Hiring a commercial roofer is an important decision for a commercial building, and the most common mistake is comparing bids that do not describe the same work. First Class Roofing has more than 25 years of experience with commercial and industrial roofing across Ohio, and this guide shows how to compare contractors and written scopes so the decision rests on the project, not just the price.
The short answer: ask every contractor to put the services, investigation, system, exclusions, schedule and warranty in writing, and compare them side by side. Bids that cannot be lined up this way are not truly comparable. To talk through a project, call 888-699-9321.
Important Considerations
Confirm Who Is Qualified for the Job
Before comparing numbers, confirm that each contractor is allowed to do the work. Ask what licensing and insurance requirements apply to your project and request current certificates of insurance. Ask for references on commercial roofs similar in system and complexity, and verify the information offered. A comparison need not be held up by a specific project photo or testimonial. Treat credentials as something each contractor should be able to document, not something to assume.
Get Everything in Writing
A verbal promise is not a scope of work. A useful written proposal identifies the deliverables, the specified materials or system, the intended schedule and pricing assumptions, and it explains how changes are handled. This protects both sides and prevents disputes over what was and was not included.
Look Beyond the Lowest Price
The lowest bid is not always the best comparable scope. A low number may leave out deck repair, drainage corrections or flashing details, or specify a thinner system, and those gaps can lead to later change orders. Compare what is included before you compare totals. Price matters, but only between bids that describe the same work.
Side-by-Side Bid Review
Use the table below to line up bids for a repair, coating or commercial roof replacement. The follow-up questions help reveal when two bids are not truly comparable.
| Bid item | What to compare | Follow-up question |
|---|---|---|
| Confirmed services | Each bid covers the same work: repair, coating or replacement | Does your company perform this service itself, and which parts are subcontracted? |
| Investigation scope | How the roof was reviewed before pricing, such as walkthrough, moisture review or core samples | What was inspected, and what was assumed without checking? |
| System specification | Named membrane or system, insulation, attachment method and accessories | Which layers are included, and what is the attachment and flashing detail? |
| Exclusions | Items listed as not included, such as deck repair, drains or permits | What is excluded, and how are hidden conditions priced if found? |
| Scheduling | Start window, duration, phasing and weather plan | What happens to the schedule on rain or cold days? |
| Occupied-property protection | Access routes, tenant notice, debris and entrance protection | How will staff, customers and equipment be protected during work? |
| References | Past commercial projects of similar type and size | Can you provide references for similar roofs, and what did the work involve? |
| Warranty | Who stands behind workmanship and who backs the materials | What does the workmanship warranty cover, and what does the manufacturer’s warranty cover? |
Workmanship Versus Manufacturer Warranty
These are two different promises. A workmanship warranty, if offered, comes from the contractor and addresses covered installation work. A manufacturer warranty, if offered, applies to the specified product or roof system under its own conditions. Neither should be assumed to cover every leak, labor charge or later alteration. Ask which warranty documents apply, the term and exclusions, how claims are handled and whether inspection or registration is required. First Class Roofing lists multiple warranty options; the terms for the selected project must be confirmed in writing.
Scope and Investigation
Two contractors can quote the same roof very differently if one investigated and the other did not. A commercial roof inspection that documents conditions gives every bid a common starting point. If the scope is a smaller fix, compare it with commercial roof repair bids on the same terms.
Schedule and Occupied-Property Protection
A proposed schedule should account for weather-related interruptions. Ask each contractor how work will be phased, how the roof is made watertight at the end of each day and how entrances, rooftop equipment and interior spaces are protected. Occupied buildings need clear notice to tenants and staff, and the bid should say who coordinates access.
Resolve Bid Differences Before Signing
Ask each bidder to mark the roof areas included in its price. If one proposes a limited repair while another proposes full replacement, request the specific conditions behind each recommendation. For a coating proposal, ask what moisture and adhesion conditions must be met before application. For replacement, ask whether removal of the existing roof, insulation and deck contingencies are included. These questions distinguish a different technical recommendation from an unexplained price difference.
Where the roof is occupied by HVAC equipment, skylights, signage or regular service traffic, verify how penetrations and walkways will be detailed. Ask how a contractor will handle a discovered wet area, who authorizes a scope change and whether the price includes disposal, cleanup and final review. A bid can look complete on one page yet exclude work that another contractor has priced. Request a revised written scope rather than relying on a conversation to settle the difference.
Communication and Follow-Through
Good communication starts before the contract. Notice whether questions get clear answers, whether the bid explains the sequence of work and whether there is a named contact. After the job, ask about roof maintenance so the roof is inspected and cared for over time.
Expert Commercial Roofers
First Class Roofing works on commercial and industrial buildings and offers 24/7 emergency roofing. If you are comparing bids or planning a project in Ohio, our team can review the scope with you. Reach us through the contact page or at 888-699-9321.
Frequently Asked Questions
How many bids should I collect for a commercial roof?
Get enough independent written proposals to compare the specified work and resolve major differences. The number matters less than having comparable service, materials, exclusions and conditions.
Why are two bids for the same roof so different?
Differences often come from the investigation scope, the system specified, allowances for hidden damage and what is excluded. Follow-up questions usually explain the gap.
What is the difference between a workmanship and a manufacturer warranty?
Workmanship coverage, if offered, comes from the contractor. Manufacturer coverage, if offered, follows separate product or system terms. Check both documents.
Should I always choose the lowest bid?
No. Compare scope and specification first. A lower price that omits repairs, drainage work or flashing details may carry later change-order costs.