular checks and proper flashing can prevent these problems, ensuring a secure connection.


Flashing is a thin material, usually made of stainless steel or vinyl, that directs water away from critical areas like the ledger board. 

It prevents moisture from seeping into the structure, which can lead to rot and decay. Proper installation of flashing is essential to protect both your deck and your home from water damage.

Surface of the Deck

With the substructure in place, the next step is to focus on the surface components that define the deck’s functionality and aesthetic appeal. 

These elements are not only the most visible but also the most customizable parts of your deck, allowing you to create a space that reflects your personal style and meets your practical needs. 

Here’s a closer look at the key parts that make up the surface of your deck.


Decking refers to the surface boards that make up the deck floor. Available in various materials, colors, and sizes, decking is where you can personalize the look of your deck

Proper installation with the right fasteners ensures a smooth, secure surface for all your outdoor activities. 

Regular maintenance of the decking helps preserve its appearance and longevity.

Railing Posts

Railing posts are vertical supports for the deck’s railing system. 

Typically made of wood, they can be covered with composite sleeves or made of aluminum for a more modern look. 

Secure attachment of railing posts is essential for safety, providing sturdy support for the railings.


Railings consist of a top rail, bottom rail, and infill, all installed between the posts. 

They enhance safety and add to the deck’s aesthetic appeal. Available in various materials, railings can be customized to match your deck’s style

Proper installation is critical for safety and compliance with building codes.


Stairs provide access between your deck and the ground or other areas of your yard. 

The design of the stairs should complement your deck’s overall look while providing safe and convenient access. 

Depending on the deck’s height and layout, stairs can be straight, wrap-around, or designed in other styles to suit your needs.

Let Us Help You Bring Your Deck To Life

Building a deck involves understanding its many components and how they work together to create a safe and beautiful outdoor space. 

At Johnson Lumber, we are here to help you every step of the way. Contact us today to get started on your deck project.

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