You heard it hit. A gravel truck passed you on the Trans Canada west of Portage, something snapped off the glass, and now there is a little star about the size of a pea sitting just below the wiper sweep. The question every one of those drivers asks at our counter is the same. Can you just fill that, or does the whole windshield have to come out?

Most of the time a fresh chip can be filled, and it takes less time than an oil change. But the answer depends on four things, size, depth, where it sits, and how long you leave it, and in this province the last one matters more than anywhere else in the country. Below is how we decide, using the same rules Manitoba Public Insurance uses to approve the claim. If you already know yours has spread, our MPI glass repair page explains how the claim works and how to get the truck booked in.

Key Takeaways

• Small, fresh and away from the edge means repair. MPI's own repair criteria allow a chip to be filled when it has not been repaired before, is not through both layers of glass, and is not sitting over a heated element, a sensor or the camera.
• A loonie is the yardstick. MPI does not count chips smaller than a loonie coin, about one inch, toward its repair limits, and larger ones are capped at four anywhere and two in the driver's critical viewing area.
• Cracks have a length limit. Under MPI's criteria a crack up to 12 inches can be repaired as long as its edges do not reach the edge of the windshield.
• A Manitoba cold snap is what turns a chip into a crack. Glass contracts in the cold and a hot defroster blast pulls the inner surface the other way. Existing damage is where that tension lets go, usually overnight or on the first hard defrost of the morning.
• Repair does not cost you on your Autopac. MPI states that windshield repair claims do not impact your premiums.

Why a Chip Is Not Just Cosmetic

A windshield is two layers of glass bonded to a plastic layer in the middle. That laminate is what keeps the glass in one piece when something hits it, and it is also structural. On a modern truck the windshield is glued into the body and helps the roof hold its shape, and on anything with a forward facing camera it is the mounting surface for the eyes of the safety systems.

A rock chip is a break in the outer layer only. Left alone, dirt and water work into the break, the edges of the damage lose their clean surfaces, and the chip stops being repairable even if it never spreads. Filled early, a chip repair injects clear resin into the break under vacuum and pressure, cures it under ultraviolet light, and restores most of the strength and most of the clarity. That is the whole trick, and it only works while the break is fresh and clean.

This is why we tell people to come in the same week. Not because we want the booking, but because the repair window is short here and the weather closes it faster than most people expect.

The MPI Repair Rules, In Plain Language

Manitoba is unusual in that the insurer publishes exactly what qualifies as a repair, so there is no argument at the counter. A windshield qualifies for repair under MPI's criteria when all of the following are true:

The damage has not been repaired before. A previously filled chip that failed cannot be filled again. The resin is already in the break.

Chips are counted, and small ones do not count. MPI allows a maximum of four chips anywhere on the windshield and a maximum of two in the driver's critical viewing area when the chips are larger than one inch. Chips smaller than a loonie coin do not count toward those limits at all.

Nothing has gone through both layers, and no glass is missing. If the inner layer is broken, or a piece has actually fallen out, the laminate has failed and it is a replacement.

A crack can be up to 12 inches long, but it cannot reach the edge. Once a crack meets the edge of the windshield, the glass has lost its structural connection at that point and repair is off the table. MPI also notes that for a crack longer than 2 inches you may request replacement instead of repair.

Nothing sits over a heated element, a sensor or the camera. The strip of glass in front of the forward facing camera behind your mirror, and any heated wiper park area, are not repairable. Resin in that zone distorts what the camera sees, and that is a safety system problem, not a cosmetic one.

If all five hold, MPI treats it as a repair. If any one fails, the glass comes out. Our service centre can tell you which side of the line you are on in about two minutes with the truck in the bay, and we will be straight with you either way.

Size, Depth and Location: How We Actually Judge It

Beyond MPI's criteria, there is the judgment call a technician makes with a flashlight and a probe.

Size. The loonie rule is a good one to keep in your head. A chip you can cover with a loonie is a routine repair. Something bigger can still be repaired in many cases, but the odds of a visible blemish go up and the odds of it spreading during the repair go up with it.

Depth. A bullseye, a small star break or a short combination of the two is normal. If the probe finds the break has already reached the plastic layer, or there is a crushed area at the impact point that has lost material, the result will not be clean.

Location. Two zones matter. Directly in front of the driver, roughly the width of the steering wheel at eye level, a repair leaves a faint optical mark even when it is done well. It is safe and it is legal, but you will see it, and some people would rather replace the glass than look at it for six years. The second zone is anywhere within about two inches of the edge, where the glass is bonded to the body. Damage there puts stress on the bond and almost always runs.

Age. A chip from this morning is clean. A chip from July that has been through a dozen rainstorms, three washes and a dusty harvest is full of contamination, and the resin cannot bond to dirt. It may still be worth filling to stop the spread, but the cosmetic result will be poorer.

None of this means you need to become a glass expert. Bring it in, and we will tell you. The only thing you need to do on your own is not wait.

The Manitoba Problem: Why a Chip Becomes a Crack Overnight

Every October we see the same thing. A customer had a chip all summer, never worried about it, and one morning in the first real cold it is a crack from the wiper to the pillar.

Glass contracts as it gets cold. On a minus 25 morning the outer surface of your windshield is at air temperature. When you start the truck and put the defroster on full, the inner surface warms fast while the outer surface stays frozen. That difference in temperature puts the glass under tension, and an existing chip is the weakest point in the sheet. It is where the tension releases, and it releases as a crack.

Two things make it worse. Water that got into the chip during the fall freezes and expands, forcing the break open from inside. And a stiff scraper dragged across a chip at 30 below will finish the job the cold started.

The habit that saves a lot of windshields is simple. Start the truck, leave the fan on low or medium with the temperature warm rather than hot, and let the glass come up gradually. Ten minutes of remote start with the defroster on a moderate setting does the same thing without you standing there. Our post on how to defrost your windshield covers the method in detail, and it applies double when there is damage in the glass.

If you are going into the fall with a chip you have been ignoring, get it filled in September. The repair takes about half an hour, and it is the difference between a small claim and a full replacement with a camera recalibration on top.

Why Trucks Get More of Them Here

Half the roads around Portage la Prairie are gravel, and a half ton with a tall, upright windshield catches more of what the tires ahead throw up than a low car does. Grid roads in harvest, the shoulders of the Trans Canada when the graders have been out, and the loose stone that collects at the edge of every approach all feed the same result.

Following distance is the only real defence. Hanging back from a gravel truck or a farm truck with a loaded box gives the stones time to land before you get there. It does not take much. A few extra seconds behind a tandem on the way to Winnipeg saves a lot of glass. The rest of the gravel season prep, from tires to underbody, is in our fall gravel truck prep guide.

What Happens if It Has to Be Replaced

Sometimes the honest answer is that the chip is too big, too old, too close to the edge or sitting right in front of the camera. Then the glass comes out.

Two things to know. First, on most Ram and Jeep models built in the last several years, a replacement windshield means the forward facing camera behind the mirror has to be recalibrated afterward. MPI's own glass page notes that a replacement may require recalibration of your vehicle's driver assistance systems, and the manufacturer is clear that the camera must be recalibrated after a new windshield is installed. That is a dealer level procedure with the right scan tool, and we do it in the same visit. Second, the glass we install is the glass the truck was built with, so the camera is looking through the same optical quality it was calibrated against at the factory.

Either way, the claim is straightforward. MPI states that windshield repair claims do not impact your premiums, and you open the claim with the shop rather than at an MPI centre. If the damage came with a bigger collision, our collision department handles the glass as part of the repair.

FAQs

Can a rock chip be repaired, or does the windshield need to be replaced?

Most fresh chips can be repaired. MPI's criteria allow repair when the damage has not been repaired before, has not gone through both layers of glass, does not sit over a heated element or a sensor or camera, and stays within the chip limits. Chips smaller than a loonie coin do not count toward those limits at all.

How big a chip can be repaired in Manitoba?

MPI uses a one inch, or loonie sized, threshold. Chips under that size are not counted against the limits. Larger chips are allowed up to a maximum of four anywhere on the windshield and two in the driver's critical viewing area. Cracks can be repaired up to 12 inches long provided they do not reach the edge of the glass.

Does cold weather make a windshield chip spread?

Yes, and in Manitoba it is the most common way a repairable chip becomes a full replacement. Cold contracts the outer surface while the defroster warms the inner surface, and the resulting tension releases at the chip as a crack. Water frozen inside the chip and a hard scrape across it both make it worse.

Will a windshield repair claim raise my Autopac rates?

No. MPI states that windshield repair claims will not impact your insurance premiums.

Can a chip in front of the camera be repaired?

No. MPI's criteria exclude damage over any sensor or camera system, because resin in that area distorts what the forward facing camera sees. Damage in that zone means a replacement and a camera recalibration.

How long does a chip repair take?

Roughly half an hour once the truck is in the bay. Book it through our schedule service page and mention it is a chip so we set the right time aside.

The Bottom Line

A rock chip is one of the few things on a truck where waiting costs you and acting costs you almost nothing. Fresh, small, clean and away from the edge, it is a half hour repair that MPI does not hold against you. Left through a Manitoba fall, it is a new windshield, a camera recalibration and a truck off the road for the better part of a day.

If you have one in the glass right now, book it in this week, before the first hard frost decides for you.

Tyler Dunn, Dunn Ram Trucks, Portage la Prairie