Firefighters have fitted a chimney on top of the Sistine Chapel in the Vatican ahead of the conclave which will elect a new pope.
The election of a new pope will be marked by white smoke appearing from the chimney.
Roman Catholic cardinals will begin electing a new pope on 12 March.
Pope Benedict XVI stepped down last month after nearly eight years in office, becoming the first pontiff to resign in 600 years.
The 85-year-old blamed his failing health for his inability to carry on.
The vote will be preceded by Mass on Tuesday morning, with the first ballot due in the afternoon, the Vatican press office has said.
The first smoke will drift out of the chapel’s rust-coloured chimney early that evening, after the first vote is taken. It is likely to be black – meaning no Pope – as no frontrunner has emerged in the five days of general discussions so far among the 115 cardinals.
From Wednesday, two votes will be held each morning and afternoon – with ballots burned after each session at about 12:00 (11:00 GMT) and 18:00 – until one candidate attains 77 votes – a two-thirds majority. And then the smoke will be white.
Other preparations have been taking place at the Sistine Chapel this week.
Two stoves that will produce the white smoke from burnt ballot papers have been fitted in the chapel.
Tables and seating have been set under Michelangelo’s frescoed ceiling for the cardinals – and special technology under temporary flooring will jam any mobile phones or other devices which could breach the strict secrecy of the process, the BBC’s James Robbins reports from Rome.
Correspondents say no one candidate stands out as Benedict XVI’s likely successor.
The last election in 2005 took three days, and correspondents say the number of meetings this time is being seen as a reflection of the many challenges facing the Church.
Despite the vows of secrecy, Italian newspapers have been publishing what they say are leaked details of debate among cardinals on problems faced by the Church.
Reform of the Vatican’s bureaucracy – known as the Curia – and the Vatican bank have both been on the agenda, the reports say.
Last year, European regulators said the bank was not doing enough to combat money laundering, while intrigue in the Vatican was revealed by documents leaked by Pope Benedict’s butler.
US Cardinal Timothy Dolan wrote on a blog that most of the discussions covered preaching and teaching the Catholic faith, tending to Catholic schools and hospitals, protecting families and the unborn, and supporting and recruiting priests.
During Benedict’s reign, the Catholic Church was wracked by a worldwide scandal over the sexual abuse of children by priests.
There are also tensions between traditionalists and reformers over issues including priestly celibacy, gay rights and the role of women.