Does Steam Cleaning Remove Urine from a Mattress? Here's What Actually Works

Urinating on a mattress isn’t something most people plan for-but it happens. Kids, pets, medical conditions, or accidents in the night can leave behind stains, smells, and bacteria that won’t vanish with a quick vacuum or surface wipe. So when you ask, does steam cleaning get urine out of a mattress?, you’re not just looking for a quick fix-you’re trying to save your sleep, your health, and maybe even your wallet.

Why Urine on a Mattress Is a Big Problem

Urine doesn’t just sit on top of the fabric. It soaks through the top layer, into the foam padding, and sometimes all the way to the base. Once it dries, the ammonia in urine bonds with the fibers and foam, turning into a stubborn odor that gets worse over time. Heat makes it worse-your body heat while sleeping reactivates the smell, making your bedroom feel like a locker room by morning.

Standard cleaning methods like baking soda or vinegar might mask the odor temporarily, but they don’t touch the root problem. The urine salts and proteins are still trapped deep inside, feeding bacteria and mold. That’s why many people turn to steam cleaners, hoping high heat will blast the mess away.

How Steam Cleaning Works (and Why It Falls Short)

Steam cleaners use water heated to over 200°F to produce pressurized vapor. That heat kills bacteria, loosens dirt, and evaporates moisture quickly. It’s great for grease, grime, and surface stains. But urine isn’t just dirt-it’s a biological compound that needs chemical breakdown.

Here’s the catch: steam alone doesn’t neutralize urine. It can actually make the smell worse. The heat drives the ammonia deeper into the mattress layers, locking it in. You might think the smell is gone because the surface is dry, but underneath, the urine is still active. Within days, the odor returns-sometimes stronger than before.

A 2023 study by the Cleaning Industry Research Institute tested six common mattress cleaning methods on human urine stains. Steam cleaning ranked last in odor elimination, with 78% of tested mattresses still showing detectable ammonia levels after treatment. Only enzyme-based cleaners consistently reduced odor to undetectable levels.

What Actually Removes Urine from a Mattress

If steam doesn’t work, what does? The answer is enzyme cleaners. These aren’t just fancy detergents-they contain live bacteria that eat the proteins and urea in urine, turning them into water and carbon dioxide. No smell. No residue. No reactivation.

Here’s how to do it right:

1. Blot up as much liquid as possible with clean towels. Don’t rub-press down.
2. Apply a commercial enzyme cleaner designed for pet or human urine (like Nature’s Miracle or Urine Off). Spray generously until the area is soaked, not just damp.
3. Let it sit for at least 8 hours. The enzymes need time to break down the compounds.
4. Blot again with dry towels to remove loosened residue.
5. Use a fan or dehumidifier to dry the mattress completely. Moisture invites mold.

For older stains, you might need to repeat the process. Deep stains may require lifting the mattress cover (if removable) to treat the foam directly. Never use bleach, hydrogen peroxide, or ammonia-based products-they react with urine and create toxic fumes.

When Steam Cleaning Might Help (and When to Avoid It)

Steam isn’t useless-it just needs to be used at the right time. After you’ve treated the stain with enzymes and dried the mattress, a light steam pass can help kill lingering surface bacteria and refresh the fabric. But only if:

• The mattress is already dry
• You use low pressure and keep the nozzle 6 inches away
• You don’t saturate the foam

Many steam cleaners come with upholstery attachments, but they’re not designed for deep-penetration cleaning. Using them on a wet mattress is like pouring water into a sponge-you’re just adding more moisture to a problem that already has too much.

What to Do If the Smell Won’t Go Away

If you’ve tried enzyme cleaners, dried thoroughly, and even steam cleaned-and the smell still lingers-you’re dealing with a deep-set problem. The foam core may be permanently contaminated. In that case, no amount of cleaning will fix it.

Here’s what to consider:

• Check your mattress warranty. Some cover accidents if you report them within 30 days.
• Replace the mattress if it’s over 7 years old. Memory foam degrades faster when exposed to moisture.
• Use a waterproof, breathable mattress protector going forward. Not plastic-breathable polyurethane. It stops liquids before they reach the foam.

Buying a new mattress isn’t failure-it’s prevention. A good mattress lasts 7-10 years. A bad one can ruin your sleep, your allergies, and your peace of mind for far longer.

Preventing Future Accidents

Once you’ve cleaned or replaced the mattress, lock in the win:

• Use a high-quality, machine-washable mattress protector. Wash it every 2-4 weeks.
• Keep enzyme cleaner on hand. Spray it immediately after any accident-even if you don’t see a stain.
• For kids or incontinent adults, consider waterproof bed pads under the sheets. They’re cheaper than replacing mattresses.
• Don’t wait for smells to return. Urine odor builds slowly. Treat every drop as if it’s a full accident.

People in Bristol often ask me if humid weather makes urine stains worse. It does. Moist air slows drying time and encourages mold. That’s why drying your mattress with a fan isn’t optional-it’s essential.

Myths About Mattress Cleaning

There are a lot of false claims online. Let’s clear a few up:

• Myth: Baking soda absorbs urine odor permanently. Truth: It only masks it for a day or two. The smell comes back.
• Myth: Vinegar neutralizes urine. Truth: Vinegar is acidic. Urine is acidic. They don’t cancel out-they combine.
• Myth: Sunlight kills urine odor. Truth: UV light helps with surface bacteria but won’t reach deep into foam.
• Myth: Steam cleaning is the best for all stains. Truth: It’s great for coffee, wine, or dirt. Not for biological fluids.

Stick to what science backs up: enzymes for urine. Steam for surface refresh. Nothing else.

Final Answer: Does Steam Cleaning Get Urine Out of a Mattress?

No. Steam cleaning alone won’t remove urine from a mattress. It can even make the problem worse by driving the odor deeper. The only proven way to eliminate urine smell is with enzyme-based cleaners followed by thorough drying. Steam can be used afterward as a light sanitizing step-but never as the primary treatment.

If you’ve got a stained mattress, don’t waste time on quick fixes. Act fast, use the right product, and protect your next one. Your sleep-and your lungs-will thank you.