Formwork

Our formwork range covers everything from single residential slabs and footings through to multi-storey commercial construction, civil infrastructure and mining projects, with stress grades, systems and accessories to match each scale of work.

Yes. Our teams can advise on stress grade selection, off-form finish class requirements, reuse expectations and system compatibility across our formwork range – get in touch or visit your nearest location to talk through your project.

Formwork plywood, LVL and edgeboard products should be stored flat, dry and off the ground between pours, with panels cleaned promptly after stripping. Correct handling significantly extends the number of reuse cycles you’ll get from the product.

Formwork plywood is a strippable system – it’s fixed in place for the pour, then removed and reused across multiple jobs, making it well suited to ground slabs, footings and vertical formwork elements.

Steel decking (ArmourDeck) is a permanent system that stays in place after the pour and becomes part of the finished structure, providing composite action with the concrete and removing the need for stripping altogether.

Plywood offers more flexibility and reuse value; steel decking suits suspended slabs where speed of construction and reduced labour are the priority.

For most residential slabs, footings, and tilt-up panels, F17 formply provides sufficient load-bearing capacity under AS 6669. F22 is the preferred choice for commercial pours and system formwork where higher reuse counts and spanning capability are needed. F27 – manufactured from total hardwood – is specified for heavy civil engineering, table forms, jump forms, and mining applications where maximum strength and 50+ casting cycles are required.

Reuse cycles depend on stress grade, site handling, and surface finish requirements. ArmourForm F27 can achieve 50+ castings with good site practice. F22 typically delivers 20–30 reuses, and F17 achieves 10–20 reuses. Proper use of release agents, careful stripping, edge sealing, and flat dry storage between pours all significantly extend panel life.

Formwork plywood in Australia is certified to AS 6669, which specifies requirements for manufacture, grading, and branding of plywood used in concrete formwork. This standard works alongside AS 3610, which defines off-form concrete surface finish classes. All Big River formply is manufactured to AS 6669 and independently certified under the EWPAA product certification scheme with JAS-ANZ accreditation.

Formply is structural plywood with a phenolic resin overlay (high-density film face) specifically engineered for concrete formwork. Standard structural plywood is certified to AS/NZS 2269 for general structural applications but lacks the film overlay needed for clean concrete release and surface finish. Formply carries separate certification under AS 6669 and uses A-Bond (phenolic) adhesive for full waterproof performance during repeated wet concrete exposure.

Big River Group has manufactured formply at its Grafton, NSW mill for over 40 years. The ArmourForm range is available in F17, F22, and F27 stress grades, all produced from Australian hardwood and mixed species veneers. Big River also manufactures ArmourDeck steel decking and supplies a full range of formwork LVL, edgeboards, and accessories through 25 locations across Australia and New Zealand. All manufactured products carry PEFC chain-of-custody certification.

Formply thickness is selected against your formwork design: bearer and joist spacing, pour depth and placement load. Big River formply is manufactured to AS 6669 in a range of thicknesses, so confirm what your branch stocks against your design. For grade selection and finish class detail, see the formply range.

They are certified for different jobs: marine ply to AS/NZS 2272 for void-free construction and prolonged moisture exposure, formply to AS 6669 for the load and finish of a concrete pour. For formwork, formply is the right sheet. The full comparison is on our formply page.

Film-faced formply certified to AS 6669 is the plywood purpose-made for formwork. Big River manufactures it at Grafton in F17, F22 and F27 stress grades. Structural plywood to AS/NZS 2269 carries load but lacks the release face, so it is not a substitute where the off-form finish matters.

Formply has a film-faced surface and a water-resistant bond that hold up to water during concrete pours, but it is not a permanently waterproof product. The face sheds water and release agent. Cut edges are the vulnerable point and should be sealed. Store formply undercover and off the ground. Prolonged exposure and unsealed edges shorten its working life.

Formply is structural, film-faced plywood made for the face of concrete formwork. Big River manufactures ArmourForm formply at its Grafton NSW mill, where formply has been made for over 40 years, in F17, F22 and F27 grades certified to AS 6669. The film face gives a clean off-form concrete surface and the structural core carries formwork loads.

Off-form concrete finish is the surface left on concrete once the formwork is stripped, with no further rendering or coating. AS 3610 sets finish classes, from high-quality visual surfaces down to structural-only faces. The formply grade, the condition of its film face, and how it is handled and stored all affect the finish achieved. Cleaner, better-maintained formply gives a better off-form result.

The film-faced surface on formply is designed to release from concrete, so glues and adhesives do not bond well to the face. Adhesion is better on cut or sanded edges where the timber core is exposed. Formply is made for concrete formwork rather than joinery or fixing, so for glued or laminated work a plywood suited to that purpose is the better choice.

Formply life outdoors depends on handling, storage and edge care rather than a fixed figure. Sealing cut edges, storing sheets flat and undercover, keeping the face clean and removing concrete promptly all extend working life. Left exposed to weather with unsealed edges, formply degrades faster. Big River does not publish a set number of pours, because real-world life varies with site conditions and care.