Work has begun to protect thousands of precious books at Canterbury Cathedral.
The 16,000 works kept in the library have been under threat from fluctuating humidity and other adverse conditions because of the state of its roof.
The cathedral has received £460,000 to replace the roof and add double glazing to its windows.
Half of the money came from the Wolfson Foundation and English Heritage, with the remainder being donated by the Friends of Canterbury Cathedral.
During the building work rare books will be moved from the cathedral's Howley-Harrison library to safe storage by specialist conservators.
The library contains about 16,000 books and pamphlets that belonged to Archbishop William Howley and Archdeacon Benjamin Harrison and were bequeathed on the latter's death in 1887.
William Roe, the cathedral's head of works, said: "The plan is to address the environmental control issues in the library and turn them around.
"But before we can do any of the work we have to get the books out."
He added: "This is by far the most challenging task. It has gone incredibly well so far. I am delighted with everyone's efforts."
Christopher Irvine, the Cathedral's canon librarian, said: "The Library is a vital resource for learning and research, and when the building project is complete, we look forward to exhibiting again our fine books."
The cathedral is currently aiming to raise £50m as part of the Save Canterbury Cathedral Appeal.