One can tell that gypsum wallboard is a popular product because companies keep trying to devise alternatives to it. A recent one is Breathaboard. The company making it, Adaptavate, announced in August 2023 that it had generated around Euro2.3m in its latest investment round. It is building a pilot production line in Bristol in the UK and attempting to licence its Breathaboard product, amongst other plans. Its take on wallboard is being marketed as a sustainable substitute that is made from crop waste, that sequesters CO2 and that then can be composted at the end of its life. It is also promoting the product’s breathability and moisture buffering capabilities, hence the name.
Another new contender hoping to steal some of the gypsum wallboard market is Xeriant’s Nexaboard product. This one uses plastic waste as its alternative to gypsum. Florida-based Xeriant said in July 2023 that it had started to buy equipment and raw materials, was running pilot production and was testing its first samples. It too is working on getting its product used in pilot construction projects.
Both of these examples, and others over the years, have taken a pop at wallboard’s sustainability credentials. Adaptavate is rather quieter about what happens to all of that sequestered CO2 when its product is composted and Xeriant does not mention the environmental impact of making the plastic it uses in the first place. Yet, it is a valid question to ask how sustainable is gypsum wallboard? This column has covered issues with the supply of raw gypsum from either natural, synthetic or recycled sources previously, so we will stick to the general picture here.
The late-lamented consultant Bob Bruce pulled together data from various studies for the Global Gypsum Conference in 2019 to estimate the CO2 emissions from wallboard production. He estimated that the global average of CO2 production by wallboard was around 2.4kg/m2, equating to 24Mt/yr of CO2 for the global wallboard industry. For reference, it is estimated by the Center for International Climate and Environmental Research - Oslo (CICERO) that the process emissions from clinker production alone released around 1.6Gt/yr of CO2 in 2022. When compared by mass (as opposed to area) to other building materials, wallboard has a lower carbon intensity than many products such as glass, cement (made from clinker), plastics, steel and plywood. Timber, concrete and brick are all better than wallboard though. However, as Bruce pointed out, a lot more concrete is manufactured than wallboard. Bruce came up with a handful of suggestions for how wallboard production could reduce its CO2 emissions such as the reduction of slurry water, local delivery, co-generation, increasing drying efficiency and so on.
The two big sustainability trends from the sector over the last year have been the drive to support higher recycling rates of gypsum and a move towards ‘greener’ sources of energy. This can be seen in the growing use of electrical energy from renewable sources such as the production of net zero CO2 gypsum wallboard at Saint-Gobain’s Fredrikstad plant in Norway from April 2023. The group’s Montreal plant looks set to follow in 2024 following an upgrade, potentially making it the first net zero wallboard plant in North America. Chiyoda-Ute in Japan has also started using renewably-sourced electricity at its plants in Japan, but it is uncertain what other energy sources these sites are using. China-based BNBM also claimed in its half-year results that it had built four “nearly zero emission” gypsum board production lines in the reporting period.
Wallboard's market position in North America, Europe and elsewhere seems secure. However, it is in dynamic tension as it is both a potential replacement for more carbon intensive building materials and it could also be susceptible to new emerging products that can improve on its own emissions. The manufacturers of Breathaboard and Nexaboard are clearly hoping for the latter. Yet, as is often pointed out, giving more market share to wallboard from other common building materials could reduce CO2 emissions from construction massively. The diversification of traditional heavy building materials companies such as Holcim into light building materials in recent years suggests that some businesses are seriously preparing for this possibility. No doubt, if global wallboard usage does start to rise significantly, the pressure will grow to make wallboard more sustainable and to devise even more alternative board products.
