Composite Deck Joist Spacing — Brand‑by‑Brand Overview
Most composite decking brands specify ≤16″ o.c. for straight installations and ≤12″ for diagonal layouts. Requirements vary by product line and thickness—always follow the current installation guide for the exact product you will use.
| Brand (example) | Straight | Diagonal |
|---|---|---|
| Trex* | ≤16″ | ≤12″ |
| TimberTech* | ≤16″ | ≤12″ |
| Fiberon* | ≤16″ | ≤12″ |
*Confirm with the most recent product literature for the line you are installing.
To pick spacing now, use the deck joist spacing calculator and then verify spans with the span calculator.
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