Protecting Your Storage Assets Against Moisture Damage

Published on 10/31/2023

Excessive moisture in a storage unit can lead to the growth of mold, mildew, rust, corrosion, rot, and insect infestations. Items that are particularly susceptible to moisture damage include photos, electronics, clothing, furs, wood, leather, and mattresses. Here are some tips to help you combat moisture levels and protect your belongings while they are in storage:

  • Check for leaks: If you are using an outdoor storage unit, check for any leaks before renting. This is the easiest way to prevent water damage to your property. Take notice of any cracks in the walls or ceiling, no matter how small–they can easily widen over time and allow for damage-causing leaks.
  • Ask about the humidity level: If you are using an indoor unit, inquire about the humidity level. The relative humidity in a storage facility should be below 50 percent to prevent moisture damage, rust, mold, wood rot, and mildew growth. You can purchase a relative humidity gauge at most hardware stores and install it in your unit to monitor the RH yourself.
  • Never store anything that’s damp: Before packing your belongings away in your storage unit, verify that everything is dry and free of dampness. If you wash your clothes prior to placing them in storage, check to make sure that they are completely dry. Before packing away any aquatic equipment (surfboards, scuba gear, wet suits, bathing suits, etc.) confirm that everything is thoroughly dried and free of moisture. Anything wet or damp that is placed inside your unit will contribute to the moisture level in the air.
  • Install a vapor barrier: A vapor barrier is a polyethylene plastic or foil coating used to damp-proof any room or space. They are typically thin, flexible membranes with a permeability value of less than 1.0. They should be installed on the warm side of the storage unit’s wall to block outdoor moisture as well as beneath the floor to inhibit ground moisture from seeping inside. You can purchase vapor barrier from most hardware or home goods stores.
  • Make homemade desiccant packs: Using a piece of fabric, create a pouch filled with moisture-absorbing crystals such as silica gel or charcoal. Sew two squares of fabric together on three sides to create a pocket. Turn it inside out and fill with silica crystals. Fold in the top, pin it shut and then sew it closed. Hang the desiccant bag inside your storage unit. 

You can also place an open bag of kitty litter inside your storage unit or pour it into a bucket. The clay effectively absorbs the moisture in the air and prevents the growth of mold and mildew. Kitty litter may need to be changed every several weeks to maintain optimum freshness.

I hope these tips help you keep your belongings safe and dry!