Tar can be removed from concrete using a combination of solvent-based cleaners and hot water pressure washing.
You probably didn’t notice the black smear on your driveway until you parked on top of it. Asphalt tar from road patching or a roofing project can bond to concrete pores fast, leaving behind a stain that seems baked in. Scrubbing with soap and water usually does nothing — the tar laughs at it.
The honest answer is that removing tar takes a little chemical help and some heat. Professionals rely on solvent-based tar removers paired with hot water pressure washing to break the bond and lift the stain. This article walks through the methods that actually work, plus the mistakes that can ruin your concrete if you’re not careful.
The Two-Step Formula Professionals Use
Tar removal on concrete comes down to two actions: chemically soften the tar, then physically flush it away. Commercial-grade solvent cleaners are designed to break down the petroleum-based compounds in asphalt and tar, turning a solid stain into a liquid that can be washed off.
After the solvent does its work, heat completes the job. Hot water pressure washing doesn’t just blast the surface — the heat helps melt the tar’s molecular structure, making it easier to lift from porous concrete. A standard cold water rinse won’t achieve the same results.
For the most stubborn stains, you may need to repeat the cycle. Let the cleaner dwell longer on the second pass, and consider using a turbo nozzle to concentrate the pressure on the affected area.
Why Simple Scrubbing Won’t Cut It
Tar is sticky, waterproof, and designed to withstand weather. A brush and soap barely touch it. The misconception is that more elbow grease will eventually beat the stain, but in reality, you’re just spreading the tar deeper into the concrete pores. Professional methods address the chemistry first, then the mechanics.
- Heat breaks down tar: Hot water weakens tar’s molecular bonds — professionals consider this step essential for old or thick deposits.
- Solvent-based cleaner: Purpose-made removers dissolve tar without damaging concrete, unlike gasoline or thinner.
- Blot fresh tar stains: If the tar is still wet or soft, scrape or blot away the excess before applying any cleaner to prevent spreading.
- Excessive pressure damages concrete: Cranking your pressure washer to max PSI can etch or pit the surface — a common mistake homeowners make.
- Dwell time matters: Letting a degreaser sit for several minutes before washing significantly improves stain lift-off.
Hot Water Pressure Washing for Tough Stains
When a solvent alone doesn’t finish the job, hot water pressure washing is the next level. The combination of chemical softening and thermal melting can handle tar footprints, old driveway patches, and even roofing asphalt drips. Many professional crews use a surface cleaner attachment to keep the pressure even and avoid channeling the concrete.
The heat from the water also helps the cleaner penetrate deeper into the concrete pores. Industry sources like Azpowerwashpros note that hot water is hot water pressure washing is the standard approach for this type of stain because cold water simply lacks the thermal power to dissolve tar effectively.
| Method | Best For | Considerations |
|---|---|---|
| Solvent-based tar remover | Fresh to moderately set stains | Needs adequate dwell time; wear gloves |
| Hot water pressure wash | Old or thick tar deposits | Requires professional-grade equipment or rental |
| Degreaser pre-treatment | Tar mixed with oil or grease | Apply before solvent for best results |
| Turbo nozzle | Stubborn footprint patches | Use with caution to avoid etching |
| Cold water + brush | Surface dust, not tar | Ineffective for set stains |
No single method works every time. The best approach usually layers a solvent soak followed by a hot water rinse and a second treatment if any residue remains.
Step-by-Step Removal Process
Following a sequence prevents wasted effort and reduces the chance of damaging your concrete. Each step builds on the last, from preparation to final rinse.
- Remove excess tar: Use a putty knife or scraper to lift off any loose or thick blobs. Don’t push it into the pores.
- Apply solvent cleaner: Saturate the stain with a purpose-made tar remover. Let it dwell for 5 to 10 minutes (check the label).
- Scrub with a stiff brush: Work the cleaner into the stain using circular motion. A push broom works for larger areas.
- Hot water pressure rinse: Use a pressure washer with water heated to at least 200°F if possible. Start from a distance and work closer.
- Repeat if needed: Stubborn stains may require a second application. Allow the concrete to dry between treatments to judge progress.
After the tar is gone, rinse the entire area with clean water to remove any solvent residue. Sealing the concrete afterward can help future stains resist bonding as strongly.
Common Mistakes That Ruin Concrete
Knowing what not to do is just as important as knowing the right steps. A few common errors turn a simple cleanup into an expensive resurfacing job.
| Mistake | Consequence | Better Approach |
|---|---|---|
| Using gasoline or diesel | Weakens concrete, harmful fumes, environmental hazard | Use a commercial solvent rated for masonry |
| Too much pressure (over 3000 PSI on old concrete) | Etches surface, strips sealant, creates rough patches | Stay under 2500 PSI unless concrete is new and strong |
| Skipping pre-treatment | Stain sits untouched; water alone pushes it deeper | Always apply degreaser or solvent first |
Guidance from Buckhornpowerwash emphasizes that pre-treat concrete degreasers are a key step that many DIYers skip. Without dwell time, even strong cleaners fail to penetrate the stain fully.
The Bottom Line
Getting tar off concrete is doable with the right sequence: scrape, apply solvent, dwell, then hit it with hot water pressure. Cold water and elbow grease rarely work. For old or deeply embedded stains, plan on two passes and consider a professional-grade machine rental.
If your driveway has a sealer or is older than five years, check with a concrete contractor or pressure washing service before cranking up the PSI — they can match the method to your specific surface without risking damage.
References & Sources
- Azpowerwashpros. “Remove Asphalt Concrete Driveway” Hot water pressure washing is more effective at breaking down and removing stubborn tar stains from concrete than regular cold water washing.
- Buckhornpowerwash. “10 Concrete Pressure Cleaner Mistakes That Ruin Your Driveway” Pre-treating concrete with appropriate degreasers and cleaning solutions before pressure washing helps loosen embedded stains and improves overall cleaning effectiveness.