RAAC in Repurposed Buildings: A Case Study in Hidden Hazards

2nd April 2024

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RAAC in Repurposed Buildings: A Case Study in Hidden Hazards

The recent spotlight on the safety risks associated with Reinforced Autoclaved Aerated Concrete (RAAC) panels has building owners scrambling to assess their structures. But what happens when a building’s past life throws a curveball? Our recent project at a repurposed port authority building highlights the challenges and importance of identifying RAAC in these unique spaces.

From Naval Base to Serviced Offices: A Hidden History

This bustling hub for serviced offices wasn’t always a haven for startups and freelancers. In its former life, the three-story structure served a much different purpose: a vital part of a naval base. This unique history presented a double challenge for our team. First, the existing layout and modern finishes completely concealed the building’s original construction methods. Second, during our initial inspection, we discovered asbestos lurking in some of the finishes, adding an extra layer of complexity and requiring additional safety measures.

The Art of Detection: Non-Intrusive Investigation

Given these limitations, our survey relied on a combination of non-intrusive methods. We meticulously inspected exposed soffits (undersides) on each floor and consulted with the building’s electrician and managers about past drilling difficulties encountered during installations.

The Plot Thickens: RAAC and Look-Alikes

Our investigation on the top floor revealed what we suspected: the tank room and surrounding stairwell walls were constructed with RAAC. It was a textbook case. However, the lower levels threw us a curveball. Precast panels with chamfered edges, the telltale signs of RAAC, lined the floors.

However, closer inspection revealed the presence of aggregate in the slabs and surprising impact resistance, reinforced by the project electrician recounting the difficulty he had drilling these panels. This unexpected twist underscored a crucial point: comprehensive material identification goes far beyond a quick visual inspection. While initial observations can be helpful, a more rigorous approach is necessary to ensure accurate characterisation and avoid potential misidentification.

Safety First: Recommendations and Next Steps

The confirmed presence of damaged RAAC panels in the plant room raised immediate safety concerns. These compromised panels posed a potential safety hazard and we immediately notified the client. To fully assess the structural integrity and determine the best course of action, we recommended further investigation, potentially including intrusive testing, of these RAAC panels.

While the lower-level panels weren’t RAAC, a definitive identification of their composition remained crucial. We suggested further investigation to pinpoint their exact material makeup and determine if they presented any unforeseen safety risks.

Don’t let RAAC lurk undetected in your repurposed building.

It’s essential to be careful when repurposing a building to ensure that there’s no hidden danger lurking in the form of RAAC. While a visual inspection may provide a starting point, a more comprehensive approach is necessary to accurately identify materials and avoid costly mistakes.

Protect Your Investment: Proactive Steps to Consider

  • Schedule a pre-renovation assessment: Engage a qualified professional to conduct a thorough investigation using non-intrusive and potentially intrusive methods (if necessary) to identify the presence and condition of RAAC in your building.
  • Develop a remediation plan: If RAAC is found, a plan for mitigation or removal should be established to ensure the safety and structural integrity of your building.
  • Proactive safety measures: Consider incorporating RAAC identification into your standard procedures for any future renovation projects involving older buildings.

Taking these steps can help ensure a safe and healthy environment for your occupants and avoid the hidden dangers that RAAC can pose. Remember, a proactive approach is key to a successful repurposed building project.


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