Understanding Deck Board Calculations
Decking calculations account for board width, gap spacing (typically 1/8" to 1/4"), and waste from cuts. The standard approach is to calculate total linear feet needed and divide by board length.
Decking Material Comparison
| Material | Lifespan | Cost/LF | Maintenance |
|---|---|---|---|
| Pressure-Treated | 15-20 years | $1-2 | Yearly sealing |
| Cedar | 15-20 years | $3-5 | Every 2-3 years |
| Redwood | 20-25 years | $5-8 | Every 2-3 years |
| Composite | 25-30 years | $4-9 | Minimal cleaning |
| PVC | 30+ years | $7-12 | Minimal cleaning |
| Ipe | 40+ years | $10-20 | Annual oiling |
Board Spacing Guidelines
| Material | Gap at Install | Notes |
|---|---|---|
| Wet Wood | 1/16" - 1/8" | Will shrink as it dries |
| Dry Wood | 1/8" - 3/16" | Standard spacing |
| Composite | 1/8" - 1/4" | Follow manufacturer specs |
| PVC | 3/16" - 1/4" | Account for expansion |
Fastener Requirements
- Face Screws: 2 per board per joist (350 screws per 100 sq ft @ 16" OC)
- Hidden Fasteners: 1 per board per joist (~175 clips per 100 sq ft)
- Use stainless steel or coated screws for composite and treated lumber
- Pre-drill hardwoods like Ipe to prevent splitting
Deck Building Tips
- Start with a straight, true first board as reference
- Stagger end joints by at least two joist bays
- Crown boards up (curved side facing up) for wood decking
- Allow composite boards to acclimate 24-48 hours before installing
- Use chalk lines to keep screws aligned
- Leave 1/4" gap at house and around posts for drainage
- Check local codes for railing and post requirements
When to Use Different Patterns
Perpendicular: Most efficient, least waste, traditional look. Diagonal: Creates visual interest, 15% more material needed. Herringbone: Premium look, requires 20%+ extra material and more complex framing.