Understanding oak timber grades
Oak is available in a range of qualities, or grades. Knowing what each grade means can help you to understand the look of the products you are buying
Most northern European oak comes from France, with most of the sawmills in the central and northern areas. When oak is cut, the sawmills group boards into quality brackets called grades. The grading rules are standardised and so an understanding of them can really help know what kind of product you will receive.
When you are comparing oak doors or flooring being sold in the UK, there can be a bewildering range of descriptions for the grade of oak you will receive.
Rustic, character, prime, tavern and many others are common to hear used to describe oak. These can be useful descriptive terms, but they normally have no fixed meaning, making comparing one product to another very hard.
At Heritage we use Rustic, Select Rustic and Prime to describe our doors, but what exactly does this mean?
Heritage uses European oak to produce its solid oak doors and floors. We buy the timber direct from the sawmills in France, as we find each mill has a slightly different interpretation of the grading rules. Here is an overview of how this works.
French mills grade oak in numbers 1 – 4, depending on the quantity and sizes of knots in the oak. Grade 1 will have few or no knots, whereas 4 will have significant quantities. Oak is bought commercially in groups of grades. So for example for our rustic doors we would buy a 2/3, whereas for prime doors we’d buy a 1/2.
Even then we have to regrade the timber when it arrives, as each load will contain around 10-15% of boards that are outside the grade. Occasionally in a 2/3 we will find a 1/2 board, but the bulk of offgrade boards would be 3/4. So our 3 door grades would be made up as follows;
Prime – 1/2
Select Rustic – 2/3
Rustic – 3/4
To further describe oak, French mills add letters. So a typical oak grade might be;
This stands for Q = Quercus/latin for oak, F denotes that the board has been cut straight at the sawmill, 2/3 shows the it is a mix of grade 2 and grade 3, and finally the x denotes that a small amount of lighter colour sapwood is allowed in the grade.