The threat of damaged storage typically comes by the climate, especially by changes in temperature and humidity. Oil paintings, for instance, must be dry a year before you can store them and should optimally be kept at 70-76°F and 40-50% humidity—never fluctuating more than five degrees within a twenty-four hour period. Also, artwork should be kept off the ground and only lightly covered with breathable, acid-free tissue paper.
Before renting a unit, consider whether or not your property requires special care, namely a climate-controlled unit. Most items you need to worry about are listed below.
Gasses/Toxins—aerosol cans, gasoline, propane tanks, paint, car batteries, pesticides, hairspray, etc.
Candles and Scented Items—the smell will permeate boxes and plastic and seep into cloth. It will never leave. Also, there is nothing that will attract bugs faster than scents or liquid.
Ammunition/Explosives—it’s illegal to store ammunition and explosives in most states. Units can become dangerously hot and, well, gunpowder and heat aren’t friends.
Food/Liquid—don’t even risk it. Even canned food can bloat in storage over time, and if something should burst, you will be overrun with rodents and mold.
Store in a Climate-Controlled Unit
Artwork—beware humidity and temperature change. It can cause canvas sagging, paint cracking, frame distortion, sunspots, and more.
Glass/Breakables—extreme temperature changes can weaken and break glass and even porcelain.
Wool/Clothing/Carpets—sunlight can fade color, and humidity will cause molding.
Books/Documents—heat and humidity are the danger with books and documents. If exposed to either, the paper’s shape will distort and its print will fade.
Electronics—temperature and humidity will ruin electronic wiring and batteries and will increase the likeliness of oxidation.
Wood—humidity will bend, expand, bubble, and decay wood furniture.
Leather—extreme temperatures will crack leather and also fade the color.
Coins—if you collect coins, know that humidity will cause oxidation of the zinc or copper metals. Any collectable items should be kept in a climate-controlled atmosphere.
Musical Instruments—you MUST keep instruments in climate-controlled units. If you don’t, wind instrument strings snap or lose their ability to be tuned. Metal instruments will corrode and build bacteria as the rubber, cork, and felt decay.
Photos—nothing will ruin pictures faster than throwing them in a box in a hot unit. Prints will stick together and bubble. If it is humid in the unit, they will also bend.