Mold is a fungal growth that reproduces by spreading spores. When it grows on fabric, it is referred to as mildew. Mold grows in a dark, warm and damp environment. It can penetrate the waterproof coating on tent canvas and destroy the fabric below. In addition to damaging the tent, mould spores cause problems for people with mould allergies. Mold has also been linked to asthma, chronic sinusitis and a weakened immune system.
A musty odour is often the first indication that your tent has a mould or mildew problem. When mildew first forms, the spores make small cross-shaped spots on the canvas. A grey discolouration in patches is another sign of mould growth. These patches usually have distinct edges and may be difficult to get rid of completely.
If you discover mould that is not too far advanced on your tent, there are several solutions you can try to remove it. Make a mild cleaning solution of five quarts water, one quart vinegar, and ½ teaspoon washing powder. Spread the solution on the tent with a soft brush and rinse completely with plain water. Dry completely before storing your tent.
Another solution that can be used to kill the mould is ½ cup Lysol mixed with a gallon of hot water. Follow with a mixture of a cup of lemon juice, a cup of salt and a gallon of hot water. If mildew stains remain, soak the damaged part again in the lemon juice and salt mixture. Dry completely before storing.
There are also some commercial products such as McNett MiraZyme and Iosso Tent & Camping Gear Cleaner made to clean dirt and mould on tents. Follow the manufacturer's directions when using these products. If the waterproof coating on the canvas has been compromised by the mould or its removal, you may have to retreat it.
Proper storage of your tent can prevent mould build-up. After using your tent, clean it with water and a brush. Because strong soaps and detergents can damage any water-resistant coating on the tent, read the label before using any cleaning agent. Make sure you completely dry the tent, if possible in the sun, before putting it away. Consider storing your tent in a cotton bag or box that is not airtight, in a cool, dry place with low humidity. While mould usually forms when the tent is stored, it can also form while it is in use. Air the tent out occasionally during prolonged use to release humidity from the inside.