VATICAN CITY, Holy See (AFP) — Besides its masterpieces by Michelangelo, the Sistine Chapel is undergoing a makeover, involving the installation of a stove for burning secret votes and a chimney which will billow smoke to announce to the world that the Catholic Church has a new pope.

Work is in full swing inside the Apostolic Palace to equip the 13th-century chapel for the vote to elect Pope Francis’s successor, according to a video released Saturday by the Vatican press office.

The nearly five-minute video shows builders laying beams on scaffolding to build a raised wooden floor, before setting up large tables for the use of the 133 cardinal electors casting their votes in the conclave.

Other builders are seen installing the heavy stove, where the ballots are burnt, in a corner of the chapel.

The video, dated Friday, also shows firefighters climbing onto the chapel’s tiled roof to secure the chimney flue.

Smoke from the flue — eagerly watched for in St Peter’s Square below — will be black if no candidate has secured a two-thirds majority, or white if the Church has a new pontiff.

Silvio Screpanti, Vatican City’s deputy director of infrastructure, said five electricians and five technicians would remain onsite for the duration of the conclave.

A technician “will remain throughout the voting” in a small room near the Sistine Chapel, “with a remote control for the stove,” which is now electronically activated, he said in an interview for the Vatican City State website.

Ahead of the vote, technicians are “blacking out all the windows” in the areas used during the conclave and deactivating “all the technological devices and sensors installed in recent years in the Sistine Chapel”.

The day before the conclave, they will install “approximately 80 lead seals at all entrances to the perimeter”.

They are also cleaning and repainting “around 200 rooms” for cardinals and their staff at the Santa Marta guest house and a building next door, including blocking views from some windows, he said.

Furniture is kept to a “necessary minimum”, including a “bed, bedside table, and wardrobe,” Screpanti said.

Some of the technicians have already taken part in conclaves, while for others it is their first time.

All those staying to help however must take an oath of secrecy and sleep in the Vatican, “without being able to contact with their families.”