Things You Should NOT Put in a Self Storage Unit
If you’re in a hurry, here’s the TL;DR: What NOT to Store in Your Self-Storage Unit
- Perishables or food items — even dry or canned goods can spoil, attract pests, and cause odors.
- Hazardous or flammable materials — such as gasoline, paint, solvents, propane, and aerosols. They pose serious safety risks.
- Living things — including plants, pets, or people—storage units lack ventilation and sunlight.
- Illegal or stolen items — prohibited and could result in criminal consequences.
- Weapons & ammunition — most facilities ban firearms and related items for liability reasons.
- Important documents and irreplaceable valuables — such as passports, legal papers, photos, heirlooms, jewelry, and cash. Better kept in a home safe or bank safety deposit box.
- Scented or damp items — scents (candles, incense, strongly fragranced items) can linger or attract pests; damp items encourage mold and mildew.
- Wet items or damp containers — should be fully cleaned and dried before storing to avoid mold and damage.
- Unregistered or inoperable vehicles — only operable, registered vehicles in the renter’s name may be allowed, depending on facility rules.
- Clutter or items you don’t need — avoid paying monthly storage for unnecessary stuff.
Before we begin, our Ultimate Self Storage Guide offers s comprehensive look at all things storage and can help you with everything you need to know—from choosing the right unit size to understanding the costs, features, and what to expect during move-in. It also covers common questions, tips for maximizing your space, and how to avoid common packing and moving mistakes. National Storage is here to make sure you know all the ins-and-outs so you can find the best rental for your needs!
However, there are some things you should not put in a self storage unit. Each storage facility will have a list of “banned” items. Make sure that you follow that list and read your contract at the time of rental. Placing any of the items that are on the banned list could get you fined or even arrested. Before you rent a storage unit, make sure that you know about what items should not be stored your unit. This list will help you protect your personal belongings as well as protect those around you.
Valuable Items– Items such as jewelry, coins (historical and collectible) and precious metals should not be stored in a self storage unit. It’s better to keep these items safely in your home or at your bank in a safe deposit box. A few storage facilities will allow rental of these items, but they require proof of individual insurance on the items. Don’t store cash, either- your unit is not a bank vault or safety deposit box. Also, keep passports, social security and tax documents in a fire-safe box in your home, not your self storage unit.
Plants and Living Items- Your storage unit is not a greenhouse, and plants cannot survive in an environment without oxygen or light. Storing them in your self storage unit is prohibited. Obviously, self storage is not a place to store animals or pets. Not only is this strictly prohibited, but it risks the life of the animal. Plants and animals that are stored in self storage will also lead to bugs and other vermin infestation. On the same note, your self storage unit is not an “apartment”- and yes, sometimes people have tried to turn their unit into a living space. Obviously this is not allowed.
Perishable Items– Do not store food in your self storage unit. In the extreme conditions of a non-climate controlled storage unit, food can spoil quickly and invite unwanted bugs to your storage unit. Opened containers of spices, cereals and other non-perishable items should not be stored in self storage. Some canned items can survive in the extreme conditions, but it really isn’t advisable to store them in a self storage unit.
Flammable or Combustible Materials-Do not store fireworks, gas, oil or paint and paint thinner in self storage. Gasoline or propane can very easily ignite in an enclosed unit and put the entire facility at risk. That is why it is important to drain the fluids from lawn mowers and other outdoor equipment before putting them in self storage. Also, any item in an aerosol can is extremely flammable and not allowed in your self storage unit.
Toxic, Hazardous, Stolen or Illegal Substances- Do not store chemicals, fertilizers and every day cleaning products in self storage. These items are very toxic and dangerous in extreme temperatures. They could cause a fire or chemical accident in your unit and the surrounding storage units. Some storage facilities also will not allow the storage of firearms and ammunition. Even if the firearms are antique and no longer in working order, they could pose a dangerous threat. It should also go without saying that you should not store illegal or stolen items in your unit. Self storage facilities are subject to searches, so illegal items will not be any safer there than they would be in your home. Check with your storage facility before you store to make sure you are storing items properly and are not storing a “banned” item. Stop in to any of our 34 National Storage locations to find out more information.
Additional Storage Tips
1. Climate Sensitivity & Environmental Risks
Some items just don’t hold up well in a regular storage unit. Wood furniture can swell or crack when the temperature changes too much. Leather dries out and becomes brittle. Books and artwork are quick to mildew if the humidity spikes. Even electronics can corrode if they sit in a damp environment for too long. If you’re storing any of these, a climate-controlled unit is the safer choice because it keeps both the temperature and humidity steady.
Another thing to watch out for is how you cover your items. It might feel natural to throw a plastic tarp over furniture or boxes, but plastic traps moisture. That trapped moisture can cause mold and mildew before you even realize it’s there. A better option is to use cotton sheets, moving blankets, or other breathable covers that let air flow while still keeping dust off your things.
2. Storage Container Choices
The kind of container you use makes a big difference. Cardboard is fine for short-term storage, but it doesn’t stand up to moisture or pests. Over time, boxes can sag, collapse, or even attract rodents. Sturdy plastic bins with tight lids are a better choice when you want your belongings to stay dry and protected.
Documents, photos, and keepsakes need extra care. Tossing them into a regular box or a plastic sleeve is risky because they can yellow, fade, or get stuck together. Acid-free sleeves or archival boxes are designed to protect paper and photos long term, and they don’t cost much more than standard supplies. For truly important paperwork or irreplaceable items, you may want to keep them at home in a fireproof safe or at the bank instead of in storage.
3. Plan for Access & Organization
How you set up your unit can save you a lot of frustration later. Think about what you’ll need most often and keep those items at the front. Holiday decorations, seasonal clothes, or tools are good examples. That way, you don’t have to move half the unit around just to grab a single box.
Labeling is just as important. Write clearly on the outside of every bin, and if you’ve got a lot of boxes, keep a simple list of what’s in the unit. Some people even sketch out a quick map so they remember where certain things are stacked. Leaving yourself a small pathway down the middle is also a smart move—it makes it easier to get to the back without climbing over everything.
4. Elevate & Protect from Moisture
Even clean, well-kept facilities can have condensation or minor leaks, and water damage usually starts at floor level. If your boxes or furniture are sitting directly on the concrete, they’re the first things to get wet.
Lifting your belongings just a few inches off the ground makes a big difference. Wooden pallets, cinder blocks, or sturdy shelving all do the trick. This not only keeps your items safe from potential water problems, but it also makes it easier to sweep, check for pests, and keep the unit clean.