Many chimney sweeps are not licensed, bonded or insured. Sometimes companies hire “subcontractors” who also have no insurance or licenses. It is not illegal for someone not to have a license if the work they do is under $500, however, there is a danger in having someone climb up on your roof with no insurance. The danger is that if they fall and get hurt, they can sue you.
Today, a customer told me that he had a friend who had a chimney sweep fall from his roof and die. This was 15 years ago. The homeowner was sued.
So before you let anyone climb on your roof, check if they have insurance.