Engineering a Sustainable Built Environment

From new builds to adaptive reuse, Interspan delivers high-performance, low-carbon solutions

for the future of construction.

Interspan Group is a specialist in sustainable design and construction, delivering end-to-end capability backed by unrivalled quality assurance.

As a global leader in post-tensioning and structural strengthening, we partner with clients to reduce embodied carbon across new builds, existing assets, and repurposed structures.

>2 million sqm post-tensioning

> Over 2 million square metres of post-tensioned floors delivered each year.

CARES Quality Assurance

Market Leading CARES Accredited Quality Assurance.

750+ Strengthening Projects

750 + strengthening & remediation projects delivered.

350 Team Worldwide

350 passionate & dedicated design & delivery specialists worldwide.

NEW STRUCTURES

The Interspan Group brings unique expertise in post-tensioning, construction methodology, and lifting operations that reduce CO₂ emissions, material usage, and construction program.

The Post-tensioning Method

What is Post-tensioned Concrete?

Specialist Slab Post-tensioning

Through effective design, post-tensioned slabs enable material and embodied carbon reductions versus a conventionally reinforced slab, while maintaining the inherent benefits of concrete construction.

Construction Methodology

Innovative construction methodologies enable works to be completed outside the critical path in a safe and controlled environment. This approach reduces project costs and schedules, improves safety, and minimises disruption.

Multi-Strand Tensioning Systems

Interspan has extensive experience in the supply and installation of post-tensioning works in bridges, using state-of-the-art equipment to apply uniform stress to the separate strands of the tendon simultaneously.

Stress Bar Post-tensioning

Stress bar post-tensioning systems provide a cost-effective solution for applying post-tensioning forces to short, straight tendons without requiring any profiles.

Post-tensioning Reduces Carbon Emissions

Post-tensioning is a powerful technique that can enable reductions in materials and carbon emissions through effective design within the construction industry. By adopting post-tensioning, we can build more sustainable, resilient, and environmentally friendly structures, paving the way for a greener future.

Lifting & Jacking

Lifting and jacking operations are essential when prefabricated elements or existing structures need to be moved, raised, or installed with precision.

These techniques reduce reliance on heavy craneage, minimise risks, and enable construction in challenging environments or tight timeframes.

EXISTING STRUCTURES

We specialise in helping clients extend the life of concrete structures through advanced repair, strengthening, and carbon fibre solutions. Adaptive reuse projects are a perfect fit for our expertise, helping to minimise waste while delivering safe, modern outcomes that support community growth.

Over the last decade, the Interspan Group has become a market leader in the application of CFRP-strengthening solutions, with notable projects including the award-winning The Space House in London and the Quay Quarter Tower in Sydney.

CFRP Strengthening

We promote innovative, proven solutions utilising various CFRP-based strengthening techniques depending on the nature of strengthening required for your project. Our knowledge and experience in this area are second to none, and we’re extremely proud of the work our teams do every day.

Structural Concrete Repair

We provide solutions for all types of concrete repair. Whether it is due to deterioration, carbonation, damage, or defective concrete, we put forward a remediation solution to ensure the section’s durability and strength are fully reinstated.

Crack Injection

We understand structures. We know why they crack and how to fix them. Our experienced teams design custom solutions to address any kind of crack that emerges. Typically, a crack is the symptom of a problem, not the cause.

External Post-tensioning

External post-tensioning is a proven active strengthening method for upgrading existing structures, including bridges, buildings and tanks. It involves installing prestressing cables or bars outside the structural section, guided by deviators along the most effective load path.

Forensic Investigations

Forensic services are often utilised to assess potential compliance issues between the approved structural documentation and
the built structure. We utilise both non-destructive and destructive testing methods to understand the composition of existing structures.

Tendon Truncations

Over the last decade, Interspan has developed proven epoxy-based, retrofitted Tendon Truncation procedures that ensure post-tensioned tendon forces can be safely transferred into the remaining structure.

Our teams have decades of experience with post-tensioned structures, and we know how and where to use truncations as well as how to install them safely.

Remedial Grouting

We have significant experience with structural grouting, and our pumps can mix and place proprietary grouts with or without cementitious or epoxy-based aggregate.

Cathodic Protection

Corrosion is one of the most common and expensive durability issues stakeholders encounter in both building and civil structures.

Bearing & Joint Replacement

Replacing bearings and expansion joints is essential to restore performance and extend the service life of ageing bridges and civil structures. Upgrading these components restores the structure’s ability to accommodate movement, rotation, and stress, improving durability and long-term serviceability.

Quay Quarter Tower Sydney,. Adaptive Reuse

Interspan Group Joins DYWIDAG

The combination of DYWIDAG, Interspan, and Slabtec brings together decades of specialist expertise in post-tensioning, structural strengthening, and concrete solutions – delivering more value to our clients across Australia, New Zealand, Europe and beyond.

“Interspan is an exceptional business with a strong track record of customer satisfaction and financial performance. The combination of Interspan and DYWIDAG reinforces our position as a global market leader in the provision of post-tensioning, stay-cable solutions, geotechnical products and specialist repair and strengthening solutions” – Hugh Pelham, DYWIDAG Group CEO

READ THE FULL ANNOUNCEMENT