How to Get Tar Out of Toilet: Proven 2026 Fix

Immediate Action (first 5 minutes)

Last July, my neighbor hired a cheap crew to seal his driveway. They decided to wash their tools in his guest bathroom sink, and a massive glob of driveway sealer ended up in the toilet. I got the frantic call at 8 PM. If you have kids who track mud everywhere, you might be used to messes, but tar is a whole different beast that won't just mop up.

Do not flush. I repeat, do not touch that flush handle.

Tar melts at high heat and turns to concrete in cold water. If you flush, the tar hits the 50°F water in the P-trap. It will harden into a solid mass. You'll be calling a plumber to snake a $300 clog, and they will likely have to pull the toilet off the flange. Stop the water immediately. Turn the silver valve behind the toilet base clockwise until it stops completely.

Next, flush the toilet exactly once. This empties the tank and stops new water from entering the bowl. Grab a plastic Solo cup and a bucket. Bail out every last drop of standing water from the bowl. I know this takes about five minutes of tedious scooping, but you absolutely cannot skip this step. Finally, put on thick nitrile gloves. Tar contains polycyclic aromatic hydrocarbons, and you don't want that toxic sludge soaking into your bare skin.

What You'll Need (tools/products)

I've tested dozens of solvents on asphalt, roofing pitch, and driveway sealer. Most household cleaners just smear the black mess around the bowl. You need specific chemical breakdowns to lift petroleum bonds without etching your porcelain. Here is the exact gear I keep in my cleaning caddy for this nightmare scenario.

Tool/Product	Why You Need It	Estimated Cost	My Top Pick
Heavy-Duty Citrus Solvent	Breaks down petroleum bonds safely	$12 - $18	Zep Heavy-Duty Citrus Degreaser
Plastic Putty Knife	Scrapes without scratching porcelain	$4 - $6	Stanley 1-1/2" Plastic Scraper
Nitrile Gloves	Protects skin from toxic chemicals	$8 - $12	Venom Steel Nitrile Gloves
Microfiber Rags	Absorbs dissolved sludge effectively	$10 - $15	Amazon Basics Microfiber Cloths
Heavy Trash Bags	Safe disposal of hazardous waste	$5 - $8	Hefty Ultra Strong Tall Kitchen Bags

Step-by-Step Removal

This isn't the cheapest option, but buying the right tools saves you from replacing a $400 toilet. Follow these steps exactly as I've outlined them.

Step 1: Dry the porcelain completely

Water and oil don't mix. Tar is essentially a heavy petroleum oil. If the bowl is wet, your solvent will just float on top of the water droplets and never reach the stain. Take a dry rag and wipe down every inch of the stained area. I usually go over it twice with paper towels just to be absolutely sure the surface is bone dry.

Step 2: Apply the citrus solvent generously

Spray or pour your Zep Citrus Degreaser directly onto the tar spots. Don't be shy with the application. You want the tar completely submerged in the liquid. Let it sit for exactly 15 to 20 minutes. The d-limonene in the citrus solvent needs time to penetrate the hardened petroleum bonds and turn the solid mass back into a gooey paste.

Step 3: Scrape the bulk material

Take your Stanley plastic putty knife. Hold it at a 45-degree angle against the porcelain. Push gently against the edge of the tar blob. It should peel up like thick chewing gum. If it resists, stop immediately. Apply more solvent and wait another 10 minutes. Never use a metal razor blade here. Metal will leave permanent gray scratches on your porcelain glaze that will trap dirt forever.

Step 4: Wipe away the sludge

Once the bulk is gone, you'll have a sticky brown residue left behind. Fold your microfiber rag into a square. Wipe the area firmly in one direction. Flip the rag to a clean side and repeat until the black streaks are gone. Throw these rags in a sealed trash bag immediately. The fumes will stink up your bathroom for days if you leave them in an open bin.

Step 5: Final polish and flush

Spray a standard bathroom cleaner like Method Antibacterial Bathroom Cleaner on the area. Wipe it down to remove the oily citrus film left behind by the degreaser. Turn your water valve back on. Let the tank fill completely and flush twice to clear any microscopic debris from the trap.

Alternative Methods

Sometimes the tar is baked on, or it's a specific type of roofing pitch that laughs at citrus solvents. I'll be honest, this takes elbow grease and some weird science. Here are three backup methods I've used when the Zep degreaser just won't cut it.

The Dry Ice Freeze Method

Tar becomes incredibly brittle at low temperatures. Buy a small bag of dry ice from your local grocery store (usually around $15). Put on thick leather work gloves. Drop a few pellets directly onto the tar stain. Wait about 3 minutes. The extreme cold (-109°F) causes the tar to shrink and crack. Tap it with the handle of your plastic scraper. It will shatter and pop right off the porcelain. This is my favorite trick for thick, stubborn drips near the water line.

The Heat Gun Technique

If you have a DeWalt heat gun in your garage, you can melt the tar. Set it to 200°F. Hold it about 6 inches away from the stain. Move it constantly in small circles. You just want to soften the tar, not boil it. Once it gets gooey, scoop it out with a plastic spoon. Be extremely careful with this method. If you heat one spot too fast, the thermal shock can crack your toilet bowl right down the middle. I only recommend this for small spots.

WD-40 Specialist Heavy-Duty Degreaser

Don't use regular WD-40. It leaves a terrible oily ring that is hard to wash out. Instead, grab the WD-40 Specialist Industrial-Strength Degreaser (about $9 at Home Depot). It contains stronger surfactants that lift the tar without leaving a greasy film. Spray it on, wait 10 minutes, and wipe. It works exceptionally well on driveway sealer splatters that have cured for more than 48 hours.

Prevention Tips

Dealing with tar is a nightmare. Preventing it takes five minutes and saves you a massive headache.

If you have contractors working on your roof or driveway, close the bathroom windows. Dust and drips travel further than you think. When your landlord inspects next week, you don't want them seeing black streaks in the porcelain. So, if you are doing DIY home repairs, tape the toilet lid shut. I use 2-inch blue painter's tape across the lid and the tank to keep it sealed.

Better yet, buy a $5 plastic toilet bowl liner from a hardware store. These are thin plastic bags that fit inside the bowl during renovations. If a roofer drops a glob of hot pitch, it hits the plastic. You just pull the bag out and throw it away. Never let anyone wash painting or roofing tools in your plumbing. It's illegal in most municipalities to dump petroleum products down the drain. It ruins your septic tank and clogs city sewer lines.

FAQ

Will tar ruin my toilet's porcelain finish?

Tar itself won't chemically etch or ruin the porcelain glaze. However, using metal scrapers or abrasive pumice stones to remove the tar will leave permanent scratches. Always stick to plastic tools and chemical solvents to keep your bowl smooth and shiny.

Can I flush the tar down the drain once it's removed?

Absolutely not. Tar will cool and harden inside your P-trap or main sewer line, creating a massive clog that requires professional hydro-jetting. Always wipe the removed tar into paper towels and throw it in your outdoor garbage bin.

What if the tar is deep inside the toilet trap?

If tar has slipped past the visible bowl and into the S-trap, you'll need a closet auger with a polymer coating. Run the auger gently to break up the mass, then pour a half-gallon of boiling water mixed with dish soap down the drain to melt the remaining residue.

Is it safe to mix citrus solvents with bleach?

Never mix citrus degreasers, mineral spirits, or any petroleum solvent with bleach. This combination can create toxic chloramine gases that are highly dangerous in a small, enclosed bathroom. Always rinse the bowl thoroughly with plain water before using any bleach-based toilet cleaners.