Choosing a roofing contractor is a verification job, not a judgment call.

A certificate of liability insurance is a one-page summary, issued by an insurance agency, listing the policies a business held on the day the certificate was issued. It is not the policy, and in some states the law says so in terms. New York Insurance Law § 502(c) provides that a certificate “shall not amend, extend, or alter the coverage provided by the insurance policy to which the certificate of insurance makes reference,” and “shall further not confer to any person any rights beyond those expressly provided by the policy of insurance referenced therein.” The Texas Department of Insurance, applying that state’s Insurance Code chapter 1811, puts the same rule to consumers in plainer words: a certificate “may not use terms that would alter, amend, or extend coverage that is provided in the insurance policy.” New York and Texas are two states, chosen because both have written the point down; whether your own state regulates certificates the same way is a question for your state insurance department, not for this page.

So the certificate is evidence, not armour. What it is good evidence of is narrow and precise: that on one specific date, an agency recorded these policies with these numbers running between these dates. Which makes reading it a matter of comparing dates.

A worked example

The certificate below is constructed for this page — the dates are invented to make the arithmetic visible, and it is not a real document from a real company. The pattern, however, is the ordinary one, because a business’s general liability and workers’ compensation policies are usually bought at different times and renew on different calendars.

• Certificate issued: 14 March 2026
• General liability policy period: 1 February 2026 → 1 February 2027
• Workers’ compensation policy period: 1 July 2025 → 1 July 2026
• Contract signed: 2 April 2026
• Work scheduled: 8 → 12 September 2026

Now do the three subtractions that matter.

1. Certificate age at the start of work. 14 Mar 2026 → 8 Sep 2026 = 178 days. The document describing your contractor’s insurance is nearly six months old on the morning the crew arrives.
2. General liability against the work dates. 8–12 Sep 2026 falls inside 1 Feb 2026 → 1 Feb 2027, with 142 days to spare. This line is fine.
3. Workers’ compensation against the work dates. The policy ended 1 Jul 2026. Work starts 8 Sep 2026. That policy expired 69 days before anyone set foot on the roof.

Nothing about that certificate was false when it was issued. Nobody misrepresented anything. And yet the single line with the largest consequence for a property owner — the one covering injury to the people working at height on your building — covers none of the days they are actually there. It was probably renewed. It might not have been. The certificate cannot tell you, because it was written before the question existed.

The National Roofing Contractors Association states the corresponding rule for consumers directly: ask for copies of the liability and workers’ compensation certificates “and make sure both are in effect through the duration of your job.” That is the whole fix, and it costs one email.

What to actually do

• Ask the contractor for the name of the insurance agency, not just the certificate. CSLB frames these as alternatives; treating them as a sequence is stronger.
• Ask that agency to issue a fresh certificate directly to you, naming you as certificate holder, dated within a week or two of the scheduled start.
• On that certificate, check both policy periods against your work dates — the general liability line and the workers’ compensation line, separately.
• Ask the agency one question in plain words: are both of these policies in force today? An agency can answer that. A PDF cannot.
• If the work slips by a month — and roofing schedules slip constantly for weather — the dates you checked may no longer be the dates that matter. Re-check if the delay crosses a renewal.

On the amounts

It is tempting to treat a large liability limit as reassurance and a small one as a warning. Resist reading much into it without context. What a state requires can be startlingly low: to register as a contractor in Washington, the statutory minimum is $200,000 public liability and $50,000 property damage, or a $250,000 combined single limit — alongside a bond of $30,000 for a general contractor or $15,000 for a specialty contractor.

Those are floors for lawful registration, not judgments about adequacy. A tear-off leaves a building open; a failed overnight cover-up during a storm can damage interior finishes, contents, and framing well beyond a $50,000 property-damage limit. This page will not tell you what number is “enough”, because that depends on the building, the contents, the season, and what your own property policy would and would not do — which is a conversation with your own insurance agent, not with a roofing company. The useful takeaway is narrower and firmer: “insured” is not a threshold, it is a number, and the number is on the certificate.

General liability insurance is about damage the contractor does — to your building, your neighbor’s car, your landscaping. Workers’ compensation is about injury to the people doing the work. On a roof, at height, over several days, that is not a remote category of risk. OSHA states that falls are the leading cause of death for workers engaged in residential construction, and requires conventional fall protection at six feet or more above lower levels.

When the crew is covered, an injury is handled inside a system built for exactly that. When it is not, the question of who pays becomes a legal one, decided by your state’s law and by the specific facts — including whether the injured person was an employee, a subcontractor, or a sole proprietor who lawfully exempted themselves. California’s licensing board describes the exposure in its owner-builder guidance without hedging: if workers are injured, or subcontractors are unlicensed or carry no liability or workers’ compensation insurance and are injured, “you could be asked to pay for injuries and rehabilitation through your homeowner’s insurance policy or face lawsuits.”

That statement is about California and about owner-builders specifically. The mechanism it describes — that an uninsured injury looks for the next available party, and that the property owner is standing right there — is not unique to California, but the law that decides it is different in every state. This is precisely the kind of question where a page written nationally has to stop and hand you to somebody local.

One practical note that makes this fair to small contractors: in many states a genuine sole proprietor with no employees may lawfully carry no workers’ compensation, because there is nobody to cover. That is a legitimate structure, and it is also a different risk profile for you than a five-person crew. It is not universal either: California requires holders of certain license classifications, roofing (C-39) among them, to carry workers’ compensation regardless of whether they have employees. Which is exactly the point — the answer is set where you live. The question to ask is not “do you have workers’ comp?” but “how many people will be on my roof, and who covers each of them?”

References: ask for six, choose three

A list of three references is a list of three people the contractor was confident about. That is not dishonest — anyone assembling references does the same — it just means the list carries almost no information. Asking for six addresses and choosing which to call moves the selection to you, and it costs the contractor nothing if the work is good.

Two filters matter more than the number:

• Scope match. A full tear-off and replacement is a different operation from a repair or a recover. Ask each reference what was actually done. References for the wrong scope tell you the company is pleasant, not that it can run a five-day job.
• Age. A roof finished last month proves the crew showed up and cleaned the site. A roof finished two or three winters ago has been through weather, and its owner knows whether the company answered the phone about a callback. Ask for a spread of both.

The questions worth asking a reference are mostly about the exceptions:

• What did they find that was not in the original quote, and how was the price handled?
• Did the final invoice match the contract? If not, why not?
• Was anyone on site each day who could answer a question?
• How was the site left each evening, not just at the end?
• Has anything needed attention since — and what happened when you called?

That last one is the whole point. Every roofing company is pleasant during the sale. The informative period is the callback.

Complaint history: the public record is a different dataset

Searching a company name returns review platforms, which are curated, incentivized, and in places purchasable. They are not worthless, but they are not the record. Two other places hold different information:

• Your state consumer-protection office. USA.gov publishes the directory of these offices, which “can help with complaints against businesses, investigating scams and fraud, and more.” What they will disclose about a specific business varies by state; asking is free.
• The licensing or registration authority, where one exists. California’s lookup includes complaint disclosure. Washington’s hiring guidance points consumers to review a contractor’s license history “for previous lawsuits or license violations.” Where a state licenses nothing, this record does not exist and the consumer-protection office carries more weight.

Private accreditation and rating organizations are worth a look and worth keeping in proportion. They are businesses with their own criteria and frequently a paid membership tier; a rating from one is a data point, not a clearance. The NRCA, itself a trade association, recommends checking both a local Better Business Bureau and industry-association membership — which is reasonable advice and also worth reading with the awareness that associations recommend associations.

Finally: a complaint is not a disqualification. A company that installs three hundred roofs a year and has never generated a single complaint record would be remarkable. What matters is the pattern, the resolution, and above all whether the company’s own account of its record matches the public one.

Most large roofing manufacturers run tiered contractor programs, and a proposal will often lead with the badge. Understanding what sits behind it is straightforward once you know who sets the criteria.

What they generally do require

CertainTeed describes its own credential programs as requiring that contractors “receive education-based training on proper installation, maintain necessary licenses and insurance, and have experience working with the materials.” That is a manufacturer describing its own program, so read it as self-reported rather than audited — but the structure is common across the category: product training, evidence of the licenses and insurance the law requires, and time working with the material.

That structure supports three genuine signals:

• Somebody else checked the paperwork. A program that requires licenses and insurance has verified them at least once. It has not verified them on your work dates, which is why check 3 and check 4 in the ledger above still stand.
• Familiarity with that product’s instructions. This is more consequential than it sounds. A covering’s published installation instructions dimension a great deal of what actually gets built — fastener count and placement, flashing details, what happens at low slope — and the manufacturer’s own warranty is written against them. Knowing the instruction sheet is not a formality; it is close to the specification. Where an adopted building code sits on top of that, and how much of the detail it defers to those instructions, depends on the edition your jurisdiction adopted and what it amended — the flashing guide sets out the model-code text and its limits, and your building department governs.
• Access to enhanced warranties. Extended or system warranties are typically available only through credentialed companies, and usually require that manufacturer’s own accessories. If you want that document, the credential is not optional.

What they do not tell you

• Nothing about the crew on your house. The credential belongs to the company. The people installing your roof may be excellent and may never have attended a manufacturer training day.
• No inspection of your roof. Unless a specific enhanced warranty requires one, no manufacturer looks at your job. The credential is about the company, ongoing; not about this project.
• Nothing about independence. The criteria are set by the company selling the material, and the program exists partly to sell more of it. That does not make the criteria meaningless; it does mean they are not a consumer-protection instrument.
• Nothing permanent. Program membership can lapse and tiers can change, sometimes between quote and installation.

The fair conclusion — and it is worth stating plainly, because this page spends a lot of words on checking up on people — is that plenty of excellent roofing companies hold no manufacturer credential at all, often because they install several brands and decline to tie themselves to one. A credential is a tiebreaker and a warranty gate. It is not a filter, and treating it as one would exclude some of the best installers in most markets.

The two questions worth asking: which specific program and level, and is it current? And which enhanced warranty does that make available for this proposal? The second question is the one with a document behind it — and reading that document is worth more than the badge.

Roofing is a hard business run mostly by small companies in a trade with real physical risk, weather-driven scheduling, and thin margins. The overwhelming majority of roofing contractors are trying to do good work for a fair price, and a homeowner who arrives at the first meeting armed with an interrogation is not going to get the best of them.

The distinction worth holding onto:

• Verification is administrative. It is done with agencies and registries and one email to an insurance broker. It says nothing about the person in front of you, and most of it happens after they have left.
• Judgment is what you use on the scope of work. Does this proposal name the flashings, the deck allowance, the underlayment, the ventilation? Does this person explain what they do not know? That is where competence is visible, and it is a much better use of a conversation than credential-checking.

The tell to watch is not whether someone finds these questions tedious — plenty of good tradespeople do — but whether they can answer them. A contractor who says “I’ll have my agency send that over tomorrow” has just answered the most important question on this page, and you did not have to form an opinion about them to get it.

When the checks are done, the work is not: the harder half is making three proposals describe the same roof. That is what quote comparison is for, and the sequence that works is define the work first, get proposals against it, verify the companies, then sign.