{
 "name": "calculiva-home-improvement-constants",
 "title": "Calculiva home improvement constants register",
 "version": "2026-10-14",
 "license": "CC-BY-4.0",
 "rights": "CC BY 4.0 covers Calculiva's own contribution only: the compilation, its structure, the statuses, the scopes and the notes. Third-party values (published charts, list prices, product dimensions, tool outputs) are attributed to their sources and dated; no right over them is granted or claimed. Third-party text is not reproduced: each record names the page it was read on, and the excerpts read stay in Calculiva's working files. Calculiva is not affiliated with any company named.",
 "homepage": "https://calculiva.com/data-sources/",
 "publisher": "Calculiva",
 "records": [
  {
   "id": "asphalt-unit-weight-observations",
   "label": "Hot mix asphalt: in-place unit weight, lift thickness rules and what ranking calculators assume",
   "status": "market_survey",
   "scope": "Compacted hot mix asphalt on residential paving in the United States. The unit weight of a delivered mix belongs to its mix design; the values here are what named publishers state or what their tools compute on the verification date. No pavement thickness recommendation is included: none was read in a normative source.",
   "source_name": "Asphalt Institute, Engineering FAQs",
   "source_url": "https://www.asphaltinstitute.org/engineering/engineering-faqs/",
   "verified_at": "2026-09-18",
   "expires_at": "2027-03-18",
   "sample_size": 4,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.asphaltinstitute.org",
    "www.asphaltisbest.com",
    "www.vulcanmaterials.com"
   ]
  },
  {
   "id": "batten-spacing-conventions",
   "label": "Usual spacing between battens on an interior wall",
   "status": "convention",
   "scope": "decorative interior wall paneling (faux board and batten). Does not apply to exterior siding, where spacing depends on board width and substrate.",
   "source_name": "Inch Calculator, first organic result for \"board and batten calculator\" (SERP read on 2026-09-09)",
   "source_url": "https://www.inchcalculator.com/board-and-batten-layout-calculator/",
   "verified_at": "2026-09-09",
   "expires_at": "2027-09-09",
   "sample_size": 1,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.inchcalculator.com"
   ]
  },
  {
   "id": "carpet-roll-observations",
   "label": "Carpet estimators: what they multiply, observed executions",
   "status": "market_survey",
   "scope": "Behaviour of public estimators on the day tested, with the inputs recorded. The 12-foot roll width, 3-inch cut margin and 10 percent flat waste are the defaults those tools displayed, not Calculiva conventions: enter the roll width and margin of the product actually quoted. Broadloom is sold by the linear foot from the roll; no price or regional labor figure is recorded.",
   "source_name": "Live executions of ranking carpet calculators, 10 September 2026 (MeasureSquare carpet calculator as reference)",
   "source_url": "https://calculator.measuresquare.com/carpet",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 7,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "calculator.measuresquare.com",
    "www.carpetguys.com",
    "www.godfreyhirst.com",
    "www.lowes.com",
    "www.omnicalculator.com",
    "www.theperfectcarpet.com"
   ]
  },
  {
   "id": "ceiling-panel-guidance",
   "label": "Suspended ceiling module and border planning",
   "status": "convention",
   "scope": "Nominal module sizes observed in the manufacturer planner. Border-edge profiles and lighting need product-specific installation instructions; no universal fit deduction, support capacity or clearance is asserted.",
   "source_name": "Armstrong / Kanopi manufacturer planning resources",
   "source_url": "https://kanopibyarmstrong.com/pages/how-to-cut-borders",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "kanopibyarmstrong.com",
    "www.armstrongceilings.com"
   ]
  },
  {
   "id": "curtain-measuring-conventions",
   "label": "Curtain sizing and drapery yardage conventions as published by the ranking tools and guides, with their executions",
   "status": "market_survey",
   "scope": "Every figure is attributed to the publisher that states it; ranges are theirs, not a consensus. Calculiva's calculators preload one value from each range as an example and every field can be changed. Nothing here is a standard: US curtain sizing has no governing standard, and the publishers disagree on extension, height and finish.",
   "source_name": "Home Depot measuring guide, Omni, Home Project Calculator, Sailrite Fabric Calculator, TwoPages, Jane Clayton, Best Fabric Store, sew-helpful, House of Ekam, the AI Overview; read and executed 10 September 2026",
   "source_url": "https://www.homedepot.com/c/ah/how-to-measure-curtains/9ba683603be9fa5395fab90a2ca03be",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 12,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "houseofekam.com",
    "twopagescurtains.com",
    "www.fabric-calculator.com",
    "www.homedepot.com",
    "www.janeclayton.com",
    "www.omnicalculator.com",
    "www.sew-helpful.com"
   ]
  },
  {
   "id": "deck-module-guidance",
   "label": "Interlocking deck module planning",
   "status": "convention",
   "scope": "The repeating installed module is the counting unit. Cut locations require inspection of the product backing and screws. No universal gap, connector ratio, structural capacity or pack size is asserted.",
   "source_name": "NewTechWood installation guide and IKEA decking measurement guide",
   "source_url": "https://www.newtechwood.com/composite-deck-tile-installation/",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.ikea.com"
   ]
  },
  {
   "id": "epoxy-coverage-observations",
   "label": "Epoxy floor coverage: physical basis and observed estimator rules",
   "status": "market_survey",
   "scope": "The physical basis is exact and product-independent: one US gallon is 231 cubic inches, one mil is 0.001 inch, so one gallon spread at one mil dry film with 100 percent volume solids covers 231,000 square inches, 1,604.17 square feet. Vendor coverage rates, kit sizes and mix ratios below belong to their publishers on the day tested; they illustrate how public estimators multiply and are never Calculiva defaults. Every thickness, solids figure, loss allowance, kit size, ratio and broadcast rate preloaded in the calculator is a hypothetical exercise to be replaced by the product's technical data sheet.",
   "source_name": "NIST Handbook 44 Appendix C (gallon = 231 cubic inches) and live executions of ranking epoxy calculators, 10 September 2026",
   "source_url": "https://www.epoxy.com/epoxy_calculators/coatingcalc.aspx",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 7,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "magicresin.ca",
    "www.epoxyfx.com",
    "www.omnicalculator.com"
   ]
  },
  {
   "id": "flooring-cost-estimator-bases",
   "label": "What ranking flooring cost estimators multiply (observed executions)",
   "status": "market_survey",
   "scope": "Observed behaviour of public estimators on the day of the test, with the inputs recorded here. Merchant prices, tiers, freight thresholds and unit costs belong to their publishers and change without notice; they are cited as examples of a multiplication basis, never as Calculiva pricing. Lowe's and Home Depot pages could not be executed from the test environment (location gate, then access denied).",
   "source_name": "Live executions of ranking flooring cost estimators, 10 September 2026",
   "source_url": "https://floorfreight.com/cost-calculator",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 6,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "pro.houzz.com",
    "skyciv.com",
    "www.homewyse.com",
    "www.omnicalculator.com"
   ]
  },
  {
   "id": "flooring-joint-checks",
   "label": "Pergo Classics: example of product-specific plank checks",
   "status": "market_survey",
   "scope": "Specific Pergo Classics instructions, not all laminate, wood or vinyl. Numeric checks do not establish installation compliance. This source does not supply a minimum final-row width or final-piece length for this tool.",
   "source_name": "Pergo Classics Installation Instructions, 03/2021, page 4, steps 5–6",
   "source_url": "https://pdf.lowes.com/productdocuments/47daec0b-407e-4991-81de-582e5786a097/65848084.pdf",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 1,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "pdf.lowes.com"
   ]
  },
  {
   "id": "grout-coverage-tables",
   "label": "Cement grout coverage as published by two manufacturers, and the joint model and powder density each table implies",
   "status": "market_survey",
   "scope": "Two cement-based grouts sold in the United States, as each maker tabulates its coverage by tile size and joint width. Tables transcribed from the PDF text; Calculiva keeps an archived copy of both PDFs as read and does not republish them. The implied density is derived here from each table, it is not a figure the makers print.",
   "source_name": "MAPEI Ultracolor Plus FA technical data sheet (Edition Date: August 28, 2026); LATICRETE PERMACOLOR Grout data sheet DS-250-0926",
   "source_url": "https://cdnmedia.mapei.com/docs/librariesprovider67/products-documents/1_3000144_ultracolor-plus-fa_en-us_979a424a35724d82980fa0332f798319.pdf",
   "verified_at": "2026-09-25",
   "expires_at": "2027-03-25",
   "sample_size": 2,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "cdnmdm.laticrete.com",
    "cdnmedia.mapei.com"
   ]
  },
  {
   "id": "grout-joint-practice",
   "label": "Sanded or unsanded cement grout by joint width, caulk instead of grout at changes of plane, and joint width against tile variation, as TCNA answers them",
   "status": "convention",
   "scope": "Answers published by TCNA on its grout FAQ page, read on the verification date. TCNA frames the joint-width rule as common opinion (\"Many people feel\"); it is quoted as such, not as a standard. Product instructions govern.",
   "source_name": "Tile Council of North America (TCNA), Resource Center FAQ: Grout",
   "source_url": "https://tcnatile.com/resource-center/faq/grout/",
   "verified_at": "2026-09-25",
   "expires_at": "",
   "sample_size": 1,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "tcnatile.com"
   ]
  },
  {
   "id": "gym-flooring-observations",
   "label": "Gym flooring estimators: what they multiply, observed executions",
   "status": "market_survey",
   "scope": "Behaviour of public estimators on the day tested, with the inputs recorded. Mat sizes, interlock losses, set sizes and weights belong to the products actually quoted; the 4 × 6 ft mat, 24-inch tile with a 1-inch interlock loss, sets of four and the 4 × 25 ft roll preloaded in the calculator are examples drawn from these listings, not Calculiva conventions. Prices, stock and freight are not recorded.",
   "source_name": "Live executions of ranking gym flooring calculators, 10 September 2026 (GrytFit layout visualizer as reference)",
   "source_url": "https://grytfit.com/pages/flooring-calculator-new",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 6,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "grytfit.com",
    "musclesquad.com",
    "www.alpinefitness.com",
    "www.greatmats.com",
    "www.living.fit"
   ]
  },
  {
   "id": "hardwood-racking-guidance",
   "label": "Somerset SolidPlus racking example and random-length disclosure",
   "status": "market_survey",
   "scope": "Example applies to the cited Somerset SolidPlus engineered guide, not all hardwood. The guide generally calls for an adjacent-row end-joint stagger at least twice flooring width and instructs racking to avoid stair steps and H joints. This planner checks adjacent seams and H alignments; it does not inspect all repeating visual patterns.",
   "source_name": "Somerset SolidPlus Engineered Installation, racking paragraph",
   "source_url": "https://www.somersetfloors.com/engineered-installation",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 2,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.somersetfloors.com"
   ]
  },
  {
   "id": "herringbone-format-guidance",
   "label": "Rectangular herringbone format examples",
   "status": "market_survey",
   "scope": "Manufacturer pattern selector includes nominal 4 by 12 inch tile under herringbone. This demonstrates a non-1:2 rectangular example; it does not certify every product or nominal dimension for installation.",
   "source_name": "MSI Patterned Floor Tile Tool — Herringbone",
   "source_url": "https://www.msisurfaces.com/patterned-floor-tile-tool/",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 1,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.msisurfaces.com"
   ]
  },
  {
   "id": "laminate-layer-guidance",
   "label": "Pergo Classics layer selection example",
   "status": "market_survey",
   "scope": "Conditional example for Pergo Classics covered by this document. Attached-pad flooring: do not add another cushion layer. Unattached product: appropriate single underlayment. Concrete membrane overlap at least eight inches in this guide. This does not establish universal instructions or authorize a particular assembly.",
   "source_name": "Pergo Classics installation instructions, March 2021, page 2",
   "source_url": "https://pdf.lowes.com/productdocuments/47daec0b-407e-4991-81de-582e5786a097/65848084.pdf",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 1,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "pdf.lowes.com"
   ]
  },
  {
   "id": "lowes-rectangular-tile",
   "label": "Lowe’s rectangular tile: verified faces and sales units",
   "status": "market_survey",
   "scope": "Two specific US product records, inspected in the browser with Specifications expanded. Dimensions and package declarations only. No price or stock promises. Store context was already Presque Isle 04769. Recheck the purchased package and measured tile before cutting.",
   "source_name": "Lowe’s live product specifications",
   "source_url": "https://www.lowes.com/pd/Satori-Statuario-Polished-Porcelain-Common-Actual-23-62-in-x-11-81-in/1002802304",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 2,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.lowes.com"
   ]
  },
  {
   "id": "lumber-nominal-actual-softwood",
   "label": "Nominal and actual dimensions of softwood boards sold in the United States",
   "status": "standard",
   "scope": "softwood boards surfaced four sides (S4S) and dried, sold at retail in the United States. DOES NOT APPLY to MDF, PVC or composite moldings: see trim-nominal-actual-mdf.",
   "source_name": "PS 20, American Softwood Lumber Standard (NIST) — table \"Boards dressed, S4S, dry\" as reproduced by the Southern Forest Products Association",
   "source_url": "https://www.southernpine.com/resources/specifying-southern-pine-lumber/standard-sizing/",
   "verified_at": "2026-09-09",
   "expires_at": null,
   "sample_size": null,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.southernpine.com"
   ]
  },
  {
   "id": "mosaic-sheet-planning",
   "label": "Mosaic sheet and chip planning",
   "status": "convention",
   "scope": "Measured rectangular chips arranged in a uniform rectangular sheet. MSI calls for sheet inspection, alignment and attention to transitions; cutting guidance distinguishes the mounting system from the tile itself. No universal chip format, seam, substrate, grout type or cutting method is prescribed here.",
   "source_name": "MSI mosaic and paper/film faced installation guides",
   "source_url": "https://cdn.msisurfaces.com/files/flyers/mosaic-installation-guide-decorative-accents-flyer.pdf",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "cdn.msisurfaces.com"
   ]
  },
  {
   "id": "mulch-bag-observations",
   "label": "Bagged mulch sizes and label instructions of one product line, and what the five ranking mulch calculators assume",
   "status": "market_survey",
   "scope": "What one bagged mulch line offered and stated on 25 September 2026, and what the five tools ranking first for 'mulch calculator' in the United States assume. Sizes are those offered on the page read; no claim is made that they are the only sizes on sale. No price is recorded.",
   "source_name": "Scotts Nature Scapes product page; five mulch calculators ranking in the United States",
   "source_url": "https://scottsmiraclegro.com/en-us/brands/scotts/products/browse-all-scotts-products/scotts-nature-scapes-color-enhanced-mulch/88559442.html",
   "verified_at": "2026-09-25",
   "expires_at": "2027-03-25",
   "sample_size": 6,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "scottsmiraclegro.com",
    "www.homedepot.com",
    "www.landscapecalculator.com"
   ]
  },
  {
   "id": "mulch-depth-guidance",
   "label": "Landscape mulch: depth, distance from the trunk, size of the tree ring and topping up, as published by five extension services and two tree programs",
   "status": "convention",
   "source_name": "Penn State Extension; University of Maryland Extension; Iowa State University Extension; UC Marin Master Gardeners (UC ANR); NCUFC; Casey Trees; City of Maple Grove, Minnesota",
   "source_url": "https://extension.psu.edu/mulching-landscape-trees/",
   "verified_at": "2026-09-25",
   "expires_at": "",
   "scope": "Organic landscape mulch around trees, shrubs and in beds, for a homeowner in the United States. The publishers disagree; each figure belongs to the publisher named, read on the verification date. No figure is a standard. Playground surfacing depths are a separate record (CPSC).",
   "sample_size": 7,
   "publishers": [
    {
     "id": "psu",
     "publisher": "Penn State Extension",
     "url": "https://extension.psu.edu/mulching-landscape-trees/",
     "depth_in": [
      2,
      4
     ],
     "fine_depth_in": [
      1,
      2
     ],
     "trunk_gap": "keep all mulch material away from the trunk; allow the root flare to show",
     "ring": "preferably to the outermost edge of the tree's canopy, referred to as the “drip line”"
    },
    {
     "id": "umd",
     "publisher": "University of Maryland Extension",
     "url": "https://extension.umd.edu/resource/mulching-trees-and-shrubs",
     "depth_in": [
      1,
      3
     ],
     "trunk_gap_in": 3,
     "by_material_in": {
      "bark": [
       1,
       3
      ],
      "wood chips": [
       1,
       3
      ],
      "sawdust": [
       1,
       1
      ],
      "pine needles": [
       2,
       3
      ],
      "grass clippings": [
       1,
       2
      ],
      "leaves": [
       2,
       3
      ],
      "compost": [
       1,
       1
      ],
      "gravel, stone, lava rock": [
       1,
       1
      ]
     }
    },
    {
     "id": "isu",
     "publisher": "Iowa State University Extension",
     "url": "https://yardandgarden.extension.iastate.edu/how-to/using-mulch-garden",
     "depth_in": [
      2,
      4
     ]
    },
    {
     "id": "ucm",
     "publisher": "UC Marin Master Gardeners (UC ANR)",
     "url": "https://ucanr.edu/site/uc-marin-master-gardeners/applying-mulch",
     "trunk_gap_in": [
      6,
      12
     ],
     "fine_depth_max_in": 2,
     "house_gap_ft": 5
    },
    {
     "id": "ncufc",
     "publisher": "NCUFC",
     "url": "https://www.ncufc.org/proper-mulching-for-trees.php",
     "depth_in": [
      2,
      4
     ],
     "tree_depth_in": [
      2,
      3
     ],
     "trunk_gap_in": [
      1,
      2
     ],
     "ring_min_ft": [
      2,
      3
     ],
     "ring_radius_by_tree_ft": {
      "small": 3,
      "medium": 8,
      "large": 12
     }
    },
    {
     "id": "casey",
     "publisher": "Casey Trees",
     "url": "https://caseytrees.org/2024/05/mulching-dos-and-donts/",
     "rule_333": {
      "depth_in": 3,
      "radius_ft": 3,
      "trunk_gap_in": 3
     }
    },
    {
     "id": "maplegrove",
     "publisher": "City of Maple Grove, Minnesota",
     "url": "https://www.maplegrovemn.gov/DocumentCenter/View/1996/How-to-apply-mulch-around-trees-PDF",
     "rule_333": {
      "depth_in": 3,
      "radius_ft": 3,
      "trunk_gap_in": 3
     }
    }
   ]
  },
  {
   "id": "painted-paper-wallpaper-observations",
   "label": "Painted Paper roll formats, prices, repeats and the on-page estimator, observed",
   "status": "market_survey",
   "scope": "Formats, prices and estimator rules as published by Painted Paper on the day read. Prices are the list prices of the four products read, identical across them; a sale code was advertised site-wide and is not applied. The 4-inch trim allowance used in the worked examples is Calculiva's exercise value, not a Painted Paper figure; the +28-inch allowance is the vendor's.",
   "source_name": "paintedpaper.com product pages, product JSON, measuring guide, FAQ and the estimator script hc-custom.js, 10 September 2026",
   "source_url": "https://paintedpaper.com/products/odette-arboretum-wallpaper",
   "verified_at": "2026-09-10",
   "expires_at": "2026-12-10",
   "sample_size": 4,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "paintedpaper.com"
   ]
  },
  {
   "id": "playground-surfacing-cpsc",
   "label": "Loose-fill playground surfacing: minimum depths by equipment height, compression of the initial fill, and how far the surfacing extends",
   "status": "standard",
   "source_name": "U.S. Consumer Product Safety Commission, Outdoor Home Playground Safety Handbook (Publication 324) and Public Playground Safety Handbook (Publication 325)",
   "source_url": "https://www.cpsc.gov/s3fs-public/324.pdf",
   "verified_at": "2026-09-25",
   "expires_at": "",
   "scope": "Wood mulch or wood chips used as protective surfacing under home play equipment in the United States. The home handbook is the reference; the public handbook is quoted for the 25 percent compression rule and its table. Equipment taller than 8 feet, rubber mulch, sand, pea gravel and unitary mats are outside what the calculator models.",
   "sample_size": 2,
   "home_handbook": {
    "publication": 324,
    "url": "https://www.cpsc.gov/s3fs-public/324.pdf",
    "file_modified": "2025-06-11",
    "loose_fill": {
     "wood_mulch_chips_max_equipment_ft": 8,
     "maintained_depth_in": 9,
     "initial_fill_in": 12,
     "low_equipment_ft": 4,
     "low_equipment_min_depth_in": 6,
     "low_equipment_initial_fill_note": "The home handbook gives no first fill for the 6-inch case; Calculiva derives 8 inches from the public handbook's 'at least 25%' compression (6 / 0.75)."
    },
    "extent": {
     "all_directions_ft": 6,
     "swing_front_back_multiple_of_top_bar": 2,
     "tire_swing_extra_ft": 6
    }
   },
   "public_handbook": {
    "publication": 325,
    "url": "https://www.cpsc.gov/s3fs-public/325.pdf",
    "dated": "2025-08-05",
    "dated_note": "Date of the PDF 325 currently online at the same URL (latest ModDate in the file: 2025-08-05). Values re-read on 2026-10-09, identical.",
    "compression_min_fraction": 0.25,
    "table_2_minimum_compressed_depths": [
     {
      "material": "Shredded/recycled rubber",
      "depth_in": 6,
      "fall_height_ft": 10,
      "note": "does not compress in the same manner as other loose-fill materials"
     },
     {
      "material": "Sand",
      "depth_in": 9,
      "fall_height_ft": 4
     },
     {
      "material": "Pea gravel",
      "depth_in": 9,
      "fall_height_ft": 5
     },
     {
      "material": "Wood mulch (non-CCA)",
      "depth_in": 9,
      "fall_height_ft": 7
     },
     {
      "material": "Wood chips",
      "depth_in": 9,
      "fall_height_ft": 10
     }
    ],
    "table_read_as": "page image of the PDF (page 11), the text layer being incomplete"
   }
  },
  {
   "id": "pool-band-planning",
   "label": "Pool waterline band measurement",
   "status": "convention",
   "source_name": "PoolTile measurement guide and Ezarri mosaic calculator",
   "source_url": "https://pooltile.ca/how-to-measure-and-calculate-your-pool-size/",
   "comparison_source_url": "https://www.ezarri.com/us/mosaic-calculator",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "scope": "Waterline band area uses perimeter at the band times its height. It is distinct from the entire pool interior. No universal band height, grout specification, corner gap, submerged material rating or box coverage is supplied.",
   "notes": "30x15ft pool,6in tile and band,20 tiles/box,10% reserve and zero grout/setbacks are hypothetical arithmetic examples. Users must enter product dimensions, packaging and installation clearances. Individual rectangular tiles only; no mosaic sheet cutting or structural/waterproofing design."
  },
  {
   "id": "sod-format-observations",
   "label": "Sod piece and roll sizes, pallet coverage and weight, and the cutting allowance used by the ranking sod calculators",
   "status": "market_survey",
   "scope": "What seven pages ranking for sod queries in the United States stated on 25 September 2026 about piece sizes, pallet coverage, pallet weight and the extra to order. Farms cut to their own sizes; no size here is a standard. No price is recorded. Calculiva keeps on file the verbatim excerpts read on 25 September 2026 and does not republish them.",
   "source_name": "Sod Solutions (Sod University); Tri-Turf Sod Farms; Tip's Turf; Royal Landscape Nursery; Saratoga Sod Farm; Inch Calculator; Texas A&M AgriLife Extension",
   "source_url": "https://sodsolutions.com/sod-university/square-feet-per-pallet/",
   "verified_at": "2026-09-25",
   "expires_at": "2027-03-25",
   "sample_size": 7,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "triturfsod.com",
    "www.inchcalculator.com",
    "www.saratogasod.com",
    "www.tipsturf.com"
   ]
  },
  {
   "id": "sod-installation-guidance",
   "label": "Laying sod: brick pattern, cut edges, topsoil and compost under new sod, first watering, as published by four extension services",
   "status": "convention",
   "source_name": "Penn State Extension; Texas A&M AgriLife Extension; UF/IFAS Extension (LH013, LH010); NC State Extension",
   "source_url": "https://extension.psu.edu/lawn-establishment/",
   "verified_at": "2026-09-25",
   "expires_at": "",
   "scope": "Solid sod laid by hand on a home lawn in the United States. Each figure belongs to the publisher named and was read on the verification date; Calculiva keeps on file the verbatim excerpts read on 2026-09-25 and does not republish them. No figure is a standard. The four publishers agree on the staggered (brick) pattern; they differ on how much organic matter to work in.",
   "sample_size": 6,
   "publishers": [
    {
     "id": "psu",
     "publisher": "Penn State Extension",
     "title": "Lawn Establishment",
     "url": "https://extension.psu.edu/lawn-establishment/",
     "pattern": "staggered, similar to laying bricks",
     "topsoil_settled_in": [
      4,
      6
     ],
     "topsoil_transition_in": 2,
     "organic_layer_in": [
      1,
      2
     ],
     "organic_worked_in": [
      4,
      6
     ],
     "organic_layer_max_single_pass_in": 2,
     "till_min_in": 4
    },
    {
     "id": "tamu",
     "publisher": "Texas A&M AgriLife Extension",
     "title": "How to select and install sod",
     "url": "https://mytexas.ag.tamu.edu/publications/how-to-select-and-install-sod/",
     "pattern": "brickwork",
     "pallet_sqft_about": 450,
     "sqyd_per_1000_sqft": 111,
     "first_watering_wet_depth_in": 4,
     "then_moist_depth_in": [
      3,
      4
     ],
     "then_every_days": [
      2,
      3
     ],
     "install_within_hours": 36
    },
    {
     "id": "ifas-lh013",
     "publisher": "UF/IFAS Extension",
     "title": "Establishing Your Florida Lawn (LH013)",
     "url": "https://ask.ifas.ufl.edu/publication/LH013",
     "pattern": "staggered brick",
     "offcut_reuse": "fill cracks with cut up pieces of sod",
     "fertilize_after_days_min": 30,
     "pallet_life_summer_hours_max": 48
    },
    {
     "id": "ifas-lh010",
     "publisher": "UF/IFAS Extension",
     "title": "St. Augustinegrass for Florida Lawns (LH010)",
     "url": "https://ask.ifas.ufl.edu/publication/LH010",
     "pattern": "staggered brick-like"
    },
    {
     "id": "ncsu",
     "publisher": "NC State Extension",
     "title": "Carolina Lawns",
     "url": "https://content.ces.ncsu.edu/carolina-lawns",
     "pattern": "bricklike",
     "organic_cuyd_per_1000_sqft": [
      1,
      2
     ],
     "organic_worked_in": [
      6,
      8
     ],
     "organic_when": "if planting in heavy clay or very sandy soils",
     "install_within_hours": 24
    },
    {
     "id": "ncsu-hb",
     "publisher": "NC State Extension",
     "title": "Extension Gardener Handbook, chapter 9: Lawns",
     "url": "https://content.ces.ncsu.edu/extension-gardener-handbook/9-lawns",
     "pattern": "bricklike",
     "note": "Carolina Lawns, from the same publisher, gives about April until July 1 for warm-season sod."
    }
   ],
   "derived": {
    "ncsu_organic_as_layer_in": {
     "value": [
      0.324,
      0.648
     ],
     "rule": "1 cu yd = 46,656 cu in spread over 1,000 sq ft = 144,000 sq in → 0.324 in; 2 cu yd → 0.648 in",
     "note": "NC State's rate, spread as a layer, is about a third to two thirds of an inch; Penn State's layer is 1 to 2 inches."
    }
   }
  },
  {
   "id": "sod-plugging-ifas",
   "label": "Plugging a lawn from solid sod: spacing by species and square feet of sod per 1,000 square feet, UF/IFAS Table 3",
   "status": "convention",
   "source_name": "UF/IFAS Extension, Establishing Your Florida Lawn (LH013), Table 3; NC State Extension, Carolina Lawns",
   "source_url": "https://ask.ifas.ufl.edu/publication/LH013",
   "verified_at": "2026-09-25",
   "expires_at": "",
   "scope": "Warm-season grasses planted as 2-inch plugs cut from solid sod, on a square grid. The table is UF/IFAS's, for Florida; the spacing ranges quoted from NC State are for North Carolina. Sprigs are recorded but not modeled.",
   "sample_size": 2,
   "conversions": {
    "two_inch_plugs_per_sqyd": 324,
    "sprig_linear_ft_per_sqft": 80,
    "sprig_bushels_per_sqyd": 1
   },
   "table3": [
    {
     "species": "St. Augustinegrass",
     "method": "2-inch plugs",
     "spacing_in": 12,
     "sod_sqft_per_1000": [
      30,
      50
     ]
    },
    {
     "species": "St. Augustinegrass",
     "method": "sprigs",
     "spacing_in": 12,
     "sod_sqft_per_1000": [
      10,
      15
     ]
    },
    {
     "species": "Centipedegrass",
     "method": "2-inch plugs",
     "spacing_in": 6,
     "sod_sqft_per_1000": [
      100,
      150
     ]
    },
    {
     "species": "Centipedegrass",
     "method": "sprigs",
     "spacing_in": 6,
     "sod_sqft_per_1000": [
      30,
      50
     ]
    },
    {
     "species": "Zoysiagrass",
     "method": "2-inch plugs",
     "spacing_in": 6,
     "sod_sqft_per_1000": [
      100,
      150
     ]
    },
    {
     "species": "Zoysiagrass",
     "method": "sprigs",
     "spacing_in": 6,
     "sod_sqft_per_1000": [
      8,
      15
     ]
    },
    {
     "species": "Bermudagrass",
     "method": "2-inch plugs",
     "spacing_in": 12,
     "sod_sqft_per_1000": [
      30,
      50
     ]
    },
    {
     "species": "Bermudagrass",
     "method": "sprigs",
     "spacing_in": 12,
     "sod_sqft_per_1000": [
      2,
      5
     ]
    }
   ],
   "table3_note": "The numbers in the column refer to the sq ft of solid sod from which either 2-inch plugs or sprigs can be obtained.",
   "derived": {
    "grid_arithmetic": "Plugs on a square grid at spacing s cover one plug per s² of lawn: 1,000 sq ft takes 1,000 plugs at 12 in and 4,000 at 6 in. At 324 two-inch plugs per sq yd, that is 27.8 and 111.1 sq ft of sod, just under or at the low end of the Table 3 ranges (30-50 and 100-150)."
   }
  },
  {
   "id": "soil-bag-observations",
   "label": "Bagged garden soil sizes, a manufacturer's coverage statement, a contractor wheelbarrow's volume, and what ranking soil calculators assume",
   "status": "market_survey",
   "scope": "What was offered or stated on 25 September 2026 by one bagged-soil product line, one wheelbarrow model and the five tools ranking first for 'soil calculator' in the United States. Bag sizes are those of the product titles read; no claim is made that they are the only sizes on sale. No price is recorded.",
   "source_name": "Scotts Miracle-Gro product page and retail listings; True Temper listing; five soil calculators ranking in the United States",
   "source_url": "https://scottsmiraclegro.com/en-us/brands/miracle-gro/products/raised-bed-in-ground-soils/miracle-gro-garden-soil-all-purpose/70551430.html",
   "verified_at": "2026-09-25",
   "expires_at": "2027-03-25",
   "sample_size": 11,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "scottsmiraclegro.com",
    "soildirect.com",
    "www.acmetools.com",
    "www.homedepot.com",
    "www.inchcalculator.com",
    "www.omnicalculator.com",
    "www.quill.com",
    "www.samsclub.com",
    "www.walmart.com"
   ]
  },
  {
   "id": "soil-weights-and-sale-units",
   "label": "Bulk soil and fill: loose and in-place weights per cubic yard, how bulk and bagged soil must be sold, and the vehicle payload label",
   "status": "standard",
   "scope": "Soil, topsoil and fill dirt bought for a residential project in the United States, in bags or in bulk. The weights are Caterpillar's reference values for earthmoving; the source itself says weight varies with moisture, grain size and compaction, so they are used as published figures, not as the weight of a given load. The sale rules are the NIST uniform regulations that states adopt; whether a state has adopted a given section is not checked here.",
   "source_name": "NIST Handbook 130 (2026 edition), Sections IV-A and IV-B; Caterpillar, Earthwork volumes reference tables; NHTSA interpretation of FMVSS No. 110, S4.3",
   "source_url": "https://www.nist.gov/document/2026-hb-130-section-iv-b",
   "verified_at": "2026-09-25",
   "expires_at": "",
   "sample_size": 5,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.cat.com"
   ]
  },
  {
   "id": "stock-lengths-us",
   "label": "Board lengths actually sold at retail in the United States",
   "status": "market_survey",
   "scope": "finish board lengths observed on the shelf. Availability varies by store and by item: the list is a starting point, not a stock guarantee.",
   "source_name": "The Home Depot, primed MDF 1x3 and 1x4 product pages",
   "source_url": "https://www.homedepot.com/b/Lumber-Composites-Boards-Planks-MDF-Boards/Primed/N-5yc1vZchzsZ1z0sfky",
   "verified_at": "2026-09-09",
   "expires_at": "2027-09-09",
   "sample_size": 3,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.homedepot.com"
   ]
  },
  {
   "id": "tile-joint-guidance",
   "label": "Tile joint and offset guidance, attributed to published sources",
   "status": "convention",
   "scope": "Published manufacturer/education guidance, not an independent verification of the complete ANSI standard; tile-specific instructions govern.",
   "source_name": "Daltile and Ceramic Tile Education Foundation — installation guidance",
   "source_url": "https://www.daltile.com/trend-hub/design-ideas-library/grout-joints-for-large-format-tile",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.ceramictilefoundation.org",
    "www.daltile.com"
   ]
  },
  {
   "id": "trim-nominal-actual-mdf",
   "label": "Actual dimensions of primed MDF boards sold in the United States",
   "status": "market_survey",
   "scope": "primed MDF boards sold at retail in the United States. MDF is NOT covered by PS 20: its actual thickness differs from that of softwood.",
   "source_name": "The Home Depot, MDF Boards / Primed category — \"Common\" and \"Actual\" labels on the product pages",
   "source_url": "https://www.homedepot.com/b/Lumber-Composites-Boards-Planks-MDF-Boards/Primed/N-5yc1vZchzsZ1z0sfky",
   "verified_at": "2026-09-09",
   "expires_at": "2027-09-09",
   "sample_size": 4,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.homedepot.com"
   ]
  },
  {
   "id": "trim-waste-allowance",
   "label": "Usual waste allowance on trim installed in lengths (running trim)",
   "status": "convention",
   "scope": "interior moldings installed in lengths — baseboard, chair rail, panel molding, applied frames. Does not apply to sheet panels or to siding.",
   "source_name": "WoodWeb Knowledge Base — \"Waste Allowance for Running Trim\", a thread among millwork professionals",
   "source_url": "https://www.woodweb.com/knowledge_base/Waste_Allowance_for_Running_Trim.html",
   "verified_at": "2026-09-09",
   "expires_at": "2027-09-09",
   "sample_size": 2,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.woodweb.com"
   ]
  },
  {
   "id": "wainscot-height-conventions",
   "label": "Usual wainscoting height on an American interior wall",
   "status": "convention",
   "scope": "decorative interior wall paneling (framed wainscoting, picture frame molding, beadboard) on American residential walls. Does not apply to exterior siding or to accessibility standards.",
   "source_name": "Bob Vila — \"The Right Wainscoting Height for Every Scenario, Solved!\"",
   "source_url": "https://www.bobvila.com/articles/wainscoting-height/",
   "verified_at": "2026-09-09",
   "expires_at": "2027-09-09",
   "sample_size": 2,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.bobvila.com",
    "www.finehomebuilding.com"
   ]
  },
  {
   "id": "wallpaper-roll-observations",
   "label": "Wallpaper estimators and published roll formats, observed executions",
   "status": "market_survey",
   "scope": "Roll formats and estimator rules as published on the day tested. The American bolt of 20.5 in × 33 ft (56 sq ft), the European roll of 52 cm × 10 m and the 24 in × 13 ft or 27 ft Painted Paper roll are the formats those publishers state; the calculator preloads the 20.5 × 33 ft bolt as an example and every roll dimension must be taken from the product page. The 4-inch trim allowance and 21-inch repeat preloaded in the calculator are hypothetical.",
   "source_name": "York Wallcoverings roll estimation chart and live executions of ranking wallpaper calculators, 10 September 2026",
   "source_url": "",
   "verified_at": "2026-09-10",
   "expires_at": "2027-03-10",
   "sample_size": 8,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "carnegiefabrics.com",
    "mahoneswallpapershop.com",
    "paintedpaper.com",
    "schumacher.com",
    "www.brewsterwallcovering.com",
    "www.decoratorsbest.com",
    "www.omnicalculator.com",
    "www.phillipjeffries.com",
    "www.romo.com",
    "www.thibautdesign.com",
    "www.yorkwallcoverings.com"
   ]
  },
  {
   "id": "york-wallpaper-observations",
   "label": "York Wallcoverings bolt chart, product roll formats, prices and the product-page calculator, observed",
   "status": "market_survey",
   "scope": "Chart, formats, rules and prices as published by York Wallcoverings on the day read. The chart's bolt is 20.5 in × 33 ft (56 sq ft); the two products read are 20.9 in × 33 ft (about 57.5 sq ft) double rolls. The 4-inch trim allowance in the worked examples is Calculiva's exercise value; York's chart and calculator add no trim.",
   "source_name": "yorkwallcoverings.com wallpaper calculator chart, two product pages, the installation FAQ and the script WallpaperCalculator.js, 10 September 2026",
   "source_url": "",
   "verified_at": "2026-09-10",
   "expires_at": "2026-12-10",
   "sample_size": 2,
   "values_withheld": "Values not redistributed: the publisher's terms do not allow republication. Read them at the source or on the Calculiva page that cites them.",
   "withheld_hosts": [
    "www.brewsterwallcovering.com",
    "www.yorkwallcoverings.com",
    "yorkwallcoverings.com"
   ]
  }
 ]
}