Why Your 30-Year-Old Leaking Curtain Wall Might Not Need Replacing

When water starts leaking through a commercial curtain wall system, the immediate reaction is often panic. For building owners, facility managers, and survey teams, a leak in an ageing system—especially one around 30 years old—usually signals one terrifying prospect: a expensive complete replacement.

We recently attended a site inspection after receiving an enquiry from a client who assumed they needed a full curtain wall replacement. Water was penetrating the envelope, and given the age of the installation, they were preparing for major disruption and a heavy capital expenditure.

However, once our technical team got on site, the diagnosis revealed a much simpler—and vastly less expensive—fix.

The Diagnosis: Shrinkage, Not Failure

When curtain wall systems reach the 25 to 30-year mark, the aluminium framing itself is often still structurally sound. What fails first are the perishable components exposed to three decades of UV radiation, thermal expansion, and weather cycling.

Upon inspecting the building, we identified the root cause immediately: gasket contraction. Over time, synthetic rubber seals (like EPDM) dry out, lose their elasticity, and shrink. As the gaskets contract and pull back from the pressure plates and corner joins, they leave microscopic to large gaps. During heavy rainfall and wind-driven weather, water bypasses the primary drainage paths and makes its way inside the building.

The system wasn't failing—the rubber was just tired.

Refurbishment vs. Replacement: The Numbers Speak

Instead of quoting tens or hundreds of thousands for a full teardown and replacement, we recommended a targeted gasket restoration and re-sealing package.

Here is why opting for repair over replacement made sense for the client:

• Massive Cost Savings: Gasket and seal replacement typically costs a fraction of the price of full structural replacement—often saving up to 70–80% of the project budget.

• Minimal Business Disruption: A full curtain wall replacement requires extensive scaffolding, internal office decanting, and noise interference. Replacing gaskets is carried out via localised access or rope access, keeping internal tenant disruption to near zero.

• Sustainability: Reusing sound aluminium extrusions keeps tonnes of embodied carbon in place rather than sending materials to landfill or recycling plants unnecessarily.

  
  

3 Signs Your Ageing Curtain Wall Just Needs a Refurbishment

If your building is experiencing water ingress, ask yourself these three questions before signing off on a full replacement:

1. Is the frame structurally sound? If there is no major structural distortion, frame damage, or severe corrosion, the metalwork likely has decades of life left.

2. Where is the water entering? Water pooling along transom joints or near floor levels often points directly to gasket shrinkage or clogged drainage slots.

3. Are the double-glazed units intact? If the glass isn't blown (misted up) and the frames are solid, updating the seals and perimeter flashings can completely restore weatherproofing performance.
   

Don't Guess—Get an On-Site Diagnostic Inspection

It’s easy to assume an older building envelope needs a modern overhaul, but a thorough visual and intrusive survey often reveals a straightforward solution.

At HEM Projects Ltd, we believe in providing honest, practical advice. Whether your system needs a full modern upgrade or simply a targeted seal and gasket overhaul, our team will give you an accurate diagnosis that protects both your property and your bottom line.