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 evaluates roofing products for wind performance under the Florida Building Code. Interlock systems hold approval FL7263-R7 (revision 7, August 2023), evaluated to the 8th Edition (2023) FBC by Robert Nieminen, P.E., with maximum design pressures from −30.0 to −187.5 psf depending on assembly — tested to UL 1897, UL 580 and TAS 125. The approval is non-HVHZ: it excludes Broward and Miami-Dade counties, and does not cover fire classification. It is evidence the interlocked, concealed-fastener design performs in wind zones far beyond anything a New England nor'easter delivers.

MDP to −187.5 psf
Rev. 7 · Aug 2023
Non-HVHZ

View FL7263-R7 (PDF)

Corrosion & finish

Alunar® coating — measured to ASTM methods

The finish is where a roof either lasts or doesn't. Alunar® is a PVDF fluorocarbon coating applied to a minimum 1.0 mil on the weather surface. It passed 1,000 hours of ASTM B117 salt-spray exposure at a rating of 7 or better and 2,000 hours of ASTM G155 accelerated weathering with no color change, flaking or cracking — the tests behind every claim we make about salt air and fading. The coating carries a 30-year warranty against chalking beyond a rating of 8 (ASTM D-4214) and fading beyond 5 Hunter ΔE (ASTM D-2244).

1,000-hr salt spray — ASTM B117
2,000-hr weathering — ASTM G155
30-yr coating warranty, measured thresholds

See the test results (PDF)

For architects, builders & inspectors

Full specification manuals

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

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

The Guardian Warranty — Guardian Lifetime Limited Material Warranty

ICC-ES Evaluation Report ESR-1790

UL 2218 Class 4 — Intertek listed

CCMC 10475-R — National Research Council of Canada

Florida Product Approval FL7263-R7

Alunar® coating — measured to ASTM methods

Full specification manuals

Slate & Cedar Shingle

Shake

Mediterranean Tile

Standing Seam

Want these terms explained on your actual roof?