Plywood isn't one product — it's a family of boards that look similar but behave very differently once water, weight or weather gets involved. Buy the wrong grade and you either overpay for performance you don't need, or you get a board that delaminates, sags or rots. This guide breaks the three families you'll actually choose between — marine, structural and non-structural — down to the one thing that separates them: the glue bond.
It starts with the glue bond
Every sheet of plywood is thin veneers glued together. What that glue can survive is what defines the board. In Australia and the relevant British standards you'll see bonds described as Type A (A-Bond) through to interior bonds:
- A-Bond (Type A) — a permanent, boil-proof phenolic glue line. It does not break down under constant moisture. This is what makes a board "marine" or fully exterior-rated.
- Structural / exterior bonds — durable, weather-resistant bonds suited to framing, bracing and protected outdoor use, but not designed for permanent immersion.
- Interior bonds — economical bonds for dry, indoor, non-load-bearing work.
The three families at a glance
| Marine | Structural | Non-structural | |
|---|---|---|---|
| Glue bond | A-Bond (permanent, boil-proof) | Type A / durable exterior | Interior bond |
| Load-bearing | Yes (fully structural) | Yes — this is its job | No |
| Moisture | Constant / immersion | Weather-exposed, not immersed | Dry, indoor |
| Face quality | High, low-void core | Functional (C–D faces common) | Varies — often good faces for finishing |
| Typical standard | BS1088 / AS 2272 | AS 2269 | AS 2270 / interior grades |
| Best for | Boats, wet areas, outdoor furniture | Flooring, bracing, formwork, framing | Cabinetry, linings, decorative panels |
Marine plywood
Marine ply is defined by its A-Bond (Type A) glue line and a hardwood veneer core with minimal voids, giving it exceptional resistance to moisture, delamination and rot. The face is sanded smooth for clear coating or paint. We stock BS1088 marine grades in thicknesses from 6 mm to 25 mm.
Reach for marine ply for boat hulls and transoms, bathroom and laundry linings, outdoor furniture, planter boxes — anything exposed to constant water. It costs more than structural ply, and that premium is the permanent glue line. If the board will genuinely stay wet, it's worth it; if it won't, you're paying for performance you don't need.
Structural plywood
Structural ply is engineered to carry load. It's the board behind flooring, wall and roof bracing, hoarding, formwork and general framing. It uses a durable bond and is stress-graded, so it's the right (and more economical) choice whenever strength — not immersion — is the requirement. It handles weather exposure during construction, but it isn't built to sit in water permanently the way marine ply is.
Non-structural plywood
Non-structural ply is for dry, indoor work that doesn't carry load: cabinetry, shelving, wall linings, and decorative or feature panels. Because it isn't paying for a permanent glue line or a stress grade, it's the most economical family — and it often comes with attractive faces (birch, hoop pine, decorative and V-groove options) ready to finish.
Still not sure? Match by the job
- Will it get wet often or permanently (boat, bathroom, outdoors)? → Marine.
- Does it need to carry weight (floor, bracing, formwork, framing)? → Structural.
- Is it dry, indoor and non-load-bearing (cabinets, linings, panels)? → Non-structural.
- Need a timber look on a wall? → a decorative / V-groove non-structural panel.
- Unsure between marine and a good exterior structural sheet? The deciding question is immersion — permanent water means marine.
Every sheet we stock is sourced from certified mills, held at our Epping yard, and delivered on our own crane trucks across Melbourne and Greater Melbourne — with cut-to-size available on request. If you'd rather not decide from a table, run the plywood finder and we'll match you to the right board in about a minute.