PocketCalcs

Decking Calculator

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Approx. 350 screws per box

Frequently Asked Questions

What are standard deck board sizes?

Deck boards come in several standard sizes:

  • 2x6 boards: Actual width of 5.5 inches - the most common choice for residential decks
  • 2x4 boards: Actual width of 3.5 inches - sometimes used for smaller decks or specific designs
  • 2x8 boards: Actual width of 7.25 inches - provides a different aesthetic
  • Composite boards: Typically 6 inches wide - popular for low-maintenance decks

Standard board lengths are 8, 10, 12, 16, and 20 feet. Choose a length that minimizes waste based on your deck dimensions.

What joist spacing should I use for my deck?

Joist spacing depends on your decking material and expected load:

  • 12 inches on center: Required for diagonal decking patterns, heavy loads, or some composite materials
  • 16 inches on center: Standard spacing for most residential decks with perpendicular boards
  • 24 inches on center: Only for light-use areas with thicker or stronger decking materials

Always check your local building codes and the decking manufacturer's recommendations for specific requirements.

How do I calculate deck materials accurately?

To accurately calculate deck materials:

  • Measure carefully: Get exact length and width measurements of your deck area
  • Calculate square footage: Multiply length by width to get total area
  • Add waste factor: Include 10-15% extra for cuts and waste (more for diagonal patterns)
  • Consider board length: Choose boards that minimize cuts and waste
  • Count joists: Divide deck length by joist spacing, then add one for the end

For fasteners, plan approximately 350 screws per 100 square feet of decking when using two screws per board at each joist.

What's the difference between composite and wood decking?

Both materials have distinct advantages:

  • Wood (Pressure-Treated): Lower upfront cost, natural appearance, requires regular staining/sealing, 10-15 year lifespan with maintenance
  • Wood (Cedar/Redwood): Naturally rot-resistant, beautiful grain, higher cost than pressure-treated, needs periodic maintenance
  • Composite: Made from wood fibers and plastic, low maintenance, won't rot or splinter, higher upfront cost, 25-30 year lifespan
  • PVC: 100% synthetic, completely waterproof, lowest maintenance, highest cost, may feel less natural

Consider your budget, maintenance preferences, and desired aesthetics when choosing decking material.