Mould Growing on Mattress: Causes, Removal Methods and More

Mould appearing on the mattress is very common in the UK. The weather’s damp almost the entire year. There’s plenty of rainy days, cold nights and clouds. Lots of people keep their windows shut to stay warm. However that traps moisture inside. Add in a bit of body sweat, maybe a spill or two, and you get the perfect mould conditions.

This is why we created this guide, which will help you learn why mould grows on mattresses at all. You will also learn how to get rid of it and stop it from coming back. Let’s get started.

How does a mattress get mouldy?

Mould is a type of fungus that spreads fast. You’ll find it on walls, windowsills, food and yes, even your mattress. What causes mould on a mattress? A few things, really. Soft fabric, trapped air, and just the right amount of moisture. Thats all mould needs and your mattress has just that.

It starts with sweat and spills. We all sweat at night, and over time, the sweat builds up. A drink spill makes it worse. That moisture sinks into the mattress and stays there.

Then there’s poor airflow. If your bedroom is stuffy and you mostly keep your windows shut, moisture hangs around. The mattress can’t dry out.

And lastly, no proper cleaning. People wash their sheets but forget the mattress. Dust, dead skin, and humidity pile up. That’s mould’s favourite snack.

A mattress holds moisture. Once it sinks in, it’s hard to dry. That’s why your mattress gets mouldy. If you always sleep in the same spot, heat and damp pile up there. That’s where mould starts most times. If you see odd stains that don’t fade, it’s likely mould.

Is mould on mattress dangerous, and should you be sleeping on a mouldy mattress?

Mould on your mattress IS dangerous. Read that again.

Here’s what happens if you sleep on a mouldy mattress. You might wake up with a sore throat ,blocked nose, itchy eyes or a headache. Some folks get rashes or feel tired all day. These are signs your body doesn’t like the mould in the air.

Over time you can get all sorts of problems, especially if you’ve got asthma, allergies, or a weaker immune system. For babies, it’s even more risky. Their lungs are still growing, and mould can make them ill much faster.

Ok, you say, but how to know if mould is inside the mattress at all? Maybe something else is causing these problems. The following visual indicators will always show themselves when your mattress is mouldy. Do keep an eye for:

• Mould spots. Black, green, brown, or white dots. They might spread over time;
• Musty smells. That damp, old smell that doesn’t go away is another warning sign. Even after you wash your sheets you will still smell it;
• Waking up feeling unwell. If you’ve got sniffles, coughs, or itchy skin every morning, mould might be the cause.

What are signs of mould sickness? Look out for coughing, sneezing, itchy eyes, rashes, or chest tightness. If you feel fine elsewhere but bad in bed, that’s the final clue you’ve been looking for. But you don’t need to wait that long to take action, though.

What to do if you discover mould on your mattress?

Don’t panic. You might still save the mattress, depending on how bad it is. The key is to act fast. The longer you leave the mould to spread, the deeper it sinks in. Let’s look at the best ways to remove mould from mattress. These range from DIY fixes to professional help.

1. Clean mould off mattress with vinegar

Best for small patches or early mould spots. Vinegar kills the spores and helps stop them from spreading.

What you’ll need:

Steps to apply it correctly:

1. Mix equal parts white vinegar and water in a spray bottle.
2. Spray the mouldy area. Don’t soak it.
3. Let it sit for 30-60 minutes.
4. Scrub gently with a soft brush.
5. Wipe the area with a clean, damp cloth.
6. Sprinkle baking soda over the spot. Let it sit overnight. It helps dry and deodorise.
7. Vacuum up the baking soda the next day.
8. Let the mattress air out in a sunny, dry spot if you can.

2. Cleaning a mouldy mattress with rubbing alcohol

Best for killing the fungus when the mould is mild to moderate. It kills the spores and disinfects the surface at the same time.

What you’ll need:

Steps:

1. Mix one part alcohol with one part water in a spray bottle.
2. Lightly spray the mouldy area.
3. Wipe with a clean cloth.
4. Spray again if needed and let it sit for 15–20 minutes.
5. Dry the area with a towel or leave it under the fan.

3. Hydrogen peroxide

Best for stubborn or coloured mould like black or orange mould.

What you’ll need:

Steps:

1. Pour hydrogen peroxide into a spray bottle (no need to mix).
2. Spray directly on the mould.
3. Let it bubble and sit for 10 to 15 minutes.
4. Wipe it down with a damp cloth.
5. Repeat if needed
6. Let it dry fully.

4. Commercial mould removers

Best for serious mould patches or deep-set infestations. These products contain stuff like bleach, strong chemicals, or enzymes in them.

They kill mould fast, but might affect the fabric negatively sometimes. Always check the label first. Only use them if the mattress still looks salvageable and you can dry it out after.

5. Professional mould treatment

If the mould covers a large area, smells strong or keeps coming back, it’s time to call in the pros.

When to get professional help:

Benefits:

• They use high-powered cleaning and drying tools.
• They can deep clean and won’t damage the mattress.
• They’ll check if the mould has gone too deep to save the mattress.

Don’t wait until the mould in your bedroom becomes unbearable; that will also raise the price of removal. Although each case is individual, you should become familiar with the factors which will determine your mould removal cost.

In this case, it’s logical to ask can a mattress with mould be saved? Is it even worth it? Sometimes, yes. But if it’s soaked through or the mould’s been there for months, honestly, it might be time to replace it.

When to clean and when to replace a mattress?

Not all mould is the same. Sometimes you can clean it off and carry on. Other times, the damage is too deep. No scrub or spray will remove it and you have to kiss the mattress goodbye. Not in the literal sense, of course. Here is how to decide what to do.

When to clean the mattress:

When to replace the mattress:

Can you prevent mould spots from returning?

Mould on a mattress can come back. Even after a good clean, the spores might still be hidden deep inside. If the same damp conditions return, so will the mould; you can be completely sure of that. That’s why prevention matters just as much as removal.

To keep mould away for good, you need to follow a few simple habits.

Clean regularly. Dust, sweat, and dead skin build up over time, and that mix can trap moisture. Vacuum your mattress once a month. Clean up spills straight away, and flip or rotate the mattress every few months to help it air out.

Next, get a protective mattress cover. A good one keeps out sweat, spills, and damp air. It also stops dust and makes cleaning easier. Wash the cover regularly, just like your sheets.

Good airflow is key. Open windows when you can, even just for a bit each day. If that’s not an option, use a fan to keep air moving. Still, stale air creates the perfect space for mould to grow.

Humidity is another big factor. Bedrooms should stay below 50% humidity level. If your room feels damp or stuffy, use a dehumidifier. Even a small one can help a lot , especially in winter when windows stay shut.

Cold rooms hold more damp. That’s just how it is. Keep the bedroom warm if you can. There is no need to overdo it, just warm enough so moisture doesn’t build up.

In the morning, pull the covers back. Let the mattress breathe a bit. If there’s sun, even better. Let it hit the bed. Sunlight helps kill mould. Don’t be quick to make the bed. Give it a chance to dry out first, if you have the time.

And finally, check your bed base. Slatted frames are better than solid ones because they let air flow underneath. If your mattress sits flat on the floor or on a solid base, moisture can get trapped underneath, and mould will find its way back.