Two systems, two product families
The Kaswood catalogue uses two classifications. Solid panel uses the AA-AB-AC and BB-BC-CC letter system; planed timber, panelling, decking and profiles use Extra with grades 1-2-3.
The letter system describes the two faces separately: the first letter is the visible face, the second the back. AB means face A, back B. So asking for AA on a job where only one face is seen is money spent for nothing — AB or AC gives the same appearance.
What sets the class: knots, colour and continuity
The main factors are the number and size of knots, whether a knot is sound or loose, the colour variation between lamellae and boards, and how continuous the grain is.
Because timber is a natural material, colour and grain variation does not disappear entirely even at the top grades. It reduces as the grade rises; it does not reach zero — that is the nature of the material, not a defect.
Which grade for which job
The practical rule: the more the surface is seen, and the closer it is looked at, the higher the grade.
- Visible furniture faces, worktops, doors: top grade (AA-AB / Extra)
- Visible but viewed from a distance — cladding, panelling: mid grade (AB-AC / grade 1)
- Semi-visible shelf interiors, carcass sides: BB-BC / grade 2
- Hidden structure, backs, sub-frames: CC / grade 3
Where the cost of an unnecessary grade appears
Higher grades cost more because less of them comes out of the same log. Choosing one high grade for every part in a project means paying that premium on the hidden parts too.
Splitting the cutting list into visible and hidden, and writing a separate grade for each, lowers the total noticeably on most projects. The technical office can go through that split with you.
The grade is recorded for every batch
Species, grade class, joint type and moisture content are recorded for every batch, and dimensional and surface control is carried out before dispatch. The grade the delivered material came out at can therefore be traced later.