Using composite decking fasteners tailored to TimberTech® capped polymer and capped composite deck boards is crucial for correct installation — and deck longevity.
What Are Composite Decking Fasteners & Why Choose Them?
What: Composite decking fasteners secure your capped polymer or capped composite deck boards to their foundational joists
Why: In short, composite decking fasteners are specifically engineered to work best along with TimberTech composite decking. Using the correct fasteners ensures you don’t damage your deck boards and you won’t undermine the fastener’s integrity. This means a greater likelihood of correct installation and an enduringly beautiful deck.
Variables That Will Influence the Fastener You Choose
Before you start deciding which composite decking fasteners pair best with your deck, you’ll need to determine certain variables.
- Preferred decking line
- Preferred collection within that line
- Board shape / type of board (scalloped, full-profile, grooved, square-shoulder)
Once you’ve got these details locked in, you can choose the right fastener for your build.
Step 1: Decide Your Preferred TimberTech Decking Line
Choose from either capped polymer decking or capped composite decking lines.

TimberTech AZEK® Capped Polymer Decking
With exceptional durability and the best warranties in the industry, our capped polymer decking line wins when it comes to performance — and looks fantastic, too.

TimberTech PRO® Capped Composite Decking
TimberTech PRO is our premium capped composite decking line, with a 4-sided cap that provides mold, mildew, and moisture resistance for excellent durability.

TimberTech EDGE® Capped Composite Decking
With 3-sided capping on durable composite decking boards, TimberTech EDGE stands up to the elements, including moisture damage, for a lasting deck build.
Step 2: Decide Your Preferred Collection Within That Line
TimberTech composite decking collections offer varying colors, grain patterns, and finishes to suit your home’s style. They also offer different board profiles that will influence which composite decking fasteners are compatible with that collection.
Most collections offer a choice in board profiles so you can choose your preferred one. However, the TimberTech PRO Terrain Collection™ and TimberTech EDGE Prime+ Collection offer only scalloped boards, as opposed to full-profile, which affects the compatibility of particular fasteners.
Step 3: Decide Your Preferred Board Shape
Why Board Shape Matters
TimberTech deck boards come in different shapes and certain composite decking fasteners are only compatible with specific board shapes.
The Differences in Board Shape
- Scalloped and full-profile refer to how the board appears when viewed from below.
- Grooved and square-shoulder refer to how the board appears when viewed from the sides.

Scalloped
These boards can be more cost-attainable and lighter, without compromising on a sturdy feel.

Full-Profile
A full-profile board is one with a flat bottom. This gives the board a solid feel underfoot.

Grooved
Grooved boards have grooves along their sides that allow for certain hidden fasteners to clip in.

Square-Shoulder
Square-shoulder boards have flat sides, making them compatible with certain top-down, hidden, and/or color-matched fasteners.
You’ll choose your board shape based on several factors:
Step 4: Find the Right Composite Decking Fasteners for Your Deck
Based on your previous determinations, you can now choose the composite decking fasteners that will work best for your build.
Select Color-Matched or Hidden
Color-Matched Fasteners
Color-matched fasteners pair well with all TimberTech decking, providing a secure hold without taking away from your deck’s beautiful design.
Hidden Fasteners
Hidden fasteners pair with all types of deck boards and create a seamless, fastener-free surface.

FUSIONLoc® Hidden Fastener
Compatible with grooved boards across all TimberTech decking lines.
- Pneumatic installation for faster application.
- Each clip provides 3 points of board-to-joist connection for increased strength.
- Stronger hold for tighter butt joints and miters (great for more complex deck board patterns).

Cortex Hidden Fastener
Compatible with only full-profile boards from the three TimberTech decking lines.
- Top-down installation.
- Strongest hidden fastener connection.
- Can be used on the entire deck surface including stairs and the perimeter.
- Plugs to hide the fastener are made from TimberTech decking for a perfect match.
- No pre-drilling required for Cortex for AZEK.
With so many composite decking fastener options, you have a lot to consider. Working with a TimberTech-registered contractor can get you your ideal build while also ensuring your deck is built with application best practices, no matter which product line you choose.
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