The Guardian Warranty: What Interlock's Lifetime Roof Warranty Covers
Quick answer
Interlock's Guardian Warranty is a lifetime, non-prorated limited material warranty. It covers manufacturing defects that cause rusting, rotting, splitting, cracking (including hail up to 1.5 inches), curling, loss of impact resistance, or burning, warrants 120 mph wind resistance, and warrants the Alunar aluminum coating for 30 years. It transfers once to a second owner.
What does the Guardian Warranty cover?
The Guardian Warranty is a material warranty on Interlock's aluminum and copper roofing panels, cladding, and trims. It warrants the product against manufacturing defects that result in rusting, rotting, splitting, cracking (including splitting, cracking, and perforation from hailstones measuring 1.5 inches in diameter or less), curling, loss of impact resistance with age, and burning or supporting combustion — where the defect materially affects performance. Separately, the manufacturer warrants the product to resist wind speeds up to 120 mph (193 kph) when installed to Interlock's procedures, and warrants the aluminum Alunar coating for 30 years against chalking beyond an ASTM D4214 rating of 8 and color change beyond 5 Hunter delta-E units (ASTM D2244).
Who is covered, and for how long?
For an individual, the warranty is a lifetime warranty: it remains in effect for the life of the original purchaser as long as they remain the registered owner of the property. It is non-prorated, meaning coverage is not reduced as the roof ages. If the property is owned by an organization — a company, condominium, trust, or public entity — the product is warranted for 50 years from substantial completion, with the coating warranted 30 years; an organization's warranty cannot be transferred. Your installation contractor provides a separate workmanship warranty covering the installation itself.
How does the warranty transfer work?
The Guardian Warranty is transferable one time, from the original owner to the first subsequent registered owner of the home. Once transferred, the second owner's material warranty runs 50 years from substantial completion, with the coating warranted 30 years. To transfer, the second owner sends proof of purchase to Interlock within 60 days along with a $300 transfer fee, and receives a confirmation email as proof. Under the transferred warranty the manufacturer covers material costs to repair, refinish, or replace nonconforming product; labor costs become the second owner's responsibility.
What is not covered?
Like any roofing warranty, the Guardian Warranty has exclusions, and it is worth knowing them. It does not cover damage from severe-weather "Acts of God" (earthquake, fire, flood, lightning), hail larger than 1.5 inches, impact from foreign objects, improper installation or use, contact with dissimilar metals or fasteners, inadequate ventilation, condensation, ice damming, or ice and snow shedding. It also excludes normal wear such as minor scratches and dents, dirt and mildew accumulation, and cosmetic characteristics like oil canning that do not affect function. Copper roofing naturally develops a patina and is not guaranteed against surface corrosion. Simple care — annual gutter cleaning, prompt debris removal, and good attic ventilation — keeps the roof performing and the coverage intact.
Frequently Asked Questions
Is the Interlock warranty really a lifetime warranty?
Yes. For an individual homeowner it lasts the life of the original owner while they own the home, and it is non-prorated, so coverage is not reduced as the roof ages. It can also be transferred once to a second owner for 50 years.
Does the Guardian Warranty cover hail damage?
It covers splitting, cracking, and perforation from hailstones 1.5 inches in diameter or less. Larger hail is excluded, but the roof itself is independently tested to UL 2218 Class 4 — the highest impact-resistance class — which is why many insurers offer a discount for it.
Can I transfer the warranty when I sell my house?
Yes, one time. The first subsequent owner sends proof of purchase and a $300 transfer fee to Interlock within 60 days of buying the home. The transferred warranty runs 50 years for materials (labor is the new owner's responsibility).
What voids or is excluded from the warranty?
Exclusions include Acts of God, hail over 1.5 inches, improper installation or alteration, contact with dissimilar metals, poor ventilation and condensation, and cosmetic items like minor dents, scratches, and oil canning. Unpaid installation balances and denial of inspection access can also void coverage.
Sources
- Interlock Roofing Ltd. — Guardian Lifetime Limited Non-Prorated Material Warranty — Warranty certificate terms
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Last reviewed 2026-07-11 · Reviewed by Scott Plumptree, Director of Marketing