Height Design Parameters
- Ergonomic Standards Step height: 6.5-7.75". Landing depth: 36" min. Riser consistency: ±1/8". Tread depth: 10-11". Nosing projection: 3/4-1.25". Handrail height: 34-38".
- Structural Requirements Live load: 40-60 psf. Point load: 300 lbs/4ft². Deflection limit: L/360. Lateral load: 200 lbs/ln.ft. Guard post capacity: 500 lbs. Uplift resistance: 1.5× DL.
- Safety Specifications Guard height: 36-42". Baluster spacing: <4". Lighting: 1fc min. Slip resistance: 0.5 SCOF. Landing size: 36×36" min. Emergency egress: 36" clear path.
- View Optimization Sight lines: 42-48" seated. Rail transparency: 70% min. Privacy screening: 72" max. View angle: 15-30° optimal. Railing post spacing: 4-6ft typical.
Engineering Considerations
- Foundation Impact Soil bearing: 1,500-3,000 psf. Frost depth: +6" min. Post spacing: 6-8ft max. Lateral bracing: 2:1 height ratio. Settlement tolerance: 0.5" max.
- Wind Load Analysis Basic wind speed: 90-120 mph. Exposure category: B/C. Gust factor: 0.85. Pressure coefficient: ±0.8. Height factor: 1.0-1.21. Uplift coefficient: -0.5.
- Seismic Design Design category: A-D. Response modification: R=3. Importance factor: 1.0. Drift limit: 0.025h. Connection ductility: moderate. Base shear: 0.2-0.3×DL.
Performance Standards
- Material Durability Weather exposure: Class 3+. UV resistance: 5-7 years. Moisture content: <19%. Corrosion protection: G185. Fire rating: Class C min. Impact resistance: 8-10 ft·lbs.
- Maintenance Metrics Inspection interval: 12 months. Coating life: 2-3 years. Hardware torque: annual check. Structural review: 5 years. Movement tolerance: ±1/4" lateral.
- Accessibility Standards Slope: 1:12 max ramp. Clear width: 36" min. Turn radius: 60". Rest intervals: 30' max. Edge protection: 4" min. Surface gap: 1/2" max.