Crèche Roodt Blocks, Mortar & Plasters

"Crèche Roodt" is a nursery for children aged 0-3 years. It is a pilot project in sustainable and circular construction, putting people at the core of its processes. Bioregional supply chains are integrated in this project, such as excavated earth from nearby construction sites, wood from local forests or reclaimed and reused wood, selected vegetation. The wellbeing and health of the children are at the forefront of architectural and material design.

ZRS Berlin did preliminary research on local excavated earths from construction sites "Pompier" and "Cactus" in the village of Roodt-sur-Syre. Based on these analyses, it became clear that this earth contained enough high quality clays, silts and sands to be used as building earth in reformulated recipes for blocks, mortar and plasters. Like this local supply chains could be setup in order to produce low-carbon, zero-VOC, breathing walls for the best interior climate for the future children.

BC materials was asked to develop following material typologies in order to be integrated in a wood post-and-beam structure :

• Infill earth block masonry (visible or plastered)
• Fire-resistant infill earth block masonry (visible or plastered)
• Earth plaster as base layer
• Clay Finish

The "Pompier" and "Cactus" earth was mixed 1:1 and prepared for moulded earth block production through milling, and for earth masonry mortar and earth plaster mortar through milling, drying and crushing. These prepared earths were subsequently mixed with local sands from the river Moselle or from excavation sites. Blocks were then prototyped and moulded in the brick factory of Vande Moortel, and plaster was prototyped and projected onto the walls by machine.

The resulting moulded earth blocks, earth masonry mortar and earth plaster mortar were validated following the German norms DIN18945, DIN18946, and DIN18947 respectively, ensuring compliance and insurability for this public project. Contractor Kuhn Construction executed the works to perfection.

The resulting walls are beautiful, healthy, hyperlocal and circular masonry walls, borrowed from the soft crust of the earth to the benefit of our most precious fellow human beings, until the end of the life cycle of the building at which point the earth building materials can be given back as earth to our planet.