Joist Engineering Parameters
- Structural Properties Modulus of elasticity: 1.6-2.1×10⁶ psi. Fiber stress: 1,000-1,500 psi. Shear strength: 175-225 psi. Compression perpendicular: 625 psi. Specific gravity: 0.42-0.55.
- Load Distribution Dead load: 10 psf min. Live load: 40-60 psf. Point load: 300 lbs. Snow load: 30-40 psf. Deflection limit: L/360 live, L/240 total. Load duration: CD 1.0-1.6.
- Dimensional Standards Crown orientation: ±1/8". Lateral restraint: 1:1 ratio. End bearing: 1.5" min. Notch depth: d/6 max. Hole diameter: d/3 max. Location: 2" min from edges.
Installation Specifications
- Connection Details Hanger capacity: 1,250-1,500 lbs. Nail size: 16d min. Bolt edge distance: 1.5". Washer size: 3× dia. Split resistance: 3D min. Withdrawal: 150 lbs/in.
- Support Requirements Bearing length: 3" min. Cantilever: 1/4 span max. Blocking interval: 8' max. Bridging size: 2×2 min. Rim joist thickness: match joists. Ledger depth: full joist.
- Material Protection Treatment retention: 0.40 pcf. Moisture barrier: 15 lb felt. Flashing width: 4" min. End grain seal: water repellent. Hardware grade: ASTM A153 Class D.
Performance Criteria
- Serviceability Limits Vibration frequency: >8 Hz. Acceleration limit: 0.02g. Damping ratio: 3-5%. First mode shape: sinusoidal. Human comfort threshold: ISO 2631-2.
- Environmental Factors Temperature range: -20 to 120°F. Moisture cycling: 8-19%. Creep factor: 1.5-2.0. Wet service factor: CM 0.85. Temperature factor: Ct 0.8-1.0.
- Quality Assurance Grade stamp: visible. Straightness: 1/4" in 10'. Twist: 1° per foot. Wane: 25% max. Knot size: 2" max. Split length: 12" max or reinforced.