Most advice on choosing a roofer is a list of things to check: licence, insurance, references, three quotes. All of it is worth doing, and none of it explains the thing that actually decides whether you are protected in year eight. A roof carries two separate warranties. The material warranty comes from the manufacturer and is conditional on how the roof was installed. The workmanship warranty comes from the crew and exists only if the contractor offers one. The contractor you choose determines whether you end up with both, one, or neither, and that is the real question underneath every checklist.
Start with the two warranties, because everything else follows from them
Ask a homeowner who has just had a roof done what their warranty is, and most will name one number. Ask which warranty that number belongs to, and the answer is usually less certain. That gap is where the trouble lives.
The material warranty is the manufacturer’s. It covers the shingles themselves against defects. It is not automatic and it is not unconditional: it is tied to the roof being installed to the manufacturer’s requirements, which includes things a homeowner would never think to check, such as whether the attic ventilation meets the required intake-to-exhaust balance. Inadequate ventilation is one of the most common conditions that voids or restricts coverage on an asphalt roof. A crew that relays the surface and leaves a starved attic has handed you a warranty that may not answer when you need it.
The workmanship warranty is the crew’s. It covers the installation rather than the product, and it exists only because a contractor chose to offer it. If nobody writes it down, it does not exist. This is the one that tends to matter most in the first years, because a roof that fails early usually failed at the installation rather than in the shingle.
The two fail in opposite directions, which is why you need both. A perfect shingle installed badly fails on workmanship. A well-installed roof using a defective batch fails on materials. A contractor who offers only one leaves you exposed on the other side.
What manufacturer certification actually does
Certification programs get used as a badge in roofing marketing, and it is fair to be skeptical of badges. Here is the mechanical part that is not marketing.
Manufacturers restrict their better warranty products to contractors they have vetted. An uncertified installer can buy and fit the same shingles but cannot register the enhanced coverage that sits on top of the standard product warranty. That is not a difference in the shingle. It is a difference in what you can claim against later.
Here is the part almost no contractor website explains, and it is the thing worth knowing. Certification is not one badge. It is a ladder, and the rung determines what can be registered on your roof.
At the entry tier a contractor can register enhanced material coverage: longer, less prorated protection on the shingles themselves. Manufacturer-backed coverage of the workmanship is a different product and it sits at the higher tiers. So a contractor can be genuinely certified, genuinely able to register an upgraded material warranty, and still not be able to hand you a manufacturer-backed workmanship warranty. Both are real. They are not the same thing, and the marketing rarely separates them.
YS Roofing is a GAF Certified™ Residential Roofing Contractor, a designation awarded to roofers meeting GAF’s standards including up-to-date professional licensing and comprehensive insurance coverage, and it allows enhanced manufacturer-backed material coverage to be registered on the work.
So when you are comparing contractors, the question is not “are you certified.” It is three questions: which tier, what exactly does that tier let you register on my roof, and will you send me the registration afterwards. Ask us the same three.
What to verify before you sign
Certification is one signal. These are the others, in the order they matter.
Insurance and coverage for the crew. Ask for proof, not assurance. A crew working on your roof without proper coverage is a liability that lands on your property. This is the single check most homeowners skip and the one with the largest downside.
A written scope, not a total. A quote that names a number and a shingle brand is not comparable to anything. Here is the translation key for the paperwork in front of you, line by line, and what each one means when you actually read it.
| What the quote should say | What it means, and why you care |
|---|---|
| The material and grade, named | Not "shingles" but the actual product line and tier. Without it you cannot tell whether two quotes are pricing the same roof. |
| Full tear-off and disposal | The old roof comes off rather than being covered over, and hauling it away is priced in rather than added later. |
| Underlayment, plus eave and valley protection | The water-resistant layer under the shingles, and the extra self-adhered strip along the bottom edge and in the valleys. That strip is what stops ice-dam meltwater reaching the wood. Its absence does not show until February. |
| Flashing at chimneys, walls, and penetrations | The metal that seals where the roof meets something else. Most leaks start here rather than in the open field of the roof. |
| Attic ventilation, including correction | Whether they will fix airflow while the roof is open. Skipping it shortens the life of the new roof and can affect warranty coverage. |
| A per-sheet decking rate, agreed before tear-off | The price of one sheet of new plywood, fixed in writing now, so rotted wood found on the day is not an open-ended charge. |
| The workmanship warranty, stated separately | The crew's own guarantee on the installation, written down. Different from the shingle warranty. |
| Payment terms tied to completed work | What you pay and when. Heavy money up front is the line to question. |
If a quote is missing three of these, it is not a lower price. It is a smaller job.
Evidence they looked at the attic. A contractor who quotes a replacement without going into the attic has priced half the job and has no idea whether the ventilation will support the warranty they are about to promise you.
Local work you can actually look at. Not a testimonials page. Addresses or streets in your area, ideally on housing similar to yours, because a century home in East York and a newer subdivision roof in Markham are different jobs and not every crew does both well.
The red flags worth walking away from
The knock on the door after a storm. Storm-chasing crews follow weather across regions, sell fast, work fast, and are gone before the first hard winter tests the job. They are also the hardest to reach when a workmanship claim comes up in year three, because there is nothing local to reach.
A firm price without seeing the roof. Nobody can tell you what your roof costs from the street or over the phone, because the deck condition, the layer count, and the access are invisible until someone looks. A confident number sight unseen is either padded to cover the unknowns or set low to win the job, with the difference recovered later.
Pressure tied to a deadline. A roof that genuinely needs doing will still need doing next week. Urgency that comes from the contractor rather than from the roof is a sales technique.
Vagueness about decking. Rotted sheathing is the most common surprise at tear-off. A contractor who will not commit to a per-sheet rate in advance is preserving the option to name a number when you have no leverage, which is the morning the roof is open.
No mention of ventilation at all. In the GTA, roofs frequently fail from the inside out. A quote that treats the roof as a surface rather than a system is quoting the wrong job.
The questions worth asking
Five questions, and the answers tell you more than any brochure.
- Which warranties will be registered on this roof, and will you send me the registration once it is done?
- What would void the manufacturer coverage on my roof specifically?
- What is your workmanship warranty, and what does it exclude?
- What happens if you find rotted decking, and what is the rate agreed in advance?
- Have you been in my attic, and what did the ventilation look like?
A contractor who answers all five directly is telling you they have thought about the roof rather than the sale. A contractor who deflects on any of them has told you something too.
Frequently asked questions
How do I know if a roofing contractor is legitimate?
Ask for proof of insurance rather than accepting the claim, check that they have a fixed local address rather than only a mobile number, ask for recent work in your municipality that you can look at, and confirm they will provide a written itemized scope before any deposit. Manufacturer certification adds a layer on top of that, because it means a third party has vetted the licensing and insurance rather than only the contractor asserting it.
What is the difference between a material warranty and a workmanship warranty?
The material warranty is from the manufacturer and covers the shingles against defects, conditional on correct installation. The workmanship warranty is from the contractor and covers the installation itself. They fail in opposite directions and you want both in writing. Most early roof problems are workmanship rather than material.
What voids a roof warranty?
The most common cause on an asphalt roof is inadequate attic ventilation, because it cooks the shingles from underneath and manufacturers set a required intake-to-exhaust balance. Installation that departs from the manufacturer’s requirements, and later work by another party that disturbs the roof, are the other frequent causes. This is why a contractor who never looks in the attic is a warranty risk regardless of how good the shingle is.
Should I get three roofing quotes?
Three is a reasonable number, but only if they are comparable. Three quotes describing three different scopes tell you nothing except which contractor left the most out. Put them side by side on scope, warranty, and payment terms before you look at the totals. See what affects the cost of a roof replacement in Ontario
Does the shingle brand matter when choosing a contractor?
Less than the tier and the install, with one exception that does matter: contractors carry what they are certified and supplied to fit, so the brand your contractor is certified in determines which coverage can be registered on your roof. Choose the contractor first. See best roof shingles for Ontario homes.
Is a certified roofer worth it?
It depends on what you want out of it. If you are buying the shingle alone, certification changes nothing about the product. If you want enhanced manufacturer-backed coverage registered on your roof, an uncertified installer cannot provide it at all. What certification does not do is guarantee manufacturer-backed workmanship coverage, because that sits at the higher tiers. The value is in what you can claim against in year eight, and in knowing precisely which of the two you have.
How long should a roof replacement take?
A typical detached home is a one- to two-day replacement once materials are on site and the weather cooperates. Larger, steeper, or more complex roofs run longer, and three days is common on those. The expected timeline should be confirmed in the written proposal before work starts. See what to expect during a roof replacement.
What happens next
- Book a free roof inspection. The exterior, the flashing, the drainage, and the attic are all assessed, because the ventilation decides both the life of the roof and the warranty that sits on it.
- Receive a written verdict with photographs: a repair, a planned replacement, or a roof with years left. If it has years left, we say so.
- If replacement is the answer, receive a clear, itemized written quote naming every line above, with the per-sheet decking rate fixed before the roof is opened and the workmanship warranty stated separately from the material warranty. No vague line items.
- Ask us the five questions. We would rather answer them than have you skip them with someone else.
Free estimates and financing options are available once you know what the roof actually needs. For the full decision sequence, see roof replacement in the GTA: the complete homeowner guide, and to place your own roof in its lifespan, see how long a roof lasts in Ontario.