Grout & Adhesive Coverage Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Everyday & Life

Tranche

tranche-7

Evidence ID

t7-125

Ledger rows

1

No ledger note is attached.

Review findings

The thinset division formula is conditionally valid, but the grout formula supplied in the specification is not a standard general grout-usage algorithm. The instrument needs a documented, product-specific lookup table or the geometric grout-volume formula above, plus explicit grout depth, density, waste, bag size, and rounding rules. The reference values used here are typical published-reference values rather than universal manufacturer guarantees; production results must identify the exact product data-sheet convention.

Formula and scope findings

• The grout formula area × joint_width × tile_thickness × coverage_constant is not generally correct: it omits tile length and tile width, which determine total joint length per unit area.
• Grout depth is not necessarily equal to tile thickness. The calculation must explicitly take grout depth, normally joint depth or an approved fraction of tile thickness.
• A dimensionally consistent grout calculation is grout_volume = area × 144 × joint_width × grout_depth / ((tile_length + joint_width) × (tile_width + joint_width) × 1728), with inch dimensions and area in square feet; grout weight then equals volume × product density.
• The grout calculation lacks a product-specific density or coverage table and lacks an explicit waste allowance.
• Thinset bags = area / coverage_per_bag is mathematically valid only when area and coverage use the same area unit and the coverage rate corresponds to the specified product, bag size, trowel notch, substrate, tile type, and installation conditions.
• The thinset result must be rounded up to a whole bag for purchasing; the spec does not state this.

Unit assumptions

• Area is in square feet.
• Tile length, tile width, joint width, and grout depth are in inches.
• The conversion 1 foot = 12 inches and 1 square foot = 144 square inches is exact.
• The conversion 1 cubic foot = 1728 cubic inches is exact.
• Grout density is expressed in pounds per cubic foot.
• Thinset coverage is expressed in square feet per bag.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The calculator can produce an undefined thinset result when coverage_per_bag is zero unless it rejects the input. Results are also non-unique without a supplied manufacturer lookup table, and an unlabelled area-unit convention changes the computed material substantially.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "area_ft2": 100,
    "tile_length_in": 12,
    "tile_width_in": 12,
    "joint_width_in": 0.125,
    "grout_depth_in": 0.25,
    "thinset_notch": "1/4 x 1/4 in square notch",
    "thinset_bag_size_lb": 50
  },
  "expected_outputs": {
    "grout_weight_lb": 0.19485,
    "thinset_bags_exact": 1.11111,
    "thinset_bags_to_buy": 2
  },
  "reference_data": {
    "grout_density_lb_per_ft3": {
      "value": 110,
      "source_convention": "widely tabulated standard value; nominal cementitious-grout density, product-specific variation applies"
    },
    "thinset_coverage_ft2_per_50lb_bag": {
      "notch": "1/4 x 1/4 in square notch",
      "value": 90,
      "source_convention": "widely tabulated standard value; typical published thinset-coverage reference, manufacturer-specific variation applies"
    },
    "unit_conversions": {
      "in_per_ft": 12,
      "in2_per_ft2": 144,
      "in3_per_ft3": 1728,
      "source_convention": "widely tabulated standard exact unit conversions"
    }
  },
  "working": "Joint-cell dimensions: 12 + 0.125 = 12.125 in in each direction. Joint cross-sectional area fraction = (0.125 × 0.25) / (12.125 × 12.125) = 0.03125 / 147.015625. Grout volume = 100 × 144 × 0.03125 / 147.015625 ÷ 1728 = 0.00177136 ft3. Grout weight = 0.00177136 × 110 = 0.19485 lb. Thinset bags = 100 ft2 ÷ 90 ft2/bag = 1.11111 bags. Round upward: ceil(1.11111) = 2 bags."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json