Exterior Pine ply BC has a Grade B face and Grade C inner plies and backside. Knots and other defects on the B-grade face have been filled in with veneer patches and the face sanded smooth for application of paint, varnish or other finish. BC plywood is an exterior product intended for applications where the panel will be exposed to weather and moisture. Exterior Pine Ply BC is exceptionally strong and stiff and is generally available in the standard board size 2440mm x 1220mm and in thickness we offer 4mm Interior grade and 6mm, 9mm, 12mm, 15mm, 18mm, 21mm thickness in an exterior grade..