Permitted up to an individual max Ø 20 mm, if the cumulative Ø does not exceed 50 mm/m²
Quality requirements for uncoated plywood
Plywood quality grades
Riga Ply grading conditions are in compliance or stricter in comparison with requirements set by the following regulatory documents:
- EN 635-2 Plywood – Classification by Surface Appearance – Part 2. Hardwood;
- SFS 2413 quality requirements for appearance of plywood with outer plies of birch;
- ISO 139 Recommendations and Conditions Drawn by Work Group II of the Technical Committee (1994).
The quality grade of plywood, evaluated based on its surface veneer, is defined by the type and quantity of visible defects.
Recommended applications of Riga Ply, depending on grade.
* Plywood grade photos are made of a compilation of A5 samples
Plywood quality grades
Riga Ply grading conditions are in compliance or stricter in comparison with requirements set by the following regulatory documents:
- EN 635-2 Plywood – Classification by Surface Appearance – Part 2. Hardwood;
- SFS 2413 quality requirements for appearance of plywood with outer plies of birch;
- ISO 139 Recommendations and Conditions Drawn by Work Group II of the Technical Committee (1994).
The quality grade of plywood, evaluated based on its surface veneer, is defined by the type and quantity of visible defects.
Recommended applications of Riga Ply, depending on grade.
* Plywood grade photos are made of a compilation of A5 samples
S (II)
BB (III)
WG (IV)
WGE
For good quality staining and lacquering. Total number of defects ≤ 6.
For finishing and coating with transparent and non-transparent thicker overlays and films, veneering and applications where a solid face is required. Total number of defects ≤ 9.
For use where surface appearance is not important, reverse grade. The total number of defects is unlimited.
Plywood of WG grade without open defects (repaired with filler), for overlaying with non-transparent finishing material.
Categories of defects
Pin knots
Sound intergrown knots
Unsound adhering knots
Other knots and holes
Irregularities in the structure of the wood
Curly grain
Open splits and checks
Open splits and checks, repaired by putty
Closed splits and checks
Wood discolouration
Coloured streaks
Other discoloration, coloured streaks. Brown, but not rot.
Inserts
Open joints
Overlap
Imprints and bumps
Roughness
Sanding through
Glue penetration
Unsanded areas
Composed face veneers
Defects at the edges caused by the sanding or trimming
Defect
Plywood Grades
Pin knots
Sound intergrown knots
Permitted up to an individual max Ø 25 mm, if the cumulative Ø does not exceed 60 mm/m²
Permitted up to an individual max Ø 65 mm, if the cumulative Ø does not exceed 600 mm/m²
Unsound adhering knots
Permitted up to an individual max Ø 20 mm, if the cumulative Ø does not exceed 200 mm/m²
Other knots and holes
Permitted up to an individual max Ø 6 mm, if the cumulative Ø does not exceed 25 mm/m²
Permitted up to an individual max Ø 15 mm, if the cumulative Ø does not exceed 100 mm/m²
Irregularities in the structure of the wood
Curly grain
Open splits and checks
Permitted for an individual max width up to 4 mm, not more than 2 per meter of panel width
Open splits and checks, repaired by putty
Permitted for an individual max width up to 2 mm and for an individual max length up to 200 mm, not more than 1 per meter of panel width
Permitted for an individual max width up to 2 mm and for an individual max length up to 200 mm, not more than 1 per meter of panel width
Permitted for an individual max width up to 4 mm, not more than 2 per meter of panel width
Closed splits and checks
Permitted for an individual max length up to 200 mm and not more than 2 per meter of panel width
Permitted for an individual max length up to 200 mm and not more than 2 per meter of panel width
Wood discolouration
Permitted slightly
Coloured streaks
Permitted slightly
Other discoloration, coloured streaks. Brown, but not rot.
Permitted up to 30 % of the surface area
Inserts
Permitted, if properly inserted and match the plywood colour, not more than 1/m²
Permitted up to 10 pieces per square meter
Open joints
Permitted up to an individual max width 2 mm and individual max length 200 mm, not more than 1 per meter of panel width, repaired with putty
Permitted up to an individual max width 3 mm
Overlap
Imprints and bumps
Permitted slightly, up to 2 cm² per panel
Permitted slightly
Roughness
Permitted slightly, up to 10 cm²/m², if repaired with putty – max 3 defects per panel
Sanding through
Permitted ≤ 10 cm²/m²
Permitted ≤ 20 cm²/m²
Glue penetration
Permitted, if occasionally
Permitted up to 5 % of the surface area
Unsanded areas
Permitted up to an extent of 5 % of the panel surface
Composed face veneers
Permitted, if composed properly, conformable colour
Defects at the edges caused by the sanding or trimming
Permitted up to 5 mm from the edge, not in whole length
Permitted up to 5 mm from the edge, not in whole length
Permitted up to 5 mm from the edge