In an era marked by growing environmental awareness and the urgent need for sustainable practices, the construction industry is undergoing a paradigm shift towards eco-friendly solutions. When it comes to refurbishing flat roofs, there’s a number of options to consider to not only minimise environmental impact but also enhance the durability and performance of the roof. 

In this blog, we'll explore the intersection of sustainability and durability in flat roof refurbishment, highlighting materials and design considerations that promote energy efficiency, reduce environmental footprint, and contribute to a greener future.

1.    Overlaying existing waterproofing membranes

Overlaying existing waterproofing membranes is a sustainable practice that can enhance the efficiency of flat roof refurbishment projects. Rather than removing and replacing the entire waterproofing membrane, overlay systems allow for the installation of new waterproofing systems directly over the existing membrane. This approach reduces construction waste, minimises disruption to building occupants, and can be more cost-effective than full roof  replacement.

By overlaying existing waterproofing membranes, property owners can extend the lifespan of their flat roofs while reducing environmental impact. However, it's essential to ensure compatibility between the existing and new membrane materials. Consult our experts to assess the condition of the existing membrane and determine the most appropriate refurbishment approach. 

2.    Green Roof Systems

Installing green roof systems involves covering the roof surface with vegetation, soil, and drainage layers. Green roofs offer numerous environmental benefits, including improved air quality, stormwater management, and energy efficiency. The underlying waterproofing membrane must be suitable for any green roof, or blue / green roof system.

Important system properties for consideration include hydrolysis resistance together with root and rhizome resistance. When adding a green roof its important to consider the impact of the increased structural load of both the new system and the saturated weight in use.

3.    Energy-Efficient Roofing Design

Incorporating energy-efficient design elements into flat roof refurbishment projects can further enhance sustainability. Considerations such as:

• Cool Roofing: Roofing finishes with high solar reflectance and thermal emittance properties, known as cool roofs, can help to minimise heat absorption and reduce cooling energy consumption.
• Insulation Upgrades: Enhance the thermal performance of the roof by incorporating thermal upgrades to the latest standards. With the right solution provider, this can be combined with an overlay solution. Tapered insulation schemes can also be encompassed improving drainage as well as enhancing energy efficiency.
• Solar Panel Installation: Harness renewable energy with the use of solar panels in conjunction with the flat roof system. Solar photovoltaic (PV) arrays can generate clean electricity onsite, offsetting energy costs and reducing reliance on fossil fuels. It’s important to consider fixings and maintaining the waterproofing membrane’s integrity, as well as any associated plant. Subsequent safe maintenance access needs and appropriate surfacing for walkways also need consideration.

4.    Water Management Strategies

Effective water management is essential for sustainable flat roof refurbishment. Implementing strategies such as:

Blue roofs: Incorporating rainwater attenuation and stormwater management can help prevent urban flooding. The government has recommended that sustainable drainage systems (SuDS) become mandatory for new developments in England from 2024. Including attenuation trays in a flat roof refurbishment requires structural consideration as well as the careful choice of a waterproofing membrane.

Rainwater Harvesting: Install rainwater harvesting systems to capture and store rainwater for non-potable uses such as irrigation, sanitation and fire sprinkler systems reducing demand on billable water supplies.

5.    Lifecycle Analysis and Maintenance

Conducting lifecycle assessments and implementing regular maintenance practices are critical for ensuring the long-term sustainability of flat roof refurbishment projects. Factors to consider include:

• Durability and Longevity: Choose roofing materials with proven durability and long lifespan to minimise the need for premature replacements and reduce overall environmental impact. Modern materials such as Triflex PMMA systems can be overlayed again decades later further reducing their environmental impact. 
• Proactive Maintenance: Establish a proactive maintenance schedule to inspect and address minor issues promptly, preventing costly repairs and extending the lifespan of the roof system.

In conclusion, flat roof refurbishment can encompass a range of strategies that prioritise sustainability. Property owners can enhance the durability, efficiency, and environmental performance of their flat roofs, contributing to a more resilient and sustainable built environment.