- Priced per meter
- Please call the sales team for lengths and availability on 01702 711366
- May contain splits and shakes, these do not compromised the structural integrity of the timber.
The grading of European Sawn Green Oak typically follows the standards and guidelines set by various timber grading systems, with the most recognized being the BS 5756 (British Standard) or EN 1912 (European Standard). The grading process evaluates the quality of the wood, taking into account aspects like the presence of defects, strength, and general appearance.
Here’s an overview of the grading details:
1. Strength Class:
- European Green Oak is often assigned a strength class, which determines how much load it can bear. This is typically represented by numbers such as C16, C18, or C24. C24 is one of the most common strength classes for European Oak.
2. Grading Categories:
- Prime Grade: The highest quality of oak with minimal knots and defects, suitable for fine woodworking, joinery, and aesthetic applications.
- Standard Grade: Slightly lower quality, which may have some small defects, such as small knots or imperfections. Often used for general construction purposes.
- Utility Grade: Typically used in construction for structural purposes. This grade may contain larger knots and defects, but it still meets the strength and stability requirements for structural use.
3. Key Grading Parameters:
- Knots: The size, number, and location of knots influence the grade. Knots are classified by their diameter and frequency (e.g., "knots up to 30mm" or "knots up to 50mm").
- Wane: Wane refers to the presence of bark or missing wood from the edges of the timber. Excessive wane can reduce the grade.
- Cracks and splits: These defects can be a determining factor in the grading, especially if they compromise the strength of the timber.
- Twisting or warping: European Green Oak timber may be graded based on its tendency to twist or warp once dried.
- Moisture content: Green oak is classified based on its moisture content when graded. Timber with higher moisture content is considered "green," and it must be properly dried before use for certain applications.
4. Sizes:
- Oak is graded not only by the quality but also by its size. Typically, the thickness, width, and length of the planks are considered. There are usually restrictions or guidelines regarding the allowable size of defects for each grade.
5. Visual Grading:
- Timber is visually inspected for imperfections such as discoloration, streaks, or resin pockets.
- For higher grades, a cleaner appearance is necessary with less noticeable grain variation.
- For construction uses, such as framing or beam work, the timber may be allowed to have more imperfections.
6. Drying and Moisture:
- Green oak has a higher moisture content than seasoned or kiln-dried oak. Grading can be based on how much moisture remains in the timber and whether it has been partially air-dried or completely kiln-dried.
- Kiln-dried oak will generally have fewer defects and may achieve higher grading than green oak.
7. European Standards:
- EN 1912 standard for timber grading specifies the different grades of timber, their corresponding strength classes, and characteristics.
- BS 5756 standard in the UK governs grading rules, focusing more on timber used for structural purposes.
Product Code: E50100
