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 VisualStandard VisualBest Visual
Type of wood- European spruce
- Fifths grade pine
- European spruce
- Unsorted grade pine
- Douglas Fir.
- European spruce
- Unsorted grade pine
- Douglas Fir.
Lamella thickness40mm to 45mm.30mm to 45mm.20mm to 45mm.
SurfacePlaned 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.
BevelBevelled / sharp-edged.3mm to 4mm bevel.3mm to 4mm bevel.
KnotsNo 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 pocketsNo requirements.Loose knots, knot holes up to 35mm diameter allowed.
InbarkPermissible (no rot).Not permissible.Not permissible.
DiscolouringPermissibleBlue stain and red stripe permissible up to 5% of the surface,Not permissible.
Inset infestationPermissible subject to strength grading requirements.Not permissible.Not permissible.
CracksNo 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.
FlawsOnly 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.