Expansion joint systems are designed to accommodate movement.
Yet, failures still occur — and more often than not, the issue isn’t the product itself.

Understanding why expansion joints fail is critical for architects, engineers, and contractors who want long-term performance and compliance.

Movement Is Underestimated

Buildings are constantly moving — expanding, contracting, creeping, settling, and swaying. When an expansion joint system is not designed to handle actual site movement:

• Seals can tear
• Cover plates may buckle
• Concrete edges can crack

Accurate movement calculation is essential to avoid premature failure.

Waterproofing Is Not Properly Integrated

Water ingress is one of the most common causes of building damage. If waterproofing membranes and expansion joints are not coordinated:

• Leaks develop
• Corrosion begins
• Internal finishes deteriorate

A fully integrated waterproofing and joint system is essential for long-term durability.

Fire Rating Is Inadequate

Expansion joints create openings in fire-rated structures. If the fire-rated joint system:

• Does not match the slab’s fire rating, or
• Cannot accommodate full movement under fire conditions

…it compromises both compliance and safety.

The Wrong System Is Specified

Not all expansion joint systems are interchangeable. Different environments require different solutions:

• Car parks demand heavy-duty, trafficable systems
• Hospitals require hygienic, antimicrobial seals
• Podium decks need waterproof and UV-resistant systems
• Seismic joints must accommodate large, multidirectional movement

Specifying the wrong system leads to early failure

Poor Installation Practices

Even the best-designed expansion joint system will fail if installed incorrectly. Common installation issues include:

• Uneven joint gaps
• Over-tightened fixings
• Compressed or damaged fire barriers

Quality installation is just as important as design and product selection.

The Bottom Line

Expansion joints are critical building systems — not finishing details.

Successful performance depends on early coordination between:

• Structural design
• Waterproofing systems
• Fire compliance
• Architectural finishes

When treated as an afterthought, failures are inevitable. When prioritised early, expansion joint systems protect both the building — and your reputation — for decades.

The post Why Expansion Joints Fail appeared first on Unison Joints High Performance Bespoke Coverplates.

Unison Joints were appointed by main contractor Laing O’Rourke to supply architectural cover plates and fire seals for the new Engineering and Technology Precinct at the University of Sydney.

All the products supplied by Unison Joints complied with applicable Australian standards and the national construction code and arrived onsite fully assembled and installation ready, saving time onsite.

The aluminium three piece mechanical cover plates were used to conceal large expansion joints between the new and old buildings which were required to deal with settlement, shrinkage, thermal, seismic and wind movements.

Unison Joints also provided fire blankets to stop fire spread within pressurised risers. A new clamping method had to be designed to ensure the blankets could withstand the riser pressure.

“It’s very common for us to design bespoke solutions,” said Bernie Scott, Managing Director. “We liaise with the designer or contractor to explore design alternatives and value engineer solutions.”

In addition to developing bespoke solutions, Unison Joints holds a large range of stock products which allows them to dispatch materials very quickly in most cases, helping builders meet challenging timescales.

Unison Joints offers a combination of excellent customer service, expertise and inhouse manufacturing and certification capability. “We never stop developing our products,” said Bernie. “We are always looking for ways to expand our product offering and deliver better solution for our clients.”

As Australia’s leading provider of cover plates, expansion joints and movement solutions for construction, Unison Joints have a close relationship with all leading contractors. Their prior experience with Laing O’Rourke includes Brisbane Airport, IKEA Logan, Brisbane International Convention Centre and many other projects.

The post University of Sydney Engineering & Technolgy Precinct appeared first on Unison Joints High Performance Bespoke Coverplates.