Updated : August 2, 2025
Published : July 23, 2025
Guides

Finding mould on your mattress is one of those truly stomach-dropping moments. You lift the corner to change the sheets and there it is – those telltale dark spots that definitely weren't there last month. Or were they?

In our years of designing beds and working with mattresses, we've had customers talk to us about all kinds of mould horror stories - but there's good news: you can usually fix this without binning your entire mattress.

Why Mould Loves Your Mattress (Unfortunately)

Mould's pretty basic in its needs – moisture, warmth, and something organic to feed on. Your mattress? It's basically a mould paradise. We sweat about half a pint each night (delightful, I know) and our body heat keeps things cosy, and all those dead skin cells we shed... well, that's the buffet.

But here's where it gets interesting. Mould doesn't just appear because you're a sweaty sleeper – usually there's something else going on. Maybe your mattress sits directly on the floor, which is terrible for airflow, or perhaps you're in one of those Victorian conversions where the bedroom walls are basically damp sponges come winter.

Sometimes it's simpler; that mattress protector you keep meaning to wash? If it's not breathable, you've essentially wrapped your mattress in cling film and all that moisture has nowhere to go but down.

What Mould Actually Looks Like

Now, not to alarm you, but mould's sneakier than you'd think. Those black spots everyone recognises? That's usually advanced mould having a party, but early stages might just look like shadowy patches or you might notice a musty smell that won't shift.

Pink or orange stains can be mould too – not just that dodgy fake tan incident you're pretending didn't happen. Even what looks like general discolouration might be mould starting its conquest.

The smell test matters, too - if your bedroom's developed that damp, mushroomy scent despite your best Febreze efforts, trust your nose because mould often announces itself through smell before you see anything.

Getting Rid of Mould (Without Setting Fire to Everything)

Right, deep breath. You've found mould and here's what actually works.

First, get that mattress into sunlight if you possibly can. UV light kills mould spores and it's free, it's effective, and it's why our ancestors used to air their bedding religiously. Prop it up outside on a dry day and let both sides get several hours of direct sun.

Can't manage outdoor drying? Fair enough, British weather being what it is. Mix equal parts white vinegar and water in a spray bottle and lightly mist the affected areas – and I mean lightly because you're not trying to soak it. Let it sit for an hour, then blot with a clean cloth and the vinegar smell will fade, promise.

For stubborn patches, bicarbonate of soda is your friend. Sprinkle it over the mouldy areas after the vinegar treatment, leave overnight, then vacuum thoroughly because it pulls out moisture and neutralises odours.

Some people swear by hydrogen peroxide (3% solution, diluted) and it can work brilliantly but test it somewhere hidden first – it might bleach fabrics. Whatever you do, don't mix cleaning products because that's how you accidentally create chlorine gas in your bedroom.

When to Give Up and Get Professional Help

I'm all for DIY solutions, but sometimes you need to know when you're beaten. If the mould covers more than a small patch (we're talking bigger than a dinner plate here) – it's probably too far gone, because mould that's penetrated deep into the mattress core isn't coming out with vinegar and hope.

Black mould especially isn't worth messing with. If you're dealing with extensive black patches or you're getting headaches, breathing issues, or allergic reactions, stop. Get the mattress out and call professionals because your health trumps mattress salvation every time.

The Prevention Game

Once you've dealt with mould, you really don't want it coming back and the trick is airflow – your mattress needs to breathe. If it's on the floor, get it off.

Invest in a decent mattress protector but make it breathable. Those plastic-backed ones might protect against spills but they're mould magnets, so look for materials that specifically mention breathability or moisture-wicking.

Flip and rotate your mattress regularly. I know, I know, modern mattresses claim they don't need flipping but giving it a quarter turn monthly helps air circulation and prevents moisture building up in one spot.

The bedroom environment matters too. If you're waking up to condensation on the windows, you've got too much moisture in the air so crack a window, even in winter, and use a dehumidifier if needed. That romantic habit of never opening the bedroom curtains? Your mattress hates it.

Storage Beds: A Special Note

We need to talk about storage beds and moisture because it's something we think about constantly in our design process. The concern is real – storing stuff under your bed can block airflow to your mattress.

But here's the thing: well-designed storage beds actually help prevent mould. Our ottoman beds, for instance, have ventilation built into the base and when you view our clever lift-up bed designs, you'll notice they're engineered to allow air circulation even when closed.

The key is not overpacking the storage space – leave some breathing room. And here's a tip: those silica gel packets that come with shoes? Chuck a few in your under-bed storage because they absorb excess moisture brilliantly (but only if you don’t have any toddlers or pets crawling around).

The Bottom Line

Finding mould on your mattress isn't a failure of housekeeping, it's usually just British humidity meeting modern living. The good news is that if caught early, it's fixable - and the better news is that once you understand what causes it, prevention becomes second nature.

Keep air moving, control moisture, and give your mattress the respect it deserves because after all, you spend a third of your life there. And if you're thinking about upgrading to something with better airflow built in, well, you could transform your bedroom with space-saving beds from Furl that actually help prevent these problems.

Life's too short to worry about mattress mould. Deal with it once, properly, then get back to what beds are actually for – sleeping soundly.