Infrared Patching: How It Works, Equipment, and When to Use It

After years of working with paving contractors, we've seen how infrared patching turns what used to be a full day of cutting, hauling, and repaving into a 30-minute fix. It blends right into the existing surface by heating the asphalt in place, reworking it, and compacting it into a seamless repair.

What Is Infrared Patching?

Infrared patching is a repair method that uses radiant heat to soften damaged asphalt so it can be reworked in place. 

Instead of sawing out the bad section and replacing it entirely, the heater warms the existing material to around 325°F, making it pliable enough to rake, blend with fresh hot-mix asphalt, and compact into a finished patch.

The result is a thermally bonded repair with no cold joints or visible seams, so water and ice can't sneak between old and new material the way they do with conventional cut-and-patch jobs.

Unlike traditional approaches, infrared patching recycles the asphalt already on the ground. You heat what's there, add new material where needed, and compact it into a single continuous surface. This saves time, material, and labor on every repair.

Infrared patching is a surface-level fix. It corrects damage in the asphalt course itself. If the subgrade (the foundation underneath) has failed, infrared won't solve the problem long term. 

You'll get a patch that looks great for a few weeks, then the same failure will reappear. Always evaluate the base before deciding on a repair method.

How Infrared Patching Works: Step by Step

The infrared patching process looks simple from the outside, but each step directly affects how long the repair lasts. Here's how it breaks down:

Step 1: Clean and prep the area

The crew starts by clearing the repair zone of loose aggregate, debris, and vegetation. Blowers and brooms are the go-to tools here (not pressure washers, since introducing water to asphalt before heating causes problems). 

If there's standing moisture, the heater can evaporate it, but excess water during the heating phase risks scorching the surface unevenly.

Step 2: Position the infrared heater

The heater gets placed directly over the damaged section. Depending on the unit size, it covers anywhere from 2 square feet on a small portable model up to 48 square feet on a full trailer-mounted rig. 

Infrared rays penetrate the surface and heat the asphalt to a depth of 1.5 to 2.5 inches. This prevents the scorching you'd get with open flame or direct-contact methods.

Step 3: Heat the asphalt to working temperature

This step typically takes 7 to 15 minutes, depending on the ambient temperature, wind conditions, depth of damage, and how old the asphalt is. The target is 325°F to 350°F, which is close to the original plant temperature when the asphalt was first laid.

Older, oxidized asphalt (the white or gray material) absorbs heat more slowly than newer, darker pavement. Wind pulls heat away from the surface. These can slow the process down. 

And cold weather means the heater needs more time to reach working temperature. Experienced crews learn to read these conditions quickly and adjust their schedule accordingly.

Step 4: Rake, scarify, and apply rejuvenator

Once the asphalt softens, the crew rakes and scarifies the heated material, pulling up the top layer to remove contamination and expose fresh binder. 

A rejuvenating agent gets applied at this stage to replace the maltenes (light oils in the asphalt cement) that oxidize out of the material over time. This step is critical because it restores flexibility to the existing asphalt and helps it bond with the new material.

A good lute operator makes or breaks this step. Over-raking pulls large aggregate to the surface, which creates voids and weakens the finished patch. The goal is one or two efficient passes that level the material without disturbing it more than necessary.

Step 5: Add new hot-mix asphalt

Fresh hot-mix gets blended into the raked surface. The crew works it in with the existing material so old and new asphalt don't segregate into separate layers. 

For best results, contractors use a finer aggregate mix (often called top mix or sheet mix) because it compacts more tightly and produces a smoother finish.

The amount of new material depends on the depth of the repair, so crews need to understand how to calculate asphalt yield to avoid over- or under-filling. 

Some patches only need a light top-up to bring the surface back to grade. Deeper repairs (like potholes that have lost significant volume) need more material to fill the void before compacting.

Step 6: Compact and finish

The final step is compaction with a vibratory plate or roller. Timing matters here. Compacting at the highest possible temperature produces the tightest bond. 

If the material cools too much during raking, the crew can reheat it for 1 to 2 minutes to bring it back up to 325°F before compacting.

Once compaction is complete, the patch is ready for traffic in about 30 minutes. No curing time. No barricades sitting out for hours. 

The repaired area blends flush with the surrounding pavement and, when done right, you can barely tell where the patch ends and the original surface begins.

Equipment You Need for Infrared Patching

Infrared patching requires four core components: an infrared heater to soften asphalt, a hot box to keep the mix workable, hand tools for raking and blending, and compaction equipment to finish the repair. 

If you're thinking about adding infrared patching to your service lineup, here's a breakdown of the core equipment involved:

Infrared heater

This is the centerpiece. Infrared heaters come in several sizes, and the right one depends on the type and volume of work you do.

• Portable units (2x2 to 2x4 ft): These are entry-level heaters built for small repairs. They run on standard propane tanks and one person can operate them. A 2x2 unit covers about 4 square feet per heat, which is enough for a single pothole or minor seam repair. 
• Mid-size units (up to 23 sq ft): Models like the KM 2-18X cover more ground per heat and work well for commercial parking lot repairs, utility cut patches, and larger potholes. 
• Trailer-mounted units (40 to 48 sq ft): Full-size rigs like the KM 4-40 or KM 4-48 are designed for high-volume production work. They fold up and tow behind a pickup truck, giving contractors the ability to tackle large repair areas and move between job sites quickly. 

Hot box or reclaimer

You need a way to keep your fresh hot-mix asphalt at working temperature throughout the day. A hot box (also called a reclaimer) holds 1 to 3 tons of material and uses propane or diesel to maintain it at laying temperature. 

Without one, your mix goes cold and becomes unusable, which kills productivity on multi-patch days.

Hand tools

Every infrared patching job requires a few basics: an asphalt lute (preferably with a magnesium head that can handle extreme heat), a rake for scarifying, a tamper for tight spots, and a rejuvenator sprayer. These aren't expensive, but having the right ones on the truck saves time.

Compaction equipment

A vibratory plate compactor handles most infrared patching jobs. For larger repairs or production-level work, a small drum roller delivers more consistent results across bigger areas.

Safety gear

Infrared patching involves extreme heat and hot asphalt. Crews need heat-resistant gloves, steel-toe boots, and proper PPE per OSHA requirements. Many municipalities also require safety protocols like traffic control cones and signage around active repair zones.

When To Use Infrared Patching (and When Not To)

Use infrared patching for surface-level asphalt damage with a solid base, and avoid it when the subgrade has failed or the damage is structural.

Best use cases for infrared patching

• Potholes with an intact base: If the hole is in the asphalt surface but the gravel and subgrade underneath are still solid, infrared patching gives you a long-lasting, bonded repair.
• Seam failures: When joints between old and new paving sections separate, infrared heat re-fuses the materials into a single surface with no cold joint.
• Utility cut repairs: After trenching for water, gas, or electrical lines, infrared patching blends the backfilled asphalt into the surrounding pavement.
• Low spots and birdbaths: Depressions that collect standing water create trip hazards and accelerate pavement damage. Infrared patching raises these areas back to grade.
• Manhole and catch basin adjustments: Infrared heat lets you raise or lower the asphalt around utility covers without cutting or sawing.
• Raveling and surface deterioration: When the top layer of asphalt starts losing aggregate, infrared patching reheats and re-bonds the surface.
• New overlay corrections: If a fresh overlay has a raveled area or imperfection, infrared heat lets you rework it without creating new seams.
• Speed bump installation: Infrared heat bonds speed bumps directly to the existing surface for a stronger attachment.

Note: Infrared patching is especially useful in commercial lots where crews already handle maintenance tasks like sealcoating and parking lot striping training.

When infrared patching won't work

• Subgrade failure: If the base beneath the asphalt has collapsed, settled, or washed out, an infrared surface repair will fail quickly. You need full-depth removal and base reconstruction first.
• Widespread alligator cracking: This pattern usually signals base failure, not surface damage. An infrared patch might look good for a few weeks, but it won't hold. Be upfront with your customer about this.
• Coal-tar sealed surfaces: Infrared heaters can't properly soften asphalt that's been sealed with coal-tar products. The chemistry is different and the material won't blend correctly.
• Severely oxidized asphalt: If the pavement is so old that it's turned white or gray throughout its depth, infrared patching will struggle to restore enough binder to create a lasting repair.

Infrared Patching vs. Traditional Cut-and-Patch

Infrared patching is faster, seam-free, and reuses existing asphalt, whereas traditional cut-and-patch handles deeper structural failures but takes more time, labor, and material. Here's how the two methods compare side by side:

The biggest advantage of infrared patching is speed. A typical 6 x 13 foot repair (about 78 square feet) takes roughly 20 minutes from start to finish. 

The same area with cut-and-patch could take over an hour. Multiply that across a full day of repairs, and the difference in production is significant.

The other advantage is longevity at the seams. Traditional patches create cold joints on every edge, and those joints are where water gets in and causes future failure. 

Infrared patching eliminates those joints entirely, which means the repair integrates with the surrounding pavement instead of sitting next to it.

That said, cut-and-patch is still the right choice when the base needs attention. No amount of surface heating will fix a foundation problem. A good contractor knows when to use each method and prices the job accordingly.

How Much Does Infrared Patching Cost?

Infrared patching typically costs $2 to $6 per square foot or $100 to $450 per repair, depending on size, material, and job complexity. Here's a general breakdown of what drives pricing:

Cost per repair

Most contractors charge per heat (one cycle of the infrared heater), often using a paving estimate template to standardize pricing across different job sizes. Pricing varies widely by region and job size, but typical ranges fall between $100 and $450 per heat. 

The size of the heater, the amount of new material added, and the complexity of the repair all affect the final number.

For property owners hiring a contractor, expect to pay between $2 and $6 per square foot for infrared patching. A small pothole repair might run $100 to $300, and larger commercial repairs can reach $1,000 or more, depending on total area.

Remember: Clear pricing backed by a detailed asphalt paving proposal template helps set expectations and close jobs faster.

Equipment investment

If you're a contractor looking to buy infrared patching equipment, here's what the investment looks like:

• Small portable heater (2x2 ft): $1,000 to $3,000
• Mid-size heater (up to 23 sq ft): $3,000 to $7,000
• Trailer-mounted heater (40 to 48 sq ft): $7,000 to $20,000+
• Hot box/reclaimer (1 to 3 ton): $5,000 to $15,000

The math on ROI usually works in your favor. A crew running a mid-size heater can complete 8 to 12 repairs per day. At $150 to $450 per heat, the equipment can pay for itself within a few weeks of steady work.

Profit margins

Infrared patching tends to carry strong margins because material costs are low (you're reusing most of the existing asphalt) and labor needs are minimal (2 to 3 crew members). 

Contractors who track their job costs closely can identify exactly which infrared patching jobs deliver the highest returns and focus their bidding there. 

Tips for Getting the Best Results with Infrared Patching

Even experienced crews can run into problems if they skip the fundamentals. Here are the details that separate a patch lasting 5+ years from one that falls apart in a single season:

Watch for moisture

Water is the enemy of infrared patching. If moisture is present in the asphalt when the heater goes on, it evaporates unevenly and can cause the surface to scorch in some spots and stay cool in others. 

Blow or brush the area clean before heating. If the pavement is visibly wet, let it dry before you start.

Use rejuvenator on every repair

Rejuvenator replaces the oils that have oxidized out of the binder over time, and those oils are what make the asphalt flexible enough to bond with new material. 

The industry standard is about one-tenth gallon per square yard. It's a small cost that dramatically improves the life of the repair.

Don't over-rake

A common mistake is working the heated material too aggressively. Every extra pass of the lute pulls large aggregate to the surface, which creates voids and weakens the finished bond. One or two level passes is all you need. Get in, get it flat, and move on.

Compact hot

Compaction at peak temperature produces the tightest bond. If your material cools below working temp during the raking process, take 60 to 90 seconds to reheat before compacting. Compacting cool material gives you a loose patch that won't hold up under traffic.

Use heat shields near utilities

Many local codes prohibit heating near sewer grates, manholes, or drainage components. A thin aluminum sheet placed over the area you need to protect deflects the infrared rays and keeps that section cool. Simple fix that avoids code violations and damage to utility infrastructure.

Evaluate the base first (always)

This is worth repeating because it's the most common mistake in infrared patching. If the base has failed, the surface repair will fail too. 

Check for signs of base failure (alligator cracking, excessive settlement, soft spots) before quoting the job. Be honest with the customer if infrared isn't the right fix. It builds trust and saves you from callbacks.

Manage Your Infrared Patching Jobs from Estimate to Invoice

OneCrew was built for project-based asphalt and concrete contractors. It replaces the patchwork of tools that slow you down, whether you're running infrared patching crews, overlay jobs, or full-scale paving projects. Here's what you can do with it:

• Estimate from PDFs or satellite maps with built-in calculators and configurable cost automations: Set up your infrared patching rates (per heat, per square foot, or however you price), along with labor, material, equipment, and subcontractor costs. 
• Schedule crews and assign roles to specific job phases with clear accountability: Assign your infrared patching crew to morning repairs and your overlay crew to an afternoon pour, all from one schedule. 
• Track leads and customer relationships from first call through repeat business: Every inquiry, conversation, quote, and project history lives in one system.

You don't need five different apps to run your paving business. You need one platform that ties project management together from takeoff to final invoice Book a free demo and learn how OneCrew helps you take control of your jobs from start to finish.

FAQs

1. What is infrared patching?

Infrared patching is an asphalt repair method that uses radiant heat to soften existing pavement to around 325°F. Once softened, the material gets raked, blended with fresh hot-mix asphalt, and compacted into a bonded patch with no seams or cold joints.

2. How long does an infrared patching repair take?

Most infrared patching repairs take 20 to 45 minutes from setup to completion. Heating alone typically requires 7 to 15 minutes, depending on the asphalt's age, thickness, and weather conditions. The finished patch is ready for traffic within about 30 minutes after compaction.

3. Can infrared patching fix potholes?

Yes, infrared patching fixes potholes when the base underneath is still intact. The heater softens the surrounding asphalt, the crew fills and blends new material into the void, and the compacted patch bonds thermally to the existing surface. If the base has failed, you need full-depth repair first.

4. Does infrared patching work in cold weather?

Yes. Infrared patching works year-round because the heater raises the asphalt to plant temperature regardless of ambient conditions. Cold weather and wind increase heating time, but the repair quality stays the same. Rain, hail, and snow should be avoided since moisture interferes with the heating process.

5. How long does an infrared asphalt patch last?

A properly installed infrared patch on a solid base can last 3 to 5 years or more. The main factors that affect longevity are base condition, compaction quality, use of rejuvenator, and traffic volume. Patches over failed subgrade will deteriorate faster, regardless of how well the surface repair was executed.