Glulam Visual Grades and Finishes
We have some standard visual quality gradings that are available, classed as non-visual, standard visual and best visual. Download our table showing more details.
We recognise that some projects will require more specific requirements – we can work to other specifications – for example, knot-free or jointing approaching furniture grades. It is always good when a particularly high level of finish is required to work out what this looks like as a specification first – this is something we can help with.
| Non Visual | Standard Visual | Best Visual | |
|---|---|---|---|
| Type of wood | - European spruce - Fifths grade pine | - European spruce - Unsorted grade pine - Douglas Fir. | - European spruce - Unsorted grade pine - Douglas Fir. |
| Lamella thickness | 40mm to 45mm. | 30mm to 45mm. | 20mm to 45mm. |
| Surface | Planed and levelled. | Neatly planed on all sides, sanded where there are planer marks - visible from 2m away. | Sanded on all sides, finished with minimum 80 grit orbital sander. |
| Bevel | Bevelled / sharp-edged. | 3mm to 4mm bevel. | 3mm to 4mm bevel. |
| Knots | No requirements. | Loose knots, knot holes up to 35mm diameter allowed. | No loose knots or knot holes. Knotholes under 15mm diameter to have filler repair, larger to have infill timber repair. Permissible up to 50mm long and 2mm wide, otherwise repaired. |
| Resin pockets | No requirements. | Loose knots, knot holes up to 35mm diameter allowed. | |
| Inbark | Permissible (no rot). | Not permissible. | Not permissible. |
| Discolouring | Permissible | Blue stain and red stripe permissible up to 5% of the surface, | Not permissible. |
| Inset infestation | Permissible subject to strength grading requirements. | Not permissible. | Not permissible. |
| Cracks | No requirements or crack depth maximum. One sixth of component width. | Top layer cracks up to 2mm wide permissible, radial shrinkage cracks up to 30cm in length permissible. | Cracks up to 2mm to be filled, over 2mm to have timber infill repair. |
| Flaws | Only severe damage is repaired. | Maximum three longitudinal / round wooden plugs behind each other, otherwise a wooden strip is used. | Repaired using strips of infill timber to match lamination. |
| Hit & Miss (planing) | Permissible. | Not permissible. | Not permissible. |