Cabinetry material choice is primarily determined by an individual’s intended use as well as their expectations regarding load capacity, moisture exposure, durability, etc. Each material offers specific advantages, although long-term performance will vary between the two (marine plywood and blockboard).
Structural Strength
Marine plywood consists of many bonded layers of hardwood veneer, with waterproof resin bonding providing superior strength and impact resistance capabilities. In contrast, blockboard consists of a core of softwood sandwiched between two layers of veneer; therefore, although it is lighter, blockboard will not support as much of a load as marine plywood when subjected to higher loads (i.e., weight).
Moisture Resistance
Marine plywood performs best in wet environments due to its construction and ability to maintain stability over time (even when subject to excessive moisture exposure). The blockboard has some moderate level of moisture resistance and is designed to absorb water through the edges and joints; therefore, it can swell.
Durability & Lifespan
Marine plywood exhibits considerably more resistance to warping, cracking, and delaminating than blockboard will over the lifespan of the cabinet. While blockboard performs adequately in dry areas (e.g., closets), it is likely to break down faster in kitchens or utility rooms.
Suitability of Surface Finishes
Marine plywood will accept both laminate and veneer finishes evenly across the surface without any distortion/warping. Blockboard may require thicker laminate for the prevention of surface undulation.
Weight Support Capability
The structural rigidity provided by marine plywood makes it advantageous when installing wall-mounted cabinets, as there will be reduced risk of long-term sagging.
Cost
While blockboard is typically the least expensive and may be appropriate for use in closets and lightweight furniture (minimal exposure to moisture), marine plywood carries an initial higher price; however, marine plywood also has a longer service life and therefore less frequent replacement will occur.
For homeowners or individuals seeking consistency in quality and controlled standards of manufacturing, marine plywood grades are recommended from established name brands, such as Royale Touche, as they ensure that the thickness of the plywood is calibrated, that the bonded strength across all grades of plywood is uniform, and that all grades of plywood have long-term dimensional stability.