All major brands of shingles, laminates and roofing materials require proper ventilation!     Warranties are like playing 'Roulette', it all depends on what kind of roofing material, model, brand, warranties offered, who installed it, was the installers certified at the time, is the installer still certified, is the installer still in business, how it was installed and when it was installed BUT its a fact that most roofing brands rarely calculate