Eelgrass

Reconstructing a Practice

‘Reconstructing a Practice’ explores the evolution and craft of the ancient eelgrass thatched houses on the Danish Island of ‘Læsø’. A study into the historical, cultural and ecological past of the island reveals the former contextual practices of the local building processes, and forms a future perspective towards maintaining the rich cultural heritage.

The washed up eelgrass on the shores of the island, as well as various other surrounding resources, have for centuries dictated the local building tradition. Being isolated on the island forced the inhabitants to regard the eelgrass as a replenishing building resource, giving birth to a local roof thatching tradition. While historical knowledge and craftsmanship are slowly fading away, the eelgrass carries a valuable heritage and strong ecological potential for further development.

Through an in-situ period of untangling the hidden eelgrass layers together with local craftsmen, the material narratives and properties of the eelgrass roofs have become visible. By documenting and working along with the roof-thatchers, traditional techniques and knowledge are being passed along and form the base for further development.

This project aims at revitalising the local building culture amongst inhabitants, by passing on collected knowledge in an engaging setting. For this craft to sustain in the future, alternative eelgrass-based building methods need to be developed. An interactive installation on the island unfolds the original building process, and opens up to a collective moment of reinterpreting the initial thatching technique.

The field work and research of this project has resulted in a documentation booklet, compiling the whole process and reflections. A scale model illustrates the final proposal of a collective workshop setting, in which locals can participate in the restoration process of the roofs.

Diving further into eelgrass as a material, various properties with high potential for the building industry can be observed. If well-built, the lifespan of these traditional eelgrass roofs can last up to three to four centuries, before having to be restored. The material absorbs great amounts of CO2 and due to its high concentration of salt from the sea, the fibres become fire retardant. Besides this, the material has great insulation and sound absorbing properties.
As about 40 tonnes of eelgrass are required to thatch a full roof, large amounts need to be harvested each year, making the process costly and weather dependent. With all the cultural heritage and ecological benefits, the culture of this material deserves to be preserved through further investigations.

Making process

The process of this project consists of an in-depth field research, following the restoration process of two different eelgrass roofs on Læsø. By working along craftsmen, Luna Wirtz-Ortvald aimed at understanding the material, the local building technique as well as the reasoning behind these methods. Talking to locals, and diving into the local archives, helped her form a solid understanding of how historical events have influenced the landscape and consequently informed the specific building technique. Gaining different perspectives from various stakeholders, led her to come up with a proposal in which locals are welcomed into the process of restoration.

Text submitted by the maker and edited by the Future Materials Bank. For information about reproducing (a part of) this text, please contact the maker.