Class 4 Impact-Resistant Shingles — Hail-Rated Roof Replacement
Your roof has been through two hail claims in ten years and you want the next one to shrug it off, or your insurer is offering a discount for an impact-rated roof and you want to know what you are buying.
Class 4 impact-resistant shingles are architectural asphalt shingles that pass the highest level of a steel-ball drop test for hail. JMB Builders installs them as part of a full roof replacement across the Twin Cities metro, options such as the Class 4 lines from GAF, Owens Corning, CertainTeed and Malarkey. They cost more per bundle than standard shingles and some insurers discount the premium for them; ask your agent, and ask about a cosmetic-damage endorsement first. Priced per project.
- Class 4: highest rating on the steel-ball impact test
- Some insurers discount the premium; ask your agent
- Check for a cosmetic-damage endorsement first
- Send photos, reply within one business day
- Licensed MN contractor BC809005
Send photos and hear back within one business day — or book a free in-home estimate.
The impact rating comes from a lab test. Steel balls of set sizes are dropped from set heights onto the shingle, and the shingle passes a class if the back of the mat does not crack. Class 4 is the largest ball from the greatest height. Makers get there two ways: a thicker, more flexible asphalt layer, or a polymer-modified asphalt (often sold as SBS or rubberized) that bends instead of cracking. The polymer-modified shingles tend to stay flexible in the cold, which matters here because a hailstorm in May lands on a shingle that has just been through a Minnesota winter.
The rating is about the mat cracking, not the granules. A Class 4 roof can still lose granules and show marks after a big storm; what it is far less likely to do is bruise through so water gets to the mat. That is the distinction insurers care about, and it is why some of them offer a premium discount for a Class 4 roof. It is also why some of them attach a cosmetic-damage endorsement to that discount: it says they will pay for hail damage that affects the roof's function but not for marks that are only cosmetic. Read that before you take the discount.
On the job a Class 4 shingle installs like any other architectural shingle, over the same ice and water shield, underlayment and flashing. The upgrade is the bundle cost. On an insurance roof, the approved scope pays for a shingle like the one that came off; the difference to a Class 4 line is your own line on top, and it is often the cheapest time to make the upgrade because the rest of the roof is already being paid for.
What you supply
- A call to your agent: do they discount for Class 4, how much, and does it come with a cosmetic-damage endorsement
- Your color and line choice from samples at the free in-home estimate
- The adjuster's scope if the roof is going through a claim, so the upgrade shows as its own line
- Clear driveway space for the dumpster and delivery
What JMB supplies
- Class 4 impact-rated architectural shingles (options such as the Class 4 lines from GAF, Owens Corning, CertainTeed and Malarkey)
- The manufacturer's Class 4 documentation for your insurer, from the bundle labels and product sheet
- Full roof replacement under them: tear-off, deck repair, ice and water shield, synthetic underlayment, flashing, ventilation
- Matching starter and hip-and-ridge cap from the same line so the whole roof carries the rating
- The city's building permit and inspection, magnet sweep and finished photos in your job folder
How it is priced: per project
Quoted in writing from your photos, with a reply within one business day. What moves the number:
- Bundle cost of the Class 4 line vs. a standard architectural shingle, which is the whole upgrade
- Squares of roof, since the bundle difference scales with area
- Whether the roof is a straight replacement or a claim, where only the difference to Class 4 is your own line
- The rest of the roof: tear-off, layers, decking, pitch, flashing and access, same as any reroof
- Matching hip-and-ridge and starter from the Class 4 line
Ask your agent for the discount and endorsement details in writing before choosing. We show the Class 4 upgrade as its own line on the scope so you can weigh it.
How long it takes
Same as a standard roof replacement: one to two days on site for most houses. Class 4 lines are stocked by the local suppliers and do not add lead time in most colors.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized reply within one business day. Prefer a look in person? A free in-home estimate is always an option.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Polymer-modified (SBS) Class 4
Asphalt blended with rubber-like polymer so the shingle bends under a hit instead of cracking, and stays flexible in cold. The lines we see most for Minnesota hail.
Thick-mat Class 4
A heavier standard asphalt shingle that passes the test on mass. Good hail performance, usually a bit less flexible in the cold than the polymer-modified lines.
Class 4 on an insurance roof
The claim pays for a shingle like the one that came off. The upgrade to Class 4 is your own line on top, and it is the cheapest time to make it because the tear-off and everything under the shingle is already covered.
Class 4 with the discount and endorsement
Some insurers pair the premium discount with a cosmetic-damage endorsement: functional hail damage is covered, cosmetic marks are not. Decide with your agent whether the yearly savings is worth that trade over the life of the roof.
Class 4 Impact-Resistant Shingles — Hail-Rated Roof Replacement: questions, answered
What does Class 4 impact resistant mean on a shingle?
It means the shingle passed the top level of a standardized impact test in which steel balls are dropped onto the shingle from set heights; Class 4 uses the largest ball from the greatest height, and the shingle passes if the mat on the back does not crack. It is a lab rating for resistance to cracking through, not a promise that hail will leave no marks. Class 4 shingles are architectural shingles made with a thicker or polymer-modified asphalt layer.
Are impact resistant shingles worth it in Minnesota?
If your area gets hail every few years and your insurer discounts for them, usually yes: the upgrade is only the bundle cost, since everything under the shingle is the same. If the discount comes with a cosmetic-damage endorsement, weigh that: you would be giving up coverage for marks that do not affect function. If you are replacing the roof through a claim anyway, the upgrade is the difference in bundle price and that is the cheapest it will ever be.
Do insurance companies give a discount for Class 4 shingles?
Some do, and the size of the discount varies by company and by how they rate your area. Ask your agent before you choose a shingle, get the number in writing, and ask whether the discount requires a cosmetic-damage endorsement. We provide the manufacturer's Class 4 documentation from the bundles and product sheet for your insurer after the install. We cannot tell you what your insurer will do; your agent can.
What is a cosmetic damage endorsement on a roof?
It is a change to your policy that excludes hail or wind damage that only affects how the roof looks, not how it works. Insurers sometimes attach it when they give a Class 4 discount. With it, dents and granule loss that do not let water through would not be a covered claim; a cracked or bruised-through shingle still would. Read it before accepting the discount, because it stays on the policy for the life of the roof.
Will a Class 4 roof still get hail damage?
It can show marks and lose some granules in a big storm; the rating is about the mat not cracking, so water does not get through. In practice Class 4 roofs come through the common Minnesota hail far better than standard shingles, which is the whole reason insurers discount for them. A severe storm with very large hail can damage anything, including metal.
Can I upgrade to Class 4 shingles on an insurance claim roof?
Yes. The approved scope pays for a shingle comparable to the one that was damaged. We show the Class 4 line as a separate upgrade line on the scope, and you pay the difference along with your deductible. Minnesota law does not allow us to absorb that difference or the deductible. Tell your agent you are upgrading so any discount starts when the roof is done.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners, builders and dealers. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough: a reply within one business day, or ask for a free in-home estimate. Or text the photos to 763-333-4066.
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Read morePage reviewed October 2, 2026 · JMB Builders LLC, MN license BC809005 · All roofing pages
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