text: Asbestos has been discovered in the roof at New York City's mayoral residence and work to remove the potentially cancer-causing materials from Gracie Mansion will begin this month. The hazardous material was discovered last month as crews prepared to replace the mayoral mansion's leaky roof. Officials do not believe the work poses any health risk to Mayor Bill de Blasio and his family, who will remain in the home during the renovation. Asbestos has been discovered in the roof at New York City's mayoral residence and work to remove the potentially cancer-causing materials from Gracie Mansion will begin this month . Mayor Bill de Blasio and First Lady Chirlane McCray hosting a black history month youth event at Gracie Mansion in February: The family expect to remain in the property during the building work . 'Gracie Mansion is one of Manhattan's oldest structures built more than 200 years ago and as with any older homes, maintenance is necessary,' mayoral spokesman Peter Kadushin said on Wednesday. 'Beginning this month Gracie Mansion will undergo asbestos abatement and some long-needed roof repairs.' The cost of removing the asbestos will be about $250,000 and the contract was awarded this week to Regional Management Inc., officials said. The replacement of the mansion 30-year-old roof, which is being done by Nicholson and Galloway, should cost an additional $3.4 million, officials said. The roof was frequently overmatched during rain storms, forcing city work crews to be dispatched to patch problem areas multiple times this winter, officials said. The two projects will be undertaken concurrently and should be completed by October or November, officials said. de Blasio poses with his son Dante (left), daughter Chiara (right), and wife Chirlane outside of their Park Slope home which the family had considered remaining in before moving to Gracie Mansion last July . A storage shed also is being built on the mansion's property. And officials said that about 10 of the building's windows were undergoing upgrades to become energy-efficient at the cost of another $13,000. De Blasio's predecessor, Michael Bloomberg, earmarked $3 million to the Parks Department capital budget in 2012 to replace the tired roof. Bloomberg never lived in the mansion during his 12 years in office — he instead opted to remain at his tony Upper East Side townhome — but oversaw extensive renovations to the home, which he used for meetings and ceremonial events. After considering remaining in his Brooklyn home, de Blasio, his wife and their two children moved into Gracie Mansion last July. The home, which is managed by the nonprofit Gracie Mansion Conservancy, was built in 1799, at which time it sat in the countryside more than five miles north of what was then a very small New York City. The mansion was seized by the city in 1896 after its owner failed to pay taxes. It became the official mayoral residence in 1942. The home, which is managed by the nonprofit Gracie Mansion Conservancy, was built in 1799, at which time it sat in the countryside more than five miles north of what was then a very small New York City .
target: Hazardous material was discovered last month as crews prepared to replace the mayoral mansion's leaky roof .
  Officials do not believe the work poses any health risk to Mayor de Blasio and his family, who will remain in the home during the renovation .
  Work will take place at same time as replacement of the mansion 30-year-old roof .
  Both jobs should be completed by October or November .