This INSTA Standard identifies the characteristics and defines grading specifications for visual strength grading of sawn timber to be used for load-bearing structural purposes. This INSTA standard fulfills the principles of EN 14081-1 for CE marking.
This INSTA covers the species defined in Annex A1 and grown in the geographical areas defined in the same annex. Defined by the dimensions and intended use of the timber, three different sets of requirements are given. They are for: - timber with thickness t >= 45 mm or width b > 75 mm (cf. clause 6.2.2). - timber with thickness 25 mm <= t <= 45 mm and width 50 mm <= b <= 75 mm. Provisions for the grades T2 and T1 only (cf. clause 6.2.3). - timber with thickness t <= 50 mm for the manufacture of glued laminated timber (cf. clause 6.2.4). NOTE: For requirements concerning treated timber see EN 14081-1 and EN 15228. NB: The transitional period for INSTA 142 runs until 2010-02-01.