How to Get Tar Out of Grout: 5 Best Proven Methods

By Amara Johnson · December 19, 2025

Immediate Action (first 5 minutes)

Tar is incredibly stubborn. It binds directly to the microscopic pores in your cementitious grout lines, creating a massive headache if left untreated. If you have kids who track mud everywhere, or if you recently had your driveway sealed and accidentally walked across the fresh asphalt, you know the sheer panic of seeing those thick black smudges on your pristine tile floor. In my experience cleaning tile for 12 years, the first five minutes dictate your success rate.

Don't wipe it. Wiping warm tar just pushes the petroleum deeper into the porous grout. Grab a plastic scraper immediately. I use the Stanley 10-inch plastic putty knife because it won't scratch your surrounding ceramic or porcelain tiles. Gently lift the bulk of the tar off the surface. Next, grab a handful of ice cubes from your freezer. Wrap the ice cubes in a thin plastic sandwich bag so you don't introduce excess moisture to the floor. Place them directly on the remaining tar residue for exactly three minutes. This drops the temperature of the tar below 40 degrees Fahrenheit, making it brittle and much easier to chip away without smearing. You'll save yourself hours of scrubbing later by taking these quick initial steps.

What You'll Need (tools/products)

Gathering the right supplies before you start is crucial. I'll be honest, this takes elbow grease, and having the proper tools makes the difference between a 15-minute fix and a ruined Saturday afternoon. Here is my exact toolkit for tackling petroleum-based stains on porous surfaces.

Solvent: Goo Gone Pro-Power Spray Gel ($14.99 for 24 oz). This isn't the cheapest option, but the citrus-based d-Limonene formula breaks down asphalt binders faster than standard household cleaners.
Scraper: Stanley 10-inch plastic putty knife ($6.48). Metal scrapers will gouge your grout lines. Stick to high-density plastic.
Brush: OXO Good Grips Deep Clean Brush ($8.99). The stiff nylon bristles are exactly 3/8 inch long, which is perfect for reaching into standard 1/4 inch grout joints without damaging the edges. The ergonomic handle also prevents wrist fatigue during long scrubbing sessions.
Safety Gear: 4-mil nitrile gloves. Petroleum solvents will dry out your skin rapidly and can cause contact dermatitis if you have sensitive hands.
Absorbent: Microfiber cloths and heavy-duty paper towels.
Neutralizer: Krud Kutter Original ($11.98) or a simple Dawn dish soap solution to remove the oily solvent residue.

Let's compare the top three solvents I've tested on my own garage and bathroom floors.

Product	Active Ingredient	Dwell Time	Best For
Goo Gone Pro-Power	d-Limonene (Citrus)	5-10 minutes	Sealed grout, fresh tar
WD-40 Specialist Degreaser	Aliphatic Hydrocarbons	3-5 minutes	Heavy buildup, outdoor tile
Mineral Spirits	Petroleum Distillates	1-2 minutes	Unsealed grout, old stains

Step-by-Step Removal (4-7 steps)

Now we get to the actual cleaning process. I recommend this specific sequence because it isolates the tar, breaks the chemical bonds, and extracts the residue without pushing it deeper into the cement. When your landlord inspects next week, you want that floor looking flawless.

Step 1: Isolate and Protect the Area

Open your windows. Solvents emit strong volatile organic compounds (VOCs), and you need cross-ventilation. Put on your nitrile gloves to protect your skin from both the tar and the citrus degreasers. Lay down a few dry paper towels around the perimeter of the stain to catch any chemical runoff.

Step 2: Apply the Citrus Solvent

Spray the Goo Gone Pro-Power directly onto the remaining tar in the grout line. Don't be shy. You want the grout completely saturated. Let it sit for exactly 8 minutes. I've timed this extensively; anything less than 5 minutes won't penetrate the asphalt binder, and leaving it for over 15 minutes allows the solvent to evaporate, leaving a sticky mess behind.

Step 3: Agitate with a Stiff Nylon Brush

Take your OXO Good Grips Deep Clean Brush and scrub the grout line using firm, circular motions. Keep the brush at a 45-degree angle to the floor to force the bristles directly into the joint. Apply about 5 pounds of downward pressure. You'll see the tar start to liquefy and turn into a dark, muddy sludge. The stiff 3/8 inch bristles are crucial here. They reach deep into the 1/4 inch joint to dislodge the petroleum from the microscopic pores.

Step 4: Extract the Sludge

Immediately wipe away the dissolved tar sludge with a dry microfiber cloth. Fold the cloth frequently to ensure you are always lifting the stain with a clean surface. If you just push the sludge around, you will re-deposit the tar into adjacent clean grout lines. Throw the dirty paper towels and cloths in an outdoor trash can, as they can be a spontaneous combustion fire hazard if left bunched up indoors.

Step 5: Repeat if Necessary

Inspect the grout under a bright LED flashlight. If you still see dark shadows in the pores, repeat steps 2 through 4. Older, baked-on tar from a summer roof repair might require two or three applications. Patience is your best tool here.

Step 6: Neutralize and Rinse

Citrus solvents leave an oily film that will attract dirt for weeks if not removed. Mix two tablespoons of Dawn Ultra dish soap into a spray bottle filled with warm 100-degree Fahrenheit water. Spray the area generously. Scrub lightly with a soft sponge, then mop the entire floor with a bucket containing exactly two gallons of clean water. Change the mop water if it turns cloudy. This final step restores the natural pH and removes the slippery solvent residue.

Alternative Methods (2-3 backup methods)

Sometimes the citrus approach doesn't cut it. If you are dealing with heavily oxidized, decade-old tar, or if your grout is completely unsealed and highly porous, you need a heavier chemical punch. Here are three backup methods I keep in my professional cleaning van.

Method 1: WD-40 Specialist Heavy-Duty Degreaser

This isn't the standard blue and yellow can of WD-40. The Specialist Heavy-Duty Degreaser ($12.49) uses a powerful aliphatic hydrocarbon blend that dissolves industrial adhesives and roofing tar. Spray it on, wait 4 minutes, and scrub. I'll be honest, the smell is intense, so this is best reserved for well-ventilated areas like a garage or an outdoor patio. It cuts through thick tar layers about 30% faster than citrus solvents, but it requires a very thorough soap wash afterward to remove the chemical film.

Method 2: Mineral Spirits for Unsealed Grout

If your grout has never been sealed, water-based or citrus cleaners can sometimes cause the raw cement to crumble or discolor. Mineral spirits ($9.99 a quart at any hardware store) are highly effective and safe for raw cementitious materials. Dampen a clean white rag with the mineral spirits. Press the rag into the grout line and let it sit for 60 seconds. Wipe firmly in one direction. The petroleum distillates dissolve the tar without adding moisture that could weaken unsealed grout. Always test this on a hidden corner first to ensure it doesn't pull the dye out of colored grout.

Method 3: The Heat Gun Technique (For Thick Globs)

If you have massive, thick globs of roofing tar that won't scrape off cold, a heat gun can save the day. Set a Wagner HT1000 heat gun to its low setting (around 750 degrees Fahrenheit). Hold it exactly four inches above the tar for 15 seconds. The heat softens the asphalt binder, allowing you to scoop it out with your plastic putty knife like warm butter. Be extremely careful not to overheat the surrounding tile, as rapid temperature changes can cause ceramic to crack or pop off the subfloor.

Prevention Tips

Stopping tar before it penetrates is always easier than extracting it. After hosting a dinner party where someone accidentally tracks in driveway sealant, you want to be able to just wipe it up without a chemical battle.

Seal Your Grout Annually: I swear by Aqua Mix Sealer's Choice Gold ($22.99). It penetrates the pores and creates a hydrophobic barrier. When tar lands on sealed grout, it sits on the surface rather than sinking in. Apply it with a small foam brush, let it cure for 24 hours, and wipe off the haze.
Use Heavy-Duty Entry Mats: Place a rubber-backed scraper mat outside every exterior door. The coarse bristles physically scrape asphalt and mud off shoe treads before they reach your tile.
Winter Road Tar Protocol: If you live in a climate with harsh winters, road tar used on local highways can easily hitch a ride on your boots. Keeping a dedicated shoe tray in the garage stops this problem before it reaches your interior tile.
Keep a Solvent Pen Handy: Keep a small bottle of Goo Gone in your cleaning caddy. Treating a scuff mark within 10 seconds of it happening prevents the petroleum from curing and hardening in the porous cement.

FAQ

Will tar permanently stain unsealed grout?

Yes, if left untreated for more than a few days, tar will permanently dye unsealed grout. The petroleum oils seep deep into the microscopic pores of the cement, creating a dark shadow that surface cleaners cannot reach. If this happens, your only option is to use a grout saw to physically remove the top 1/8 inch of the stained cement and re-grout the joint.

Can I use a wire brush on grout to scrub out tar?

Absolutely do not use a steel wire brush on your tile floors. The hard metal bristles will easily scratch the glaze off ceramic and porcelain tiles, leaving permanent dull marks. Furthermore, wire brushes can aggressively dig into the grout line, causing the cement to crumble and crack over time.

How long should I let the solvent sit on the tar?

For most commercial citrus degreasers, a dwell time of 5 to 10 minutes is the sweet spot. This gives the d-Limonene enough time to break down the complex hydrocarbon chains in the asphalt binder. If you let it sit for longer than 15 minutes, the solvent will evaporate into the air, leaving behind a sticky, hardened residue that is even harder to remove.

Does bleach remove tar from grout?

Bleach is completely ineffective against tar and petroleum-based stains. Sodium hypochlorite is an oxidizing agent designed to kill mold, mildew, and organic bacteria, but it cannot dissolve asphalt binders. Using bleach on tar will just create a toxic, sticky mess and potentially discolor the surrounding grout without lifting the black stain at all.

Can I use a magic eraser on tar stains?

Melamine foam sponges like the Mr. Clean Magic Eraser are completely useless against thick petroleum stains. The micro-abrasive structure of the foam will just smear the black tar across the grout line and ruin the sponge instantly. Save your magic erasers for scuff marks, soap scum, and light dirt, but keep them far away from sticky asphalt residues.