Marine plywood is manufactured to tighter construction standards using high-quality veneers and waterproof adhesive. Internal consistency is the key difference. Fewer voids and more uniform bonding reduce the risk of moisture-related failure over time.

Marine plywood is typically specified for:

• External joinery in exposed locations
• Wet area substrates
• Waterfront and marine-adjacent structures
• High-risk moisture zones in residential and commercial projects

At Bord, we generally see marine plywood perform best where ongoing moisture exposure is unavoidable, not simply because a project is near the coast.

Exterior plywood is also bonded with weather-resistant adhesive, but its internal construction allows for greater natural variation. Minor core gaps are acceptable as long as the panel meets structural requirements.

This makes exterior plywood a practical and cost-effective option for:

• External walls and soffits
• Covered outdoor areas
• Construction applications where panels are protected and sealed

When detailed and finished correctly, exterior plywood performs exceptionally well across many East Coast applications. It is often dismissed too quickly, particularly on NSW and Victorian projects where exposure is controlled.

One of the most common over-specifications we see is marine plywood being used where exterior plywood would perform just as well. This usually happens early in the design phase, before exposure conditions are properly assessed.

Over-specifying marine plywood can:

• Increase costs without improving outcomes
• Extend lead times
• Add unnecessary material weight

This distinction sits alongside guidance in Plywood for Outdoor Projects: Choosing the Right Grade for Australia’s Harsh Climate and Plywood in Australian Coastal Homes: How to Combat Moisture and Humidity.

Whether marine or exterior plywood is selected, grade choice remains critical. Face quality, bond classification and intended exposure all influence durability. The principles outlined in Australian Plywood Grades Explained: A, B, C, D, and O apply equally to both materials.

Marine plywood is essential in high-risk moisture environments. Exterior plywood remains a reliable solution for many outdoor and semi-exposed applications. The difference comes down to exposure, detailing and long-term expectations, not proximity to the ocean alone.