Infrared asphalt repair in NZ — how it works, when it makes sense, and why you rarely see it

Infrared asphalt repair heats the existing surface until it softens, rakes fresh hot mix through it, and recompacts — a repair with no cold joint. It works when the defect sits in the top 50–75 mm of asphalt. It cannot fix a failed base, which is what causes most Auckland potholes, and few NZ contractors run the plant.

How infrared repair works

An infrared panel sits over the damaged area and heats it for several minutes until the old asphalt softens enough to rake. The crew scarifies the softened surface, works fresh hot mix through it, and compacts the blended material. Because the old and new asphalt fuse while both are hot, there is no cold joint — no seam between patch and surround. Joints are where conventional patches fail first, which is the whole appeal.

What it is genuinely good at

• Surface-layer defects. Ravelling, minor depressions, scuffed or torn surface, and the seams of a previous patch that has started to open.

• Joint elimination. A fused edge sheds water instead of admitting it. On a sound base, expected life is comparable to a cut-and-patch repair.

• Less new material. The method reuses the asphalt already in the ground and adds only a topping of fresh mix — less cartage in, less spoil out.

Where it falls over

• Base failure. Infrared reworks roughly the top 50–75 mm. If the hole keeps forming because the layers underneath have failed, reheating the surface repairs the symptom and leaves the cause. Base failure and surface failure look similar from above — the diagnosis matters more than the method.

• Water-driven potholes. Most Auckland potholes are water working on the pavement, not frost. A pothole that formed because water sits in or under the pavement will reform through an infrared patch just as it did through the original surface.

• Deep holes and wet days. A hole deeper than the reheated layer needs cutting out and rebuilding anyway, and heating a wet surface wastes most of the energy boiling water off before the asphalt softens.

• Operator error. Held too long, the panel burns the bitumen. Overheated binder oxidises and goes brittle, and the repair ravels early. The method is only as good as the crew running the panel.

Why you rarely see it in New Zealand

Infrared rigs earn their keep in North American cities, where freeze-thaw climates produce huge volumes of shallow surface defects and joint failures. New Zealand's damage profile is different — water and base failure dominate — and the market is smaller, so the specialist plant rarely pays for itself here. That is why our six-method comparison lists infrared as legitimate but scarce: the method is sound, the economics mostly are not. We cut and patch with hot mix because it fixes the base as well as the surface, on any depth of failure, in any month of the Auckland calendar.

If someone quotes you infrared

Ask three questions. Is the defect confined to the surface layer, and how was that established? What happens to the base? And does the warranty match what a cut-and-patch repair would carry? Straight answers to all three mean you are dealing with someone who knows the method's limits. Vague answers mean you are buying the machine, not the repair.

The short version

Infrared repair is a real method with a narrow lane: shallow, surface-only defects on a sound, dry base. For the typical Auckland pothole — water in the pavement, base going soft — cutting out the failure and rebuilding it with fresh hot mix remains the repair that lasts. For a fixed price from three photos, start at our pothole repair page.