Which term describes a warp across the width of wood where the edges are higher or lower than the center?

Which term describes a warp across the width of wood where the edges are higher or lower than the center?

• A. Density
• B. Creep
• C. Creosote
• D. Cupping

Answer: (D)

Cupping describes a warp across the width of a board where the edges end up higher or lower than the center, forming a curved, bowl-like shape. This happens because moisture content or drying is uneven across the board, causing the fibres near the edges to swell or shrink differently from those in the center. The result is the edges rising or dipping relative to the middle, which is distinct from other wood properties: density is about how heavy the wood is for its size, creep is slow, permanent deformation under sustained load, and creosote is a preservative chemical.

Cupping describes a warp across the width of a board where the edges end up higher or lower than the center, forming a curved, bowl-like shape. This happens because moisture content or drying is uneven across the board, causing the fibres near the edges to swell or shrink differently from those in the center. The result is the edges rising or dipping relative to the middle, which is distinct from other wood properties: density is about how heavy the wood is for its size, creep is slow, permanent deformation under sustained load, and creosote is a preservative chemical.