It's safe to get on the roof and work with the chimney. Here, homeowners have mounted roof rails and a bridge to ensure safe operation and work with the chimney.
Roof rails are available in different lengths: 1500, 2400, 3000, 3800. Do not forget to complete a sliding cover for attachment to the ladder end.
Pedestrian bridges are also available in different sizes: 1200, 2400, 3000.
If the chimney is higher than 1.2 meters from the ceiling there should be a fixed ladder on the chimney with a platform to stand on.
Read More about roof safety in the article: Roof safety, how safe is your roof really?