In the world of construction and building maintenance, ensuring the safety and longevity of structures is paramount.

One critical aspect of this process is the assessment of Reinforced Autoclaved Aerated Concrete (RAAC), a material commonly used in buildings constructed between the 1950s and 1980s.

As these structures age, the need for thorough RAAC surveys and inspections becomes increasingly vital.

RAAC inspection

RAAC Surveys: Understanding RAAC and Its Challenges

RAAC is known for its lightweight, insulating properties and ease of use, making it a popular choice during its time. However, over the years, it has been discovered that RAAC can deteriorate, leading to potential structural weaknesses. This is where the importance of RAAC inspections comes into play. Regular assessments help identify any signs of degradation early, allowing for timely interventions that can prevent more significant issues down the line.

It is worth noting that concrete roofs aren’t necessarily precast, and precast concrete roofs aren’t necessarily RAAC!

RAAC without defects isn’t necessarily a problem, but you do need an expert review to know where you are on this spectrum!

The Role of Experienced Structural Engineers

When it comes to conducting RAAC surveys, the expertise of an experienced structural engineer cannot be overstated.

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RAAC inspection


Experienced structural engineers bring a wealth of knowledge and practical insight, crucial for accurately assessing the condition of RAAC structures.

Their ability to identify subtle signs of wear and potential failure points is invaluable in ensuring the safety and integrity of a building.


Why Choose an Experienced Structural Engineer for Your RAAC Survey?

Precision in Assessment

An experienced structural engineer can conduct a comprehensive RAAC inspection, employing advanced techniques and tools to pinpoint areas of concern. This precision is critical in formulating effective maintenance and reinforcement strategies.

Tailored Solutions

Every building is unique, and so are its challenges. Expert structural engineers can provide customised solutions that address specific issues, ensuring that the recommended interventions are both effective and efficient.

Long-term Safety and Savings

By opting for a detailed RAAC survey conducted by a professional, building owners can avoid costly repairs and potential safety hazards. Early detection and intervention are key to preserving the structural integrity of a building and extending its lifespan.

Conclusion

In building maintenance and safety, RAAC inspections play a crucial role.

Choosing an experienced structural engineer for your RAAC survey ensures a thorough, accurate assessment and gives you peace of mind that your building is in expert hands.

With their expertise, you can confidently address the complexities of RAAC assessments, protecting both your investment and the people who depend on the structure every day

Next Steps

If you’re a building owner concerned about the condition of your RAAC structures, or still need to check if you have RAAC, don’t hesitate to reach out to our team of experts.

We’re here to help you ensure the safety and longevity of your property.

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RAAC Solutions?

Read about Carbon Fibre Reinforced Polymer (CFRP) here

For more information about RAAC from the Institution of Stuctural Engineers click here

 

Project Overview

Reading Borough Council sought to expand their vehicle workshops at Bennet Road, where they service and maintain refuse vehicles. This extension was crucial as the Council had begun transitioning their fleet to electric vehicles (EVs).

The existing workshop facilities were too small to accommodate these larger, more complex vehicles and required additional space for future maintenance needs. The objective was not only to extend the workshops but also to future-proof the facilities for the Council’s evolving fleet.

Existing warehouse facility at Bennet Road, Reading

Key Objectives

The primary goal was to extend the height and depth of the existing workshop, providing ample space to accommodate the new EVs and ensuring efficient future maintenance. The Council was under significant time pressure and required the expanded facility to be fully operational by September 2024.

We were appointed in the summer of 2023, with the challenge of taking the project from planning approval to site construction and completion within a tight 15-month window.

Unique Challenges & Constraints

1.  Time and Budget Pressure

The timeline was critical, as the Council needed the new facility open and functioning by September 2024. The initial budget was set low, and we advised the client early on that this might be insufficient. Cost-saving measures were prioritised, focusing on sustainable solutions that aligned with the client’s environmental goals.

warehouse site plan


2.  Site Constraints

The workshop is located on a busy, operational site. We needed to maintain smooth traffic flows for refuse vehicles while constructing the extension in a rear corner of the property.

One of the workshops remained operational throughout the construction process, with alternative offsite provisions made by the Council.


3.  Boundary & Compliance Challenges

The project site was very close to the property boundary, necessitating detailed fire safety considerations for the new cladding.

Although the existing building did not meet current standards, we had to bring the entire structure up to building regulations, a challenge that significantly increased costs.

One area that needed improvement was the fire safety measures. Building Control required a fire refuge to be added on the first floor. The ground floor was already fully compliant with the Disability Discrimination Act (DDA), ensuring accessibility for office staff and visitors.

Tight rear boundary


Cladding going in 


Structural & Engineering Solutions

1.  Reuse of Existing Structures

To stay within budget and maintain sustainability, we reused as much of the existing structure as possible.

The original steel frame was retained and extended both vertically and horizontally to accommodate the new height requirements and additional bays.

The yard’s existing 250mm thick concrete slab was also reused, screeded over to integrate it seamlessly with the new floor plan. This approach eliminated the need for a new ground floor slab, significantly reducing costs and environmental impact.

Frame extended upwards to increase headroom


Slab out to allow new ramped entrance to be formed



2.  Screw Piles
The decision to use screw piles for the foundations was a pivotal solution that saved both time and money.

Traditional excavation would have risked disturbing potentially contaminated soil on the refuse site, requiring expensive removal and disposal.

By using screw piles, we minimised digging and avoided disturbing the ground, thus cutting costs and adhering to environmental best practices.


3.  Sustainability Focus

Sustainability was a driving factor throughout the project. In addition to reusing the structural frame and floor slab, we used high-efficiency, insulated cladding and installed roller shutter doors with built-in insulation.

These elements exceeded standard building regulation requirements, as per the Council’s brief to create a comfortable working environment for their technicians while improving energy efficiency.

4.  Architectural & Engineering Coordination

The project required intricate coordination between the structural and service designs, which we managed through advanced software tools like Revit.

This allowed us to integrate third-party services into our structural framework seamlessly and avoid design-related issues during construction.

This technology was crucial in coordinating complex elements, such as integrating heating systems that were controlled by the roller shutter doors to ensure no heat was wasted when the doors were open.

Overcoming Project Hurdles

Phased Construction Delays

The project was originally divided into two phases to ensure two workshop bays could be handed back early while the rest of the extension was completed.

However, due to site proximity issues—particularly the inability to gain permission from neighbouring properties to access their land—the planned phasing had to be overhauled. This caused a delay in handing over the initial two bays but did not impact the final deadline for the entire building.

New frame in!


Office annex roof, beams going in



Budget Adjustments

Despite the initial cost-saving measures, the best tender came in 20% over the original budget due to material costs and additional compliance requirements.

The budget continued to rise, eventually reaching 1.5 times the original due to increased client specifications for fixtures, fittings, and office space requirements.


Conclusion

The Bennet Road workshop extension project successfully met its objectives of expanding Reading Borough Council’s maintenance facilities to accommodate their growing fleet of electric vehicles.

Through strategic reuse of existing structures, innovative foundation solutions, and sustainable building practices, we were able to minimise costs and environmental impact while delivering a state-of-the-art facility. Although there were significant challenges, including tight deadlines, budget adjustments, and compliance hurdles, the project remained on track for completion by September 2024.

The Council now has a future-proofed facility that not only serves their current needs but is also prepared for the growing demands of their electric vehicle fleet.

bennet road warehouse

As a commercial property owner or manager, your building is one of your most valuable assets. However, maintaining and maximising the lifespan of your property can be a costly challenge—especially when structural issues emerge unexpectedly. That’s where structural engineers come in. They don’t just solve problems when they arise; they play a vital role in preventing costly repairs and even extending the useful life of your building, ultimately saving you money in the long run.

In this post, we’ll explore how a proactive approach to structural engineering can keep your commercial property in top condition while protecting your bottom line.

Structural Engineers for Commercial Property – Early Detection of Issues

Many structural issues are invisible to the untrained eye, silently eroding the integrity of your building over time. Cracks in walls, uneven flooring, or even subtle shifts in the building’s foundation can be early signs of structural stress. Left unchecked, these issues can snowball into expensive repairs or, worse, require extensive rebuilding.

Structural engineers conduct regular assessments and detailed inspections to detect these problems early.

structural engineers for commercial property


By identifying potential weak points and implementing targeted repairs or reinforcements, they can stop damage before it escalates. The result? You avoid major disruptions, and the cost of minor repairs is a fraction of what you’d pay to fix a larger problem.


Optimising Maintenance Plans

One of the biggest mistakes commercial property owners make is adopting a reactive maintenance strategy—fixing issues as they occur. This “band-aid” approach can result in unforeseen expenses and may shorten your building’s lifespan.

RAAC inspection

Structural engineers help you shift from a reactive to a proactive maintenance plan. By understanding the materials and design of your building, they can recommend tailored maintenance schedules that address the specific vulnerabilities of your property. These strategies not only help extend the lifespan of your building but also allow for more predictable maintenance budgets, reducing unexpected costs.

Strengthening Aging Structures

Even the most well-built structures degrade over time due to natural wear and tear, environmental stressors, and changing usage patterns. However, structural engineers specialise in assessing aging buildings and devising solutions that restore and enhance their structural integrity. Through reinforcement techniques like retrofitting or upgrading building materials, engineers can breathe new life into older properties.

These upgrades can also improve the building’s safety, energy efficiency, and overall market value, making it a smart investment for property owners looking to maximise returns on aging assets.

Extending Usable Life with Sustainable Solutions

Sustainability has become a crucial consideration in the commercial property sector. Green buildings are in high demand, and there’s growing pressure to make existing structures more sustainable. Structural engineers can identify opportunities for incorporating environmentally friendly solutions, such as energy-efficient reinforcements or sustainable materials that extend the life of your building while reducing its carbon footprint.

This dual benefit—extending the building’s lifespan and making it more attractive to eco-conscious tenants or investors—can lead to significant long-term savings and increased property value.

Reducing Insurance Premiums

Another overlooked benefit of working with structural engineers is the potential reduction in insurance premiums. By maintaining the structural integrity of your building and taking preventative measures, you can demonstrate to insurers that your property is less of a risk. This often results in lower premiums, adding yet another layer of financial savings.

Conclusion: A Smart Investment in Longevity

Investing in a structural engineer is more than just a safeguard for your commercial property—it’s a strategic decision that can yield significant financial returns. By catching issues early, optimising maintenance plans, and strengthening aging structures, engineers can extend the life of your building and help you avoid expensive, unexpected repairs.

In the long run, this proactive approach doesn’t just save you money; it ensures the longevity and value of your property for years to come. So, if you want to maximise the lifespan of your building and protect your investment, working with a structural engineer is one of the smartest decisions you can make.

In the ever-evolving field of construction, one of the most promising advancements in building reinforcement is the use of Carbon Fibre Reinforced Polymer (CFRP). Unlike traditional materials like steel and concrete, CFRP offers a unique combination of high strength, lightweight properties, and resistance to corrosion, making it an increasingly popular choice for structural reinforcement.

However, the true strength of CFRP lies not just in the carbon fibre itself, but in its integration within a plastic, or resin, matrix. This blog explores the future of building reinforcement with CFRP and highlights the critical role structural engineers play in its design and inspection.

Understanding Carbon Fibre Reinforced Polymer (CFRP)

CFRP is composed of carbon fibres embedded within a resin matrix, typically an epoxy. This combination of materials results in a composite that leverages the superior tensile strength of carbon fibre along with the flexibility and durability provided by the plastic matrix. The resin binds the carbon fibres together, distributing loads more evenly across the material, which enhances its overall performance in structural applications.

This synergy between carbon fibres and the plastic matrix is what makes CFRP particularly effective in building reinforcement. The carbon fibres provide exceptional tensile strength—up to five times that of steel—while the plastic matrix contributes to the material’s resistance to environmental factors such as moisture, chemicals, and temperature fluctuations. This makes CFRP ideal for reinforcing structures in harsh conditions, such as water and marine environments.

The Role of Structural Engineers in CFRP Application

Structural engineers are at the forefront of utilising CFRP in construction, as the material requires specialised knowledge for effective application. Engineers must carefully design CFRP reinforcement strategies that take full advantage of its properties while ensuring that the material is used where it is most needed.

One of the primary responsibilities of structural engineers is to determine the appropriate placement of CFRP within a structure. For example, CFRP can be applied to beams, columns, and slabs to enhance their load-bearing capacity without significantly increasing their weight. This is particularly beneficial in retrofitting older structures, where adding more weight could compromise the existing foundation.

In addition to design, engineers must ensure that the CFRP is properly installed. The process of embedding carbon fibres in a resin matrix requires precision, as improper application can lead to weak points in the structure. Engineers oversee the curing process of the resin to ensure that it bonds effectively with the carbon fibres and the substrate, creating a strong and durable reinforcement.

The Future of CFRP in Construction

As the construction industry continues to prioritise sustainability and efficiency, the use of CFRP is expected to grow.

The material’s lightweight nature reduces the overall load on structures, which can result in lower construction and transportation costs. Additionally, CFRP’s resistance to corrosion and environmental degradation extends the lifespan of reinforced structures, reducing the need for frequent repairs and replacements.

Ongoing advancements in CFRP technology are also making the material more accessible. Innovations in manufacturing processes are lowering production costs, which will likely lead to broader adoption across various types of construction projects. As a result, CFRP could become a standard material not just for high-profile infrastructure projects, but also for everyday buildings, including residential and commercial properties.

Conclusion

Carbon Fibre Reinforced Polymer represent a significant advancement in building reinforcement, offering a combination of strength, durability, and versatility that traditional materials cannot match. The future of construction will increasingly rely on CFRP, particularly in applications where weight, environmental resistance, and longevity are critical concerns.

Structural engineers, with their expertise in design and material science, are essential to unlocking the full potential of CFRP, ensuring that it is used effectively to create safer, stronger, and more sustainable buildings for the future.

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The role of a structural engineer is crucial when carrying out a structural assessment on a contaminated site due to the complex interaction between environmental hazards and structural integrity.

Contaminated sites often pose unique challenges that can significantly impact the stability and safety of existing structures.

Here’s why a structural engineer’s expertise is necessary;

1. Ensuring Structural Stability During Remediation

Sites contaminated by spills often require extensive remediation activities, such as soil removal, excavation, or chemical treatments, which can destabilise the ground and, consequently, the structures on it.


A structural engineer assesses the potential risks associated with these activities, ensuring that the building remains stable throughout the remediation process. 


By designing appropriate underpinning, propping, and temporary works, the engineer prevents additional damage and ensures the safety of the structure and its occupants.

2. Protecting Against the Impact of Contaminants

Contaminants can degrade building materials over time, leading to structural weaknesses that may not be immediately apparent.

A structural engineer evaluates how different contaminants might affect various materials, such as concrete, steel, or masonry, and recommends appropriate construction techniques and materials that are resistant to such degradation.

This foresight helps to prolong the life of the structure and reduce the likelihood of future structural failures.

3. Compliance with Regulatory Standards

Structural engineers ensure that all work on contaminated sites complies with relevant building regulations and safety standards.

This is particularly important as many remedial activities fall under the scope of Building Regulations, which govern structural safety, material quality, and construction practices.

Engineers ensure that the remediation process does not inadvertently violate these regulations, protecting the property owner from legal and financial repercussions.



4. Safeguarding Human Health and Safety

Contaminated sites often pose direct risks to human health, especially if the contamination affects indoor air quality or if structural failures occur during remediation.

Structural engineers play a vital role in minimising these risks by designing solutions that not only preserve structural integrity but also prevent the spread of contaminants. Their work ensures that buildings remain safe for occupants, contractors, and the wider community.

5. Providing Reassurance and Support

The presence of contamination in a property can be distressing for homeowners and stakeholders, who may be concerned about the safety of their buildings and the implications of the necessary work.

Suitably qualified and experienced structural engineers provide critical reassurance through their assessments, detailed reports, and clear communication.

Their expertise ensures that all parties understand the measures being taken to secure the structure, easing concerns and fostering trust in the remediation process.

screw piles design

6. Cost-Effective Solutions

A well-thought-out structural assessment by an experienced engineer can lead to cost-effective solutions that prevent further damage and reduce the need for future repairs.

By addressing potential structural issues early in the remediation process, engineers help avoid costly delays and ensure that the project stays on budget.

Conclusion

In summary, structural engineers play an essential role in managing the unique challenges of contaminated sites. Their expertise ensures that buildings remain safe, compliant, and resilient throughout the remediation process, protecting both the property and the people involved.

In the construction industry, precision and clarity are vital.

However, a concerning trend has emerged where some contractors are using structural calculations as reference for ordering steels, overlooking crucial practical considerations.

It’s essential to address this misconception and highlight the true purpose of structural calculations in the construction process.

Structural Calculations Serve A Specific function:

  • ensuring compliance and
  • validating the design
structural calculations

Assumptions May Be Inaccurate

It’s crucial for contractors to understand that structural calculations don’t directly determine the exact size of steels or clear spans.

Steels should ALWAYS be ordered from drawings and final site measurements. This is because finishes may be unusually thick (or thin) meaning assumptions about structural openings may be inaccurate.

Misinterpreting or misusing these calculations can result in significant consequences, including ordering incorrectly sized steels or costly on-site adjustments that may compromise structural integrity but will certainly cost time and money.

In Summary

Structural calculations serve to ensure design compliance not provide details for the order such as steel length.

Contractors, building control engineers, and clients each have distinct roles in understanding and utilising these calculations.

It’s essential to recognise that assumptions in these calculations may be inaccurate, and steel should always be ordered based on drawings and site measurements to avoid costly mistakes.

While structural calculations are vital, they’re only part of the construction process, emphasising the importance of a holistic approach to building safely and efficiently.

RIBA Stage 4: Technical Design – What’s the Rush?

As structural engineers, we understand the eagerness to proceed directly to the technical design phase. However, it’s vital to prioritise completing phases 1-3 of the RIBA plan of work for several key reasons.

Integrated Design

Skipping the concept phases may result in disjointed designs.


integrated design

By going through these phases, architects and engineers can collaborate to seamlessly integrate structural considerations into the architectural vision. This ensures that structural elements not only support the building but also enhance its aesthetics and functionality.


Alignment with

Structural Requirements

Early collaboration during stages 1-3 allows us to seamlessly integrate structural considerations into the architectural concept. 


alignment

This integrated approach ensures that the structural framework supports the architectural vision effectively, leading to a more robust and cohesive design solution.


Risk Mitigation

Rushing into technical design without a thorough understanding of the project’s context and constraints can increase the risk of errors and omissions.


increased risk

Completing phases 1-3 allows for early identification and mitigation of potential risks, such as site conditions, regulatory requirements, and budget constraints, reducing the likelihood of costly revisions or delays during technical design.


Client Collaboration and Approval

Engaging clients throughout stages 1-3 ensures that their expectations and preferences are incorporated into the structural design process. 


client approval

Regular feedback and approval during these stages foster client satisfaction and confidence in the final technical design.


Innovation and Sustainability Integration

Early engagement in the concept phases provides an opportunity to explore innovative and sustainable design solutions.


environmentally friendly buildings

Architects and engineers can collaborate to incorporate sustainable practices and technologies from the outset, resulting in more efficient and environmentally friendly buildings.


Efficient Resource Management

Completing stages 1-3 before moving to technical design optimises the utilisation of resources, including time and manpower. 


greater efficiency

A thorough understanding of project objectives and constraints minimises the need for rework or adjustments during later stages, leading to greater efficiency and cost-effectiveness.


Summary

While it may be tempting to jump straight into technical design, completing phases 1-3 of the RIBA plan of work is essential for;

  • aligning project objectives
  • integrating design elements effectively
  • managing risks
  • engaging clients, and
  • promoting sustainability and innovation

Taking the time to establish a solid foundation in the concept phases ultimately leads to smoother project delivery and better outcomes for all stakeholders involved.

This approach lays the groundwork for a successful technical design phase and ultimately contributes to the overall success of the project.

Don’t let structural challenges stall your project. Talk to us to help you ensure your project stays on track. Get in touch today!

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Julie joined the team in June 2023 and comes with strong organisational skills and a customer service background. Before joining us Julie worked for the NHS through the GP surgery side of things, dealing with patients and clinical staff.

She managed a team of fifteen and dealt with patients through COVID.

Julie is a real “people person” and is loving the challenge of her new role outside of the NHS.

One of Julie’s main roles is to support our sales team, speaking to clients, following up on enquiries .

In Julie’s spare time she enjoys going to the theatre and concerts with her husband, spending time with her family and meeting up with friends.

She is very excited to be welcoming a new grandchild in 2024!

Julie biscuits


Favourite Biscuits

Shortbread or dark chocolate ginger!


Olivia joined us in November after working for a private property developer, carrying out design work in Autocad and sketchup – working mainly in high end residential developments.

Her experience includes two barn conversions: a home gym and yoga study and a two-bedroom annexe in addition to the design of a new build property in Chichester.

She has always had a passion for residential projects and has enjoyed learning about Autocad and sketchup.

Since starting with us a few weeks ago she has been thrown in at the deep end! working with one of our structural engineers, Olivia has completed a wall removal project on a residential property. She has also completed a measured survey of a 4 bedroom house for an extension project, and surveyed a period property and drawn up the existing layout ready for a retaining wall design.

I love watching a model come to life. I love meeting people and seeing a project from concept to build – giving people what they love I enjoy all of it.

In my spare time I love going on long walks, ideally via a local pub! I’m also teaching myself the piano and relaxing watching Netflix.

Olivia biscuit


Favourite Biscuits

Ginger nut creams or custard creams!

Today John Staves, our Managing Director attended the Institution of Structural Engineers “Engineers Declare” summit in London.

Climate change and its impact on the construction industry have been recognised for some time. Recently, the UK government announced a groundbreaking move to legislate a Net Zero Carbon target, ringing the alarm bells for all involved in the built environment. This shift will place substantial responsibilities on structural engineers to tackle the challenges and seize the opportunities that lie ahead.

Supporting a Positive Change

In response to this pivotal moment, IStructE (Institution of Structural Engineers) is embracing the “Structural Engineers Declaration,” an initiative led by influential structural engineers. This declaration urges companies to transform their working methods to address climate and biodiversity emergencies.


The Role of IStructE

IStructE is committed to supporting its members by sharing best practices and providing opportunities for cross-disciplinary professional development. This support will help individuals navigate the changing landscape of structural engineering.


The Urgency of Climate Action

The declaration highlights the dire consequences of climate breakdown and biodiversity loss. The construction industry contributes significantly to these issues, being responsible for nearly 40% of energy-related carbon dioxide emissions. It’s time for a paradigm shift in our industry, where we create buildings, cities, and infrastructures as integral components of a self-sustaining system in harmony with nature.

  • Commitment to Change
  • Structural engineers are committing to:
  • Raising awareness of climate and biodiversity emergencies among clients and collaborators.
  • Advocating for regenerative design practices and government funding.
  • Measuring success by climate and biodiversity mitigation principles.
  • Sharing knowledge and research openly.
  • Evaluating projects to contribute positively to climate mitigation.
  • Prioritizing extended use of existing buildings.
  • Incorporating life cycle costing and whole-life carbon modelling.
  • Embracing regenerative design principles.
  • Collaborating to reduce construction waste.
  • Shifting to low embodied carbon materials.
  • Minimizing wasteful resource use in structural engineering.

A Call to Action

IStructE hopes that every structural engineering practice in the UK will join in this commitment to tackle climate change and biodiversity loss. It’s time for the industry to embrace change, advocate for sustainability, and work toward a more regenerative future. The “Structural Engineers Declaration” is not just a starting point; it’s a collective step toward a sustainable and resilient future for all.

RAAC Panels – The Silent Threat Lurking Above

In the world of construction, some dangers are concealed, lurking high above our heads.

Reinforced Autoclaved Aerated Concrete (RAAC) panels, once hailed for their thermal efficiency and fire resistance, have now become a cause for concern.

Today, I’m sitting down with our Managing Director, John Staves, to shed light on the risks associated with RAAC panels and discuss potential solutions for those who find themselves in the shadow of this hidden peril.

RAAC inspection

A Relic from the Past

RAAC panels emerged as a construction method of choice during the 1960’s and 1970’s primarily used in public buildings like schools, hospitals, and corporate structures. These panels found their niche as roofing materials due to their lightweight nature and excellent fire-resistant properties.

The Singlewell Primary Wake-Up Call

The alarm bells began to ring when part of the ceiling at Singlewell Primary School in Kent collapsed on a weekend in 2018. Thankfully, no one was harmed, but this incident underscored the urgent need for action in dealing with the potential dangers of RAAC.


Unseen and Unaware

Many schools and building owners remain blissfully unaware that RAAC panels make up their roofs. The general assumption that concrete roofs are structurally sound has left these hidden time bombs unchecked.

The crisis we face today is partly due to the prolonged use of RAAC panels and inadequate maintenance over the years.

RAAC Concrete panels. Image credits: New Civil Engineer


The Silent Threat

RAAC panels are not like typical concrete structures that give warning signs of impending failure through stress cracks. Instead, they are highly porous, prone to deflections, cracks, and structural weaknesses. Failure in RAAC panels can be attributed to various factors, including manufacturing defects, suboptimal original designs, and moisture ingress.

The Role of Moisture Ingress

Moisture ingress is a particularly insidious problem with RAAC panels, especially when they serve as roofing material. Over time, weatherproof membranes, such as asphalt, deteriorate, allowing moisture to infiltrate the panels. This moisture corrodes the reinforcement within, weakening the bond with the concrete and eventually leading to failures in the panels.

Identifying RAAC Panels

To determine if a building contains RAAC panels, a visual inspection is the first step. Competent structural engineers look for telltale signs such as panel width, span, and edge details. If suspicions persist, core sampling can be employed to confirm the presence of RAAC.

The Next Steps

If RAAC is confirmed, immediate actions are crucial. Affected areas should be cordoned off, and temporary propping may be necessary to prevent collapse. Depending on the severity, options include the removal and replacement of panels or the addition of a new structural layer beneath them.

The priority is to ensure the safety of the occupants below.



Ceiling support at Queen Elizabeth Hospital in King’s Lynn, Norfolk


Strengthening Bearing Support

Another consideration is reinforcing the bearing points to alleviate stress on the RAAC panels. This can involve extending support to where the reinforcement lies within the panels.

Seeking Guidance

For those grappling with RAAC-related concerns, the Department of Education has issued a guidance document in 2022, updated in August 2023, titled “Reinforced Autoclaved Aerated Concrete (RAAC): Identification guidance.” This resource provides valuable information for identifying and addressing RAAC-related issues.

Conclusion

In conclusion, RAAC panels are a hidden danger that can fail without warning. Awareness and proactive inspections are essential to ensure the safety of occupants in buildings constructed with RAAC panels. By following guidelines and seeking expert advice, we can mitigate the risks associated with this silent threat that looms above our heads. Your safety and the structural integrity of your building depend on it.

Do you suspect RAAC in your building? Contact us for expert advice

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