What the rating actually measures, and what it does not promise.
Class 4 is the top impact rating under UL 2218, and in Alberta — which has had at least one major hailstorm every year for two decades and over $11 billion in insured hail damage — it is the most consequential product decision on a roof.
It is also routinely oversold. Class 4 does not make a roof hail-proof, and any contractor who implies it does is setting you up to be angry with them later.
UL 2218 drops a steel ball onto the shingle from a set height and checks the mat for cracking. The classes differ by ball size: Class 1 is 1.25 inches, Class 2 is 1.5, Class 3 is 1.75, and Class 4 is a 2-inch steel ball. For Class 4 the ball is dropped twice on the same spot, and the shingle passes only if the mat doesn’t crack. Two things follow from that. First, it’s a laboratory impact test with a steel ball — not hail, which is less dense, arrives at an angle, and comes with wind. Second, it tests the mat, which is precisely the right thing to test, because a cracked mat is what actually ends a shingle’s life.
Many Alberta insurers offer a premium discount for an impact-rated roof. **Reported discounts vary widely — figures in the 5–25% range circulate — and we are not going to quote you a number, because it depends entirely on your insurer, your policy and your postal code.** What to actually do: call your insurer or broker before you buy, ask specifically whether they discount for a UL 2218 Class 4 roof and by how much, and get the answer in writing. Then ask what documentation they need — usually the manufacturer’s certificate and an invoice naming the product. We supply that certificate as a matter of course. Any contractor who quotes you a discount percentage is quoting you someone else’s policy.
IKO Nordic is our Class 4 option — the Hail Shield tier. IKO Cambridge AR is Class 3, the Hail Defender tier. The cost difference between them is real but smaller than most people expect, and it’s the smallest variable in a replacement quote next to area, pitch, complexity and decking. In the north and northeast, where the storms keep landing, Class 4 is the easiest recommendation we make.
A Class 4 roof that survives a storm your neighbours’ roofs didn’t is a good outcome, not a claim. That sounds obvious and it catches people — having paid more for the roof does not entitle you to a settlement when it worked. What it does entitle you to is a roof you didn’t have to replace, and a lower premium if your insurer discounts for it.
Usually yes, and more so the further north and east you are. It’s a small line in the overall quote and it changes your exposure in a region that gets a major hail event most years. If your insurer also discounts for it, the case gets easier.
No, and don’t buy on that assumption. Some do, some don’t, and the amount varies a lot. Confirm with your own insurer in writing before you count it toward the decision.
Not automatically — impact rating and warranty term are separate things. IKO’s material warranty runs 24 years and up on both tiers. Our workmanship warranty is 5 years on either. Ask any contractor to state both separately, because blurring them is common.
That happens, and it’s a legitimate claim. Class 4 raises the threshold; it doesn’t remove it, and a storm with hen-egg or larger hail is well past what the standard tests. The rating is about odds, not immunity.
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