Calculations and comparisons
From the perspective of the Chemical Fabrics and Film Association’s (CFFA’s) vinyl roofing division, there are shortcomings with the way carbon data is reported. To date, since these calculators have been limited to what are referred to as the A1-A3 impacts (i.e. cradle-to-gate) for a single purchase of a product, and thus they should not be used for direct comparisons of products. What these calculations do not consider are the longevity of the finished product, the embodied carbon that would result from multiple installations with an overall building’s service life, as well as its contributions to reductions in energy and waste consumption over decades.
This paints an inaccurate picture of the overall CO2 emissions associated with a product such as PVC roofing because factors such as the “use” and “end-of-life” stages are not being considered. Further, CO2 emissions are either reduced or never created when using PVC roofing as a building material because these roofs dramatically reduce a building’s energy consumption. These results outweigh and offset any CO2 emitted during its creation.
The energy-saving benefits of PVC roofing are well-documented. It is a product that deserves a more accurate method of conveying embodied carbon to end-users. Therefore, a more accurate way to measure embodied carbon is through cradle-to-grave calculations, which take into account the entire product lifecycle. This is a much more complete measurement of a product’s environmental impact.
Reducing the carbon footprint of construction
Limiting carbon in construction focuses on building products that are long-lasting and resilient, can reduce operational carbon, and are made or partially made of recycled content. PVC roofing checks all three boxes. PVC roofing that has reached the end of its use phase is recyclable and can be repurposed into new roofing material or other vinyl-based products.
Post-consumer recycling of PVC roofing began in 1999 in the U.S., and the industry continues to make strides in increasing this recycled content in its products. Currently, roughly 453,592 kg (1 million lb) are recycled each year at the end of a PVC roof’s life. Estimates indicate approximately 8 million kg (19 million lb) of PVC roofing membranes are currently available for recycling, based on the historical volumes of installed roofs and the average lifecycle of the material. The CFFA’s goal is to increase the number of PVC roof membrane recovery projects each year, resulting in an increased amount of material being diverted from the landfill.
Beyond embodied carbon
Embodied carbon is merely one attribute to consider in the product evaluation process. For roofing, informed decisions on product specifications should be made in the context of the application. Using a multi-attribute approach and looking at aspects such as performance, durability, and reference service life (RSL) provides a more comprehensive measurement of the sustainability and impact of a product.
