The National Library of Luxembourg has been bursting at the seems for a long time and books had been temporarily stocked in the basement but humidity rose unexpectedly and damaged over 30,000 books.

The 30,000 books that represent a kilometre long shelf have been brought to a specialised workshop in Germany to be restored for a total cost of 200,000 euros.

The basement stock was supposed to be temporary but the sandstone proved to be much more porous than originally assumed so air conditioning was put in place to avoid moisture and fungus. The humidity level and temperature in the basement rose unexpectedly in 2009 and caused the development of fungus that damaged 30,000 books.

Source & Full Story