12x20 Wood Deck Material List: Complete DIY Guide

Embarking on a DIY 12x20 wood deck project? You've come to the right place. Here's a comprehensive, SEO-optimized guide to help you understand the essential materials you'll need for this exciting venture. Let's dive right in.

Before we delve into the material list, it's crucial to grasp the project's scope. A 12x20 deck offers ample space for relaxation, entertaining, or simply enjoying your outdoor living area. Let's break down the materials required, ensuring you're well-prepared for a successful deck build.

Decking Materials

At the heart of your new deck lies the decking material. For a 12x20 deck, you'll need a substantial amount, approximately 720 square feet (12' x 20').

Cedar and pressure-treated lumber are popular choices for decking material due to their durability and weather resistance. Keep in mind, however, that pressure-treated lumber may require periodic staining or sealing.

Cedar Decking

Cedar decking offers a warm, natural look that enhances any outdoor space. Its rot-resistance and dimensional stability make it an excellent choice for outdoor construction. For a 12x20 deck, you'll need around 36 bundles of 5/4x6" cedar decking boards.

While cedar is more expensive than other options, its longevity and low maintenance requirements can justify the upfront cost. Plus, it offers a wide range of grades, from #1 Clear to #2 Common, allowing you to choose the look and feel that best suits your taste.

Pressure-Treated Lumber

Pressure-treated lumber is a more affordable alternative to cedar, making it a popular choice for budget-conscious homeowners. It's treated with preservatives to resist rot, decay, and insect damage. For a 12x20 deck, you'll need approximately 40-45 5/4x6" pressure-treated decking boards.

To maximize the lifespan of your pressure-treated deck, it's essential to apply a quality stain or sealer within eight weeks of installation, and then periodically thereafter. This will help protect the wood from ultraviolet rays and moisture, maintaining its structural integrity and appearance.

Structural Components

With the decking material sorted, let's turn our attention to the structural components that will provide the foundation for your DIY deck.

For a 12x20 deck, you'll need a combination of joists, beams, and posts to create a sturdy frame. The exact quantity will depend on your chosen deck design and local building codes, but here's a general breakdown:

Joists & Beams

Joists and beams work together to support the weight of your deck and its occupants. Typically, you'll use 2x8 or 2x10 pressure-treated lumber for joists and 4x4 or 6x6 pressure-treated lumber for beams.

For a 12x20 deck with joist spacing of 16" on center, you'll need around 24-26 joists (depending on your chosen spacing) and 4-6 beams. Be sure to check local building codes and consult with a professional if you're unsure about sizing or spacing.

Deck Posts

Posts are the cornerstones of your deck, providing the necessary vertical support. For a 12x20 deck, you'll need around 16-18 4x4 or 6x6 pressure-treated posts, depending on your chosen post spacing and local building codes.

Be sure to use post-to-beam connecters and adjustable post bases to ensure a solid, level connection between posts, beams, and the ground. This will help protect your deck from settlement and moisture damage.

Fasteners & Hardware

With the major components sorted, let's not forget the fasteners and hardware that hold everything together. Here's what you'll need:

• Galvanized or stainless steel deck screws (3" long) for attaching joist hangers and decking boards
• Galvanized or stainless steel post-to-beam connectors
• Adjustable post bases
• Hidden or surface-mounted deck fasteners for attaching railings and stair systems (if applicable)

Using the right fasteners is essential for a safe, long-lasting deck. Galvanized or stainless steel fasteners are more resistant to corrosion than regular steel, helping to prolong the life of your deck.

Railings & Stairs

Depending on your deck design and local building codes, you may also need railings and stairs. Railings provide safety and enhance the overall aesthetic of your deck, while stairs make it easily accessible.

For a 12x20 deck, you might need around 8-10 6' rail sections and an appropriate number of post caps, balusters, and stair treads. Be sure to research local building codes and consult with a professional if you're unsure about rail height, spacing, and other requirements.

As your project comes to a close, take a moment to visualize your completed 12x20 wood deck. With the right materials and some elbow grease, you'll soon be enjoying your new outdoor living space. Happy building!