Repair Systems — 02 — Concrete & Structural Defects
Formwork timber, bearers and props
Technical product reference for MGP10 stress-graded pine framing, DAR pine soldiers, hardwood timber props, and Acrow adjustable steel props used in concrete spalling repair formwork. Covers timber grade selection, bearer design, prop types, and Australian standards compliance under AS 3610 and AS 1748.
Formwork timber in concrete spalling repair
Structural timber framing is the backbone of concrete formwork in remedial repair — MGP10 stress-graded pine bearers support the plywood form face, soldiers stiffen the ply panels against lateral mortar pressure, and Acrow or timber props provide vertical support for overhead soffit and beam formwork. The timber framing must be rated for structural use — MGP10 (Machine Graded Pine to AS 1748) is the minimum grade for all concrete formwork framing in Australia. Non-graded or appearance-grade timber must not be used as structural formwork framing.
Product Reference
Individual products — one card each — scroll to view all
BGC Timber / Bowens / Bunnings
MGP10 Pine — 70x45 / 90x45 mm Formwork Framing
MGP10 stress-graded pine — concrete formwork framing and bearers
MGP10 stress-graded pine framing in 70x45 mm (3x2) and 90x45 mm (4x2) sections is the standard structural timber for concrete formwork in Australian residential and remedial construction. MGP10 (Machine Graded Pine to 10 MPa) is stress-graded to AS 1748 and provides reliable, consistent structural performance for formwork bearers, stringers, and walers. In concrete spalling repair, MGP10 framing is used to support F11 plywood form faces — as bearers spanning between props, as soldiers on the back of ply panels to stiffen against lateral mortar pressure, and as ledger boards for soffit forms.
Bowens / Independent Timber
DAR Pine — 90x35 mm Soldierboard
DAR pine 90x35 mm — soldierboard and fine-boxing in concrete repair
Dressed all round (DAR) pine in 90x35 mm is used in concrete spalling repair formwork for soldier framing behind plywood panels, as the vertical stiffening members in column boxing and wall forms, and for fine-joinery boxing where a smooth, consistent-dimension timber is required. DAR pine is finished to consistent dimensions with smooth faces — unlike rough-sawn framing pine, DAR members provide consistent contact with the back face of plywood panels and do not cause local point loading that can indent or deflect thin plywood. In Australian remedial repair practice, 90x35 mm DAR pine is the standard section for soldiers in column boxing and slab edge side forms — fixed to the back of F11 plywood panels using clouts or screws at 150–200 mm centres.
Bowens / Timber Merchants
100x50 mm Hardwood Timber Props
100x50 mm hardwood timber — adjustable props and vertical support
Hardwood timber props in 100x50 mm section are traditional adjustable shoring members used in remedial concrete repair to support formwork for beam soffits, overhead slabs, and other overhead forms during repair mortar placement and curing. Hardwood props are used in pairs with timber wedges at the base — the wedges are driven to adjust prop height and pre-tension the support system against the form. Typical Australian hardwood species used for props include spotted gum, messmate, and box — these are available from timber merchants in the eastern states.
Coates Hire / Kennards Hire
Acrow Props — Adjustable Steel Formwork Props
Adjustable steel Acrow prop — rated vertical formwork support
Adjustable steel Acrow props (also called forkhead props or adjustable steel props) are the standard vertical shoring element for supporting overhead formwork in remedial concrete repair — beam soffit boxing, slab soffit forms, and any overhead formwork system where a rated vertical support is required. Acrow props consist of an outer and inner steel tube with an adjustment pin and nut system that allows continuous height adjustment over a range of typically 1.8 m to 3.8 m, depending on size. The top of the prop terminates in a fork head (U-head) that accepts a bearer or ledger board.
System Comparison
Concrete spalling — confirm all selections against the current manufacturer TDS before specifying.
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Do not confuse formwork timber and props with:
- Ungraded or non-structural pine — appearance grade pine from hardware stores may look identical to MGP10 structural pine but has no stress grade certification and must not be used as structural formwork framing — always confirm MGP10 certification from the supplier
- Softwood pine as vertical props — pine timber must not be used as vertical compression props — pine does not have the buckling resistance and compression strength of hardwood — use hardwood props or rated Acrow steel props for all vertical formwork support
- Scaffold tube systems — proprietary steel scaffold tube and coupler systems (kwikstage, cup-lock, RingSCaff) are a different product from Acrow props — scaffold systems are for access and working platforms, not direct concrete formwork support unless specifically engineered as shoring
- Steel RSJ or UC props — while structural steel members can be used as shores and props, they require engineering design and are different from standard Acrow adjustable props — do not substitute unless an engineer specifies steel member sizes and connections
- Falsework for new construction — large-scale formwork and falsework for new concrete structures is designed by a structural engineer to AS 3610 — remedial repair formwork for small patches is less complex but still requires the same minimum material grade standards
Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer technical data sheet, project specification, substrate condition, exposure classification, AS 3600 requirements, and applicator warranty conditions. Do not rely on this reference as a substitute for professional engineering or remedial building consultant advice.