Does the family have the right to demand that the father, who works as a builder for his brothers without pay, receive payment for his work to meet the family's needs?

You are permitted to demand financial support from your father if you do not possess wealth and are unable to earn a living, whether this support comes from his work or other permissible means. He must fear Allah concerning those whose financial support is obligatory upon him and provide them with their sufficient needs; otherwise, he is sinful.