Most molds found indoors – and a camper or trailer is an indoor environment - are commonly called mildew and are plant-like organisms that grow along surfaces and that require food and moisture. Paper, leather, cardboard, cloth, and even dust on surfaces can support mold growth. A small patch of mold can cause a musty odor, but surfaces can be spotted with mold colonies and have little or no odor. Breathing in living or dead mold spores can cause health symptoms, so you don’t want mold to remain in spaces where you spend time.With very few exceptions, however, mold does not degrade wood. Wood-decaying fungi may be present, though, if wood on or in the trailer or camper remained wet for many weeks.If you see rotten or soft wood or even mushrooms, repairs may be needed.

If the relative humidity is over 75 to 80%, mold can grow on wood and other surfaces that contain dust or other biodegradable materials like canvas, or on the dust on solid surfaces like plastic, metal or glass. Mold can also grow on the dust captured in insulation, carpeting and upholstery. Like any other indoor environment, a camper or trailer contains plenty of nutrients for mold. All mold will then require is oxygen and moisture. It can be difficult to control moisture in a camper or trailer, because it sits outside and may have leaks. Some campers and trailers are like small houses, so people can spill food and splash water on surfaces inside.