Idaho · Metal shingles · Buyer's guide

Idaho metal shingles: a buyer's guide

Metal shingles come in three kinds: painted steel, stone-coated steel and aluminum. Steel depends on its coating to keep from rusting; aluminum has no steel to rust. In Idaho, also ask for the impact rating of the exact profile and whether the roof is a Class A fire-rated assembly.

Reviewed by Scott Plumptree, Director of Marketing, The Interlock Group · Updated October 8, 2026

Get a free quote (208) 842-4762

Three kinds

Painted steel, stone-coated steel, aluminum

The base metal decides how the roof ages.

Hail

Ask for UL 2218

Interlock: Class 4 in Slate, Cedar Shingle, Shake and Mediterranean Tile (Intertek, for Delta Building Products).

Idaho rule

DOPL registration over $2,000

The number must be on the contract.

The three kinds of metal shingle

"Metal shingles" covers three different products that look alike from the street and behave differently on a roof for decades. The difference is the metal underneath the paint.

Painted steel, stone-coated steel and aluminum metal shingles compared
Type	What it is	What protects it	Weight	What to watch
Painted steel shingles	Steel sheet with a metallic coating and baked paint, stamped to a shingle, tile or slate look	A zinc (galvanized) or aluminum-zinc (Galvalume) coating under the paint	Heaviest of the bare metals for the same thickness	Rust can start where the coating is cut, scratched or worn through, and at cut edges as the coating is used up
Stone-coated steel shingles	Steel shingles with stone granules bonded to the surface for a matte, textured look	The metallic coating, plus the granule layer	Heavier than painted metal	Granules can wear off in valleys and walkways; the steel underneath has the same coating dependence
Aluminum shingles	Aluminum sheet with a baked finish, interlocked panel to panel	Aluminum's own oxide film, which blocks further oxidation; there is no steel to rust	About one-third the density of steel	Aluminum can dent under large hail or foot traffic; usually costs more than steel up front

Steel coating behavior: ArcelorMittal Dofasco (Galvalume product information) and Gibraltar Building Products. Aluminum properties: ASM International. Full references at the end of the page.

What matters most on a roof in Idaho

Hail

Hail comes with Treasure Valley thunderstorms. Ask for the impact rating of the exact profile you are buying, and who tested it. Interlock's Slate, Cedar Shingle, Shake and Mediterranean Tile profiles carry UL 2218 Class 4, verified by Intertek for Delta Building Products.

Embers

Idaho's Ready, Set, Go! guide calls the roof the most vulnerable part of a home in a wildfire. Metal doesn't burn; ask whether the roof is rated as a Class A assembly, because the rating belongs to the covering, underlayment and deck together. In Boise's wildland-urban interface areas, the city's fire code asks for a Class A roof.

Freeze–thaw and snow

Metal absorbs no water, so freeze–thaw has nothing to split, and it sheds snow, so plan snow guards over entries, decks and driveways before the first slide. Ice dams come from heat escaping into the attic and from ventilation, not from the roof covering; no metal shingle stops them on its own.

Concealed fasteners

Exposed screws through the face of a panel depend on rubber washers that age in hot sun and cold nights. Shingles that interlock with the fasteners hidden under the next course have no exposed screw heads to re-seal.

Questions to ask any metal shingle contractor in Idaho

What is the base metal, steel or aluminum, and what is its thickness?
What is the impact rating of this profile, and who tested it?
Who is the warrantor of the material warranty, the manufacturer or the contractor, and does coverage reduce over time?
Is the finish warranty separate from the material warranty, and what does it cover (chalking, fading, peeling)?
Are the fasteners exposed or concealed?
What is your Idaho DOPL contractor registration number? (Idaho requires registration for jobs over $2,000, and the number must appear on the contract.) Will you show me your liability and workers' compensation insurance certificates?
Will you pull the building permit? Boise, Meridian and Nampa require one for a re-roof.
Is the price in writing, and what happens if you find rot once the old roof is open?

Interlock® metal shingles

We install one metal shingle system: the Interlock® aluminum roof, made in North America by Interlock Roofing at its plant in Delta, BC. Panels interlock on all four sides with the fasteners concealed, in Slate, Cedar Shingle, Shake and Mediterranean Tile, in nine colors.

The specification: aluminum alloy per ASTM B209, 0.019-inch base metal in the Slate and Cedar Shingle profiles and 0.0276 inch in Shake and Tile (ICC-ES ESR-1790), an Alunar® PVDF finish with a 30 Year Alunar® Coating Warranty, and the Guardian Lifetime Limited Material Warranty on material and finish. Wind resistance is warranted to 120 mph when installed to manufacturer specification.

In Idaho the installer is Interlock Metal Roofing (PNW) Inc., from our office in Boise, Idaho General Contractor Registration (DOPL) #6181938. Idaho is a new market for us: we have no Idaho installs or reviews to show yet, and we say so.

Questions, answered

What are metal shingles?

Metal shingles are roofing panels stamped from painted steel, stone-coated steel or aluminum to look like asphalt shingles, slate, cedar shake or tile. They install in overlapping or interlocking courses, like shingles, rather than as long vertical sheets.

Are metal shingles good for the Idaho climate?

For a house you plan to keep, they suit it well: they absorb no water, so freeze–thaw has nothing to split; they shed snow; metal doesn't burn, which matters for wildfire embers; and they outlast asphalt. The choice that matters most is the base metal and the impact rating of the profile.

Steel or aluminum metal shingles?

Steel usually costs less up front and depends on its coating to keep from rusting. Aluminum doesn't rust and weighs about a third as much for the same thickness. Aluminum can dent under large hail; so can thin steel. Compare the impact rating of the exact profile.

Are metal shingles hail resistant?

It depends on the product. Look for a UL 2218 impact rating on the exact profile. Interlock's Slate, Cedar Shingle, Shake and Mediterranean Tile carry UL 2218 Class 4, verified by Intertek for Delta Building Products. Large hail can still leave cosmetic dents on any metal roof.

Do metal shingles cost more than asphalt shingles?

Yes, up front. Over the years you own the home the comparison usually turns, because an asphalt roof is replaced and torn off again. You get a written price for an Interlock® roof after your roof consultation; compare it with an asphalt price over the years you'll stay.

Can metal shingles go over existing asphalt shingles?

Sometimes. A single layer of asphalt can be roofed over only if an inspection finds it suitable and your city permits it. Cedar shakes, concrete tile and natural slate always come off first.

Who installs metal shingles in Idaho?

Interlock Metal Roofing (PNW) Inc. installs Interlock® aluminum metal shingles from our office in Boise, serving Boise and the Treasure Valley first. Call (208) 842-4762 or book a free consultation at home or over Zoom.

Sources

Product specifications are the manufacturer's (Interlock Roofing). Reviewed by Scott Plumptree, October 8, 2026.

Related guides

Get metal shingles priced.

A written price after your roof consultation, at your home or on Zoom. Interlock Metal Roofing (PNW) Inc. · 3295 W Elder St, Suite 209, Boise, ID 83705

Get a free quote (208) 842-4762