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).

Recommended applications of Riga Ply, depending on grade.

* Plywood grade photos are made of a compilation of A5 samples

Plywood S(II) class Plywood B(III) class Plywood WGE(IV) class Plywood WGE class

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).

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
Pin knots
Sound intergrown knots
Sound intergrown knots
Unsound adhering knots
Unsound adhering knots
Other knots and holes
Other knots and holes
Irregularities in the structure of the wood
Irregularities in the structure of the wood
Curly grain
Curly grain
Open splits and checks
Open splits and checks
Open splits and checks, repaired by putty
Open splits and checks, repaired by putty
Closed splits and checks
Closed splits and checks
Wood discolouration
Wood discolouration
Coloured streaks
Coloured streaks
Other discoloration, coloured streaks. Brown, but not rot.
Other discoloration, coloured streaks. Brown, but not rot.
Inserts
Inserts
Open joints
Open joints
Overlap uncoated plywood quality requirement
Overlap
Imprints and bumps
Roughness
Roughness
Sanding through
Sanding through
Glue penetration
Glue penetration
Unsanded areas
Composed face veneers
Composed face veneers
Defects at the edges caused by the sanding or trimming
Defects at the edges caused by the sanding or trimming

Permitted

Not permitted

PDF
Defect
Plywood Grades
S
BB
WG
Pin knots
Pin knots
Sound intergrown knots
Sound intergrown knotsSound intergrown knotsSound intergrown knots

Permitted up to an individual max Ø 20 mm, if the cumulative Ø does not exceed 50 mm/m²

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
Unsound adhering knotsUnsound 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
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
Irregularities in the structure of the wood
Curly grain
Curly grain
Open splits and checks
Open splits and checksOpen 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
Open splits and checks, repaired by puttyOpen 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
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
Wood discolouration

Permitted slightly

Coloured streaks
Coloured streaks

Permitted slightly

Other discoloration, coloured streaks. Brown, but not rot.
Other discoloration, coloured streaks. Brown, but not rot.Other discoloration, coloured streaks. Brown, but not rot.Other discoloration, coloured streaks. Brown, but not rot.

Permitted up to 30 % of the surface area

Inserts
InsertsInserts

Permitted, if properly inserted and match the plywood colour, not more than 1/m²

Permitted up to 10 pieces per square meter

Open joints
Open jointsOpen 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
Overlap uncoated plywood quality requirement
Imprints and bumps
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
Glue penetration

Permitted, if occasionally

Permitted up to 5 % of the surface area

Unsanded areas
Unsanded areas

Permitted up to an extent of 5 % of the panel surface

Composed face veneers
Composed face veneers

Permitted, if composed properly, conformable colour

Defects at the edges caused by the sanding or trimming
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