Dee Verma
it depends if there is building work involved, in which case you may require the help of both. builder or a carpenter roof specialist who constructs the roof with timber and then depending on your material choice for the roof a roofer specialist. you can choose your roof specialist by first knowing what you want in terms of material and then going on to google to source the material supplier for that type and ask if they have approved installers who are versed in installing that type of system as each system has its method of instillation. if you are lucky you may find who is good enough to do both and guide you correctly.