Claims, documentation, sorting, price and limits of this course

A grade only has value if the buyer accepts it. This lesson covers the paperwork behind a grade, how claims are handled, how grading feeds sorting and price, what automatic grading can and cannot do, and the limits of this course.

Documents that support a grade

The portal's trade article gives a contract checklist (its own synthesis, not a legal template) that includes grade or strength class, moisture content and method, inspection and acceptance (where, by whom, sampling method, reference standard), documents, and claims, governing law and forum. For grading, the practical points are:

• Name the standard and year, or the rule set and edition, and attach a one-page summary of the limits.
• Agree the moisture measurement method and sampling plan before shipment.
• State whether dimensions are nominal or actual, and cite the tolerance standard.
• Photograph packs at loading.
• Keep invoice, packing list, certificates and bill of lading consistent. Mismatched documents are a common pitfall.

CE marking of structural timber concerns product performance such as strength class, not the legality of the wood. Legal questions need a qualified adviser.

Handling claims

There is no single global procedure; the contract decides. The portal's general practice, labelled as interpretation, is to require written notice within a short period of arrival and before processing, keep goods and packs identifiable, use an independent surveyor agreed in advance, define remedies (replacement, price reduction, credit) and who pays the surveyor, and separate grading defects, transit damage and documentation failures, because evidence and responsibility differ for each.

The separation matters for stain. Fungi do not grow at or below 20% MC, yet NELMA warns that stain-free packaging can stain later from wet outdoor storage or condensation in transit, and the trade article lists ignoring moisture and transit time in closed containers as a pitfall. A stain complaint on kiln-dried boards therefore needs evidence on moisture on arrival and storage, not only the grading rule. Keep kiln curves and results for claims.

How grading feeds sorting and price

Value yield rewards sawing patterns that produce higher-grade boards, even if volume yield falls.

Worked example (illustrative prices, not market data). From 100 m3 of boards, 20 m3 are top grade at 600 EUR/m3 and 80 m3 are standard at 400 EUR/m3, so revenue is 20 x 600 + 80 x 400 = 44,000 EUR. If better sorting lifts top grade to 25 m3, revenue is 25 x 600 + 75 x 400 = 45,000 EUR, up 2.3%. If the price gap were 800 versus 400, the same shift lifts revenue from 48,000 to 50,000 EUR, up 4.2%. The same shift is worth twice as much when the spread doubles.

That is the pattern in the scanning literature. Rais et al. (2017, Douglas fir, 36 logs, Microtec-affiliated authors) found CT-guided rotation raised sawn product value by 4%, 8% and 20% under three price scenarios, with the largest gain where strength grade prices differed most. Chang and Gazo (2009, US hardwoods, simulation) found average value gains of 46%, rising from 27% for Grade 1 logs to 97% for Grade 3 logs. These are simulations, not mill results. The portal found no open source giving a price premium per sawn appearance grade, so use your own price list.

Automatic grading: what is shown so far

• Birch boards (Ji et al., 2023, 4,000 boards): type and size detection about 89.69% accurate, location 92.25%, but holes and mineral were weak, and the paper has internal inconsistencies (a reported 14.13% value gain where its own figures give 1,608.25 / 11,236.27 = 14.31%).
• Beech boards (YOLOv8m variant, 2026): mAP@50 of 91.8% against 90.8% for the baseline, on one public dataset, with small knots scoring lowest of the four classes reported. Detection is not a grade decision.
• Birch veneer logs (Latvia): knot recall only 44%, class agreement with a reference scaler 57%, against 79% for human line scalers versus a control scaler (different units, not directly comparable). The authors work for the developer and propose decision support.

A 2026 review found only 50 qualifying papers in eleven years, mostly laboratory studies. Pilot on your own species and defects, and keep a person in the loop for knots.

Limits of this course

This course was drafted by an AI from the portal's fact-checked articles and no other source. The standards it names (EN 975-1, EN 1611-1, EN 1316, EN 1927, EN 14298, DIN 4074-1, INSTA 142 and NHLA) are paywalled or only partly read, so limits come from catalogue pages, secondary summaries and trade pages. Oak grade criteria come from one supplier summary with illegible values. Knot and shake figures come from models and single studies. Drying data are mostly North American. No price series by sawn appearance grade, no Polish merchant grading for hardwood and no EN 975-2 text were available. Check every limit against the current standard and your contract.

Key points

• A grade is supported by named standard, edition, limits summary, agreed moisture method, tolerances and loading photographs.
• Claims depend on the contract; separate grading defects, transit damage and documentation failures.
• The revenue effect of sorting grows with the price spread between grades; scanning gains are simulated, not proven mill results.
• Vision systems detect some defects well and others poorly (knots); use them as decision support with piloted checks.
• Verify every limit in this course against the current standard and your contract.