BS EN 975-1:2009 pdf download – Sawn timber — Appearance grading of hardwoods Part 1: Oak and beech
1 Scope
This European Standard specifies the rules determining the quality of appearance graded sawn timber. It describes various grades of temperate hardwood rough sawn timber and regularized timber for which it lays down denominations and definitions. It also gives rules for composition and acceptance of batches.
This standard gives minimum requirements for each grade classification. Sawn timber not included within limits given in this standard may be defined, if necessary, by contract specifications established on the basis of this standard.
This standard applies to grading of green and dried timber. Characteristics apply at the time of grading.
This standard does not apply to the strength grading of structural timber or to sawn timber for pallets.
This standard is applicable to the following products:
a) Oak sawn timber, in the following categories:
1) Un-edged boards: individual selected pieces and boules;
2) Square edged timber and strips (not exceeding 41 mm thickness);
3) Baulks (sum of thickness + width ≥ 200 mm and thickness ≥ 80 mm).
b) Beech sawn timber, in the following categories:
1) Un-edged boards: individual selected pieces and boules;
2) Square edged timber and strips;
3) Prepared timber (dried timber).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 844-1:1995, Round and sawn timber – Terminology – Part 1: General terms common to round timber and sawn timber
EN 844-3:1995, Round and sawn timber – Terminology – Part 3: General terms relating to sawn timber
EN 844-4:1997, Round and sawn timber – Terminology – Part 4: Terms relating to moisture content
EN 844-6:1997, Round and sawn timber – Terminology – Part 6: Terms relating to dimensions of sawn timber
EN 844-7:1997, Round and sawn timber – Terminology – Part 7: Terms relating to anatomical structure of timber
EN 844-9:1997, Round and sawn timber – Terminology – Part 9: Terms relating to features of sawn timber
EN 844-10:1998, Round and sawn timber – Terminology – Part 10: Terms relating to stain and fungal attack
EN 844-11:1998, Round and sawn timber – Terminology – Part 11: Terms relating to degrade by insects
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 844-1:1995, EN 844-3:1995,
EN 844-4:1997, EN 844-6:1997, EN 844-7:1997, EN 844-9:1997, EN 844-10:1998, EN 844-11:1998 and
EN 844-12:2000 and the following apply.
3.1
dried timber
timber with a stipulated reduced moisture content
3.2
green timber
timber that has not been dried to or below the fibre saturation point
NOTE Green timber has a moisture content normally above 30 %.
[EN 844-4:1997]
3.3
width or length reduction
notional decrease in the actual dimensions of a board to exclude features that may subsequently be removed 4 Method of determination of sawn timber quality
4.1 Rules for grading
Hardwood (oak and beech) can be put into grades using the principles laid down in 4.2, the criteria defined in 4.3 and the following tables:
Table 2 gives rules for grading oak un-edged boards;
Table 3 gives rules for grading oak strips and square edged timber;
Table 4 gives rules for grading oak baulks;
Table 5 gives rules for grading beech un-edged boards;
Table 6 gives rules for grading beech strips and square edged timber;
Table 7 gives rules for grading beech prepared timber.
4.2 Grading principles
4.2.1 Assessment of the quality For individual selected boards and boules grading is made on the faces. For other pieces grading is made on faces and edges. The size, position and frequency of features, sawing defects and deteriorations are taken into account. Non-conformity with the conditions applicable to any one of these elements is sufficient to downgrade the piece.
Dimensional variation is not taken into account for quality grading of the pieces. It is already covered by EN 1313-2 or by any specific requirements defined contractually.
Only the following categories can be reduced in width and/or length:
Individual selected boards,
boules.