Some contractor charge by the hour, others charge by the job. To get the best rate you need to look around for a while to ensure you find one with the best price and also one that can provide good references.
A general Contractor does not typically charge by the hour. They usually charge by the job or by percentage. A G.C.'s job is to hire and coordinate not to "work" so hours would be a pore measure of...
A contractor that deals with the tiles on your roof. If your roof was slightly decaying, there was a leak in it, or you just wanted it re-done, you would want to contact a roofing contractor.
The best way to find a quality roofing contractor is to talk to the people in your neighborhood who have recently gotten new roofs. Since roofs do not last an incredibly long time, you should be able...