Re-roofing is a process of replacing your old roof with a new one. It is not a process of repairing the existing room which is damaged or broken. Re-roofing is just like a re-investment on your home. You should not invest on new roof until your existing roof can’t be repaired any more or it is dangerous to stay more under the existing roof because of extreme damage.
Re-roof is a big investment and for this you need to be very precise on your requirements. When you hire a roofing contractor for services you should have a contract with contractor to ensure quality in work. Here is an infographic illustrating some tips to save money on re-roofing.