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Structural Decking

Structural decking offers a simplified method of roof construction by dispensing with the need for purlins. The liner sheet is used to span the structural frame of the building resulting in fewer components and giving clean, uncluttered lines to the interior of the roof structure. Use of structural decking can also stiffen the structure and act as a bracing if required.

Acoustic properties can be designed into the system, thereby engineering sound absorption and transmission characteristics.

Structural decks will span up to 10m, dependant on the design load, and once in place provide a strong, walkable surface for the rest of the roofing works.

Design requirements

Design of structural decking is complex in that certain information is required to tabulate the particular specification. We offer this design service, provided that full information is provided on the requirements of the deck, including:

Maximum span between steel frames

Whether single, double or multi-span

Design imposed loads – these should include all positive loads which the decking is required to support, i.e. design loads of the system above, design loads of anything attached to the underside, snow loads, wind loads and loads imposed by foot traffic.

  • Wind loads (uplift)
  • Whether diaphragm action is required
  • Acoustic requirements


Decking is available solid or web perforated. Selection will depend on the acoustic requirements of the building.

Generally, where sound transmission is an important factor, either in or out of the building, then the solid deck should be used. Where sound absorption is critical for example in sports halls, then the perforated deck should be used. Web perforation is generally preferred to full perforation as full perforation significantly reduces the load carrying capacity of the product. We can advise on the most appropriate acoustic solutions.


Most decking is supplied either plain galvanized, for when the underside is to be hidden by a suspended ceiling, or in white polyester.

Two versions of paint are available. Interior grade is for where no part of the deck is exposed to external weathering and has a cost advantage over exterior grade which must be used where the deck extends beyond the perimeter walls creating a soffit on the outside.

Other colors and finishes are available on request and all decks are also available in plain mill to finish aluminum if required or in ARS RAL 9016 for high humidity environments.


Our OD Structural Roof Decking and OT Structural Tray ranges offer the designer a long span solution reducing the amount of structural frame whether steel frame or timber frame or glulam beams, providing an uncluttered, clean internal finish to any roofing system in a vast array of design solutions such as;

  • Waveform
  • Curved barrel vaulted
  • Convex
  • Concave
  • ‘Hockey stick’ complex shape
  • Simple low pitch flat roofing solutions

Structural decking is trapezoidal or profiled in shape, whereas by comparison the structural tray has a lightly profiled base and two raised flanges which provide its strength. The internal aesthetic of each system is different with the structural decking show the trapezoidal shape whereas the structural tray provides a flatter finish.


18 profiles of the structural deck and structural trays in a large range of gauges and finishes

A vast range of outer sheet solutions for both roof and wall solutions

U Value as low as 0.10W/m2K

Composite and built-up wall cladding systems including bespoke rain screen systems to complement our roof system

Single Source Supply for all aspects of the roofing & cladding system from liners and structural decks through soffits, and fascias and rainwater goods, complete with perimeter flashings and bespoke fabrications reducing carbon emissions through efficient and minimal deliveries to site

Systems available for both the New Build, Modular or Volumetric and refurbishment sectors, SpeedDeck® OD Structural Decking, and OT Structural Trays are the ‘Natural Choice’ for long span roofing & cladding.

More Information

  • Plan galvanized
  • BBA approved, high-quality systems
  • White polyester
  • Expert metal roofing and cladding solutions
  • Mill aluminum
  • Trusted technical expertise
  • Other colour options
  • Choice of systems, materials, and finishes