Fact-Checking Policy

At Free Construction Calculator, accurate calculation is not just a preference—it is a safety requirement. We are committed to making sure all statistics, material bulk densities, structural weights, and building code rules are completely factual, verifiable, and up to date.

1. Multi-Step Verification Framework

Every single calculator, table, and guide follows a strict verification pipeline:

• Source Evaluation: We only extract physical material properties (e.g. density of wet plain concrete, weights of rebar sizes, dimensions of 2x4 studs) from certified technical manuals, peer-reviewed engineering papers, or official code standard bodies (such as ASTM International, American Concrete Institute, or national lumber grading agencies).
• Cross-Referencing: Before listing a constant, it must be cross-checked across at least three independent authoritative databases (e.g. matching quarry data sheets, civil engineering manuals, and wholesale materials books).
• Mathematical Verification: Every formula is validated by translating typical layout dimensions into manual math calculations and checking the outputs against commercial estimation programs like Bluebeam Revu and PlanSwift.

2. Sourcing Standards

We strictly do not use unverified forum posts, anecdotal estimations, or promotional marketing brochures for our baseline calculations. Our primary sources include:

• International Building Codes (IBC) and International Residential Codes (IRC) for spatial safety rules (stair heights, handrail regulations, structural span metrics).
• American Society for Testing and Materials (ASTM) publications for structural classification and block dimensions.
• National Ready Mixed Concrete Association (NRMCA) for concrete volume adjustments and placement tips.
• Manufacturer technical sheets for coverage yields of specialty paints, underlayments, and adhesive materials.

3. Corrections and Updates Protocol

Despite our rigorous standards, construction standards and local regulations can evolve. If we receive reports of mathematical variations or outdated code limits, we apply our correction workflow:

1. Review: Our technical editing team (led by our Senior Civil Estimator) reviews the reported value against primary engineering sources.
2. Resolution: If a discrepancy is confirmed, the database or calculator script is immediately corrected in our next deployment cycle.
3. Log: The page's "Last Updated" timestamp is updated to maintain transparent status history.

If you notice a typo, formula discrepancy, or code change, please notify us immediately through our Contact Us page.