Choosing the wrong commercial roofing contractor in New Jersey can cost you far more than the initial savings. Shoddy installation, improper membrane selection, inadequate flashing, and voided manufacturer warranties are all risks when working with inexperienced or unqualified contractors.
This guide from GenSun Roofing NJ gives you the exact criteria to use when evaluating commercial roofing contractors in NJ — so you make the right choice the first time.
- Verify NJ State Contractor Licensing
In New Jersey, all roofing contractors must hold a valid Home Improvement Contractor (HIC) license issued by the NJ Division of Consumer Affairs. For any commercial project, verify that the contractor’s license is current and in good standing. GenSun Roofing NJ holds NJ License #13VH11963000. Any contractor unwilling to provide their license number should be disqualified immediately.
- Confirm Adequate Insurance Coverage
Before signing any contract, require a Certificate of Insurance showing at minimum: General Liability coverage of at least $1 million per occurrence, Workers Compensation coverage for all employees, and Commercial Auto coverage. Have the certificate list your property as an additional insured. This protects you from liability if a worker is injured on your property or if damage occurs during the project.
- Evaluate Commercial Roofing Experience
Commercial and residential roofing are fundamentally different disciplines. Flat roof systems — TPO, EPDM, Modified Bitumen, and PVC — require specialized training, equipment, and certifications. Ask prospective contractors how many commercial flat roof projects they complete annually, and request references from similar projects in your county.
- Look for Manufacturer Certifications
Top roofing membrane manufacturers — including GAF, Firestone, Carlisle, and Johns Manville — offer certified contractor programs. Certified contractors have demonstrated proper installation training and often have access to extended manufacturer warranties (sometimes up to 30 years) that non-certified contractors cannot offer. Ask each bidder which manufacturer certifications they hold.
- Get a Fully Itemized Written Proposal
Your proposal should clearly specify:
- Exact membrane brand, type, and thickness
- Scope of tear-off and disposal
- Insulation type, thickness, and R-value
- Flashing specifications — drip edge, wall flashing, HVAC curbs
- Warranty terms — both workmanship and manufacturer
- Payment schedule and project timeline
- Permit responsibility and municipality requirements
- Compare Estimates on Equal Terms
Never compare roofing bids simply by bottom-line price. A lower number often means lower membrane thickness, omitted insulation, minimal flashing, or a shorter warranty. Insist that all bids include the same membrane type, thickness, insulation scope, and warranty terms before comparing pricing. GenSun provides side-by-side comparison guidance for customers receiving multiple bids.
- Assess Communication and Professionalism
How a contractor communicates before the contract is signed tells you a great deal about how they will behave during and after the project. Are calls returned promptly? Are questions answered clearly and honestly? Is the proposal professional and detailed? A contractor who is difficult to communicate with before the project begins will be even more difficult to reach when you need warranty work.
GenSun Roofing NJ is built on referrals — which means our reputation for communication, quality, and transparency is everything to us.
Ready to Get Started?
Request a free commercial roofing consultation with GenSun Roofing NJ. We will walk you through your options, answer every question, and provide a fully transparent written proposal.
Call us: 201-806-6186
Visit: www.GenSunRoofingNJ.com