(Photo by Wang Kaihao/China Daily)

After the plastering is done, the gathered people use elm sap to polish the material and coat it with rape oil to make the surface smooth and water-proof.

This process dates back to the Tang Dynasty (AD 618-907).

"As this method is very time-consuming, ordinary Tibetans no longer use it for their homes," says Champa Tsering, director of the Shannan cultural heritage bureau.

"But we follow the tradition for the monastery."

The renovation of the main temple of the monastery began in April, though a three-year rehabilitation of its auxiliary structures was completed in 2015.

In the 1980s, the monastery was renovated using cement.