Development of a Bio-Based Plasterboard

The use of gypsum plasterboard is ubiquitous within the construction industry and equates to an approximate 3.5% of the UK’s green house gas emissions. Production alone accounts for 67% of gypsum plasterboard’s life cycle global warming potential. Developing alternative boards, using materials with lower life-cycle impacts, offers significant scope to reduce current environmental impacts of plasterboard use. There has been an increase in research that demonstrates the potential of plasters with bio-aggregates to enhance indoor environmental quality. Board solutions that contain bio-aggregates within the core will help to further develop this potential. Such boards can be used in a conventional manner reducing on-site barriers to adoption, while offering a value added product with improved hygrothermal performance.

This paper presents the development of an alternative plasterboard composed of hemp shiv which is bound by mineralogical aggregate composition. Different boards were developed using the binding properties of clay to ensure a low embodied environmental impact. The results of the different binding mechanisms of the clay based plasterboards were experimentally investigated and compared to conventional gypsum plasterboard. A range of mechanical and hygrothermal properties were investigated to establish the potential of a bio-based plasterboard. Standard test methods developed for gypsum plasterboard were used to establish the flexural, shear and impact resistance of the boards, while the investigation of hygrothermal properties considered the thermal conductivity, moisture buffering performance and isotherms.

The alternative plasterboard had up to five times better moisture buffering properties compared to a gypsum plasterboard and a significantly lower thermal conductivity. While significant improvement of the hygrothermal properties have been observed, there has been a reduction in the mechanical performance of the alternative boards. However, rationale is presented indicating that the alternative plasterboards developed could be adopted in a comparable manner to conventional plasterboards, resulting in an improved indoor environmental quality with a reduced environmental impact.