A small chip or crack rarely stays small. Heat, cold, road vibration, and even closing a door hard put stress on damaged glass, and a crack that started the size of a pea can run across the windshield in a single afternoon.
The good news: what you do in the first day or two makes a real difference. Here is what actually helps, what doesn't, and how to tell when it is time for a professional.
Step 1: Keep the damage clean and dry
Dirt and water that work their way into a chip make it harder to repair cleanly and can leave a more visible mark afterward. Until you can get it looked at:
- Cover the damage from the outside with a small piece of clear packing tape. This keeps out dirt and moisture — it does not hold the glass together.
- Avoid automatic car washes and pressure washers.
- Don't poke at the chip or try to clean debris out of it.
Step 2: Avoid sudden temperature changes
Temperature shock is the most common reason a crack suddenly grows. The inside and outside of the glass expand at different rates, and the damaged spot is where the stress releases.
- Don't blast the defroster on high against a cold windshield. Warm the cabin gradually.
- On hot days, don't point the A/C straight at the glass after the car has been sitting in the sun.
- Park in the shade or a garage when you can.
- Never pour hot water on an icy or frosty windshield.
Step 3: Reduce stress on the glass
- Close doors gently — slamming creates a pressure wave inside the cabin.
- Avoid rough roads and potholes when possible.
- Leave a little extra following distance on the freeway to reduce the chance of a second rock hitting the same area.
DIY myths that make cracks worse
Drilling a hole at the end of the crack. This technique comes from other materials and is not a safe fix for laminated windshield glass. It can weaken the glass further and usually makes a proper repair impossible.
Nail polish or superglue. These seal the surface but trap air and dirt inside the break, which blocks professional resin from filling it later. What could have been a repair often becomes a replacement.
Store-bought repair kits on long cracks. Kits can sometimes help a small, fresh chip, but they are not designed for cracks that are already running. A failed kit repair also can't be undone.
"It's small, it'll be fine." Most chips eventually spread. Waiting is the most expensive option.
When can a crack still be repaired?
In general, damage can be repaired when it is small — about the size of a quarter or less — and not in the driver's direct line of sight or at the edge of the glass. Common repairable damage includes bullseyes, star breaks, and small combination breaks. Our rock chip and crack repair page shows the damage types we repair and what to expect.
Once a crack is longer than that, reaches the edge of the windshield, or sits right in front of the driver, replacement is usually the safer choice. Our guide to repair vs. replacement explains the difference in detail, and if you commute on the I-580 corridor, our article on what to do about rock chips before they spread covers the freeway side of the problem.
Why speed matters
A professional repair injects resin into the break, restoring strength and stopping the damage from growing. The sooner it is done, the cleaner the result and the better the chance of avoiding a full windshield replacement. Chip repair at our shop is $80 ($70 cash), and many comprehensive insurance policies cover chip repair — coverage always depends on your policy.
Bottom line
You can't un-crack a windshield, but you can slow the damage down: keep it clean, avoid temperature shock, skip the DIY tricks, and get it looked at quickly.
Low Price Auto Glass & Tint serves Dublin, Pleasanton, Livermore, San Ramon, and Danville from 6355 Scarlett Court, Suite 8, Dublin. Call 925-492-7272 or request a quote and we'll tell you whether your damage can be repaired or needs replacement.