Grabbing whatever sheet is cheapest at the yard is how good jobs go wrong. A dry-interior sheet used under a bathroom vanity will swell and delaminate; a cabinet-grade ply screwed to an exterior wall blows apart the first wet winter. The fix is simple: match three things to the job — the standard the sheet is built to, its bond type, and (for anything load-bearing) its stress grade.
In Australia, structural plywood is manufactured to AS/NZS 2269 and stamped with an F-grade (F8, F11, F14, F17, F22). Interior and decorative ply follows AS/NZS 2270, and moisture-resistant MDF panelling sits under AS/NZS 1859.2. Bond type describes the glue line: A-Bond is a fully waterproof phenolic for permanent wet or exposed use, B-Bond is intermediate, and C-Bond is for protected interior work. Get those right and everything else is detail.
Start with the bond, not the price
Bond type is the single biggest decision because it decides whether the sheet survives moisture at all. Before you compare grades or face quality, ask one question: how much water will this panel ever see — none, occasional, or constant? That answer usually picks the product for you. Here is the shortlist by job.
| Project | Recommended sheet | Standard | Bond |
|---|---|---|---|
| Subfloor & flooring | Structural F11–F14, tongue & groove | AS/NZS 2269 | A-Bond |
| Bathroom & wet area | Marine ply or wet-area VJ panel | AS/NZS 2269 / 1859.2 | A-Bond |
| Furniture & cabinetry | Hoop pine or birch (interior) | AS/NZS 2270 | C-Bond |
| Formwork | Film-face formply F17 | AS 6669 / 2269 | A-Bond |
| Wall bracing | Bracing ply F22 | AS/NZS 2269 | A-Bond |
| Cladding & exterior | Exterior structural ply | AS/NZS 2269 | A-Bond |
If the sheet will ever get wet — even occasionally — buy A-Bond and stop second-guessing it.
Flooring & subfloors
Structural flooring ply carries live loads and spans between joists, so it must be made to AS/NZS 2269 with a stress grade to suit your joist spacing — F11 and F14 are the common picks for domestic work. Tongue-and-groove edges lock adjacent sheets together, remove the need to land every edge on a joist, and stop squeaks and stepping at the joins.
Even for a covered subfloor, choose an A-Bond glue line. Slab moisture, a plumbing leak or a wet trade during the build can all reach the underside, and a phenolic bond shrugs it off where an interior bond will let go.
RecommendedT&G Plywood FlooringShop →Bathrooms & wet areas
This is where cutting corners costs the most. Standard interior ply and standard MDF will not tolerate the humidity and splashing of a wet area — you need an A-Bond structural or marine plywood behind tiling and waterproofing, or a purpose-made moisture-resistant panel for exposed linings.
Marine vs moisture-resistant
Marine plywood (BS1088) is A-Bond with premium, low-void veneers — the pick for shower bases, boat fit-outs and anywhere in constant contact with water. For decorative wet-area walls, wet-area VJ panelling built on MR MDF to AS/NZS 1859.2 gives you a lined finish that handles bathroom humidity. Remember that "moisture-resistant" is not "waterproof" — MR MDF resists the damp air of a sealed, ventilated bathroom, but it is not a substitute for correct waterproofing behind it.
Furniture & cabinetry
Indoor joinery is the one place you can relax the bond requirement. Cabinets, shelving, wardrobes and built-ins live in a dry, conditioned space, so interior ply to AS/NZS 2270 with a C-Bond glue line is appropriate and more economical than paying for marine.
Here the decision shifts to the face. Hoop pine gives a clean, paint-ready or clear-finished surface, while birch plywood offers a pale, dense, near-flawless face and tight edge plies that machine crisply and look sharp when the edge is left exposed. Match the face grade to whether the panel will be painted, clear-coated or edged in solid timber.
Formwork & concrete
Formply is a specialist product: an A-Bond structural plywood, typically F17, finished with a phenolic film face so wet concrete releases cleanly and the sheet can be stripped and reused many times. It is manufactured to the formwork standard AS 6669 and should never be substituted with ordinary structural ply, which will bond to the pour and blow out under pressure.
Film-face formply gives the smoothest off-form finish for exposed concrete; a plain structural form ply suits work that will be rendered or hidden.
RecommendedFilm Face FormplyShop →Bracing, cladding & exterior
Structural bracing plywood resists the racking forces that keep a frame square in wind and earthquake loads. It is a high-grade structural sheet — commonly F22 to AS/NZS 2269 — and must be fixed to the engineer's or manufacturer's nailing schedule to reach its rated bracing capacity. Swapping in an unrated sheet quietly voids that rating.
For exterior cladding, weatherboards and soffits, stay with A-Bond structural plywood rated for external exposure. The glue line and face both have to survive sun, rain and temperature swings, so anything with an interior bond is out — no matter how good the price looks.
- Pick the bond first: A-Bond for anything wet or exposed, C-Bond only for dry interior work.
- Flooring, formwork, bracing and cladding are all structural — insist on AS/NZS 2269 and the right F-grade.
- In wet areas, marine ply goes behind waterproofing; MR MDF panels are moisture-resistant, not waterproof.
- Cabinetry can use economical interior ply (AS/NZS 2270) — spend your budget on the face, not the bond.
- Formply and bracing ply are rated products; never substitute a plain sheet and expect the same performance.