From concept design to installation and eventual recycling, flat roofs provide a wide range of environmental benefits for building projects. SIG Design & Technology offers an independent choice of systems for flat, green, and hard metal roofs for all types of buildings. The company can help choose the right roofing system for the project and ensure that it meets all the building’s requirements.

Step 1 – make the most of your flat roof
In spatial terms, flat roofs can be highly efficient, reducing the apparent mass of a building and providing easily accessible space for services, such as HVAC plant, photovoltaic panels and solar thermal tubes. Terraces, green roofs and roof gardens can also enrich the ‘fifth’ elevation, providing an important amenity for building occupants. As well as carbon capture, a green roof will optimize the structural footprint of the building, assist with urban drainage, enhance thermal and acoustic insulation, increase a membrane’s life expectancy, provide green space, absorb airborne pollutants and counter the heat island effect which is felt in cities.

Step 2 – choose the right products
When it comes to the sustainability of the roof covering itself there are a number of factors to evaluate. First, what is it made from and can it be recycled? Is there a requirement (planning or otherwise) for a BREEAM or other sustainability rating? Some flat roofing products are A+ or A rated. You can also consider whether the client has a concern for recycled content, or wishes to source products only made in the UK.

Green roofs can improve sustainability ratings and make a significant contribution to the points scored in BREEAM, WELL and Living Building Challenge assessments. Points can be accrued under a variety of headings for BREEAM, including POL5, LE4, LE5, LE6 to name but a few.

Bitumen-based mastic asphalt might initially appear unsustainable, however it is so durable over long periods that it is considered by construction professionals to have little or low impact on the environment and at the end of its useful life mastic asphalt is 100% recyclable. Mastic asphalt is also carbon neutral and in 2008 UK mastic asphalt became the first industry in the world to achieve the CarbonZero standard.

Step 3 – design for long life and maintain
The sustainability in flat roofing should be considered in terms of detailing practices and future maintenance. For architects, entering into discussion with a roofing expert at the earliest possible opportunity can be vital with regards to specifying the right product for the application and identifying key detailing issues.

For clients and end users, it is vital that flat roofs are subject to a proper and regular inspection regime. This will ensure drainage outlets remain unblocked and appropriate repairs or replacement can take place if needed. Adherence to these procedures should ensure flat roofs achieve and/or exceed their life expectancy.