A combination break is a windshield chip that displays characteristics of two or more damage types in a single impact point. The most common combination is a bulls-eye center with star-break legs radiating outward, creating a pattern that looks like a circular chip with cracks extending in multiple directions. These are among the most frequent chip types seen on Denver highways, especially along high-speed corridors like I-25, I-70, and I-225 where debris impacts carry substantial energy.
What Makes a Combination Break Different
A simple bulls-eye chip has a clean, circular damage pattern with no extending cracks. A star break has radiating legs without a significant circular component. A combination break has both: a circular or semicircular center surrounded by linear fractures extending outward.
Combination breaks form when the impact carries enough energy to create both the concentric circular fracture (the bulls-eye component) and the radiating linear fractures (the star component) simultaneously. This typically requires a higher-energy impact than what produces either type alone, which is why combination breaks tend to be slightly larger than simple bulls-eye or star-break chips.
Can Combination Breaks Be Repaired?
Yes, combination breaks can be repaired, but they represent the upper end of repair complexity. The success of the repair depends on:
- Total diameter: The span from the tip of one leg through the center to the tip of the opposite leg should be under 3 inches for reliable repair results
- Number and length of legs: Fewer, shorter legs are easier to fill completely with resin. If any single leg exceeds 6 inches, replacement may be more appropriate
- Depth of the center: If the bulls-eye center penetrates through the outer glass layer into the PVB interlayer, repair cannot adequately restore structural integrity
- Contamination: Because combination breaks have more surface area exposed, they collect dirt and moisture faster than simple chips, making prompt repair even more important
The Repair Process for Combination Breaks
Repairing a combination break requires a methodical approach. The technician essentially needs to repair both the circular and linear components, ensuring resin reaches every part of the damage pattern.
- Assessment: The technician maps every fracture line, identifying the center point, the circular boundary, and the tip of each radiating leg. This step is critical because missing a hidden fracture line means incomplete repair.
- Center treatment: The bulls-eye center is addressed first. The cone of glass at the impact point is cleaned out, and the circular cavity is prepared to accept resin.
- Leg-by-leg injection: The repair bridge may need to be repositioned to ensure resin reaches the tips of the longest legs. The technician alternates between vacuum and pressure cycles, watching for resin flow in each leg.
- Curing and polish: Because there is more resin to cure, UV exposure time may be slightly longer -- about 7 to 10 minutes instead of the standard 5. The polishing step covers more surface area as well.
Total repair time for a combination break is typically 25 to 35 minutes, slightly longer than a simple bulls-eye or star break. For a full timeline, see our article on how long chip repair takes.
Denver Conditions and Combination Breaks
Denver's climate creates unique challenges for combination breaks. The multiple fracture lines in a combination break provide more pathways for temperature-driven expansion and contraction to extend the damage. Each leg of the star component and each point on the circular boundary is a potential growth point.
During a typical Denver spring day, the glass can go from near-freezing at dawn to 70 degrees by afternoon. Every thermal cycle stresses the fracture tips. A combination break that was repairable on Monday morning might have legs that have grown past the repair threshold by Wednesday. If you have a combination break, treat it as urgent -- ideally within 24 hours.
When a Combination Break Cannot Be Repaired
Combination breaks cross into replacement territory when:
- Total diameter exceeds 3 to 4 inches
- Any single leg has grown longer than 6 inches
- The center damage penetrates both glass layers
- The chip is in the driver's direct line of sight and would cause optical distortion after repair
- The chip is within 2 inches of the windshield edge, compromising the structural seal
If your combination break has evolved beyond repair, you will need a full windshield replacement. This is another reason why prompt repair matters -- catching a combination break early keeps it in the repairable range.
What to Expect After Repair
A repaired combination break will show more residual visibility than a repaired bulls-eye because there are more fracture lines. The center typically clears up well, but the faintest outline of the star-break legs may remain visible at certain angles, especially in direct sunlight. However, the structural integrity is fully restored, the damage cannot spread further, and the repair passes Colorado vehicle inspection. Check our guide on repair visibility for more realistic expectations.