BS EN 1927-3-2008 pdf download.Qualitative classification of softwood round timber Part 3 Larches and Douglas fir.
Annex A gives a list of characteristics wtich serves as guideline for contracts describing qualities for round timber of larches and Douglas fir where the intended use is known.
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 — Pail 1: General terms common to round timber and sawn timber
EN 844-2:1997, Round and sawn timber— Terminology— Part 2: General terms relating to round timber
EN 844-5:1997, Round and sawn timber— Terminology— Pail 5: Terms relating to dimensions of round timber
EN 844-7:1997, Round and sawn timber— Terminology— Pail 7: Terms relating to anatomical structure of timber
EN 844-8:1997, Round and sawn timber— Terminology — Part 8: Terms relating to the features of round timber
EN 844-9:1997, Round and sawn timber— Terminology — Pail 9: Terms relating to features of sawn timber
EN 844-10:1998. Round and sawn timber — Terminology — Pail 10: Terms relating to stain and fungal attack
EN 844-12:2000, Round and sawn timber— Terminology — Pail 12: Additional terms and general index
EN 1309-2, Round and sawn timber — Method of measurement of dimensions — Part 2: Round timber — Requirements for measurement and volume calculation rules
EN 1310, Round arid sawn timber— Method of measurement of features
EN 1311, Round and sawn timber— Method of measurement of biological de grade
ISO 2036, Wood for manufacture of wood floonng — Symbols for marking according to species
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 844-1:1995, EN 844-2:1997, EN 844-5:1997, EN 844-7:1997, EN 844-8:1997, EN 844-9:1997, EN 844-10:1998 and EN 844-12:2000 apply.
4 Qualitative classification for which the intended use is unknown
The qualitative grading has four classes: A, B. C and D. The grading is based on the following general description of quality classes:
Quality class A
First quality timber. Generally corresponding to a butt log with clear timber, without defects or with only minor defects and with few restrictions to its use.
Quality class B
Timber of average to first quality, with no specific requirements foi clear wood. Knots are permitted to such an extent as is considered to be average for each species.
Quality class C
Timber of average to low quality, allowing all quality characteristics which do not seriously reduce the natural characteristics of the wood.
– — Quality class D
Timber which can be sawn Into usable wood, which, because of its characteristics, falls into none of the quality classes A. B or C.
The classes are defined more precisely in Table 1 and Table 2. All the listed qualitative characteristics in Table 1 and Table 2 shall be taken into account when a class is assigned, and measurements shall be made according to EN 1309-2, EN 1310 and EN 1311.
This classification shall be completed with the Latin name of specified species. The abbreviation of this Latin name can also be used instead of the full name.
EXAMPLE 1 Douglas fir: Pseudotsuga class B or PSES-81.
EXAMPLE 2 Larch: Lanx class B or LARX-B1.
6 Additional criteria
In case of doubt, any externally visible or possible hidden flaws (e.g. knots under buckles, overgrown shakes, stnpping damage) shall be laid bare and the revealed flaws assessed according to the quality specifications. Foreign bodies (e.g. shrapnel) are not dealt with In this standard.
Where some characteristics of round wood of the classes A and B do not fulfil the quality criteria on agreement, they can be compensated by higher quality in other characteristics.
Generally, the following characteristics cannot be compensated: insect attack (especially Trypcidendron lineatum), rot and stain. If there is compensation for minor rot of little consequence, an agreement is necessary.
Each log can be graded either in a single class or in more than one class by using theoretical crosscut points. The minimum length accepted for a theoretical crosscut point is 3 m.BS EN 1927-3-2008 pdf download.