When you think of a deck board, you likely picture a kind of solid rectangular plank with smooth edges — what’s called a “square-shoulder” board. But did you know that TimberTech® deck boards come with an option for grooved edges to allow for hidden fastening? With TimberTech, you have your option of square-shoulder and grooved composite deck boards, plus fasteners ranging from color-matched to hidden.
Curious to know which deck board fits your project? And once you choose between square-shoulder and grooved composite deck boards, how do know which fastener to use? This step-by-step overview breaks it all down.
Step 1: Understand Board Profile and Fastener Differences
Board profile types break down across two distinctions: their side profile — which we call “board profile” — and the profile of the underside of the board. The overall shape of a deck board will have to do with the amount of material used and the feel underfoot.
The board profile distinction depends on how the underside of the board looks. We offer two board profiles: scalloped and full.
Alternatively, the shoulders of the deck board — or how the board appears from the sides — have to do with fastening options. We offer square-shoulder and grooved composite deck boards.
The Different Types of Composite Deck Boards
Scalloped Profile
A scalloped bottom made with less material which reduce weight without sacrificing durability and strength.
Full Profile
A solid, sturdy board with a flat bottom for strength and a more solid feel underfoot, similar to traditional lumber.
Grooved Board
A board with capped grooves along both sides to allow for hidden fastening.
Square-Shoulder Board
A solid board that allows for easy top-down installation and color-matched fastening.
Types of Composite Decking Fasteners
Hidden
Used to secure grooved boards. Hidden fasteners allow for a fastener-free deck surface and a seamless finished look.
Color-Matched
Used with color-matched plugs. The visible portions of the fasteners expertly match the color of the deck boards for a polished final product.
Now that you know your composite deck board and fastener terminology, you can next ask:
- What are my options for grooved composite deck boards?
- What are my options for square composite deck boards?
- What are the fastening options for each?
Step 2: Understand Board Type and Fastener Compatibility
You will find both square-shoulder and grooved composite deck boards across the collections in our nature-inspired decking portfolio.
Below, you can find all the decking collections that feature both deck board types, plus the fastening options (by name and type) for each. Check out the overall breakdown in this section, then dive into specifics about hidden fasteners in step 3.
Product Line
TimberTech AZEK® decking
Decking Collections
Harvest Collection®
Arbor Collection®
Vintage Collection®
Types of Deck Boards
Square-shoulder and grooved composite deck boards are available in each of the three collections.
Overall Fastener Breakdown
| Applicable Fasteners | Color-Matched or Hidden |
| TOPLoc® for AZEK (grooved and square-shoulder boards) | Color-Matched |
| Cortex® for AZEK (square-shoulder boards) | Hidden |
| SIDELoc™ (square-shoulder only) | Hidden |
| FUSIONLoc® (grooved boards only) | Hidden |
| CONCEALoc® (grooved boards only) | Hidden |
Product Line
TimberTech PRO® decking
Decking Collections
Reserve Collection
Legacy Collection
Type of Deck Boards
Square-shoulder and grooved composite deck boards are available in each of the two collections.
Overall Fastener Breakdown
| Applicable Fasteners | Color-Matched or Hidden |
| TOPLoc® for TimberTech (grooved and square-shoulder boards) | Color-Matched |
| Cortex® for TimberTech (square-shoulder boards) | Hidden |
| FUSIONLoc® (grooved boards only) | Hidden |
| CONCEALoc® (grooved boards only) | Hidden |
Product Line
TimberTech EDGE® decking
Decking Collection
Premier Collection
Type of Deck Boards
Square-shoulder and grooved composite deck boards available in this collection.
Overall Fastener Breakdown
| Applicable Fasteners | Color-Matched or Hidden |
| TOPLoc® for TimberTech | Color-Matched |
| Cortex® for TimberTech (square-shoulder boards) | Hidden |
| FUSIONLoc® (grooved boards only) | Hidden |
| CONCEALoc® (grooved boards only) | Hidden |
Step 3: Discover Hidden Fastening: Square-Shoulder vs. Grooved Composite Deck Boards
Now that you know all your options, you’re likely wondering if you should choose square-shoulder or grooved composite deck boards. The answer will depend on several factors, including:
- Your materials budget (square-shoulder and grooved deck boards appear in all three TimberTech decking lines).
- Your installation budget (CONCEALoc® and FUSIONLoc® for grooved deck boards are associated with faster installation speeds).
- Whether you want hidden or color-matched fasteners for your decking project.
One major draw to grooved composite deck boards is the option for hidden fasteners and a seamless appearance. That said, we also offer hidden fastening options for square-shoulder deck boards as well.
Hidden Fasteners for Grooved Deck Boards
CONCEALoc® Hidden Fastener
Compatible with grooved deck boards from all three TimberTech decking lines.
FUSIONLoc® Hidden Fastener
Compatible with grooved deck boards from all three TimberTech decking lines.
Hidden Fasteners for Square-Shoulder Deck Boards
Cortex® Hidden Fastener
Compatible with all square-shoulder deck boards from all three TimberTech decking lines.
SIDELoc™ Hidden Fastener
Compatible only with square-shoulder deck boards from TimberTech AZEK decking.
Now that you know the differences between composite deck board profiles and the available fastening options, you’re ready to see and feel our nature-inspired decking for yourself.
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