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Parts of a Deck: A Guide to Deck Terminology

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Parts of a Deck: A Guide to Deck Terminology

A spacious wooden deck with a pergola, railings, and a built-in bench, showcasing various parts of a deck in a backyard setting.

Building a deck is like creating an outdoor oasis, but understanding the parts of a deck—from deck components to the most visible part of your deck—is crucial to making it happen. Knowing deck terminology helps you plan, build, and maintain your deck effectively. It ensures you can communicate clearly with professionals, making the whole process smoother. Whether you’re dreaming of a new deck or giving an old one a facelift, having the right knowledge is key.

At Dupont Decks, we bring over 20 years of construction experience to homeowners throughout Minneapolis, St. Paul, and surrounding communities. Our dedication to quality craftsmanship and customer satisfaction means you can trust us with your deck projects. Contact us today for a 100% free, no-obligation quote and let us help you create the deck of your dreams.

Main Parts of a Deck

A person using a power drill to fasten wooden deck boards onto a frame, showcasing the construction process and parts of a deck.


Decking, also known as deck surface, is the main area of your deck, where you walk, sit, and enjoy outdoor activities. It’s made up of individual boards that are laid out side by side to create a sturdy, flat surface. Decking materials can vary, with popular options including cedar wood, composite, and PVC. Cedar Wood offers natural beauty but requires regular maintenance. Composite decking, such as TimberTech or Azek, combines plastic and wood fibers, making it low-maintenance and durable. PVC decking is entirely synthetic, offering great durability and minimal upkeep. Choosing the right decking material depends on your budget, maintenance preferences, and desired look.


Joists, supported by joist hangers for secure installation, are an essential part of your deck’s structure, acting like the skeleton that supports the entire deck floor. These horizontal beams run between the deck’s ledger board (attached to the house) and the beam (which is supported by posts). They provide the foundational support for the deck boards that form the walking surface.

Typically made from southern pine or sometimes steel, joists must be spaced correctly to ensure the deck’s stability and strength. This spacing depends on the type of decking material used and the deck’s overall design. Properly installed joists ensure that your deck is safe, durable, and capable of handling the weight of furniture, people, and other elements.


Beams, often reinforced with lag screws for extra support, are one of the most important parts of a deck’s overall structure. They are the horizontal support components that run underneath the deck, providing stability and strength. Typically made from southern pine or steel, beams carry the weight of the deck boards and anything placed on the deck, distributing the load to the posts and footings below.

In a deck, beams are usually positioned parallel to the ledger board, which is attached to the house. They are supported by posts and can be either single or double, depending on the deck’s size and design. Properly sized and spaced beams are crucial for ensuring the deck can support the intended loads, including people, furniture, and other items.

When planning or building a deck, understanding the role of beams helps in making informed decisions about materials and construction techniques. It’s essential to ensure beams are installed correctly and securely to prevent sagging or structural failure over time. Regular maintenance, such as checking for rot or damage, is also important to maintain the deck’s integrity and safety.


Fasteners are a crucial component of any deck, vital in maintaining the structural integrity of the deck’s frame. They hold the deck together, ensuring stability and safety. There are various types of fasteners, including screws, nails, bolts, and lag fasteners, each serving a specific purpose.

Screws are commonly used because they provide a strong hold and are less likely to loosen over time. They are ideal for securing deck boards to the joists. Nails, on the other hand, are often used for framing because they are quicker to install, although they may loosen more easily than screws. Bolts are used in structural connections where extra strength is required, such as attaching beams to posts.

It’s essential to choose the right type of fasteners for your deck to ensure durability and longevity. For instance, using stainless steel or coated fasteners can prevent rust and corrosion, especially in outdoor environments. Properly installed fasteners can prevent issues like wobbling or shifting boards, which can affect the deck’s safety and appearance.

Support Structures


Deck posts are vertical support structures that play a crucial role in holding up your deck, often anchored securely using post anchors. They transfer the load from the deck to the ground, ensuring stability and safety. Posts are typically made from pressure-treated wood, which is treated to resist decay and insect damage, or steel, which offers superior strength and durability.

The installation process begins with setting the deck posts to footings, ensuring they sit just above the tops of footings to avoid water damage, and provide a stable foundation. The posts are then secured to the deck frame using metal brackets or hardware. This process ensures that your deck remains sturdy and secure, even under heavy loads and various weather conditions. Properly installed posts are essential for the longevity and safety of your deck.


Footings are a crucial part of a deck’s support structure. These are the bases that anchor the deck to the ground, providing stability and ensuring it can handle the weight of people, furniture, and other items. Properly installed footings prevent the deck from shifting or sinking over time, which is especially important in areas with changing weather conditions that can cause the ground to move.

When installing buried post footings, it’s essential to dig below the frost line to avoid any movement caused by freezing and thawing soil. This depth can vary depending on your location, so it’s important to check local building codes. Another common type of footings are Diamond Pier footings. These kind of footings are a diamond shaped concrete base that the post are attached to. The footing is then anchored into the ground with 4 metal pins that can be rotated as needed.

Additional Structural Components

Ledger Board

The ledger board, typically secured at the top of your ledger board with lag screws for additional support, is a critical component in deck construction. It is a horizontal board attached directly to your house, providing essential support for one side of the deck. Think of it as the backbone that connects the deck to the main structure, ensuring stability and strength. The ledger board must be securely fastened to the house’s framing, often using lag bolts or structural screws to prevent any movement.

Proper installation of the ledger board is crucial for the overall safety and durability of the deck. It needs to be level and flush with the house to ensure that the deck joists align correctly. Additionally, flashing should be installed above the ledger board to prevent water from seeping behind it, which can cause rot and weaken the attachment over time.

Rim Joist

The rim joist is a crucial part of a deck’s structure, acting as a frame that encloses the ends of the floor joists, providing lateral support and stability. Positioned at the outer edge of the deck, the rim joist is typically attached to the ledger board on one side and the end joists on the other, forming the perimeter of the deck’s framework.

The strength and integrity of the rim joist are vital because it helps distribute the weight of the deck and its occupants, ensuring the structure remains solid and secure. It also serves as a critical anchor point for the railing posts, adding to the overall safety of the deck. Proper installation and maintenance of the rim joist are essential to prevent sagging and other structural issues.

Railings and Accessories

Deck Railing Systems

Deck railing systems are crucial for safety and aesthetics. These systems consist of vertical and horizontal components that provide support and enhance the deck’s overall look. The main parts include the top rail, bottom rail, balusters, and posts.

The top rail, or handrail, offers a sturdy grip for people using the deck. The bottom rail connects the posts at the base, ensuring the railing’s stability. Balusters are the vertical rods or panels between the top and bottom rails that add style and prevent falls. Posts, placed at intervals along the railing, anchor the entire system securely to the deck.

Deck railing systems come in various materials, such as wood, metal, and composite, each with its benefits. Wood provides a classic look but requires regular maintenance. Metal, such as aluminum or steel, offers a sleek, modern appearance and is highly durable. Composite materials combine the best of both worlds, offering the beauty of wood with the low maintenance of metal.

Choosing the right deck railing system involves considering factors like style, durability, and maintenance needs. By understanding the components and options available, you can select a system that enhances your deck’s safety and visual appeal.


Balusters are the vertical posts that fill the space between the top and bottom rails of your deck railing. These elements are not just decorative; they play a crucial role in the safety and stability of your deck. Balusters and spindles come in various materials, including wood, metal, and composite, allowing for a wide range of styles to match your deck’s design.

When choosing balusters or spindles, consider the spacing between them. Building codes usually dictate the maximum spacing to ensure safety, especially for children and pets. The spacing should not allow a 4-inch sphere to pass through. This helps prevent accidents and ensures your deck is a safe place for everyone.

Balusters also offer an opportunity to express your style. Traditional wood balusters can provide a classic look, while sleek metal spindles can give your deck a modern touch. Composite materials are another excellent option, combining the beauty of wood with the durability of synthetic materials. Whatever your choice, properly installed balusters and spindles will enhance the overall appearance and functionality of your deck.


Handrails, often the most visible parts of your build, are an essential component of any deck’s railing system. They provide safety and support, especially on stairs, and can add a decorative element to the overall design. Typically installed along the top of the railing, handrails are meant to be sturdy and comfortable to grip. They can be made from various materials, including wood, metal, and composite materials, each offering different benefits in terms of durability, maintenance, and aesthetics.

When planning a deck, it’s crucial to choose handrails that complement the deck’s style and meet safety standards. Proper installation ensures they can withstand daily use and harsh weather conditions. Handrails not only enhance the look of your deck but also contribute significantly to its safety, making it accessible and secure for all users.

Additional Deck Features


Stairs, whether straight stairs or spiral stairs, are a crucial feature of any deck, providing access to and from the deck area. They must be sturdy and safe, especially if you plan on using the deck frequently. When building deck stairs, several components come into play, such as stringers, treads, and risers.

Stringers are the sloped boards that support the stairs, typically cut to match the rise and run of each step. Treads are the horizontal parts you step on, and risers are the vertical portions between each tread. Proper installation of these elements ensures your stairs are both functional and aesthetically pleasing.

The design of your stairs can also affect the overall look of your deck. Open risers, for instance, can give a more modern and airy feel, while closed risers offer a traditional look and extra stability. Handrails are another important safety feature, providing support and preventing falls. Whether you choose a simple or intricate design, well-built stairs enhance the usability and appearance of your deck.


Skirting is the material that encloses the space beneath a deck, providing both aesthetic and functional benefits. It can be made from various materials, such as wood, composite, or vinyl, and comes in different styles to match the overall look of your deck.

The primary purpose of skirting is to hide the structural elements and open space under the deck, giving it a more polished appearance. Additionally, skirting can help keep out animals and pests, protecting the area underneath your deck from becoming a refuge for critters. It can also provide some weather protection, reducing the accumulation of leaves and debris.

Beyond its practical uses, skirting can enhance the visual appeal of your deck. With various design options available, you can choose a style that complements your home’s architecture and landscaping, adding a finished touch to your outdoor living space.

Deck Finishing Touches

Deck Stains and Sealers

Deck stains and sealers are crucial for protecting your deck from the elements and enhancing its appearance. Stains add color and can highlight the natural beauty of the wood grain, while sealers provide a protective layer that shields the deck from moisture, UV rays, and wear and tear.

There are various types of stains, including transparent, semi-transparent, and solid. Transparent stains allow the most wood grain to show through, offering minimal pigmentation. Semi-transparent stains offer a balance, providing color while still showcasing some of the wood’s natural texture. Solid stains act more like paint, providing a rich color that covers the wood grain entirely.

Sealants, on the other hand, are designed primarily for protection rather than aesthetics. They penetrate the wood to create a barrier against moisture, preventing issues like warping, cracking, and mold growth. Some products combine both stain and sealer, offering the benefits of both in one application.

Properly applying stains and sealers can extend the life of your deck, keeping it looking beautiful and ensuring it remains structurally sound for years to come. Regular maintenance, including reapplying these finishes as needed, is essential for maintaining your deck’s durability and appearance.


Lighting is a crucial element in deck finishing touches that enhances both functionality and aesthetics. Proper lighting ensures that your deck is safe to use after dark, highlighting stairs, pathways, and railings to prevent accidents. It also creates a welcoming ambiance, allowing you to extend your outdoor enjoyment into the evening.

There are various types of deck lighting options available, including post cap lights, recessed lights, and string lights. Each type serves a different purpose, from illuminating large areas to providing subtle accent lighting. Choosing the right combination of lighting fixtures can transform your deck into a cozy, inviting space perfect for entertaining or relaxing.

When planning deck lighting, consider the placement and intensity of the lights to avoid overly bright or dim areas. Solar-powered lights are an eco-friendly option, while low-voltage LED lights are energy-efficient and long-lasting. With careful planning and the right fixtures, you can create a beautifully lit deck that enhances the overall look and feel of your outdoor space.

Pergolas and Shade Structures

Adding a pergola or other shade structure to your deck can greatly enhance its functionality and aesthetic appeal. Pergolas, typically made from wood or composite materials, consist of vertical posts supporting a lattice of beams and rafters. This open framework allows for partial shade and creates a beautiful, defined space on your deck.

Shade structures can also include awnings, canopies, and umbrellas. These additions provide protection from the sun and create a more comfortable outdoor living area. By incorporating a pergola or shade structure, you can enjoy your deck even on the hottest days while adding an elegant architectural element to your outdoor space.

What are the requirements for building a deck?

Building a deck requires compliance with local building codes, obtaining necessary permits, and following safety guidelines. It’s crucial to have a solid foundation, proper structural support, use quality materials, and ensure the deck is designed to withstand weight loads and weather conditions.

Build Your Dream Deck with Dupont Decks

In conclusion, understanding the anatomy of a deck, from the decking and joists to pergolas and shade structures, is essential for planning, building, and maintaining a beautiful and functional outdoor space. This knowledge not only helps in communicating effectively with professionals but also ensures your deck meets your needs and preferences.

With over 20 years of construction experience, Dupont Decks is the trusted choice for homeowners throughout Minneapolis, St. Paul, and surrounding communities. Our dedication to quality craftsmanship and customer satisfaction is reflected in every project we undertake. Contact Dupont Decks today for a 100% free, no-obligation quote and let us help you build the deck of your dreams.


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