As an affiliate, we may earn a commission from qualifying purchases. We get commissions for purchases made through links on this website from Amazon and other third parties.
A storage unit is useful for furniture, sealed household goods, seasonal décor, and properly packed bedding. But you should not store food, living things, hazardous materials, illegal items, damp belongings, or anything that cannot handle the unit’s temperature and humidity.
Facility rules can differ. Always read the rental agreement and check the storage company’s current list of prohibited items before moving anything in.
Items You Should Never Store in a Storage Unit
Perishable Food
Do not store food that can spoil, including:
- Meat, dairy products, and frozen food
- Fresh fruit and vegetables
- Open bags of flour, rice, cereal, or pet food
- Homemade canned goods
- Food stored in cardboard boxes
Spoiled food can leak, smell, grow mold, and attract insects or rodents. A storage unit is not a pantry or refrigerator.
Some facilities may allow factory-sealed shelf-stable food, but it is still often a poor choice. Heat, humidity, pests, and damaged packaging can ruin it. Check the facility rules before storing any food.
Plants, Animals, or Other Living Things
Never use a storage unit to house:
- People
- Pets
- Livestock
- Insects
- Houseplants
- Seedlings
Storage units are not designed for living conditions. They may lack safe airflow, plumbing, reliable temperature control, and emergency access.
Plants can also bring moisture, soil, and insects into the unit. Even dried plant material may be restricted if it can decay or attract pests.
Flammable or Explosive Materials
Do not store items that can easily catch fire, explode, or release dangerous fumes. Common examples include:
- Gasoline
- Propane tanks
- Fireworks
- Lighter fluid
- Kerosene
- Paint thinner
- Certain solvents and fuels
- Gas-powered equipment that still contains fuel
Drain fuel from lawn mowers, generators, and similar equipment before storage. Follow the manufacturer’s instructions for preparing the item.
Empty propane tanks may still be prohibited. Check with the storage facility rather than assuming an empty container is allowed.
Hazardous Chemicals
Many household and workshop chemicals should not go into a storage unit. This can include:
- Pesticides
- Pool chemicals
- Strong cleaning chemicals
- Fertilizers
- Automotive fluids
- Industrial chemicals
- Corrosive products
- Toxic materials
Chemical containers can leak, swell, rust, or react to heat. Never mix chemicals or transfer them into unmarked bottles.
Check local disposal rules for products you no longer need. Do not leave unwanted chemicals in a storage unit.
Illegal or Stolen Items
You should never store anything that is illegal to own or that was obtained unlawfully.
Storage units are private rented spaces, but they are still subject to laws, rental agreements, and facility policies. A unit does not protect illegal property from investigation or removal.
Weapons and Ammunition Without Approval
Rules for firearms, ammunition, bows, knives, and other weapons vary by location and facility. Many storage companies prohibit some or all of these items.
Ammunition and related materials may also be treated as hazardous or combustible.
Do not place weapons in a unit without checking:
- Local laws
- The facility’s written policy
- Insurance requirements
- Safe-storage rules
Never assume that a locked storage unit meets legal storage requirements.
Things That Are Usually Better Stored Somewhere Else
Some items may not be strictly prohibited, but storing them in a unit can still be risky.
Cash and Financial Items
Avoid storing:
- Cash
- Gift cards
- Checkbooks
- Credit cards
- Coins with special value
- Financial account information
Storage-unit insurance may not cover cash or similar property. Keep these items in a secure place designed for valuables.
Jewelry and Irreplaceable Valuables
Family jewelry, rare collectibles, and sentimental objects may be difficult or impossible to replace.
Even a well-managed facility can experience leaks, storms, fire, theft, or pest problems. Insurance may have limits or exclusions for valuable items.
Consider safer storage for objects with high financial or emotional value.
Original Documents
Important documents should generally remain somewhere secure and easy to reach. Examples include:
- Birth certificates
- Passports
- Property deeds
- Wills
- Tax records
- Legal papers
- Medical records
- School records
Paper can absorb moisture, develop mildew, or become damaged by insects. You may also need an important document while the facility is closed.
Use secure document storage and keep protected digital copies when appropriate.
Medication and Medical Supplies
Many medicines and medical products have strict storage instructions. Heat, cold, and moisture can affect them.
Do not store prescription medicines, temperature-sensitive products, or emergency medical supplies in a unit unless the manufacturer specifically allows those conditions.
Follow the product label, pharmacy guidance, or manufacturer instructions.
Temperature-Sensitive Electronics
Electronics may be damaged by heat, cold, humidity, dust, and condensation. This includes:
- Computers
- Televisions
- Cameras
- Game systems
- Audio equipment
- Printers
- Batteries
A climate-controlled unit may lower some risks, but it does not make every electronic item safe to store. Remove batteries when the manufacturer allows it, and keep devices completely dry.
Musical Instruments
Wooden instruments can swell, shrink, crack, or lose their shape when humidity changes. Metal parts can corrode, and adhesives may weaken in high heat.
Climate-controlled storage may be more suitable, but valuable instruments are often better kept in a stable indoor space.
Wine and Other Temperature-Sensitive Drinks
Temperature swings can affect sealed drinks, damage corks, and cause containers to leak or break. Alcohol may also be prohibited by the storage facility.
Check the rental agreement and use storage designed for the type of beverage.
Do Not Store Wet or Damp Items
Moisture is one of the most common storage problems. Never pack items that are damp from washing, rain, cleaning, or outdoor use.
Problem items include:
A storage unit is useful for furniture, sealed household goods, seasonal décor, and properly packed bedding; compare boxes and bags for stored bedding by airflow, moisture, pests, compression, material, seal, access, cleanliness, full drying, and storage duration.
- Damp bedding
- Wet towels
- Recently cleaned rugs
- Patio cushions
- Tents
- Camping gear
- Mops
- Mattresses that have not fully dried
- Clothing packed before it is dry
Trapped moisture can cause odors, stains, mildew, and material damage. It can also spread to nearby boxes.
Allow every item to dry fully before packing it.
Bedding and Mattresses That Have Not Been Prepared
Bedding can be stored, but it needs careful preparation.
Do not store:
- Unwashed sheets with body oils or food stains
- Damp comforters
- Pillows that are not fully dry
- Mattresses with existing moisture
- Bedding sealed in plastic while still warm from the dryer
- Loose linens placed directly on the floor
Wash bedding according to its care label and dry it completely. Large comforters and mattress pads may need extra drying time because moisture can remain inside the fill.
Store clean linens in breathable fabric bags or sturdy containers that suit the item. Avoid tightly compressing pillows, comforters, and other filled bedding for long periods unless the product instructions say it is safe.
Use a mattress storage bag to keep off dust. Store the mattress in the position recommended by its manufacturer. Some mattresses can bend or sag if they are leaned against a wall for a long time.
Avoid Storing Bedding in Thin Trash Bags
Trash bags tear easily and can trap moisture. They also offer little protection from crushing, dust, or pests.
Clear, sturdy storage bags or lidded containers make it easier to see what is inside. Make sure the bedding is completely dry before sealing any container.
Dirty or Pest-Exposed Furniture
Do not move furniture directly into storage if it has:
- Food crumbs
- Grease
- Pet accidents
- Heavy dust
- Signs of insects
- Signs of rodents
- Damp upholstery
Clean and dry furniture first. Vacuum seams, drawers, and the space under cushions. Pet beds should also be washed and fully dried before storage.
A storage unit should not be used to isolate furniture with a known pest problem. Follow appropriate professional or local guidance instead.
Open Food, Pet Supplies, and Scented Products
Even nonperishable products can attract pests when packaging is open or weak.
Avoid storing:
- Open pet food
- Birdseed
- Grass seed
- Scented wax products that may melt
- Soap in easy-to-chew packaging
- Food-scented crafts
- Open snack containers
Strong fragrances and oils may also leak into fabrics, mattresses, or upholstered furniture.
Items That Can Leak
Do not store a container unless you are sure it is closed, stable, and allowed by the facility.
Potential trouble items include:
- Open cleaning products
- Cooking oils
- Paint
- Ink
- Toiletries
- Liquid craft supplies
- Unsealed candles in very hot units
- Appliances that still contain water
Drain and dry washing machines, dishwashers, humidifiers, coffee makers, and similar appliances. Leave appliance doors slightly open when appropriate to reduce trapped odors. Follow the manufacturer’s storage guidance.
Appliances With Food or Moisture Inside
Refrigerators and freezers must be emptied, cleaned, defrosted, and dried before storage.
Do not store an appliance with:
- Food inside
- Ice buildup
- Standing water
- Wet shelves
- A closed, damp interior
Moisture and food residue can quickly create strong odors and mold. Secure loose shelves and parts, but avoid sealing moisture inside the appliance.
Unregistered or Improperly Prepared Vehicles
Some facilities allow cars, motorcycles, boats, trailers, or recreational vehicles. Others do not.
Vehicle storage may require:
- Registration
- Proof of insurance
- Fuel preparation
- Battery preparation
- Fluid checks
- Specific parking rules
A leaking, unregistered, or nonworking vehicle may not be accepted. Ask the facility about its current vehicle policy before arrival.
Overfilled or Unsafe Boxes
A storage unit should not contain boxes that are too heavy to lift safely or stacks that are likely to fall.
Avoid:
- Putting books in very large boxes
- Packing sharp items without covers
- Stacking crushed cardboard boxes
- Placing heavy boxes on top of bedding
- Blocking the unit entrance
- Creating unstable furniture piles
Use smaller boxes for heavy items. Place sturdy boxes at the bottom and lighter items above them. Leave a walkway so you can reach your belongings without climbing over stacks.
Anything Not Covered by Your Insurance
Do not assume the storage company will pay for every damaged or stolen item. Coverage often has limits and exclusions.
Before storing valuable belongings, check:
- What your rental agreement covers
- Whether separate insurance is required
- Which types of property are excluded
- Whether there are coverage limits
- What records or photos may be needed for a claim
Keep a basic inventory and take photos before closing the unit.
How to Decide Whether an Item Is Safe to Store
Ask these questions before packing an item:
- Is it allowed by the facility?
- Is it legal to store?
- Is it clean and completely dry?
- Can it handle heat, cold, and humidity?
- Could it leak, spoil, attract pests, or catch fire?
- Would losing it cause serious financial or emotional harm?
- Does the manufacturer give special storage instructions?
- Will your insurance cover it?
When any answer raises concern, choose another storage location.
Frequently Asked Questions
Can you store food in a storage unit?
Perishable food should never be stored in a storage unit. Open or weakly packaged dry food can also attract pests. Some facilities may allow certain factory-sealed shelf-stable products, but you should check the rental agreement first.
Can you store a mattress in a storage unit?
Yes, if the facility allows it and the mattress is clean, completely dry, and properly covered. Use a mattress storage bag and follow the manufacturer’s guidance about whether the mattress should lie flat or can be stored another way.
Can you store clothes and bedding in plastic containers?
Clean, fully dry clothes and bedding can often be stored in sturdy plastic containers. Do not seal damp or warm laundry inside. For long-term storage, avoid crushing filled comforters and pillows unless their care instructions allow compression.
Can you store gasoline in a storage unit?
No. Gasoline and other fuels are commonly prohibited because they are flammable. Gas-powered equipment should usually be drained according to the manufacturer’s instructions before storage.
Can you put a refrigerator in a storage unit?
A refrigerator can often be stored after it has been emptied, defrosted, cleaned, and fully dried. Keep the door slightly open when appropriate so air can circulate. Check the appliance manual and storage-facility rules.
What happens if you store prohibited items?
The facility may require you to remove the items, charge fees, end the rental agreement, or contact the proper authorities. Results depend on the rental terms, the type of item, and local law.
Is a climate-controlled unit safe for valuable items?
Climate control can reduce major temperature and humidity swings, but it does not remove every risk. Leaks, theft, fire, pests, handling damage, and insurance limits may still apply. Irreplaceable items are usually better kept somewhere more secure.
why avoid under bed storage. can underbed storage damage my mattress. what is the best thing to store under the bed.
