I am in the process of purchasing a 1 1/2 story house from 1904. It has a six year old roof, and the second story of the house gets very warm inside. There is one box vent on the roof and one gable vent. Prior roofing inspectors have noted blistering and one inspector stated that removing the entire roof and installing a cold roof system is the only fix, and that installing additional roof vents would be useless. Is this true? Are there any other options? The home is located in a wide-ranging climate with extreme temperatures (central Indiana).