Grading Guidelines for Radiata Pine

No.1 Clear Grade

No. 1 Clear is clear on all four faces with the occasional minor blemish permissible as per N.Z. Timber Grading Rules NZS 3631:1988. Typical end uses include mouldings, dressed boards, panelling, and products that require a stained finish.

Prem Grade

Prem, or Premium Grade, is a near clear grade used in decking which allows for a small number of tight defects on the best face and edges. Backface allows occasional large or broken knot defects and some hit and miss dressing.

SG8 Dry

SG8 Dry is a structural grade ex-pruned log that allows tight and live knot defects. Suitable for Lintels, floor joists, roof beams, general framing, trusses, decking joists, verandah posts, pergola and other outdoor applications.

Structural Grades Table

Merch Grade

Merch, or Merchant Grade, contains the next layer of wood beyond the core of the log. Grading allows heartwood and any number of knots and defects which are generally sound and tight (inter-grown). Grading allows for a small amount of pith (less than 10% of the length), cone hole, needle trace, light to moderate resin, light blue stain and wane on up to 30% of the edge. Cluster and spike knots are allowed as long as structurally sound. Grading does not allow pith (greater than 10% of length), dead knots, decaying timber and broken pieces.

Industrial OR Boxing Grade

Contains the core (pith) of the log and surrounding heavy heartwood zone.  Grading allows any amount of pith, spiral grain, large knots, broken knots, spike and cluster knots. Grading allows cone hole, needle trace, resin pockets, moderate blue stain and wane on 50% of edges. Grading does not allow decay, broken and fallen knots bigger than half the width, heavy blue stain, and pieces of timber that do not hold together (are not structurally sound).


WAT Wet After Treatment
UT Untreated
GS Green Sawn
KD Kiln Dried
R/S Rough Sawn
DAR Dressed 
D4S Dressed four sides
RHD Rougher Headed
P/G Planer Gauged
G/T  Grip Tread
T& G Tongue & Groove