How to Prevent Mould on Curtains: A Winter Care Guide

Mould on curtains is one of the most common winter complaints we hear from homeowners, and the cause, prevention and treatment are all simpler than you might think.

Quick Answer

Mould grows on curtains when condensation forms on cold windows and meets dust on the fabric. To prevent it, clean the inside of your windows regularly, vacuum your curtains every few months, and address any mould the moment you spot it. If mould has already taken hold, professional dry cleaning followed by relining is often the best solution.

Why Mould Grows on Curtains in Winter

If you've noticed dark spots, musty smells or fuzzy patches forming on the back of your curtains during winter, you're not alone. Mould on curtains is one of the most common problems homeowners face during the cooler months, and the cause is almost always the same.

When you run heating inside your home, the indoor air becomes warm and moist. That warm air hits the cold surface of your windows and creates condensation. Combined with dust, that condensation creates the perfect environment for mould to grow, both on your windows and on the curtains touching them.

The good news is that mould on curtains is almost entirely preventable with the right maintenance routine.

Everything you need to know about upholstery fabric

Upholstery is more than just covering a chair. It involves a coming together of all these considerations: your fabric's weight, your lifestyle, your upholsterer's strengths and sometimes, when to just slip cover the furniture item instead.

Ask the right questions before you buy

Where is the piece going to live, and how hard will it work? What is the best fabric for sofas? A sofa in front of the television — sat on for three hours every night — needs a heavy duty upholstery fabric as opposed to a formal sitting room chair that gets politely used twice a week. Wet swimmers coming in from the pool? You want an indoor-outdoor performance fabric. Polite guests who take their shoes off? You have far more latitude.

The other critical question: do you have animals? If you're upholstering a sofa and you have a pet, expert advice is very clear: have throws made in the same fabric as the sofa. Get two done: one on, one off. You can wash them separately, keep things fresh, and the sofa itself will last far longer. It's healthier for the animal, and smarter for you.

Understanding the Martindale rub count

The Martindale test measures fabric durability by rubbing it repeatedly until the yarn breaks. It tells you roughly how much wear a fabric can withstand — but it doesn't tell you how fabric will behave under UV light, with cleaning chemicals, or with pets. It's one useful data point, not the whole picture.

Heavyweights, naturals, and everything in between

Heavy-duty fabrics are often blended synthetics designed for high-traffic commercial use. They can be steam-cleaned, and they last a very long time, which is actually part of the problem: they're petrochemical fabrics that won't break down. They can also look a little commercial if you're not careful, and with so much boucle appearing in cheap online furniture, there's a risk that your beautifully considered interior ends up looking like it came from a fast-furniture retailer.

Says an expert:

"I would rather have something that wears out — cottons, linens, natural fibres — things that break down, that are easy to recycle. They are fabrics that have a life and then a sensible end."

Natural fabrics: heavy linen, printed cotton, woven cottons sit roughly in the 15,000–20,000 rub range for domestic use. The key thing to know is that plain, light linen is essentially impossible to spot-clean once upholstered. If you're set on linen, slip cover it. Or choose dark colours and accept that they're difficult to clean.

At the lighter end — silks, fine cottons, delicate weaves; these are best for covering bed heads, occasional chairs, and pieces that polite people sit on occasionally. These can be lined or backed to give them more body, and a skilled upholsterer will advise you honestly about what's achievable.