No, it isn’t illegal to work either on domestic roofs or chimneys without scaffolding, health regulation, & safety measures. But still, getting the best scaffolding is the most appreciable thing you can use while fixing your roof as well as the chimney. For larger jobs such as sloping roofs, HSE makes sure to recommend the use of scaffolding to stop material from falling for the worker. However, when there is only one person to work or the work is small, HSE prefers to use a safely secured ladder.