Built-Up Roofing Warranty Type & Term Chart Type: Standard Years Classic Warranty* BUR Warranty (Unlimited Type)* Spec: 20 15 10 5 20 15 10 5 20 15 10 5 920-4 * * * * * * * * * * * * 910-4 * * * * * * * * * * * * 920-3 * * * * * * * * * 910-3 * * * * * * 420-4 * * * * * * * * * * * * 410-4 * * * * * * * * * * * * 420-3 * * * * * * * * * 410-3 * * * * * * 220-4** * * * * * * * * * * * * 210-4** * * * * * * * * * * * * 220-3** * * * * * * * * * 210-3** * * * * * * *When insulation is specified for use in a Koppers roofing system, Koppers Classic and Built-Up Roofing warranties require two layers of Koppers supplied insulation. **Also applies to GP Series specifications.  Return to Roof Warranty Program