Sustainable roofing: five steps to improve sustainability, reduce waste, and maximise performance

Sustainability is no longer a trend in the roofing industry: it's an essential part of the process. With net zero deadlines edging ever closer, roofing professionals face increasing pressure to improve practices and deliver sustainable solutions.

At Recticel, we're here to support you in creating a sustainable future for roofing, which is why we've listed a handful of steps to improve sustainability, reduce waste, and maximise performance. Just in time for your next flat roofing project.

What do we mean by 'sustainable roofing' and why is it important?

Over the past decade, the way buildings are designed and constructed has changed significantly. With net zero targets set for 2030, 2035, and 2050, this is likely to only accelerate.

The role roofing can have in improving energy efficiency, reducing waste, and extending building lifespans shouldn't be downplayed. The industry is a key player on the road to net zero.

It's worth pausing here to note the recent introduction of The Code for Construction Product Information (CCPI), which requires that product information be clear, accurate, up-to-date, accessible and unambiguous.

The guidance urges us, as manufacturers, to be careful using words like "sustainable" and "eco" in relation to specific products. We use these terms to speak broadly about the building and roofing sector and the part it plays in reaching environmental targets. But when it comes to products, we must be absolutely clear, using evidence to substantiate any performance claims – including sustainability.

Then there's compliance. From meeting BREEAM to Part L, roofing professionals and clients alike are feeling the pressure to comply with – and understand – evolving, stricter building regulations. The UK Future Homes Standard (due in 2025) will further raise the bar, driving demand for low-carbon technologies and energy-efficient building solutions.

Five steps to improve sustainability, reduce waste, and maximise performance for flat roofs

Not sure where to start when it comes to improving sustainability? Consider the following steps when approaching your next project to get ahead of the game.

1. Find and specify more eco-friendly roofing materials

Sustainability starts with choosing the right materials for the job. Certain flat roofing systems are more eco-friendly than others, but even with the most sustainable roofing solutions, there are some aspects which can be overlooked. It comes down to research and knowledge at this stage.

With many choices, getting up to speed with the latest systems and how they stack up against each other is worth your time. Manufacturers should have product information and third party certification readily available, so you can compare options.

Green roofs, which have long been held as the gold standard for sustainability, have an entire system beneath the vegetative layer that needs to be considered – from structural support and insulation to the waterproofing membrane.

Recticel's PIR insulation

When considering key sustainable roofing materials for flat roofs, examining the green credentials of the whole roof build-up is crucial. Polyisocyanurate (PIR) insulation, for example, can be considered a more sustainable alternative to some traditional roofing materials, because it delivers:

• A 50-year lifespan. PIR insulation has been shown to deliver a service life of up to 50 years when correctly installed and maintained, as evidenced by PU Europe’s life cycle assessment. 
• Thermal performance. PIR insulation is tested and declared in accordance with EN 13165, which helps ensure consistent performance over time. 

When selecting long-lasting materials, you should also consider how they're fixed. Choosing a mechanically fastened or ballasted system rather than an adhered solution, for instance, makes it easier to separate and recover components if the roof is later demounted. This supports circular construction practices by facilitating the reuse or recycling of roof elements.

2. Efficient installation and maintenance

Correct installation and regular maintenance are critical. If everything else is done sustainably and this is where the project slips, then nothing else matters. The roof will likely need repairs, and can no longer be considered sustainable.

When working on refurbishment projects, there can often be an extra level of complexity in navigating technical elements and tight spaces.

Deck-VQ® – an answer for sustainable retrofit projects

At Recticel, we're constantly developing new solutions to make sustainable renovation easier and more effective. Take Deck-VQ®, for instance, which is a vacuum insulation panel designed for projects where space is limited.

For example, a 45mm thick Deck-VQ® panel can achieve thermal resistance (RD) of 5.00 m²K/W. This allows for thermal upgrades to flat roofs and terraces without requiring any costly structural alterations or compromising on insulation performance.

3. Maximise performance: improving a building's energy efficiency

Sustainable roofing is about more than choosing eco-friendly materials and reducing the environmental impact of the project – it’s about optimising the energy performance of the entire building over its lifetime.

Insulation has a direct impact on energy use: the better the insulation, the less energy is needed for heating and cooling, which in turn reduces CO₂ emissions. Building regulations such as Part L set strict U-value targets related to insulation for this reason.

Recticel’s PIR insulation boards help buildings achieve lower U-values, with performance that remains consistent over the product’s lifetime. Indeed, data from PU Europe shows PIR insulation can save up to 100 times more energy over its lifespan than is consumed during its production, significantly reducing overall energy consumption and CO₂ emissions.

4. Lengthen the lifespan of the roof

Durability and long-term performance are inherently sustainable. A roof that lasts longer reduces the frequency of replacement, conserving resources, minimising waste, and avoiding the associated carbon footprint of new production and installation.

These are a few key components for extending a roof's lifespan:

Selecting the correct materials.

Many roofing materials should be a once-in-a-lifetime investment. By choosing durable materials, you're making a more sustainable choice, as longevity is improved and energy consumption reduced.

Careful design and installation.

Mistakes in design and installation can lead to costly repairs down the line. Simple design considerations, such as creating a fall on a flat roof to ensure proper drainage, reduces the risk of damage and ultimately extends the lifespan of both the waterproofing and insulation materials.

Proactive maintenance.

Maintenance is equal to both materials and design in importance, but is often overlooked. A proactive approach to maintenance keeps the roof operating as it should for longer.

4. Reduce construction waste

Construction is an industry responsible for producing over 60 percent of the UK's total waste. Roofing falls under that unfortunate umbrella, and, if steps aren't taken, the majority of that waste is disposed of in landfills or incinerated.

Attempts to reduce waste on-site may depend on the materials that are delivered. The first step then is to partner with suppliers that actively work to reduce waste materials from the outset.

Sustainability done the correcticel way

Flat roofing the correcticel way means reducing waste wherever possible. For example, in traditional roofing, insulation consisted of multiple layers designed to prevent thermal bridging by staggering the joints between boards.

Modern single-layer systems are quicker and easier to install, reducing the risk of mistakes, while the use of advanced, factory-bonded materials, cut for a precise fit, can reduce waste and save on costs, reducing waste.

From insulation boards with lower Lamda values to made-to-measure systems that reduce the need for cutting and resizing materials on site, we're committed to exploring ways to reduce waste and reuse or recycle production waste for your projects.

5. Think circular: from manufacturing to end-of-life

True sustainability means thinking about the whole lifecycle of roofing materials – from how they’re made to how they’re used, and what happens when they need to be replaced.

At Recticel, we take our environmental responsibility seriously. We look at every stage: raw materials, design, production, transport, installation, use, and finally, what happens at the end of their life.

As part of our sustainability strategy, we consider environmental benefits and explore methods to cut down emissions, reduce waste, and find innovative ways to use recyclable materials wherever we can.

Our products are made without harmful chemicals like CFCs or HCFCs, and we use blowing agents that have low impact on the climate and no effect on the ozone layer. Our UK-made insulation also has an ‘A’ rating in the BRE Green Guide – a mark of quality that helps roofing projects earn BREEAM credits for sustainability.

Most of our factories have ISO 14001 environmental certification – which means we’re always working to use less energy and create less waste. Whenever possible, we power our plants with green energy to shrink our carbon footprint even more. On top of that, we've joined the Science Based Targets initiative (SBTi) to reduce our carbon impacts.

How Recticel can support your sustainability goals

Achieving long term sustainability and a "feel good inside" approach to roofing is at the heart of what we do – by choosing us, you know you're working with a partner that makes sustainable construction a priority, and understands the challenges you face.

Our Technical Services team are here to help

Supporting you with eco-friendly solutions beyond our insulation products, our Technical Services team can help you design project-specific layout schemes to reduce waste, streamline installation, and avoid unnecessary on-site adjustments.

Collaboration is key to meeting the targets and regulations faced by the construction industry. By working together, we can overcome the challenges faced by roofing and create a more sustainable outlook for the industry's future.