This is a checklist for hiring a commercial roofing contractor. It is written for a building owner or facilities manager running a repair, a coating or a replacement, and it covers what to verify, what to require in writing, and what to agree before anybody starts.
Work through it before the quotes arrive rather than afterwards, because most of it shapes what you ask for.
Verify before anything else
| Check | What good looks like |
|---|---|
| Contractor license | Current, in the right classification, verified with the state board |
| General liability insurance | Certificate sent by the insurer, with your interest noted |
| Workers compensation | Current, and covering the crew that will actually attend |
| Manufacturer approval | Confirmed by the manufacturer for the system being installed |
| Business history | A verifiable local address and a trading history you can check |
| References | Buildings of a similar type you can visit, not written quotes |
The written scope
| Require | Why |
|---|---|
| The system named by product | Type alone does not define what is being installed |
| Insulation type and thickness | A hidden saving here is invisible on completion |
| Tear off or recover, stated | The largest single cost difference between two quotes |
| Deck repair rate or allowance | Deck condition is unknown until the roof is open |
| Detail treatment | Upstands, curbs, penetrations, edge metal, outlets |
| Drainage work | Outlets, strainers, overflows, and any correction of falls |
| Equipment handling | Who lifts, disconnects and reinstates rooftop plant |
| Disposal | Where the old roof goes and who pays for it |
The commercial terms
| Agree | What to watch for |
|---|---|
| Payment schedule | A deposit proportionate to materials, not to the whole job |
| Change order process | How a variation is priced and who authorizes it |
| Retention | An amount held until completion and sign off |
| Lien waivers | Provided as payments are made, not promised afterwards |
| Permits | Who applies, who pays, and who schedules inspection |
| Insurance of the works | What happens if water enters while the roof is open |
The schedule
| Agree | What to watch for |
|---|---|
| Start and completion dates | With the weather assumptions behind them stated |
| Nightly watertight plan | How an open roof is secured at the end of each day |
| Storm plan | What happens if a monsoon storm is forecast mid project |
| Working hours | Summer heat and an occupied building both constrain them |
| Access and parking | Crane positions, lay down areas, and tenant disruption |
| Site conduct | Who is on the roof, and how access is logged |
The warranty
| Confirm | Why |
|---|---|
| Who issues it | Manufacturer and contractor warranties are different documents |
| What it covers | Material only, or material and labor |
| How long it runs | And from which date |
| What voids it | Unauthorized work is the commonest clause |
| Maintenance required | Who will do it, how often, and who pays |
| Transferability | Relevant if the building might be sold |
What to do with it
- Write one scope and send it to every bidder. Otherwise you are comparing three different projects.
- Verify the license and insurance directly. Not through a document the contractor forwards.
- Ask for the warranty specimen before the contract. The conditions are the warranty.
- Get the storm plan in writing. An open roof in this valley is a real exposure.
- Keep the deposit proportionate. It should cover materials, not the project.
Want the reasoning behind these checks? Read what the services cover and how a replacement runs.
Walked by Date Roof
Common questions
What should be verified rather than taken on trust?
The license, the insurance and the manufacturer approval, because all three are checkable in minutes and all three are occasionally claimed by people who do not hold them. Everything else on the list is judgment; these three are facts. All three take a single phone call or email and none of them depends on the contractor's cooperation.
- Check the contractor license with the state board directly
- Ask for a certificate of insurance naming you, from the insurer
- Confirm manufacturer approval with the manufacturer, not the contractor
- Check the license covers the class of work being quoted
- Check how long the business has traded under its current name and license
A certificate forwarded by the contractor is a document the contractor controls. One sent directly by the insurer or confirmed by the manufacturer is evidence. The difference takes one email and occasionally saves an entire project, particularly where a warranty depends on the installer holding an approval they did not actually have. Do the checks before the quotes arrive rather than after you have chosen somebody, because the verification is much harder to carry out neutrally once a preference has formed.
What makes a quote comparable?
A written scope that names the system, the build up, the preparation, the details and what happens if the deck is found to be damaged. Without those, two prices are not two offers for the same work and the lowest one usually explains why later.
- The system named by manufacturer and product, not just type
- Insulation type and thickness stated, not assumed
- Tear off or recover stated explicitly
- A named rate or allowance for deck repair
- A stated allowance for drainage work, which is routinely left out entirely
Insist on the same scope going to every bidder, written by you rather than by each of them. The alternative is three quotes describing three different projects, where comparison is impossible and the apparent saving in the cheapest is simply work that has been left out of it. Where a bidder proposes something different from your scope, ask them to price your scope as well as theirs. That gives you a comparison and their better idea at the same time.
What does a warranty actually need to say?
Who issues it, what it covers, how long it runs, what voids it and what maintenance it requires. A manufacturer warranty and a contractor workmanship warranty are different things and a roof usually needs both. The two documents cover different failures and a roof generally needs both of them to be useful.
- Manufacturer warranty covers material, and sometimes labor
- Workmanship warranty covers the installation, and comes from the contractor
- Almost all warranties require documented maintenance
- Unauthorized work by another trade commonly voids cover
- Whether it transfers to a new owner, and on what terms and fee
Ask for a specimen of the warranty before the contract, not a description of it afterwards. The conditions are where the cover lives, and a warranty requiring annual documented inspection is worth having only if somebody has already decided who will carry out that inspection and who will pay for it. Note the maintenance obligation in your own calendar on the day the warranty is issued. Most warranties that fail a claim fail it on maintenance records rather than on the defect itself.
What should the schedule include?
Start and completion dates, the weather assumptions behind them, how the roof will be made watertight each night, and what happens to the building if a storm arrives mid project. In this valley the last one is not a formality.
- A stated plan for nightly tie offs and temporary waterproofing
- What happens to an open roof if a storm is forecast
- Working hours, which matter in summer and in an occupied building
- Who is responsible for water entering during the works
- How much roof will be opened at once, which governs the exposure
A roof under replacement is the most vulnerable it will ever be, and a monsoon storm can arrive with little useful warning. Ask the question directly and in writing. A contractor who has a clear answer has done this before here; one who treats it as unlikely probably has not. Agree the storm response in writing with named contacts and a response time. An answer that depends on reaching somebody by phone on a Sunday afternoon is not a plan.
What are the warning signs worth walking away from?
Pressure to sign today, a large deposit demanded up front, no written scope, a reluctance to provide insurance details, and a price that is far below the others with no explanation of what is different about it. Any one of these on its own is a reason to slow down rather than to stop, and two together are usually enough.
- Urgency created by the contractor rather than by the roof
- An unusually large deposit, particularly in cash
- No written scope, or a scope that is one paragraph long
- Reluctance to put the warranty terms in writing
- References that cannot be visited, or that turn out to be recent and few
Storm seasons attract contractors who follow the weather and leave with it, which is a familiar pattern in this valley after a bad monsoon. A local address, a verifiable license history and references on buildings you can go and look at are the practical defenses, and all three are easy to ask for. There is rarely a good reason to sign the same day. A roof that has survived a decade will survive another week, and the contractor who objects to that week has told you something useful.