Oh, that sounds absolutely frightening. It is so emotionally exhausting trying to save them from themselves every day. The only way to attempt to stop them is to stand firm. When I have to run out for a quick errand or a short walk I either bring him with or pray that he stays put with a safe activity. I encourage him to call friends to chat ( he loves talking on the phone). I try to distract him with other activities. With home maintenance, either I do it, or with your case re: the roof, call a buddy to be on scene to talk sense into him, or tell him that I will hire a professional to do the project. I completely understand your concerns. It feels like you are training a toddler not to touch the stove 24/7.