The external documents this trade answers to, each mapped to the framework criteria that depend on it — and the date we last verified it against the issuing body’s own page.
We link to the issuing body, never to a reseller or a summary, and we do not reproduce the standards themselves. Where an edition could not be confirmed at the source, the entry says so instead of guessing.
ASTM InternationalF2170-19aCurrent
Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes
How relative humidity inside a concrete slab is measured, using probes placed in situ rather than a surface reading.
This is the test behind "was the subfloor moisture-tested" on a concrete slab. A surface reading is not this test, and a contractor who has done one has not done the other.
Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride
The calcium-chloride test — how much moisture vapour a concrete subfloor emits over a measured period.
The older of the two concrete moisture tests, and still specified by some manufacturers. Which test a warranty requires is a question worth asking before the slab is covered.
ASTM lists an open revision work item (WK96566) against this standard. The edition in force may change; check the issuing body before relying on a specific year.
Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring
Preparation of a concrete floor before a covering goes down — flatness, cleanliness, and the condition the slab has to be in.
The substrate-condition half of pillar 2. Slab flatness discovered after a deposit is the most common source of change orders on a hardwood job, and this is the document that defines what "prepared" means.
Installation of wood flooring over wood, concrete and radiant substrates: acclimation, moisture testing, subfloor flatness and preparation, fastening schedules and method selection.
The trade body whose guidelines most manufacturer warranties reference. Acclimation periods, subfloor requirements and installation method by substrate all trace here.
The NWFA also publishes separate Sand & Finish and Wood Species guidelines; this entry covers the installation document only. Membership may be required for some NWFA publications — confirm the applicable document before citing it in a specification.
National Hardwood Lumber Association2023 RulesCurrent
Rules for the Measurement & Inspection of Hardwood & Cypress
How a hardwood board is graded as lumber: minimum board size, minimum clear cutting size, and the required clear-face yield expressed in twelfths — FAS at 83-1/3%, No. 1 Common at 66-2/3%, No. 2A Common at 50%, No. 3A Common at 33-1/3%.
This is the grade fixed at the sawmill, before any flooring mill touches the board, and it never improves downstream. It is also the grade nobody quotes to a homeowner — the number on a flooring quote is an NWFA/NOFMA appearance grade, which measures something else entirely. Knowing that the two systems exist is the difference between reading a quote and taking one on trust.
The Canadian Hardwood Bureau states that hardwood lumber grading standards in Canada are published and overseen by the NHLA. We found no Canadian statute or regulation making the rules mandatory; on the evidence we have this is a voluntary trade-association standard, which is a reason to name it in a contract rather than a reason to ignore it.
National Wood Flooring AssociationNWFA/NOFMACurrent
International Standards for Unfinished Solid Wood Flooring
Appearance grades for finished flooring by species group — Clear, Select, No. 1 Common and No. 2 Common for oak; Special Clear and Select & Better for hard maple, beech and birch — together with manufactured moisture content of 6% to 9%, thickness of .750" ± .015", and the definitions of strip, plank and wide plank.
The document behind every honest flooring quote in this market. Its governing sentence is the one homeowners are never told: appearance alone determines the grades of hardwood flooring, since all grades are equally strong and serviceable in any application. A No. 2 Common floor is a character decision, not a compromise.
This document replaces all editions of the Official Flooring Grading Rules previously published by the Wood Flooring Manufacturers Association. NWFA separately lists NOFMA-certified manufacturers, including Lauzon of Papineauville, Quebec and Superior Hardwood Flooring / Herwynen Saw Mill Ltd. of Rockwood, Ontario.
USDA Forest Service, Forest Products LaboratoryFPL-GTR-190Revision open
Wood Handbook — Wood as an Engineering Material, Chapter 5: Mechanical Properties of Wood
The measured mechanical properties of North American species, including side hardness at 12% moisture content — the modified Janka test, defined as the load required to embed an 11.28 mm ball to half its diameter.
Every hardness number this site publishes traces to Table 5-3b of this document: hickory 1,880 lbf, hard maple 1,450, white oak 1,360, white ash 1,320, red oak 1,290, black walnut 1,010. It is the primary source behind figures that the rest of the industry restates without attribution.
Marked revision-open because a newer edition exists — FPL-GTR-282 (2021) — and we publish the 2010 values deliberately. Extracting hardness from the 2021 chapter returned pairs that do not convert between units, indicating adjacent columns of Table 5-3 rather than hardness; the GTR-190 values were re-verified against two independently hosted copies that agreed exactly. Anyone re-checking these numbers should expect the same column slip. The American Hardwood Export Council publishes the same figures in newtons; those are a unit conversion of this dataset, not an independent measurement.
United States Environmental Protection Agency40 CFR § 770.10Current
Formaldehyde Standards for Composite Wood Products — emission standards
Formaldehyde emission limits for the composite panels used as engineered flooring cores, tested to ASTM E1333-14: hardwood plywood 0.05 ppm, medium-density fibreboard 0.11 ppm, thin MDF 0.13 ppm, particleboard 0.09 ppm.
An engineered board is a hardwood wear layer over a manufactured core, and the core is governed by emissions law rather than by any flooring rule. This is the certificate to ask a supplier for, by name.
This is United States law. We searched for and did not find a Canadian federal instrument setting an equivalent limit, and we do not assert that TSCA Title VI binds product sold in Canada. The EPA states it worked with the California Air Resources Board so the national rule is consistent with California’s requirements.
Edition
Current eCFR text; limits apply to product sold, supplied, offered for sale or manufactured on or after June 1, 2018
Decorative Hardwoods Association / American National Standards InstituteANSI/HPVA HP-1-2024Current
American National Standard for Hardwood and Decorative Plywood
The principal types, face grades, back grades, inner ply grades and constructions of plywood made primarily with hardwood faces, including constructions with an odd number of plies where all inner plies except the innermost occur in pairs.
The nearest published standard to the cross-ply core that gives an engineered floor its dimensional stability. Its scope does not name flooring, which is itself worth knowing: the construction homeowners are sold on has no flooring-specific standard behind it.
The copy read truncated before Section 5, Definitions, so this entry makes no claim about how the standard defines crossband, veneer core or ply. Re-read the full document before citing those terms to it.
Every field catalogue — the company, the services, the stair case, the framework and the decisions, indexed by series.
Method
How this register is kept honest
Every entry carries the date it was last checked at the issuing body’s own page, and a build guard reports any entry past its 180-day review interval — so going stale is a visible task rather than something anyone has to remember. A register that silently rots is worse than no register: it asserts a currency it does not have, to readers with no way to tell.
This is not a news feed and deliberately not an aggregator. Everything we publish ourselves is at What’s new.
