Most composite brands limit joist spacing to ≤16″ o.c. for straight runs and ≤12″ o.c. on diagonal layouts. Always follow the latest manufacturer instructions.
| Brand | Straight run | Diagonal |
|---|---|---|
| Trex* | ≤16″ o.c. | ≤12″ o.c. |
| TimberTech* | ≤16″ o.c. | ≤12″ o.c. |
| Fiberon* | ≤16″ o.c. | ≤12″ o.c. |
*Always confirm with the manufacturer’s current documentation.
Planning? Try the Deck Joist Spacing Calculator and review the Span Charts.
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