A section of Robarts Library has been covered in foam casing to protect the Thomas Fisher Rare Book Library’s historical volumes from potential water damage.

A layer of purple foam, which coats the building’s exterior, has been installed after the library experienced condensation, which posed a threat to the preservation of thousands of rare books housed inside.

“The Fisher building has been experiencing condensation forming on the inside of the concrete walls. The reason for this is because the original insulation and glazed windows at the top of the building are failing from age,” said John Toyonaga, the manager of the Fisher Library’s Binding Section.

Robarts Library was built in 1973, the same year when the university’s archives and rare book collection found a permanent home in the form of the Thomas Fisher Rare Book Library. The environment inside Fisher Library is strictly controlled to maintain ideal preservation conditions for the rare volumes and artifacts stored inside. Temperatures inside the library are fixed at 20˚ C and 50 per cent relative humidity all year round.

But when external temperatures drop below freezing for long periods of time, the building begins to cool from the outside inwards, creating ideal conditions for condensation and dampness.

“When cold meets the warm moist air inside condensation forms on the interior of the exterior walls,” Toyonaga explained. “Keeping that water away from the collection is a priority.”

Toyonaga also mentioned that the protective spray foam is dyed purple so that applicators can distinguish previous applications easily when applying new coats. Once the spray foam dries completely, it will turn a mustard-yellowish colour.

“In order to prevent the collections from having to be moved, the Library decided to find a solution that allowed the building to be repaired from the outside so that it could also remain open at the same time,” said Toyonaga.

“A solution was found and the restoration is taking place so that the environment inside the building is what’s best for the long term preservation of this collection,” he said.

Toyonaga clarified that the foam coating will not be a permanent fixture on the outer walls. After the entire building has been coated with foam, sets of pre-cast concrete casings will be mounted over the insulation so that it matches with the rest of the library’s exterior.

The Fisher Library is the largest repository of public accessible rare books in Canada. The collection includes a 394-year old copy of Shakespeare’s First Folio, a journal from the HMS Terror from 1836, and an original 1555 copy of Andreas Vesalius’ De humani corporis fabrica, among many others.