HomeOutdoor Living IdeasCortex Screws: What They Are & When to Choose Them

Cortex Screws: What They Are & When to Choose Them

January 20, 2021
Cortex Screws Hidden Fastener in TimberTech AZEK Vintage Collection deck boards

“Cortex screws,” “top-down fasteners,” “hidden” or “color-matched” — what does it all mean? It can feel like there’s a lot of deck fastener lingo to keep track of.

Don’t sweat it; we’ve got the fastener guidance you need.

How Fasteners Play Into Your Deck Project

If you’ve decided to build your own deck — or are just interested in learning more about what deck installation options you have — you’ve likely thought at least a little about your deck fasteners.

Knowing which deck fastener to use for your project will depend on:

In this post, we’ll break down a popular type of deck fastener categorized as a hidden fastener: Cortex®.

Get the 411 on how to choose the right composite decking fastener before you go further in your project.

What Are Cortex Screws?

Cortex for AZEK DeckingHidden Fasteners Best Practices

Cortex screws fit into the category of hidden fasteners. Cortex fastener systems:

  • Include plugs made from the same material as the decking for a seamless final look.
  • Feature a special driving tip that automatically drives the screw at the correct depth.
  • Feature a high-quality, ACQ-approved, specialty deck screw with a TORX® ttap® drive system.

When to Choose Cortex for Your Project

Within the TimberTech® fastener portfolio, you have two Cortex options, each correlated to your choice of TimberTech decking line. No matter which decking line you choose, however:

full profile

Cortex Screws Pair With:

Full-profile TimberTech deck boards

You’ll choose your Cortex fastening system depending on the type of decking — or decking line — you choose.

For our capped polymer deck boards found in the TimberTech AZEK decking line, use Cortex® for AZEK®.

For our capped composite deck boards found in the TimberTech PRO and TimberTech EDGE lines, use Cortex® for PRO® & EDGE®.

Easiest way to build a deck with Cortex hidden fastener top-down deck fastening

Cortex® for AZEK®

Secure, hidden fastening system with collated plugs, designed for TimberTech® AZEK® decking.

Cortex Screws for TimberTech PRO & EDGE Decking

Cortex® for PRO & EDGE

Secure hidden fastening system designed for TimberTech PRO® and TimberTech EDGE® decking.

Why Choose Cortex Instead of Other Fasteners?

Cortex Screws Hidden Fastener for TimberTech AZEK Vintage Collection Dark Hickory 100-sq-ft Collated Fasteners

Cortex screws are classed as hidden fasteners.

If you’re looking for the following, Cortex screws are a good choice for your deck project.

  • Ease: Cortex offers an easy top-down installation. For TimberTech AZEK deck boards, no pre-drilling is required.
  • Strength: Strongest hidden fastener option offered by TimberTech.
  • Speed: Collated plugs with pre-aligned grain pattern provide 50% faster installation.
  • Beauty: Capture a polished final look by hiding the screw heads.

Hidden Cortex Fasteners vs. TOPLoc® Color-Matched Fasteners

Because of their similarities — primarily the inclusion of a color-matched element to the fastening system — Cortex fasteners are often considered alongside our TOPLoc for AZEK and TOPLoc for PRO & EDGE fastening systems.


Both are top-down fastener systems that offer a polished final product.


1.) Fastener Type

TimberTech Cortex for AZEK hidden deck fasteners

Cortex Screws

Hidden fasteners.

TimberTech TOPLoc for AZEK color-matched deck fasteners

TOPLoc Fasteners

Color-matched fasteners.

2.) Compatibility

Cortex screws hidden feck fastener TimberTech

Cortex Screws

Cortex fasteners are compatible with TimberTech AZEK, PRO, and EDGE full-profile boards only. Within TimberTech AZEK: Cortex is available in all 6 Vintage Collection® colors as well as Slate Gray and Brownstone from the Harvest Collection. Approved for use on deck stairs. Approved for use in MAX (1.5”-thick) boards.

TOPLoc color-matched deck fastener top-down screws

TOPLoc Fasteners

TOPLoc screws are compatible with grooved, scalloped, and full-profile boards from TimberTech AZEK, PRO, and EDGE lines.

They are also approved for use in MAX (1.5”-thick) boards.

3.) Appearance

TimberTech Cortex collated plugs

Cortex Screws

Cortex screws drive to just below the deck surface and are then capped with collated plugs made from the same deck material as the deck board (hiding the screw head).

Deck inspetion check joists, screws, and fasteners

TOPLoc Fasteners

TOPLoc screws feature screw heads that are color-matched to the hue of your deck boards. They install flush with, or just below, the deck surface.

Where Can I Get Inspiration & Guidance for Projects With Cortex Screws?

Feeling ready to get started on your decking project? Dive into the Deck Building Resource Center and get the 411 on installing TimberTech AZEK with Cortex.

How to Install TimberTech AZEK® Decking With Cortex® Hidden Fasteners

Or, if you’ve decided TOPLoc color-matched fasteners are more you’re style, learn How to Install TimberTech AZEK Decking With TOPLoc Color-Matched Screws.

Still have questions? Or just feel most comfortable with an applications and materials expert on-hand? Partner with a TimberTech-registered contractor to be sure you get the job done right.

Bring the Beauty of TimberTech to Your Backyard

Work with one of our registered contractors for a build that transforms your outdoor living space.

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