{
  "title": "Wood fence dimensions and moisture-movement reference",
  "compiledBy": "Fence Advisors",
  "reviewedAt": "2026-10-03",
  "referencePeriod": "USDA Wood Handbook, 2021 edition",
  "compilationLicense": "https://creativecommons.org/licenses/by/4.0/",
  "licenseNote": "Original compilation and graphics only; does not relicense third-party documents or trademarks.",
  "sources": [
    { "id": "fpl4", "label": "USDA Wood Handbook Chapter 4 (2021)", "url": "https://research.fs.usda.gov/download/treesearch/62243.pdf", "locator": "Table 4-3, pages 4-7 to 4-8; dimensional stability discussion" },
    { "id": "fpl6", "label": "USDA Wood Handbook Chapter 6 (2021)", "url": "https://research.fs.usda.gov/download/treesearch/62245.pdf", "locator": "Table 6-6, page 6-10; surfacing discussion" }
  ],
  "shrinkage": [
    { "species": "Western redcedar", "radialPercent": 2.4, "tangentialPercent": 5.0 },
    { "species": "Northern white-cedar", "radialPercent": 2.2, "tangentialPercent": 4.9 },
    { "species": "Redwood, young growth", "radialPercent": 2.2, "tangentialPercent": 4.9 },
    { "species": "Redwood, old growth", "radialPercent": 2.6, "tangentialPercent": 4.4 },
    { "species": "Loblolly pine", "radialPercent": 4.8, "tangentialPercent": 7.4 },
    { "species": "Eastern white pine", "radialPercent": 2.1, "tangentialPercent": 6.1 },
    { "species": "Douglas-fir, coast", "radialPercent": 4.8, "tangentialPercent": 7.6 },
    { "species": "Sitka spruce", "radialPercent": 4.3, "tangentialPercent": 7.5 }
  ],
  "dressedDryLumber": [
    { "nominal": "1 x 4", "thicknessInches": 0.75, "widthInches": 3.5 },
    { "nominal": "1 x 6", "thicknessInches": 0.75, "widthInches": 5.5 },
    { "nominal": "2 x 4", "thicknessInches": 1.5, "widthInches": 3.5 },
    { "nominal": "4 x 4", "thicknessInches": 3.5, "widthInches": 3.5 },
    { "nominal": "6 x 6", "thicknessInches": 5.5, "widthInches": 5.5 }
  ],
  "takeoffExamples": { "runLengthsFeet": [50, 100, 150, 200, 300], "measuredWidthInches": 5.5, "sideBySideGapInches": 0, "spacedGapInches": 0.125, "boardOnBoardOverlapEachEdgeInches": 1, "wastePercent": 0 },
  "limitations": [
    "Shrinkage is from green to oven-dry as a percentage of the green dimension; not measured seasonal fence movement or an installation-gap recommendation.",
    "Species values are reference averages; individual boards, grain orientation, treatment and moisture history vary.",
    "Dressed-dry dimensions are standard reference sizes, not the dimensions of every rough-sawn or proprietary fence picket.",
    "Takeoffs are original geometric models for separate flat continuous runs, not measured material consumption or a construction design.",
    "The board-on-board model has a base row, one cover board per base-row gap and no cover boards on the outer ends. End details and cut reuse can change an actual order."
  ]
}