Let's plan your last roof.

Interlock Industries (Midwest) Inc., trading as Interlock Metal Roofing – Chicagoland — the certified and exclusive installer of the Interlock® Lifetime Roofing System in Chicagoland since 2001. Office: 205 Michigan Ave, Suite 810, Chicago, IL 60601. Illinois Roofing Contractor license 104.013389 (IDFPR). The system itself is manufactured in North America by Interlock Roofing Ltd.

The city, the North Shore, the western and southwestern suburbs, and the collar counties — Lake, McHenry, Kane, DuPage and Will — from our Chicago office. 1,081 documented Illinois installs as of 2026, from Waukegan to Joliet and from Skokie to Elgin. Northwest Indiana only occasionally. If you are further out, call: we will tell you honestly whether the schedule works rather than book a visit we cannot keep.

About 30 to 90 minutes at your house. We measure the roof, look at the attic insulation and ventilation, ask about ice dams and any past hail claims, check the geometry — a bungalow hip, a two-flat's rear slope, a Victorian's dormers are all different jobs — confirm whether it is a city or a village permit, and hold the profile and color samples against the house in daylight. You get a fixed price in writing. It does not expire on Friday and there is no pressure to decide on the spot.

Where conditions allow, yes. Deep cold and snow sitting on the deck can pause a job, and we will not tear off a roof we cannot close the same day. You get a realistic window at the estimate, and after a hailstorm, when every roofer in the collar counties is booked, we will tell you where you actually sit in the schedule.

No, and we will not tell you otherwise. Ice dams form when heat escaping through the roof deck melts snow that then refreezes at the cold eave — an insulation and ventilation problem that shows up as a roofing symptom, and a 1920s bungalow with a finished attic and a low hip roof is built to produce it. A smooth interlocked aluminum roof helps: it sheds sooner, and it does not rot when water backs up behind an ice ridge. But no roof covering eliminates ice damming, and it is a stated exclusion in the Guardian warranty. If your house dams now, the fix starts in the attic, and we will look at it with you at the estimate.

Interlock aluminum is UL 2218 Class 4 impact rated, verified via Intertek, — the highest rating a roof covering can hold: a 2-inch steel ball dropped twice on the same spot with no crack in the panel. Very large hail can leave a cosmetic mark on any metal roof; the panel keeps its integrity and keeps shedding water. That is the difference from asphalt, where the same spring storm across the western suburbs means granule loss, a claim and a replacement. Ask your carrier what a Class 4 roof does to your premium and to the cosmetic-damage terms of your policy.

Yes — the bungalow belt is where a lot of our Chicago installs are. A bungalow's low hip roof and wide eaves take every profile; the finished attic underneath is why the ice-dam and ventilation conversation matters more on a bungalow than on almost any other house. A two-flat's pitched front takes the system; its near-flat rear section usually does not, because every Interlock profile needs at least a 3/12 slope, so that part is a separate conversation about a membrane roof. We will tell you which is which at the estimate.

It lands wet and heavy, and then it freezes. That puts more sustained load on a roof than the same depth of dry snow, and it feeds ice dams at the eaves. Interlock aluminum weighs 0.4–0.7 lb per square foot depending on profile — the covering adds almost nothing to what your framing carries — and a smooth interlocked surface sheds rather than holds. Snow guards over entries, walkways and the gangway are specified at the estimate for the pitch and the plane above them.

Freezing on its own does very little to any roof; freezing and thawing is what finishes asphalt. Water works into the shingle's fiberglass mat, freezes, expands and delaminates it from the inside, through forty-odd cycles a Chicago winter — a January thaw off the lake and a February refreeze. Aluminum has no mat and absorbs nothing, so the cycle has nothing to act on. The panels expand and contract through the temperature range and the four-way interlock is designed to let them move rather than fight it.

Interlock panels lock to each other on all four sides with the fasteners concealed, so there is no exposed screw head to back out through freeze-thaw and no free tab edge for a November gale or a summer derecho to lift. Wind resistance is warranted to 120 mph installed to manufacturer specification. Asphalt fails at the tab edge, which is why wind damage shows up as missing shingles.

Heavy-gauge aluminum panels, up to 95% recycled content, formed as Slate, Cedar Shingle, Shake, Mediterranean Tile, Standing Seam or Solid Copper profiles, that interlock on all four edges with concealed fasteners into the deck. Finished in the Alunar® coating system in nine designer colors. Manufactured in North America by Interlock Roofing Ltd. since 1983. Class A Fire Rated Available as a complete assembly. Minimum 3/12 roof slope on every profile.

No. Aluminum has no iron, so it cannot rust — at a cut edge, a fastener hole or anywhere else. Steel roofing depends on its coating; every cut exposes bare metal the factory finish never reached. That is why the panels are aluminum and why the finish warranty and the material warranty are separate documents.

Yes. The system is solar compatible, and a roof that will outlast the array is the right order to do things in — on an asphalt roof the panels come off and go back on at every re-roof. Mounting is done to the manufacturer's specification so the warranty stays in force beneath the array.

The Guardian Lifetime Limited Warranty covers the original homeowner for life, is not prorated, and transfers once to the next owner, who is covered to 50 years from substantial completion (transfer registered within 60 days; $300 fee). Wind is warranted to 120 mph installed to manufacturer specification, hail to 1.5-inch stones, and the Alunar® coating for 30 years. Read the exclusions: ice damming is one of them. We hand you the full document, not a summary.

Once. The second owner is covered to 50 years from the original completion date, provided the transfer is registered within 60 days of the sale ($300 fee). A buyer's inspector discounts a roof that is nearly due; this is the opposite of that, and it is worth mentioning in the listing.

More than asphalt on the day, and we do not publish a price per square, because it would be fiction. A Chicago-area roof price depends on the roof's geometry, tear-off, what is under the old covering, how the eaves are detailed for ice, whether it is a city or a suburban permit, and whether a hail claim is in play. We measure the roof and give you a fixed number in writing that does not move afterwards. The arithmetic that matters is against your second and third asphalt roof, not the first.

Some Illinois carriers do, some do not, and the terms vary — including whether cosmetic hail damage stays covered. UL 2218 Class 4 is the rating insurers look for, and Interlock carries it under an Intertek listing we will show you. Ask your own carrier before you sign anything; we will not quote a number on their behalf.

Yes. Financing on approved credit for Illinois customers, with monthly, bi-weekly and weekly payment schedules, arranged at the time of purchase through independent third-party lenders. We do not print a rate on the website because rates and terms change; you get the current terms in writing with your estimate. Interlock does not lend money or make credit decisions.

Yes. In the City of Chicago a roof replacement goes through the Department of Buildings under the Chicago Building Code; in the suburbs it is your village or city under an IRC-based code, and the two are not interchangeable. The contractor pulls the permit — only a licensed one can — and the permit and inspection are handled by us and included in the written price. A roofer who cannot tell you which process applies to your address has not done many roofs there.

Search the IDFPR license lookup at idfpr.illinois.gov by company name or license number and read the status and expiry date, not just that a number exists. Every roofing contractor in Illinois must hold an IDFPR license under the Roofing Industry Licensing Act (225 ILCS 335), and the Act requires the number on all advertising — so if it is not on the truck, the flyer and the website, that is your answer. For any job over $1,000 the Home Repair and Remodeling Act (815 ILCS 513) also requires a written contract and the state's consumer rights pamphlet before you sign.