Soaring, inspiring and prominently featuring cardboard as a building material, is the world’s first ‘Cardboard Cathedral’ by Shigeru Ban a material revolution or simply a cardboard cut out? Here are some of the benefits – and challenges – of building with cardboard.
Shigeru Ban is renowned for using humble materials, cardboard in particular, to create buildings that are stylish yet practical and cost-efficient examples of affordable, accessible architecture. For Ban, cardboard is central to this noble goal as it is a low-cost material that is easily available, recyclable and also happens to be very strong – strong enough in fact to meet the stringent earthquake codes of countries such as Japan. Following Christchurch’s devastating earthquake in February 2011 it is perhaps no surprise then that the Anglican church turned to Ban to rebuild the city’s main cathedral.
Ban envisioned a soaring cathedral built with cardboard tubes. And in fact, the completed roof features 98 cardboard tubes, each 20 m in length, 600 mm in diameter and 120 kg a piece. There is a 5 cm gap between the tubes so light dramatically falls in between. Coated with weatherproofing and fireproofing paint, the tubes certainly form a robust and unique interior environment. However, the cardboard tubes faced a number of challenges and setbacks. Firstly, uncharacteristically high amounts of rainfall in spring 2013 left a number of the cardboard tubes soggy. The soaked cardboard then had to be cut out and replaced. The tubes are now covered with a polycarbonate lid. A greater challenge was finding a local source of cardboard tubes. Local paper companies were unable to make tubes thick enough to support the building and the high wind loads it is subject to. In order to avoid importing materials, steel beams were as a result inserted into the locally manufactured cardboard tubes to lend structural support. Laminated timber beams were additionally included in the main frame of the building to provide strength.
Other materials used include a concrete foundation on top of which sit 8 shipping containers. These containers run down either side of the nave and serve not only as the cathedral’s walls but also as functional office spaces, toilets and even a small chapel. These shipping containers are likewise given additional structural strength due to steel bracing hidden within them.
A number of interesting material details include a crucifix above the alter which is made out of cardboard, along with the choir stalls and moveable pulpit. Stained glass used for the windows was etched with images of the cathedral’s destroyed predecessor.
Although cardboard is in some senses relegated to cladding in this project and therefore does not perhaps showcase its full potential, we appreciate its beauty and modesty as a building material. With a budget reaching nearly $7 Million (NZD) and a footprint of approximately 775 m2, the results are definitely spectacular.
You can read more about Shigeru Ban’s cardboard constructions here.
All photos are © Bridgit Anderson.