2.3 The warranty that actually defines your 20-year experience: Workmanship

Don't sign a contract with no workmanship warranty (or only a 1-year one), no matter how big the discount is.

What a sensible workmanship clause looks like:

• At least 10 years on roof penetrations (no-leak guarantee on every standoff and flashing they install).
• At least 10 years on electrical workmanship (terminations, conduit, wire-size selection).
• Re-flash, re-shingle, and electrical testing during repairs are the installer's responsibility.
• The "labor not covered" gap in the manufacturer's product warranty is absorbed by the installer.

If the contract says "1-Year Workmanship" and nothing more — that's the single biggest red flag in the industry. A properly executed install almost never fails in the first 5 years. Writing 1 year means the installer never intended to stand behind their work, and may even have left a defect for you to discover (and pay them to fix) two or three years later.