What plywood is
Plywood is made from multiple thin wood veneers (plies) bonded with the grain of each layer running at 90° to the next. This cross-lamination gives plywood its defining property: balanced strength in all directions and excellent resistance to splitting. Grade (MR, BWR, BWP/marine) is set by the adhesive — see BWP vs BWR.
What block board is
Block board has a core of solid wood strips (battens), typically 25–30 mm wide, laid edge-to-edge and sandwiched between one or two veneer layers on each face. Because the core runs lengthwise, block board is very stiff along its length and lighter than plywood of the same thickness — but it is weaker across its width and at the edges.
Block board vs plywood at a glance
| Property | Plywood | Block board |
|---|---|---|
| Core | Cross-laminated veneers | Solid timber battens |
| Strength direction | Balanced, all directions | Strong lengthwise, weaker across |
| Weight | Heavier | Lighter |
| Resistance to sagging (long spans) | Good | Excellent |
| Screw-holding at edges | Excellent | Variable (depends where the batten falls) |
| Moisture performance | Up to BWP/marine | Generally interior (MR/BWR) |
| Best for | Structural, flooring, packing, wet areas | Doors, long shelves, tabletops, partitions |
When to choose block board
Block board shines where you need a long, flat, rigid, lightweight panel: flush doors, wardrobe shutters, long bookshelves and wall units, conference and dining tabletops, and partitions. Its lengthwise stiffness resists the sagging that a long plywood shelf can develop over time. See block board & flush doors.
When to choose plywood
Choose plywood for anything structural, load-bearing in multiple directions, exposed to moisture, or used for packing and flooring: cabinetry carcasses, formwork, container flooring, export crates, marine and exterior applications. Its all-direction strength and the availability of waterproof (BWP) grades make it the more versatile panel. See the full catalogue.