Your commercial roof is one of the most significant investments protecting your building, your equipment, and the people inside. When it’s time to repair, replace, or maintain it, the contractor you choose matters just as much as the materials they use. The wrong hire can mean shoddy workmanship, voided warranties, and costly problems down the road.
The good news: knowing what to look for makes the decision a lot simpler. Here are the five things every property owner and facility manager should verify before signing a contract with a commercial roofing contractor.
1. Licensing, Bonding, and Insurance
This is the non-negotiable starting point. Any legitimate commercial roofing contractor should be able to provide proof of all three, without hesitation.
Licensing confirms the contractor has met the legal requirements to perform roofing work in your state. Requirements vary by location, so verify that their license is current and covers the type of work you need done.
Bonding protects you financially if the contractor fails to complete the job or doesn’t meet the terms of your agreement. It’s a layer of security that separates professional contractors from fly-by-night operations.
Insurance, specifically general liability and workers’ compensation, is critical. If a worker is injured on your property or your building is damaged during the project, you need to know you won’t be held financially responsible. Always ask for a certificate of insurance and verify that it’s current before any work begins.
If a contractor hesitates to provide any of these documents, that’s your answer. Move on.
2. Experience With Your Specific Roof Type
Commercial roofing is not one-size-fits-all. A contractor who specializes in asphalt shingles on residential homes is not the same as one with deep expertise in flat and low-slope commercial roofing systems. And within commercial roofing, there are meaningful differences between TPO, EPDM, PVC, built-up roofing, and modified bitumen systems.
Before hiring, ask directly: how much experience do you have with my specific roof type? Ask for examples of similar projects they’ve completed, and find out whether they’re a certified applicator for the manufacturer whose materials they’ll be using.
Manufacturer certifications matter for two reasons. First, they signal that the contractor has been trained and vetted by the people who made the product. Second, many manufacturer warranties are only valid when the roofing system is installed by a certified applicator. Hiring someone without that certification could leave you with materials but no warranty coverage—a costly mistake on a large commercial project.
3. Verifiable References and a Track Record You Can See
A reputable commercial roofing contractor should have no trouble providing references from past clients, ideally businesses or property managers with projects similar to yours in size and scope. Don’t skip this step, even if you’re in a hurry. A five-minute phone call with a past client can tell you more than any sales pitch.
Beyond direct references, look at:
- BBB rating and accreditation: An A or A+ rating from the Better Business Bureau indicates a history of resolving disputes and operating with integrity.
- Google and third-party reviews: Look for patterns in the feedback, not just the star rating. Consistent comments about communication, timeliness, and quality are strong signals.
- Completed project portfolios: Does the contractor have photos or case studies of finished work? A contractor proud of their work will show it.
- Years in business: Longevity isn’t everything, but a contractor who has been in business for decades has weathered economic downturns, difficult jobs, and demanding clients. That track record means something.
Be wary of contractors who are reluctant to share references or whose online presence is thin and recently created, especially following a major storm event in your area.
4. A Written, Itemized Estimate
Never accept a verbal quote for commercial roofing work. Before any project begins, you should have a written estimate that clearly outlines the full scope of work, including:
- Materials to be used, including manufacturer and product specifications
- Labor costs broken out from material costs
- Project timeline with start and estimated completion dates
- Payment terms and schedule
- What is and isn’t included in the quoted price
- How change orders will be handled if unexpected issues arise
A detailed written estimate protects both parties and gives you a clear basis for comparison if you’re gathering multiple bids, which you should be. For any significant commercial roofing project, getting two or three written estimates is a standard and smart practice.
Red flags to watch for: an unusually low bid with vague scope, pressure to sign quickly, or a request for full payment upfront. Reputable contractors typically require a reasonable deposit to schedule the work and collect the remaining balance upon satisfactory completion.
5. Warranty Coverage — Both Labor and Materials
A quality commercial roofing contractor stands behind their work with a warranty, and there’s an important distinction to understand here: material warranties and labor warranties are not the same thing.
Material warranties are provided by the roofing manufacturer and typically cover defects in the product itself. These can range from 10 to 30 years depending on the system, but they are only as good as the installation behind them. Most manufacturer warranties require that the product be installed by a certified applicator and to the manufacturer’s specifications, cutting corners during installation can void the warranty entirely.
Labor warranties are provided by the contractor and cover workmanship, meaning if something goes wrong because of how the roof was installed, the contractor will come back and fix it at no charge. These vary widely in length and scope, so read the fine print carefully.
Before signing any contract, ask your contractor to walk you through both warranty types. What does each cover? What voids the warranty? Who do you contact if a problem arises? A contractor who can answer these questions clearly and confidently is one who stands behind their work.
A Note on Storm-Season Contractors
Following a major hail event or severe weather outbreak, temporary roofing contractors flood markets looking for quick work. While not all of them are bad actors, the pressure tactics, vague estimates, and lack of local accountability that come with storm-chaser operations are well-documented. The Better Business Bureau issues warnings about these crews every storm season.
The safest approach is to work with a contractor who has an established local presence, verifiable credentials, and a track record you can actually research, before the storm ever hits. Identifying a trusted roofing contractor before you need one urgently is one of the best things a commercial property owner can do.
Why Grell Roofing Checks Every Box
At Grell Roofing, LLC, we’re fully licensed, bonded, and insured. We’re a certified Duro-Last TPO applicator with nearly four decades of experience and over 12 million square feet of roofing installed. Our A+ BBB rating and verified customer reviews reflect the standard we hold ourselves to on every project—residential or commercial, routine maintenance or full replacement.
We don’t pressure anyone. We provide written, itemized estimates. And we back every job with both labor and material warranties.
If you’re evaluating commercial roofing contractors, we’d welcome the chance to earn your consideration. Call us at 515-955-2679 or visit grell.pro/estimate to request a free estimate.