Southern Pine Deck Framing Lumber
Framing Lumber for
Southern Pine Decks
Choosing the right Southern Pine deck framing lumber is crucial for your project. While it might seem like a simple task, the quality and type of lumber you select can have a significant impact on everything from structural integrity to appearance.
One of the most important roles of Southern Pine deck framing lumber is as a supporting structure. Beams, bracing, and joists work together to provide a solid, stable deck platform that safely supports vertical loads and resists lateral (side-to-side) forces. See the Prescriptive Residential Wood Deck Construction Guide for beam sizes and assembly details, beam span types, joist sizes, spans including maximum overhang lengths, and diagonal bracing requirements.
- Joist spans are limited to a maximum of 18 feet.
- Bracing is required for any deck two feet or higher above grade.
- Beams are generally assembled with multiple 2x members but may be solid-sawn heavy dimension or timbers, glued-laminated timber, or structural composite lumber.
| Common Practice | Superior Performance | |||
|---|---|---|---|---|
| Selection | Beams | No. 2 (2)2x6, (2)2x8, (2)2x10, (2)2x12 | Beams | No. 1 (3)2x6, (3)2x8, (3)2x10, (3)2x12 Glued-laminated timber or structural composite lumber to size. |
| Bracing | No. 2 2x4, 2x6 | Bracing | No. 1 2x4, 2x6 | |
| Joists | No. 2 2x6, 2x8, 2x10, 2x12 | Joists | No. 1 2x8, 2x10, 2x12 | |
| Installation | Space joists 24" on center maximum | Space joists 16" on center maximum | ||
| Space joists 16" on center maximum if decking is diagonal | Space joists 16" on center maximum if decking is diagonal | |||
| To improve fastener grip, double joists where deck boards abut. |
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| Durability | Pressure treated for Above Ground Use | Pressure treated for Above Ground Use | ||
TIP: Support posts can be notched within limits to accommodate bearing for the beam. However, notching may expose untreated wood to decay. Notching also reduces the post cross section, thus reducing strength. To avoid notching, use a post cap connector to attach the beam directly on top of the post. Notching is prohibited in areas subject to high winds or seismic activity.
More on selecting Southern Pine deck framing lumber
Check out our Southern Pine Decks and Porches publication, a comprehensive guide to deck and porch specification and construction using pressure-treated Southern Pine, to learn more about proper planning, building, finishing, and maintenance.