The answer
Manufacturer Material Warranty: Covers product defects (shingle cupping, premature splitting, blistering); usually 25-50 yrs (10-yr non-prorated); excludes labor. Contractor Workmanship Warranty: Issued by licensed contractor (regulated by state licensing boards like CSLB); covers installation errors, improper nailing, and flashing leaks (typically 2-10 yrs). Extended system warranties bundle non-prorated material and labor coverage for 25-30+ yrs when installed by certified contractors.
Sources
This answer is drawn from the standards and guidance below. It is general information about how these systems work — not a diagnosis of your property.