New Zealand timber company Carter Holt Harvey (CHH) has regraded its Laserframe structural timber following an investigation which found the wood did not meet the advertised standard.

The company’s shares fell 3.2% after it announced plans to lower Laserframe’s classification from MGP10 to F5 grade.

The Commerce Commission started an investigation last year, involving inspections at three of CHH’s sawmills. Tests by government research centre Forest Research found Laserframe timber about 15% less stiff than the MGP10 grading.

CHH sells the largest volumes of structural timber, plywood and LVL in the country.