Proof & specs · Primary documents

Don't take our word for it. Read the documents.

Every claim on this site traces back to a warranty, a code evaluation, or an independent test report. All of them are hosted here, in full, unedited.

All documents courtesy of Interlock Roofing Ltd. — published at interlockroofing.com and mirrored here for fast access.

Warranty

The Guardian Warranty — Guardian Lifetime Limited Material Warranty

Lifetime coverage for the original homeowner — never prorated, so it doesn't shrink as the roof ages. Transferable once: the next owner is covered to 50 years from substantial completion (transfer registered within 60 days; $300 fee). The Alunar® coating is warranted for 30 years. Warranted wind resistance of 120 mph (193 km/h) and hail coverage for stones up to 1.5 inches.

  • Lifetime coverage for the original owner
  • One-time transfer — 50 yrs for the buyer
  • 120 mph warranted wind
  • 1.5″ hail coverage
Read the full warranty (PDF)

US building code

ICC-ES Evaluation Report ESR-1790

The International Code Council Evaluation Service report covering Interlock aluminum roof panels and shingles for compliance with the International Building Code and International Residential Code — the document your building inspector actually checks. Reissued September 2025; current through September 2026. Panel weights run just 0.41–0.59 psf, a fraction of asphalt (~2.5 psf) or slate (~10 psf).

  • IBC & IRC compliance
  • Reissued Sept 2025
  • 0.41–0.59 psf panel weight
Read ESR-1790 (PDF)

Impact / hail

UL 2218 Class 4 — Intertek listed

Class 4 is the highest impact-resistance rating there is: a 2-inch steel ball dropped from 20 feet, twice in the same spot, with no cracking of the panel. Interlock systems carry the rating under Intertek listing SPEC ID 33876 — the same rating many insurers reward with premium discounts.

  • Class 4 — highest rating
  • Intertek SPEC ID 33876
  • Ask your insurer about discounts
View the Intertek listing (PDF)

Canadian code

CCMC 10475-R — National Research Council of Canada

Interlock's Canadian Construction Materials Centre evaluation has been continuously active since October 24, 1983 — more than four decades of uninterrupted code listing in the harshest roofing climate in North America. Snow country is where this system was proven.

  • Active since 1983
  • 40+ years continuously listed
Read CCMC 10475-R (PDF)

High-wind approval

Florida Product Approval FL7263-R7

Florida's product approval system exists for one reason: hurricanes. Interlock systems hold approval FL7263 (revision 7, August 2023) — evidence the interlocked, concealed-fastener design performs in wind zones far beyond anything a Columbia Gorge gale or an Oregon Coast storm delivers.

  • Hurricane-state approved
  • Rev. 7 · Aug 2023
View FL7263-R7 (PDF)

Cool roof

Published solar reflectance values

Interlock's Alunar® finishes have laboratory-measured initial solar reflectance values as high as 0.67 — reflecting most of the sun's energy instead of soaking it into your attic. That's the mechanism behind summer cooling savings of up to 25%. (Historical note: these finishes were listed under the EPA's ENERGY STAR roof products program before that category was retired.)

  • Reflectance up to 0.67
  • Cooling savings up to 25%
See the reflectance data (PDF)

For architects, builders & inspectors

Full specification manuals

Complete architectural spec manuals for every Interlock profile — dimensions, fastening, flashing details, and installation standards.

Slate & Cedar Shingle

Full architectural specification manual

Open PDF →

Shake

Full architectural specification manual

Open PDF →

Mediterranean Tile

Full architectural specification manual

Open PDF →

Standing Seam

Full architectural specification manual

Open PDF →

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