A source should match the claim.
Basic geometry, product coverage, installation practice and safety guidance are different claims. We verify them differently.
Geometry and unit conversion
Area and volume formulas are published on each calculator. Rounding occurs only when a purchase requires whole bags, boxes, rolls, sheets or pieces.
Product-dependent defaults
Coverage, density, yield, package size and waste are editable starting points. The selected product label or supplier specification overrides a generic default.
Primary and industry sources
- ENERGY STAR: choosing certified insulation
- Gypsum Association
- American Cement Association: working with concrete
- National Roofing Contractors Association: consumer information
- Carpet and Rug Institute: installation standards
- U.S. EPA: mold, moisture and your home
- CDC: mold and health
- Benjamin Moore: paint coverage planning example
- QUIKRETE: product quantity calculators
Cleaning models
Cleaning time and cost tools are transparent planning models—not market surveys. Visitors can adjust pace, condition, room time, intensity and local rate. The cleaning-time reference table is excluded from search indexing until its assumptions are supported by a validated dataset.
Safety and code
A general website cannot assess structure, code compliance, gas, electrical, sewage, health or site conditions. Product instructions, local authorities and qualified professionals control those decisions.
Corrections
Report a formula, source or accessibility issue through Contact. Corrections update the page date and, when material, the release notes.