DIY Projects

How to Distinguish between American and Canadian Plywood Grades?

Submitted by: Woody Wall on October 14, 2011

Canadian Plywood Grades

  • Good Two Sides - Fully sanded on both sides, may contain neat wood patches and inlays and synthetic filler is allowed.
  • B/BB- Is the same as above but is used for describing poplar as opposed to fir. B is a grade of veneer that applies to Fir and Poplar.
  • Good One Side - Fully sanded face allowing neat wood patches and inlays, back is sanded and has open knots. Synthetic filler is allowed.
  • B/C - Same as above when describing poplar.
  • Industrial One or Two Sides - Basically the same as one or two sides but allows more patches per face and allows for the grain of the wood to be a bit more feathery or raised.
  • Factory - A fall down from good one side, face is still fully sanded but allows for a defect on the exterior of the panel, such as a sand through or piece of veneer missing, but must be able to make a a 4’ x 7’ or 3’ x 8’ panel with no defects.
  • Sanded D - Can be anything less than that allowed for a factory panel. Is lowest grade of sanded plywood. Does not include delamination. Grading will vary from mill to mill. Delamination is allowed as a part of a visible defect.
  • Select Sheathing - Fully sanded or skip sanded face with small tight knots and allows for larger and open knots on back. May not be sanded.
  • D Grade - All fall down from above, including some face or back veneer missing or loose.
  • Cull - Allows for any possible imperfection - delamination, off square or mis-sized.

American Plywood Grades

  • ACX Superply - Patch free, hardwood face veneer, very tight grain, buff sanded very smooth. Excellent for paint.
  • AC Premium - Up to 10 repairs per panel, wood and synthetic, no knots.
  • ACX - Up to 18 repairs per panel, some pin knots, very slight.
  • BC Premium - Unlimited repairs, no knots, some minor repaired splits.
  • BCX - Unlimited repairs, tight knots up to 1” across grain, some minor veneer splits allowed.
  • C Veneers - Open knots up to 1!, tight knots up to 1-1/2”, unlimited repairs, discolorations, sanding defects, limited splits. This is a veneer grade and does not describe a sheet of plywood. This grade of veneer is not always a sanded item.
  • Off Grades - Sanded Shop (Factory) - Fall down from A & B sanded products, 80% usable panel. Up to 20% allowed for delams, edge and corner damage, sanding defects. Varies from mill to mill. The actual grade does not require any % as usable.
  • PTS (Plug and touch sanded) - Fall down from APA rated underlay products. 80% usable panel, same as above. Could have core voids not allowed in on grade underlay panels. PTS is a manufacturing process that could be performed on any sheet of plywood.
  • CD Shop - Fall down from C face veneers, otherwise same as Sanded Shop above. CD shop is not normally sanded.
  • Blows - Delaminated veneers, could be pocket delams, edge delams or whole veneer section delams.