How to vet a commercial roofer in Michigan.
Ten questions that sort the pros from the pretenders — plus what EMR, NDL warranties, and manufacturer certifications actually mean. Ask every bidder. Including us.
Vetting bidders now?
Tell us about your building — we'll answer all ten questions in writing.
Every bid looks professional. The difference shows up in year five.
Commercial roofing is a strange purchase: six figures, twenty-year consequences, and almost no way to judge quality on the day the crew leaves. The proposals all have nice covers. The trucks are all wrapped. The difference between a roof that quietly works for 25 years and one that starts leaking at year six is decided by things that never make the brochure — who's actually on the roof, what got tested before the price, and what happens when you call with water coming in.
So here are the ten questions we'd ask before hiring any commercial roofer — including us. Ask every bidder. Write the answers down. The pretenders eliminate themselves.
The crew & the credentials.
Who actually does the work — your crews or subs?
Broker-model roofers sell the job, then shop it to whoever's cheapest that week. Quality control and accountability leave with the subcontract.
What's your EMR — and can I get a COI today?
The Experience Modification Rate is the insurance industry's safety grade; 1.0 is average, lower is better. A contractor who won't share it, or can't produce a certificate of insurance quickly, is telling you something.
Are you certified by the membrane manufacturer — and which warranty will I actually hold?
Manufacturer system warranties — especially no-dollar-limit (NDL) coverage — are only available through certified installers. Otherwise you hold a material-only warranty that excludes the thing that actually fails: workmanship.
Will you core-sample and moisture-scan before quoting — or quote from the parking lot?
Nobody can price a roof honestly without knowing what's under the membrane. Parking-lot quotes turn into change orders the day the tear-off starts.
What's in writing about response time when I have a leak?
Every roofer says “fast response.” Almost none will commit to a number. You're graded on downtime — your roofer should be too.
The process & the paper.
Will I get photo documentation of every visit?
If the work isn't documented, you're relying on the contractor's memory — and so is the next facility manager who inherits the building.
Repair, restore, or replace — walk me through why?
A shop that only ever recommends replacement isn't diagnosing your roof — it's selling its biggest ticket. Restoration and repair are legitimate options a real pro will price honestly.
Is the proposal itemized — insulation R-value, edge metal, details — or just a bottom line?
A single number hides the spec. Two bids $40,000 apart usually aren't the same roof — one has thinner insulation, lighter membrane, or details left out.
Who takes care of the roof after the install?
The first five years decide whether a 20-year roof lasts thirty. A contractor with no maintenance program is planning to see you at the next failure.
Can I talk to owners of buildings like mine, within 50 miles?
Anyone can produce three happy homeowners. Commercial references from your building type and your climate are the ones that transfer.
Terms that actually matter.
The vocabulary that separates a real commercial proposal from a glossy one.
EMR
Safety GradeExperience Modification Rate — the workers'-comp insurance grade of a contractor's safety record. 1.0 is industry average; below 1.0 is better than average. It's the fastest single check on how a company actually runs.
NDL Warranty
The Real OneNo-Dollar-Limit manufacturer warranty — covers the full repair cost of covered failures, labor included, for the term (15/20/30 years). Only certified installers can offer it. A “material-only” warranty covers the membrane, not the workmanship that usually fails first.
Manufacturer Certification
Earned, Not BoughtMembrane makers train and audit the contractors allowed to install their systems under warranty. Certification means the crew is trained on the system and inspected on it — and it's what unlocks NDL coverage.
Core Sample & Moisture Scan
Test, Don't GuessA core sample is a small plug cut through the roof to see the real assembly; a moisture scan (infrared or capacitance) maps wet insulation you can't see. Together they're the difference between a priced spec and a parking-lot guess.
NRCA
Industry StandardsThe National Roofing Contractors Association publishes the installation standards good commercial work is built to. Membership isn't a guarantee — but a contractor who can't tell you what NRCA details are is quoting from a different playbook.
Itemized Scope
Compare Bids FairlyA proposal broken into lines — tear-off, insulation R-value, membrane and mil thickness, edge metal, flashings, warranty — so two bids can be compared spec-to-spec instead of number-to-number.
Ask us the same ten questions.
We publish our pricing, put our response times in writing, photo-document every visit, and tell you what we don't install. We'll answer all ten — in writing.
Schedule a Free Roof Assessment →Vetting a commercial roofer: FAQs.
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A free assessment gets you a photo-documented condition report, our written answers to all ten questions, and an itemized proposal you can put beside any bid in the stack.