How to Choose a Roofing Contractor on Long Island

By Greene Group Construction Corp · Nassau & Suffolk County Roofing Experts

After a major storm or when you're finally ready to tackle a long-overdue replacement, the most important decision you'll make is who does the work. Choosing the wrong contractor on Long Island can void your material warranty, create new leak points, and leave you with costly callbacks. This guide walks you through the vetting process. Already know you need a replacement? Read our 2025 price guide to understand what a fair quote looks like.

1. Verify NY State Licensing and Insurance

Any roofing contractor working in Nassau or Suffolk County must hold a valid New York State Home Improvement Contractor license. Verify it at the NY Department of State website. They must also carry general liability insurance (minimum $1 million) and workers' compensation. Ask for both certificates before signing anything.

2. Check for Manufacturer Certification

GAF Certified Contractors, Owens Corning Preferred Contractors, and CertainTeed SELECT ShingleMasters are trained and vetted by the manufacturer. Certification unlocks enhanced warranties — including workmanship coverage — that non-certified installers can't offer. When comparing roofing materials for Long Island homes, always factor in whether your contractor can back them with a manufacturer warranty.

3. Ask for Local References — Specifically on Long Island

A contractor who does good work in Queens may not understand the nuances of coastal Long Island installation. Ask for references from projects in your specific county. Towns like Smithtown, Huntington, and Levittown all have slightly different code requirements, HOA rules, and environmental exposures.

4. Demand a Detailed Written Estimate

A legitimate estimate should line-item: tear-off and disposal, decking inspection and repair allowance, underlayment type, shingle brand and model, flashing details, ridge vent, permits, and cleanup. Any estimate that's just a single total number is a red flag. Compare this to our price guide to verify market alignment.

5. Understand the Warranty

There are two warranties: the manufacturer's material warranty (covering shingle defects) and the contractor's workmanship warranty (covering installation errors). Get both in writing. Ask specifically: How long is the workmanship warranty? Is it transferable if you sell the home?

6. Be Wary of Storm-Chaser Companies

After every major nor'easter, out-of-state storm-chaser contractors flood Long Island. They often offer suspiciously low bids and disappear before warranty issues arise. If you've had storm damage, our guide on filing a roof insurance claim on Long Island will help you navigate the process with a local, established contractor.