Composite Decking Board Calculator

Understanding Composite Decking

Proper composite decking calculations ensure optimal material usage and installation.

  • Board Specifications Standard: 5.5"×1"×12-20'. Fascia: 11.75"×0.75". Span rating: 16" O.C. Weight: 2.5-3.5 lbs/ft. Expansion: 1/8" gap per 20°F change.
  • Installation Requirements Joist spacing: 12-16" O.C. End gap: 1/8-1/4". Side gap: 1/8". Slope: 1/4" per foot. Cantilever: 3" maximum. Blocking: 4ft O.C.
  • Performance Ratings Slip resistance: >0.5 coefficient. Fire rating: Class B/C. Span rating: 100 psf. UV protection: 25-year fade. Stain resistance: 25-year.
  • Pattern Options Straight lay: least waste. Diagonal: 15% waste. Herringbone: 20% waste. Picture frame: add 10%. Inlays: add 15%. Feature strips: 5%.

Installation Guide

Fastening Systems

Hidden clips: 24/100ft². Face screws: 350/100ft². Pre-drill required. Stainless steel only. Clip spacing: 16" O.C. End clips: 1/2" from edge.

Support Structure

Joists: PT lumber only. Ledger: flash properly. Beams: 2×8 minimum. Posts: 6×6 recommended. Footings: below frost line. Hardware: ACQ rated.

Cost Analysis

Boards: $7-12/ft². Fasteners: $2-4/ft². Structure: $8-12/ft². Labor: $6-10/ft². Railing: $30-50/ln.ft. Stairs: $50-75/step.

Maintenance Guide

Clean bi-annually. Power wash <1500 psi. Remove debris monthly. Check fasteners yearly. Repair scratches with heat gun. Seal cuts.

Design Considerations

Layout

Plan board direction for best appearance.

Expansion

Allow for thermal movement.

Drainage

Ensure proper water runoff.

Support

Follow joist spacing requirements.

Pattern Guide

  • Straight Pattern Traditional look, efficient material use.
  • Diagonal Pattern Unique look, requires more material.
  • Herringbone Pattern Decorative pattern, complex installation.
  • Custom Patterns Mix patterns for unique designs.

Installation Tips

  • Acclimation Allow boards to adjust to site conditions.
  • Fastening Use manufacturer-recommended fasteners.
  • Cutting Use appropriate blades for clean cuts.
  • Maintenance Follow cleaning and care guidelines.