Once a year, the whole town turns out. Men and boys carry baskets of wet mud up ladders and onto the walls, women bring water from the river, and drummers keep up the rhythm. By the end of the day, the Great Mosque of Djenné has a fresh coat of plaster. The building, the largest mud-brick structure in the world, survives because its community renews it every year.
Djenné and the mud building
Djenné, in central Mali, is one of the oldest towns in sub-Saharan Africa. It was a centre of trade and Islamic learning, linked to Timbuktu. Tradition says the first mosque on the site was built in the thirteenth century. Later rulers neglected or destroyed earlier structures. The present mosque was built in 1907, during French colonial rule, in the Sudano-Sahelian style.
The mosque is made of sun-dried mud bricks called ferey, coated with mud plaster. Palm wood beams stick out from the walls. They support the structure and serve as scaffolding for the annual replastering.
The crépissage, threats and the masons
The annual festival, known in French as the Crépissage, is held before the rainy season. Masons guide the work, and the whole community takes part. The Old Towns of Djenné were listed as a UNESCO World Heritage Site in 1988. Insecurity in central Mali and changes in building materials threaten the town’s heritage. Djenné’s Monday market, held in front of the mosque, is famous for its crowds and colour.
Non-Muslims have not been allowed inside the mosque for many years. The mosque’s style has influenced architecture across West Africa. Djenné’s masons have their own guild, passing building knowledge through generations.
Why mud lasts
Mud plaster cracks and erodes in the heavy rains of the wet season, so the annual replastering is essential. The thick walls also keep the interior cool in the fierce Sahelian heat, one reason earthen architecture suits the region so well. Older masons teach younger ones how to mix the mud and apply it, keeping the craft alive.
The Great Mosque is built of earth, which means it must be rebuilt a little every year. That annual work is part of the reason it has stood for more than a century.
