Choosing the best plywood for wet area applications
Plywood clears the common misconception that marine plywood is the ‘only’ plywood capable of withstanding exposure to moisture.
While marine plywood is recommended for any plywood application where the timber will be directly immersed in water for a period of time as in boat building and other marine activities, Plywood advises that birch plywood offers a more functional alternative for design applications requiring general moisture resistance. Birch plywood is a suitable alternative in wet area applications.
Specifically designed with structural strength for greater impact resistance as well as to absorb the effects of water movement and pressure, marine plywood is manufactured to the very highest standard with both ply faces being A grade veneer and totally defect-free. Examples include Hoop Pine Plywood meeting Australian Standard AS/NZS2272; or Pink Marine Ply meeting British Standard BS1088.
Birch is manufactured from premium B/BB grade Northern European Birch timber, a cold climate timber featuring close growth rings to provide exceptional long-lasting strength and durability for the core and veneer ply layers. Plywood specialises in birch plywood sheets; Hex (with phenolic hexagonal film coating); Film (birch ply with a selection of 10 coloured phenolic/ melamine protective film coatings); Edge Fineline (birch ply designer sheets in either veneer or solid panels); and the classic Birch plywood sheets.
All plywood sheets, including marine and birch, are manufactured with the same Type A Phenolic Bond glue line – E0 formaldehyde rating, enabling the ply veneer sheets and core to bond securely together.
The moisture resistance of both marine plywood and birch plywood depends on the quality of the glue line, unique veneer faces and timber core as well as how well the exposed plywood edges are sealed and protected. No exposed plywood face or edge can survive immersion or exposure to water unprotected. The exposed edges of Marine Ply and Birch plywood must be protected with layers of water repellent varnish or oil/wax products.