Damp canvas, nylon and other tent material will develop mildew if the tent isn't properly dried and cleaned before storage. This commonly happens when you take down your tent while it's still wet from dew or rain. Allowing the tent to dry first prevents mildew from developing, but that isn't always possible. Mildew inside your tent smells unpleasant and looks dirty. Breathing in mould and mildew spores isn't healthy, either. Rectify the problem with supplies found around the home to remove mildew and eliminate the unpleasant musty smell.
Pitch your tent so you're able to get inside and clean all the surfaces. Place the tent in direct sunlight, if possible, allowing the sun to dry the tent's surface for a few hours. Since sunlight kills mildew you'll merely have to clean the inside of your tent to get rid of the spores.
Vacuum the interior and exterior of your tent to remove mildew spores. Dispose of the vacuum bag when you're finished so the mildew spores don't have a chance to transfer to any other surfaces.
Combine 1/2 cup bleach with 1 gallon warm water in a bucket. Dip clean cloths in the bleach solution and wash the material on the walls, floor and ceiling inside your tent. Ensure no mildew spores survive on the exterior of the tent by washing off the outside, too.
Dampen a clean cloth with plain water and wipe down your tent's surface to rinse it. After every few wipes, rinse the cloth again and wring out the excess moisture. Leave your tent up and allow it to air dry for several hours.
Lay a plastic dust sheet down inside your tent to catch drips and spills during the cleaning process. After cleaning the walls you can fold up the dust sheet and throw it away, avoiding a mess on your tent's floor. Then you simply finish the interior by cleaning the floor in the same manner. Spot clean small areas of mildew on your tent with a paste made from lemon juice and table salt. Allow the paste to dry on the material, then brush it off. Substitute a bucket of disinfectant cleaner to kill and remove mildew.