Quality Assurance

Quality Assurance holds immense significance for Interspan because it impacts the safety of our operatives and future occupants, the long-term durability of our structures, and our client satisfaction and relationships.

Our reputation as the leading post-tension service provider is also important to us, and we hold our risk mitigation and public image in high regard.

Interspan undergoes regular internal and external audits for our accreditations, which include Quality (ISO 9001), Safety (ISO 45001), and Environmental Management (ISO 14001), as well as our post-tensioning installation procedures (CARES APT04), and for the production and supply of anchorage systems (CARES APT01).

Our accreditation requires us to continue to demonstrate:

  • The ability and resources required to supply and/or install PT systems to the relevant Standards.
  • Sufficient control of resources involved in the supply chain for the manufacture of key components.
  • A quality management system which complies with the requirements of ISO 9001, CARES Supply and Installation of Post Tensioning Systems for Concrete Structures Scheme Manual (5) and the relevant Quality and Operations Assessment Schedule.
  • We are required to demonstrate traceability for all elements of the post-tensioned installation, either in paper form or by electronic means.

We are the market leader in terms of the supply and installation of Post-tensioning systems in concrete structures, demonstrated through being the only PT contractor in Australia accredited under CARES APT04.

Specialist Process-Driven Activity

High-quality products and workmanship are essential for producing post-tensioned concrete slabs. This requires sound working practices, appropriate training, and tested products adhering to standard codes.

Compared to reinforced concrete slab construction, post-tensioned slabs involve additional hold points to ensure compliance, including:

  • Pour Watch
  • Each phase of stressing operations
  • Cutting and sealing of tendons
  • Grouting of tendons

Each of these stages relies on approved products, quality processes, and skilled workmanship to ensure the structural integrity and durability of the structure and ultimately contribute to sustainability benefits associated with a post-tensioned slab solution.

Multi-strand -tensioning


CARES is an esteemed independent certification body whose primary objective is to instil confidence in the users, purchasers, and specifiers of reinforcing steel and post-tension. CARES achieves this by implementing a comprehensive system of regulation, testing, and inspection. It operates in the construction industry, offering certification schemes for companies involved in producing materials, components, or providing services, primarily within the reinforced concrete sector.

CARES certification enables companies to comply with the major specifiers’ quality requirements, which provides additional quality assurance on all major post-tensioning contracts.

CARES is able to certify PT contractors to produce and supply PT anchors, PT ducts, and PT grout for the Supply and Installation of Post-Tensioning Systems in Concrete Structures and evaluate the competency of Post-Tensioning Personnel.

CARES Appendix PT 1.

We are accredited under CARES APT01 for the Production and Supply of Post-tensioning Anchorage Systems. The Post-tensioning anchor kit we have developed in-house has been tested as a complete system of Anchor, Block and Wedges and complies with AS1314 and ETA (EAD 16004-00-0301) requirements, including static load transfer and fatigue testing. The maintenance of this accreditation requires us to conduct 2 regular auditing of our PT kit suppliers to ensure anchor kits comply with both the material properties and critical parameter dimensions of our specifications.

CARES Appendix PT 4. 

We are the only PT contractor in Australia accredited under CARES APT04 for the supply and installation of Post-tensioning systems in concrete structures.

We are, therefore, required to regularly train and assess the competencies of our site operatives. Operatives are issued CARES cards detailing their level of competency.

Site Quality Requirements

The supplier must have a quality system that complies with CARES requirements and ISO 9001.


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  • Civil Engineering Consultancy
  • Civil Works and Engineering Services


Safety is a core value for us at Interspan. The safety of our operatives and eventual occupants of our structures is imperative to us.   We do this by preparing Safe Work Method Statements (SWMS), providing health and safety training to our employees, reviewing any incident reports, holding daily toolbox talks, checking that equipment is regularly tested and in good working condition and providing the right supervision.

ISO 45001: 2018 Certified

We hold a valid certification in accordance with ISO 45001, an international standard that specifies requirements for an occupational health and safety (OH&S) management system. It provides a framework for organizations to manage risks and improve OH&S performance.



We hold a valid certification in accordance with ISO 9001, a globally recognized standard for quality management. Its requirements define how to establish, implement, maintain, and continually improve a quality management system (QMS).

Interspan has a fully compliant quality management system that is rigorously applied to ensure all works are carried out in accordance with the project scope, specification, and design.

The Interspan Group has a core team of highly experienced Engineers, Managers and Supervisors who help ensure the highest-quality standard flows from the design through to site-based works. Interspan encourages our in-house designers and site-based personnel to collaborate to achieve the best outcome.

Value to our clients is provided by our focused approach to building construction. We specialise in post-tensioned, prestressed and reinforced concrete work, and we understand the specific challenges involved with maximising sustainability while creating a high-quality product.

ISO 9001: 2015 – Quality Management Systems


We hold a valid certification in accordance with ISO 14001, the internationally recognized standard for environmental management systems (EMS). It provides a framework for organizations to design and implement an EMS and continually improve their environmental performance. By adhering to this standard, organizations can ensure they are taking proactive measures to minimize their environmental footprint, comply with relevant legal requirements, and achieve their environmental objectives.

ISO 14001: 2015 – Environmental Management Systems


SSIP – Safety Schemes in Procurement- and UK Legislation. 

SSIP is approved and recognised by the Health and Safety Executive. CHAS is a founding member of the SSIP community, having joined it in May 2009.

Interspan - Temporary Works


Safety Schemes in Procurement (SSIP) is now well established as the industry standard for Health and safety pre-tender qualifications. SSIP Accreditation shows commitment to Health and Safety standards, assuring clients and employees that the business offers a safe working environment.

Interspan on-site meeting