Quick answer
Calculate rows and total linear feet, then review board lengths and layout. Waste depends on the deck shape, board direction, stair cuts, picture framing and whether usable offcuts can be reused.
Step by step
- Measure deck zones Separate main field, stairs, landings and borders.
- Choose board direction Direction changes board lengths and offcuts.
- Calculate rows Use actual face width plus required gap.
- Review board lengths Round to purchasable lengths and keep a visible waste allowance.
Formula or rule of thumb
Example
A 144 in deck width with a 5.625 in board module needs about 26 rows before border and waste adjustments.
Common mistakes
Using nominal board width, ignoring picture-frame borders, and assuming every offcut can be reused.
Planning note: product yields, installation methods, site conditions and local requirements can change the final quantity. Use the exact manufacturer or supplier information before purchasing.
FAQ
Do composite boards need different gaps?
Follow the selected manufacturer's spacing instructions.
Are stairs separate?
Yes, stairs can change board count and create additional cuts.
Does this size joists?
No. Framing is a separate structural design.