Metal Roofing for Chicago-Area Homes

Three kinds of metal roofing: standing seam, exposed fastener, stone-coated

Standing seam

Long panels run from eave to ridge, joined by raised seams that lock together above the water line. Clips hidden under the seams hold each panel down while letting it slide as it expands and contracts. No screws pierce the field of the roof. This is the system most people picture, and the usual recommendation for houses when the budget allows.

Exposed-fastener panels

Ribbed panels screwed straight through the face into the deck or purlins, with a rubber washer sealing each screw. They cost less and go on fast, which is why they are common on barns and sheds. On a house, hundreds of washers become hundreds of future leak points as they age.

Stone-coated steel

Steel pressed into shingle, shake or tile shapes and coated with bonded stone granules. It looks less like metal, is quieter in rain, and hides small dents well. The gritty surface also holds snow longer than smooth panels, which changes the snow guard plan.

Galvalume, Kynar and what the finish is worth

Most residential steel panels start with a metallic coating that protects the steel underneath. Galvalume is an aluminum-zinc alloy coating, roughly 55 percent aluminum, that resists rust longer than plain galvanizing in most conditions. Bare Galvalume is a dull silver; for color, a paint system goes on top.

The paint is where quotes diverge. PVDF finishes, sold under resin names such as Kynar 500 and Hylar 5000, hold color and resist chalking for decades. SMP (silicone-modified polyester) finishes cost less and are fine on outbuildings, but they fade and chalk sooner. On a house you plan to keep, ask which resin is in the paint and what fade and chalk limits the paint warranty states. Thickness matters too: 24-gauge steel is stiffer and dents less than 26- or 29-gauge.

Sliding snow, eave ice and where snow guards belong

A slick metal surface is both the winter advantage and the winter hazard. Snow that would sit on shingles for weeks lets go on a sunny afternoon, often all at once. That keeps meltwater from refreezing into a thick dam at the eaves, but a slab of wet snow dropping from a second-story roof can fold gutters, crush shrubs and hit anyone standing below.

Snow guards solve the hazard. They are clamps, bars or brackets fastened to the roof that hold snow in place so it melts off gradually. They belong over entry doors, walkways, driveways, decks and lower roofs, and anywhere gutters would take the hit. On standing seam, guards that clamp onto the seams avoid drilling through the panels. A self-adhered membrane along the eaves is still worth having, because ice can still form where heat loss is uneven. Our ice dam guide explains why.

Metal roof noise, oil-canning, lightning and hail dents

Noise. A metal roof over a solid wood deck, underlayment and an insulated attic is not much louder in rain than shingles. The drumming people remember comes from panels fastened over open framing on barns and porches.

Oil-canning. Wide, flat areas of a panel can show visible waviness, especially in low-angle morning or evening light. It is cosmetic, not a leak risk. Striations or pencil ribs rolled into the panel, heavier gauge, and fastening that allows movement reduce it. Ask to see a full-length sample panel in sunlight before choosing a flat profile.

Lightning. Metal roofs do not attract lightning, and a metal roof does not make a strike on your house more likely.

Hail. Many steel panels are tested to UL 2218 Class 4, meaning they did not crack or leak in the test. They can still dent. If your policy carries a cosmetic-damage exclusion, dented panels that still keep water out may not be covered, so ask your agent before you buy.

Where metal makes sense on a suburban home

Metal is easiest to justify on a home you plan to keep for decades, on low-to-moderate pitches where shingles struggle, on porches and bump-outs that want an accent, and on houses with a long ice-dam history where shedding snow helps. It is harder to justify if you may sell within a few years, if the roof is cut up with many valleys and dormers, or if large trees overhang it. For a first cost comparison against shingles, try the roof cost calculator, then ask for both options on one roof replacement estimate. If the look you want is slate or shake rather than panels, compare synthetic slate and shake as well.

How it handles Chicago-area weather

Care and maintenance

Look the roof over from the ground each spring and fall. On standing seam, check the sealant at pipe boots, chimneys and the ridge, and look for scratches that reach bare metal. On exposed-fastener roofs, the rubber washers under each screw age in sunlight and loosen as panels expand and contract, so plan to inspect and replace fasteners periodically. Rinse off leaves and pine needles that hold moisture against the panels, keep copper flashing runoff and bare steel scraps away from aluminum-zinc coated panels, and confirm snow guards are tight before winter.

Metal Roofing: common questions

Can a metal roof go over my existing shingles?

Some codes and manufacturers allow it over a single layer of shingles with the right underlayment, but it hides deck problems and complicates ventilation. Tearing off is usually the better choice, so the deck can be inspected and the eave membrane installed correctly.

Does a metal roof make the house colder in winter?

No. The roof covering has little effect on indoor temperature; attic insulation and air sealing do. Over a well-insulated attic, a metal roof performs like any other roof in January.

Is a metal roof louder during a hailstorm?

Over a solid deck and an insulated attic, hail on metal sounds sharper than on shingles but is not dramatically louder indoors. Stone-coated panels are quieter still because the granules dampen each impact.

What gauge should a residential metal roof be?

Twenty-four gauge is the common choice for quality standing seam, with 26-gauge used to save money. Lower numbers mean thicker steel, which resists dents and oil-canning better.