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Formwork 300


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Long Span Composite Formwork

Spantech’s fast and efficient metal formwork system used to construct suspended concrete slabs, multi-level car parks and high rise buildings.

The Spantech Woomera 300 profile is an extremely versatile construction profile invented by Spantech in 1984. The rollformed metal profile can be used for curved roofing, skillion roofing, walls and composite formwork.

When used as formwork the profile is called Spantech Formwork 300.

Build suspended concrete slabs faster with minimal temporary supports and less reinforcing.

Spantech Formwork 300 is an innovative composite formwork system which can dramatically reduce the overall construction time and risks associated with constructing suspended reinforced concrete slabs.

Initially developed and tested for several Australian Department of Defence projects, the Formwork 300 system is now widely used for large commercial projects.

Typical applications include:

  • High rise hotels, residential and commercial buildings
  • Multilevel car parks
  • Mezzanine level floors for commercial and industrial projects
  • Architect designed residential projects, particularly those with sloping sites

Curved Formwork

Unlike any other composite metal formwork, the Formwork 300 profile can be pre-cambered to minimise deflection, or significantly curved to create dramatic free-span arched structures.

These arched concrete structures are regularly used in the design of earth-covered buildings, tunnels, large culverts and blast-resistant buildings.

Features and Benefits

The Spantech Formwork 300 eliminates or significantly reduces the amount and complexity of temporary formwork in suspended concrete slabs to accelerate construction programs and reduce costs.

  • Very cost effective for multilevel car parks, high rise buildings and other commercial applications
  • Suit suspended concrete slabs a minimum of 145mm thick. Typical slab thickness is 160mm
  • Unsupported spans to 3.6 metres (for 160mm slab and live load up to 10KPa). Refer Span Tables
  • Significant reduction in construction time:
    • Faster installation
    • If props are required, there are fewer props Remove props earlier and faster
    • Earlier access for all other trades
  • Integrates with all construction methods:
    • Structural steel frame
    • Tilt-up, pre-cast or formed concrete
    • Masonry walls, etc.
  • The unique flat base of the profile:
    • No infill to underside of profile
    • Minimal flashings
    • Profiles easily fastened to support structure
    • Minimal leakage
  • On-site manufacturing to minimise transport and handling costs, errors and waste
  • Profile can be pre-cambered (curved) to provide additional strength and minimise deflection
  • Profiles are connected to each other with a strong patented interlocking connection achieved without fasteners
  • Bold 110mm (nominal) high ribs act compositely with the finished slab to minimise the quantity of reinforcing required.
  • The ribs can support reinforcing mesh, eliminating bar chairs
  • Integrated multi-purpose clips available to support suspended ceilings and services
  • Excellent Fire Resistance Level (FRL) with 160mm thick slab of 25MPa concrete achieving 240/240/240 FRL. Refer to FIRE DESIGN
  • Acoustic properties meet all relevant standards. Refer to ACOUSTIC DESIGN
  • Options for coil steel protective coatings:
    • Galvanised steel
    • Pre-painted steel – select any colour from the Dulux range
    • Printed patterns emulating timber, stone and corten steel – UniCote Lux

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Recent Projects

Spantech Formwork 300 profile has been used on a number of commercial projects, high rise office buildings and architect designed residential projects.

The system is currently being used to design the new Double Tree Inn, Townsville and a major multi-level car park in Tasmania.

See all Recent Projects

Place an Order

Contact Spantech to place an order

Technical Specifications


Spantech Formwork 300 is manufactured from G300 (300MPa Yield Stress) steel to provide maximum profile strength and optimum rollforming performance.

This ensures maximum profile strength and optimum performance of the base metal’s protective coating.

Standard Base Metal Thickness (BMT) is 1.0 mm.

All Spantech profiles are manufactured from Australian and imported steel which meets or exceeds relevant Australian Standards.

These include AS 1397-2011 Continuous hot-dip metallic coated steel and strip, and AS/NZS2728-2013 Prefinished pre-painted sheet metal products for interior exterior building applications.

Table 1 – Coil steel types and properties

GIX® G300 ZM350 Zinc, Aluminium, Magnesium AS 1397:2011 1.0 300 Approx 5.1 Approx 17.00
Magnaflow® G300 ZM210 Pre-painted Zinc, Aluminium, Magnesium AS 2728:2013 1.0 300 Approx 5.1 Approx 17.00
GI G300 Z600 Zinc AS 1397:2011 1.0 300 5.10 16.99
GI G300 Z450 Zinc AS 1397:2011 1.0 300 5.00 16.67


  • Other coatings are available on request.
  • For more information on GIX® and Magnaflow® visit:

Span Tables

The following tables are a guide and should be read in conjunction with the drawings in Appendix A – Spantech Formwork 300 Drawings.

Table 2 – Span tables for Spantech Formwork 300 (BMT 1.0mm, G300)

1.5 KPa
3 KPa
5 KPa
10 KPa
(Live Loads to 10KPa)
Single Span 150 5.30 1 4.95 1 4.50 1 3.85 1 3.65
160 5.50 1 5.10 1 4.70 1 4.05 1 3.55
200 6.15 1 5.75 1 5.30 1 4.65 1 3.15
275 7.40 2 7.05 2 6.65 2 5.85 2 2.65
Internal Span
150 7.75 2 7.25 2 6.75 1 5.90 1 3.65
160 8.00 2 7.45 2 6.95 1 6.05 1 3.55
200 8.70 2 8.20 2 7.75 2 6.85 2 3.15
275 10.40 3 9.90 3 9.40 3 8.45 3 2.65
End Span
150 6.40 1 5.95 1 5.50 1 4.75 1 3.65
160 6.60 1 6.15 1 5.65 1 4.90 1 3.55
200 7.25 2 6.85 2 6.40 2 5.60 1 3.15
275 8.75 3 8.30 3 7.85 2 7.00 2 2.65


  • Slabs less than 160mm thick may require mesh or reinforcing bars within the pan to maintain sufficient cover.
  • For any other slab thickness download the Spantech Formwork 300 brochure.
  • Contact Spantech for spans for cantilevered slabs.

Table 3 – Formwork 300 pre-camber (curving) guide used to minimise and compensate for natural deflection

Single Span
2m Gauge Height
2m Gauge Height
1.50 or less 0.0 0.0 0.0 0.0
1.75 1.0 1.3 1.0 1.3
2.00 1.5 1.5 1.5 1.5
2.25 2.5 1.9 2.0 1.9
2.50 3.0 1.9 3.0 1.9
2.75 5.0 2.6 4.5 2.4
3.00 6.5 2.9 6.0 2.7
3.25 8.5 3.2 7.5 2.8
3.50 13.0 4.2 12.0 3.9
3.60 15.5 4.9 14.0 4.4


  • The table above is applicable to single span slabs 160mm thick with a single layer of reinforcing mesh.
  • For pre-camber guidance for any other single span slab thickness, contact Spantech.
  • Pre-camber is not recommended for multi-span applications.

Fire Design

Spantech Formwork 300 meets Fire Resistance Level (FRL) 240/240/240.

Passive Fire Inspection and Test Services Ltd tested a 160mm Spantech Formwork 300 slab in accordance with AS 1530.4-2014.

The tested specimen was a full scale loaded concrete flooring system consisting of the 1.00mm BMT G300 Spantech Formwork 300 system – roll formed steel profile, 200 x 200mm Grid R7.0 G500E reinforcing mesh and 160mm nominal thickness N25/19/100 concrete topping.

For more details download the Spantech Formwork 300 brochure.

Fire Test Report is available on request.

Table 4 – Results for the load bearing test of the 160mm thick concrete slab incorporating Spantech Formwork 300

Structural adequacy No failure at 240 mins
Integrity No failure at 240 mins
Insulation No failure at 240 mins
Fire resistance level 240/240/240

Acoustic Design

Wood and Grieve Engineers tested a completed Spantech Formwork 300 project and advised:

  • Acoustic tests and formulation were undertaken in accordance with AS ISO 140.7-2006. The processed results were compared against the acoustic criteria outlined by the NCC 2019 for Class 2 and 3 buildings.
  • Airborne sound insulation performance of the flooring system is expected to perform to Rw + Ctr 50. This meets the airborne sound insulation performance for NCC 2019. The addition of ceilings under the flooring will further improve airborne noise reduction performance.
  • Impact isolation performance for the bare floor system is LnT,w 82-83. This is considered typical for concrete floor systems. Treatments have been nominated to meet compliance with impact isolation performance requirements outlined in NCC 2019. Refer Table 5.

Table 5 – Recommended treatments for compliance with the acoustic requirements of NCC 2019

Bare concrete finish 160 mm thick concrete and Spantech Formwork 300; with

  • 28 mm metal furring channels and proprietary vibration isolation mounts fixed to underside of slab, at 600 mm centres; and
  • 65 mm thick polyester insulation with a density of 8 kg/m3, positioned between furring channels; and
  • one layer of 13 mm plasterboard fixed to furring channels.
Carpet finish Standard carpet with underlay on 160 mm thick concrete and Spantech Formwork 300; with

  • suspended light steel grid with ≥50 mm cavity,


  • 90 mm timber or steel stud frame fixed to underside of slab, at 600 mm centres; and
  • 65 mm thick polyester insulation with a density of 8 kg/m3, positioned between furring channels; and
  • one layer of 10 mm plasterboard fixed to furring channels.

200 mm thick concrete and Spantech Formwork 300. No additional treatments required.

Tiles or Timber 1 finish Porcelain/ceramic tiles or 14 mm thick engineered timber floor on 4.5 mm Regupol 4515 on 160 mm thick concrete and Spantech Formwork 300; with

  • suspended light steel grid with ≥50 mm cavity,


  • 90 mm timber or steel stud frame fixed to underside of slab, at 600 mm centres; and
  • 65 mm thick polyester insulation with a density of 8 kg/m3, positioned between furring channels; and
  • one layer of 10 mm plasterboard fixed to furring channels.


  • Designers should also consider any update to the acoustic requirements of the NCC 2019.
  • The Wood and Grieve Engineers Acoustic Performance Report is available on request.

On-Site Manufacturing

Mobile rollforming machines improve productivity, reduce costs and provide manufacturing location options.

Spantech operates several mobile rollform machines allowing Spantech to manufacture Formwork 300 profiles anywhere in Australia or New Zealand.

On-Site Rollforming Area

Rollforming profiles on-site can significantly reduce the cost of transport, minimise double handling and reduce the risk of transport damage and waste.

For efficient on-site rollforming, the following hard-stand areas are required:

  • Coil Storage Area – Coil steel is delivered via semi-trailer in a shipping container or individual pallets. Maximum coil weight is 4.0t. Coils stored outside must be covered. Coil steel pallets may be stacked up to two coils high (on hard-stand). The size of this area will vary for each project. Contact Spantech for further details.
  • Overall Rollforming Area – The rollforming area is governed by the length of the longest profiles required for the project. For projects requiring profiles up to 6m long an area of 25m x 10m (250m2) is preferred. See Figure 1. The rollform machine is housed in a 6m high-cube shipping container and includes hydraulic legs to unload itself from a semi-trailer. If the semi-trailer cannot directly access the area, the rollform machine can be positioned with a 25t Franna. The area should include Temporary Stacking Area. An additional 6m x 2.4m Toolbox container may also be required.
  • Coil Loading Area – A mobile crane with capacity to load 4t coil steel is required to access the coil steel feed-end of the machine. Several coils are loaded onto a track. Coil is reloaded daily.
  • Formwork 300 Storage Area – The area required will vary for each project. Straight profiles can be nestled in pairs and stacked up to 3 pairs wide and 10 pairs high. See Figure 2 on the following page. Pre-cambered profiles cannot be nested and require additional space.

Rollforming Crew

Spantech rollform crew includes a Rollform Operator and Assistant. Additional labour may be required to handle profiles longer than 6m. Contact Spantech for project specific details and options.

Off-Site Rollforming

Manufacturing Formwork 300 profiles off-site suits small projects, or projects where rollforming or storage space is limited.

Formwork 300 profiles can be rollformed at Spantech’s Gold Coast facility or other pre-approved sites.

When profiles are manufactured off-site, the following applies:

  • Maximum bundle size:
    1,000 wide x 1,200 high. See Figure 2
    (e.g. 60 profiles @ 3.7m long = 1,150 Kgs)
  • Maximum bundle weight:
    (e.g. 24 profiles @ 12m [1m wide x 450mm high x 12m long] = 1,500Kgs)

Pre-Cambered Profiles

Pre-cambered profiles cannot be efficiently stacked and transported.

Large quantities of pre-cambered profiles are curved on-site using the Spantech electric Horizontal Curver. The area required for this operation should have direct forklift or crane access and access to a 10 Amp electrical supply.

The Horizontal Curver can be operated by Spantech’s Crew, or Spantech can train others to operate the equipment.

Manufacturing Tollerances

Table 6 – Manufacturing tolerances

Profile Height 109mm (± 2mm)
Profile Width 300mm (± 2mm)
Profile Cover Width Nominally 303mm (± 2mm)
Square at Sheared Ends ± 2mm
Curved Profiles Height over a 2,000mm gauge: ± 2mm
Profile Length As nominated by client (± 5mm)


  • Profile tolerances may vary at each sheared end of the profile and where cuts are made for penetrations.

Minimum Orders

Table 7 – Minimum order criteria

Minimum orders Contact Spantech for minimum order quantities
Minimum machine cut lengths 700mm
Minimum hand cut lengths Lengths and price on application

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