Hoe verwijder je zwarte schimmelvlekken uit tentdoek?

Black mould stains on tent fabric are a common problem, especially after a wet summer or a long winter in storage. The good news is that, with the right approach, these stubborn stains can be removed effectively without damaging the fabric. In this guide, you’ll find step-by-step instructions on how to remove mould from tent fabric, how to check that it’s all gone, and how to prevent the problem from returning.

Deal with this before you pack your tent away or start the camping season. A neglected patch of mould will continue to spread through the fabric and, over time, damage the fibres, which will significantly shorten the life of your tent.

What you’ll need for cleaning

Before you start removing mould stains from your tent, make sure you have everything to hand. That way, you won’t have to stop halfway through and you’ll work more efficiently. The choice of cleaning product is crucial here: ordinary soap or washing-up liquid is not suitable for tent fabric and can damage the water-repellent coating.

A specialised cleaning product for tent fabric which is suitable for stubborn mould and stains
A soft brush or sponge (not a scouring pad, as this will damage the fabric)
A garden hose or a bucket of clean water
Enough space to fully pitch the tent, preferably outdoors
Gloves to protect your hands whilst cleaning

Also check whether the cloth is dry or wet before you start. Some cleaning products work best on a slightly damp cloth, whilst others work best on a dry surface. Read the instructions for your chosen product carefully before you begin.

Remove mould stains step by step

Now that you have everything ready, you can start cleaning the tent fabric. Work systematically and treat the affected areas thoroughly. Mould stains on tent fabric often penetrate deeper into the fibres than they appear to on the surface, so a cursory treatment is rarely sufficient.

Unfold the tent completely on a clean, flat surface outdoors. Make sure the mould patches are clearly visible and accessible.
Moisten the affected area Rinse lightly with clean water so that the detergent can soak in properly.
Apply the cleaning product Apply it to the mould stain and leave it to work for the recommended duration. For stubborn black mould stains, you’ll need a powerful product that penetrates deep into the fibres.
Scrub gently with the soft brush in circular movements. Apply light pressure, but do not use excessive force, so as not to damage the fabric.
Rinse the treated area thoroughly with clean water until there are no traces of detergent left.
Repeat the treatment if necessary, for stubborn stains that do not come out straight away.

Once you’ve rinsed it off, you’ll see straight away whether the mould has come off. The fabric should look cleaner and more evenly coloured. After the treatment, leave the tent to air-dry completely before moving on to the next step.

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Check that all the mould has completely disappeared

Once the cleaning is complete, it is important to check carefully whether all the mould stains have actually been removed. Mould that remains in the fibres can quickly grow back, even if the surface appears clean at first glance.

Examine the fabric in good daylight and run your hand over the areas that were previously affected. Mould can sometimes leave a slightly rough or discoloured surface, even if the visible stain has disappeared. Please note:

Grey or dark discolouration that remains visible after drying
A musty smell indicating that mould spores are still active
Areas where the fabric looks different from the surrounding material

Are there any remaining stains visible? If so, repeat the cleaning step on those specific areas before carrying on. A thorough clean now will save you a lot of work later in the season.

Soak the cloth after cleaning

Once the fabric is completely clean and dry, waterproofing is the next essential step. Cleaning, however thorough, damages the water-repellent coating on the tent fabric. Without a new layer of waterproofing, your tent will lose its waterproof properties and you’ll be in a right mess at the first sign of rain.

Make sure the cloth is completely dry before you start waterproofing. Moisture beneath the waterproofing layer will result in uneven protection.
Apply the waterproofing agent evenly across the entire surface, not just on the areas that have already been affected. Applying the treatment evenly provides the best protection.
Allow the product to be absorbed in accordance with the recommended time stated on the packaging.
Leave the cloth to dry Leave to air dry or cure the impregnating layer in accordance with the product instructions.

After waterproofing, you can easily test the water-repellent properties by dropping a few drops of water onto the fabric. The water should immediately bead up and roll off. If it doesn’t, apply a second coat. A properly impregnated fabric is your best protection against future mould problems.

Prevent mould from coming back

Mould on tent fabric is almost always caused by damp combined with a lack of ventilation. The most effective way to prevent it is therefore simple: never store your tent whilst it is damp. However, there are other habits that make the difference between a tent that lasts for years and one that needs to be treated all over again after every winter.

Always let the tent dry completely for storage, even after a brief rainy night at the campsite
Store the tent in a dry, well-ventilated place and avoid damp cellars or sealed plastic bags
Check the tent fabric at the start of each camping season for early signs of mould or discolouration
Clean the cloth at least once a year, preferably at the end of the season for storage
Reapply the waterproofing layer after every thorough clean, or when water no longer beads on the cloth

By adopting these habits, you’ll keep mould stains at bay in the long term and significantly extend the lifespan of your tent fabric.

How Rokimi helps with mould on tent fabric

At Rokimi, we have developed our products specifically for campers who want to look after their kit properly, without any hassle. Whether you’re dealing with slight discolouration or stubborn black mould stains, we offer a targeted solution for every problem:

Hood & Tent Shampoo for routine cleaning and seasonal maintenance of tent fabric
Heavy Duty Cleaner for severe mould growth and deep-set stains that won’t come out with ordinary shampoo
Hood and Tent Protection to fully restore the water-repellent properties after cleaning

Our products do not need to be diluted, are suitable for canvas, polyester and nylon, and are designed to penetrate deep into the fibres for a thorough and long-lasting result. This means that whether you’re a beginner or an experienced camper, you can get started straight away.

View our full product range or find out which applications our products are suitable for. Would you like to find out more about what we do? Then visit our website for further information.

Everything you need for a clean and protected outdoor lifestyle.

Discover Rokimi’s range of professional cleaning and protection products.

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Frequently Asked Questions

Can I remove mould from tent fabric using vinegar or bleach?

Although vinegar and bleach are sometimes recommended as home remedies, they are not suitable for tent fabric. Bleach damages the fibres and destroys the water-repellent coating, whilst vinegar can weaken the material in the long term. Always use a cleaning product specifically designed for tent fabric, such as Rokimi Heavy Duty Cleaner, to prevent damage and keep the fabric in good condition.

My tent still smells musty after I’ve cleaned it. What am I doing wrong?

A lingering musty smell after cleaning is a sign that there are still active mould spores in the fibres. This often happens if the cleaning product has not been left to work for long enough, or if the treatment has not been repeated thoroughly enough on stubborn areas. Treat the tent again with a powerful cleaning agent, leave it to work for longer than last time, and then make sure the tent dries completely in the open air before you put it away.

How often should I waterproof my tent, even if there’s no mould?

Even if there is no visible mould, it is advisable to waterproof your tent at least once a year, preferably at the end of the camping season. A simple test is to drop some water onto the fabric: if the water no longer beads up, it is time for a new coat of waterproofing. Regular waterproofing not only prevents mould, but also significantly extends the overall lifespan of the tent fabric.

Can I wash my tent in the washing machine to get rid of mould?

No, using a washing machine on tent fabric is strongly discouraged. The mechanical action of the drum damages the coating and the seams, and high temperatures damage the material. Furthermore, a washing machine does not clean thoroughly enough to remove deep-seated mould spores from the fibres. Hand washing on a flat surface using the correct detergent always gives a better and safer result.

What is the difference between canvas and polyester awning fabric in terms of susceptibility to mould?

Canvas (cotton) is naturally more susceptible to mould than polyester or nylon, as the natural fibres retain moisture better and provide an ideal breeding ground for mould spores. Polyester and nylon are less absorbent, but mould can still develop on synthetic tent fabric if it is stored in damp conditions for a long time. Regardless of the material, the same basic rule applies: always store your tent in a dry place and treat it with a water-repellent finish regularly.

Are there any mould patches that simply cannot be removed?

Unfortunately, yes. If mould has been left untreated in the fabric for years, the fibres may have been damaged so deeply that the discolouration is permanent and the material has been structurally weakened. You can recognise this by translucent or brittle patches in the fabric, or by stains that do not disappear after several treatments. In that case, it is wise to consider whether repairing or replacing the tent fabric is a safer option than continuing to use the tent.

What’s the best way to pack away my tent if I have to pack it up whilst it’s still damp halfway through my holiday?

Sometimes it is unavoidable to pack up a wet tent, for example in bad weather or when setting off early. In such cases, pack the tent as loosely as possible to encourage air circulation, and make sure you lay it out fully to dry within 24 hours of getting home. Never leave it crammed up for several days: mould spores can start to grow in a damp environment after just 24 to 48 hours.

How do you remove black mould stains from tent fabric?