Prototyping thatched facades: Global scaling of local knowledge

This paper discusses research executed as cross-disciplinary prototyping of reed facades with clay as fire retardant. The use of reed in construction and as an alternative to regular facade and roof claddings holds multiple advantages as reed is a fast regenerative plant, and contributes to absorbing CO2 and NOX. It takes point of departure in three different typologies: thatching on construction sites, thatched prefabricated façade elements, and thatched masonry. It discusses the challenges and benefits of the materials (reed/clay), their production, and building technologies. An SBI-test on a façade mock-up of reed sprayed with clay and with clay boards as fire stop every 100 cm showed a FIGRA at 25 W/s. This raised the question on, how these findings could form radical tectonic solution as a respond to CO2 neutral constructions in the sustainable transition. The prototyping of prefabricated clay impregnated façade elements with reed seems to have multiple possibilities regarding time optimization, transportation and (dis)assembly, whereas thatching and impregnating on construction site is possible, but slower than standard, and processes must be developed and tested further.
Generally, an unanswered question is, how the reed will respond to humidity, when thatched to a solid underlay without ventilation. Furthermore, knowledge on ceramifying process of the clay when burned, and downfall as a result, are unanswered.

This paper discusses experiences done on cross-disciplinary prototyping of reed facades and clay as fire retardant. It takes point of departure in three different typologies: thatching on construction sites, thatched prefabricated façade elements and thatched masonry and discusses existing knowledge on challenges and benefits of the materials, production, and building technology.