Mould on Curtains: How to Remove It Safely

You pull back the curtains one morning and notice a few dark spots near the window. Or perhaps there is a faint musty odour that was not present before. In any case, mould on curtains is a problem that should be addressed right away. The good news is that some mouldy curtains can be cleaned and restored. The appropriate method is determined by the fabric, the care label, the extent of the mould’s spread, and the source of the moisture.

Why Does Mould Grow on Curtains?

Mould requires moisture to grow. Curtains are especially vulnerable because they are often placed close to windows, where condensation can accumulate, particularly during colder or more humid weather. Poor ventilation can exacerbate the problem. Drying clothes indoors, persistent condensation, damp walls, or a window leak are all possibilities.

Such a scenario means cleaning the curtain is only half the job. If the source of moisture remains, mould may simply return. The US Environmental Protection Agency describes moisture control as the key to controlling mould and recommends fixing water problems and thoroughly drying affected materials. Inspect dampness around the window frame and wall surrounding area before you clean your curtains.

Is It Mould or Mildew on Your Curtains?

People often use the words mould and mildew interchangeably, but both are types of fungi that thrive in damp, poorly ventilated conditions. On curtains, they can appear when moisture repeatedly collects around windows, especially if condensation is common or the fabric stays close to a cold surface for long periods.

At first, you may notice small black, grey, green or brown marks appearing on the fabric, or lighter patches that look powdery or uneven. A persistent musty odour can be an early sign that moisture has been sitting in the fabric for some time.

Mould and mildew often develop around the bottom edges of curtains, near window frames or on the side of the fabric facing the glass. These areas are more likely to come into contact with condensation or damp surfaces, which is why the marks may seem concentrated in one section rather than spread evenly across the whole curtain.

Whatever the growth looks like, do not simply brush or rub the visible marks and assume the problem is solved. The curtain still needs to be cleaned according to its care instructions, and the source of the moisture should also be addressed. Otherwise, even properly cleaned curtains may develop the same problem again.

How to Remove Mould From Curtains

Check for the care label before removing mould from curtains. Curtains can be made from cotton, polyester, linen, velvet, silk or blends. They may also contain linings, coatings, pleats or decorative details that change how they should be cleaned.

The American Cleaning Institute recommends checking curtains before washing because sunlight and age can make the material fragile. Use an appropriate gentle cycle if the care label permits washing. Otherwise, professional dry cleaning may be needed.

For washable curtains:

1. Avoid shaking the curtains around the room while taking down the curtains..
2. Check the fabric condition and look for weakened fibres, fading or damaged lining before washing.
3. Use the specified wash temperature and cycle mentioned on the care label rather than assuming a hotter wash will work better.
4. Avoid experimenting with strong cleaning chemicals unless the care instructions confirm they are safe for the fabric.
5. Do not hang them back against a damp window while they are still wet.

A stubborn stain remaining after washing does not necessarily mean another aggressive treatment is safe. Mould can permanently stain or damage some materials.

How Should You Deal With Black Mould on Curtains?

Black mould on curtains can look particularly worrying, but colour alone should not determine how you clean it.

Start by checking how large the affected area is and whether the curtain material can safely be washed. Avoid repeatedly scrubbing delicate fabric or applying undiluted bleach. Bleach can cause irreversible colour loss on unsuitable textiles, according to the American Cleaning Institute.

If mould covers a substantial part of the curtain, has penetrated a thick lining or keeps returning after cleaning, professional assessment may be more sensible than repeated DIY treatments. The EPA also notes that mould can penetrate porous materials, making it difficult or sometimes impossible to remove completely.

How Do You Get Mould Out of Different Types of Curtains?

The safest way to remove mould from curtains depends on the fabric, the lining and how the curtains are constructed. A method that works perfectly well for a simple washable polyester curtain could damage a delicate net curtain, a blackout lining or a dry-clean-only fabric. Before trying any treatment, always check the care label and consider whether the curtain has any special coatings, linings or decorative finishes.

Net curtains

Net curtains are usually lightweight and more delicate than standard curtains, so they need gentler handling. Older netting can become especially fragile over time, which means vigorous scrubbing or a harsh wash cycle may cause the fabric to stretch, snag or tear.

Before washing, check the care label to confirm whether the curtains are machine washable. If they are, use the gentlest suitable cycle and avoid high temperatures unless the label specifically allows them. If you are treating visible mould marks, work carefully rather than scrubbing the fabric aggressively, as this can weaken the fibres or distort the netting.

It is also important to dry net curtains thoroughly before rehanging them. Putting them back while they are still damp can recreate the same conditions that allowed the mould to develop in the first place.

Curtain linings

Removing mould from curtain linings can be more complicated because the lining and the outer fabric may respond differently to water, detergent and heat. A curtain may look like one piece, but the lining could be made from a completely different material or include a special coating.

This is particularly important with blackout, thermal or bonded linings. These materials are often designed to block light, retain heat or provide structure, and soaking or machine washing them without checking the care instructions can cause peeling, bubbling, shrinking or separation between the layers.

If the mould is mostly on the lining, resist the temptation to soak the entire curtain straight away. Check the care label first and consider professional cleaning if the construction is complex or the affected area is extensive.

Dry-clean-only curtains

If the care label says dry clean only, it is best to follow that instruction rather than experimenting with home washing. Fabrics such as silk, velvet and certain structured or lined curtains can lose their shape, colour or texture when exposed to water or unsuitable detergents.

Even if the mould appears limited to a small area, washing a dry-clean-only curtain at home can cause more damage than the original stain. Water marks, shrinkage and distortion can be difficult or impossible to reverse once they occur.

For these curtains, professional cleaning is usually the safer option. A cleaner can assess the fabric, construction and level of mould before choosing a treatment that is suitable for the material.

Common Mistakes When Cleaning Mould Off Curtains

When you spot mould on curtains, it is tempting to reach for the strongest cleaner you have and try to remove it as quickly as possible. That can sometimes make the problem worse. Curtains vary widely in fabric, lining and construction, so a treatment that works on one material may fade, weaken or distort another.

One common mistake is using bleach without checking whether the fabric can tolerate it. Bleach can remove colour and damage certain fibres, especially on delicate or coloured curtains. The care label should always be your first reference before using any cleaning product.

Another mistake is washing curtains without checking whether they are actually suitable for machine washing. Some lined, coated or structured curtains may shrink, lose their shape or develop damage to the lining if they are washed incorrectly. Similarly, aggressive scrubbing can weaken delicate fabric and may spread the stain rather than remove it cleanly.

Drying is just as important as washing. Rehanging curtains while they are still damp can leave them sitting against a cold window or wall, creating the same moist conditions in which mould developed in the first place. Make sure the fabric is fully dry before putting it back.

It is also easy to focus entirely on the curtain and ignore what is happening around it. If condensation continues to collect on the window, or there is persistent damp around the frame or wall, the mould is likely to return even after the curtain has been cleaned.

Finally, avoid repeatedly treating valuable or delicate curtains when the mould has spread deeply into the fabric or lining. At that point, repeated home cleaning can do more harm than good.

A useful way to think about mould removal is as two separate jobs: clean the fabric properly and deal with the conditions that allowed the mould to grow in the first place. Both matter if you want the problem to stay away.

How Can You Stop Mould Coming Back?

Start with the window.

Wipe away condensation when it appears and improve ventilation where possible. Leave enough space for air to circulate between curtains and cold windows rather than keeping heavy fabric pressed permanently against the glass.

If you regularly see dampness on the wall or window frame, find the cause rather than relying on frequent curtain cleaning.

Make sure curtains are completely dry after washing before rehanging them. Regular vacuuming or gentle cleaning can also help prevent dust and dirt from building up on the fabric.

When Should Mouldy Curtains Be Professionally Cleaned?

Home cleaning makes sense when the affected area is small and the curtains are clearly labelled as washable.

Professional cleaning becomes worth considering when:

• the curtains are dry-clean-only
• the material is delicate or valuable
• they have specialist linings or coatings
• the mould is widespread
• previous cleaning has not removed the problem
• you are worried about damaging the colour, shape or finish

Laundryheap can clean curtains according to their care-label requirements, with services varying by location.

Instead of experimenting with a fabric you are unsure about, you can check the curtain cleaning services available in your area and arrange collection from your door.

What to Remember About Mould on Curtains

Mould on curtains is usually a sign that there is too much moisture around the window, not just a problem with the fabric itself. Cleaning the curtains is important, but it works best when you also deal with condensation, damp or poor ventilation that may be causing the mould to return. Before washing or treating mouldy curtains, always check the care label. Different fabrics, linings and coatings can react very differently to water, heat and cleaning products, so there is no single method that works safely for every curtain. Bleach, aggressive scrubbing or high temperatures can sometimes cause more damage than the mould itself.

Once the curtains are clean, make sure they are completely dry before rehanging them. Keeping the surrounding area dry and well ventilated will also reduce the chances of the problem coming back. If your curtains are delicate, dry-clean-only, heavily affected by mould or difficult to clean safely at home, it may be better to leave them to a professional. Laundryheap offers convenient curtain cleaning and dry cleaning services, with collection and delivery available in supported locations.

If you would rather avoid the guesswork, check the services available near you and arrange a Laundryheap collection from your doorstep.