12 Long-Term Storage Unit Mistakes to Avoid

Long-term storage often begins during a busy moment — a move, renovation, a major life change — which makes it easy to pack fast and move on. Items go straight into boxes without being cleaned or broken down, and small prep steps get skipped in favor of speed.

With short-term storage, that may not have significant consequences. With long-term storage, however,  any dust, moisture or residue on items stays there for months, sometimes years. Over time, this can lead to mold, odors, rust, stains and even structural damage — especially for furniture, fabrics, electronics, etc.

To avoid this, prep items with long-term storage in mind:

• Clean and fully dry everything before packing, even items that appear clean.

• Remove batteries and detachable parts from electronics to prevent corrosion.

• Disassemble furniture when possible to reduce pressure and save space.

• Wrap delicate surfaces with breathable, storage-safe materials.

Climate-controlled storage is often viewed as an “upgrade” rather than a necessity, especially if your items don’t appear fragile at first glance. It’s common to assume that sturdy furniture, boxed paperwork or electronics can handle a little heat or cold without issue, especially if everything is neatly packed away.

The reality is that long-term exposure to fluctuating temperatures and humidity quietly breaks materials down. Wood expands and contracts, leather dries out and cracks, adhesives weaken, and paper absorbs moisture even inside sealed boxes. Electronics are especially vulnerable to this: internal components can corrode or fail long before there are visible signs of damage.

One detail many people don’t realize is that temperature swings are often more damaging than constant heat or cold. Items like musical instruments, framed art, photographs and important documents hold up far better in a consistently regulated environment, which is why climate-controlled units at SmartStop Self Storage are designed to maintain stable conditions year-round rather than simply keeping things “indoors.”

When it comes to storage containers, convenience usually wins. Cardboard boxes, reused shipping cartons or thin plastic bins feel like an easy solution — especially when packing quickly or trying to save money.

Over time, though, the wrong containers become a liability. Cardboard absorbs moisture, weakens and attracts pests. Low-quality plastic bins can crack under weight or warp in temperature changes, exposing items inside. Even well-packed belongings can suffer simply because the container wasn’t built for long-term use.

To avoid this mistake, follow these tips:

• Use sturdy, sealed plastic bins instead of cardboard for long-term storage.

• Avoid vacuum-sealing fabrics for extended periods, which can trap moisture.

• Choose containers with flat, stackable lids to prevent shifting and collapse.

• Keep heavier items in smaller bins to avoid pressure damage at the bottom.

One often-overlooked point — clear bins aren’t just about visibility. They also reduce unnecessary handling. When you can see what’s inside without opening boxes, you’re less likely to disturb stacks, expose items to air and humidity or accidentally damage nearby belongings while searching. If you already have bins that aren’t clear, you don’t have to go out and replace them. Just stick a piece of large masking tape on the bin and write the contents with a marker.

To continue that thought, it’s easy for labeling items to feel unnecessary or tedious, especially if you know that you won’t be needing them anytime soon.

However, without clear labels or an inventory list, even a well-packed unit can become difficult to navigate. Over time, you’ll start to forget what you stored, and during your visits to your storage unit, you’ll need to move boxes repeatedly just to search for one item. Your storage unit, which was supposed to make your life easier, has now become a frustrating guessing game rather than a functional system.

One simple tip is labeling boxes on two adjacent sides instead of just the top — especially important in long-term storage where boxes are often stacked high. Pairing that with a simple phone note or spreadsheet inventory means you can locate items without opening boxes or disturbing carefully packed sections of your unit. If you have the SmartStop Self Storage app, you can type out the items in your unit directly within the app.

Many people underestimate how much space their belongings actually need, especially when everything looks neatly boxed on moving day. Choosing a smaller unit can feel economical upfront, but it often creates problems almost immediately.

When a unit is packed wall-to-wall, items are harder to access and more likely to shift or collapse over time. It also becomes nearly impossible to retrieve a single item without unpacking half the space. There are also potential risks: heavy boxes that are stacked may injure you if you’re not careful when moving them, and the lack of airflow in a cramped unit can trap moisture that can lead to damage over time.

Long-term storage works best when you plan for access, not just square footage. Leaving a narrow walkway and a few inches of breathing room between walls and large items can significantly reduce pressure damage and moisture buildup. Tools like our Size Guide can also help account for that extra functional space.

Even after you’ve moved your belongings into a unit, there’s no need to fret if you realize later that it’s actually too small. Many people find that their unit was the perfect size when they moved in, but they’ve since outgrown the space. Since long-term storage is rarely static — seasonal items get added, family belongings accumulate, plans change and items stay stored longer than expected — it’s easy to keep squeezing things into a unit that no longer fits your needs.

At SmartStop, you can always upgrade to a different unit within the same facility. With our flexible, month-to-month rental terms, moving to a larger space for a period of growth — then downsizing later, if needed — can actually protect items and make long-term storage easier to manage overall.

Moisture is one of the most common and least visible threats in long-term storage. Even in clean, enclosed units, small amounts of humidity can build up over time, particularly when items are packed tightly or placed directly on the floor.

If you don’t actively take preventative measures, that moisture can lead to mold, mildew, warped wood, rusted metal and persistent odors that are difficult to remove once they set in. The damage often starts subtly and goes unnoticed until items are unpacked months later.

To reduce moisture-related risk inside your unit:

• Elevate boxes and furniture on pallets or shelving to improve airflow.

• Leave small gaps between walls and large items to prevent trapped humidity.

• Use moisture absorbers or desiccants for added protection.

• Store sensitive items in climate-controlled units when possible.

Pests aren’t always top of mind when placing items into long-term storage, especially in clean, professional facilities. Because storage units feel sealed off from daily living spaces, it’s easy to assume pests simply won’t be an issue — particularly if you’re not storing anything obviously perishable.

The risk often comes from items that don’t look like pest attractants. Crumbs in upholstered furniture, residue in kitchen appliances, cardboard boxes or even pet hair on blankets can draw insects and rodents over time. Once pests find a food source or nesting material, they can damage fabrics, chew through boxes and compromise stored items before the problem is detected.

Pests are also more likely to target undisturbed areas. Units that stay completely untouched for long periods — especially those packed with cardboard or fabric-heavy items — are more vulnerable. Maintaining a clean, organized layout and choosing a well-maintained facility like SmartStop Self Storage helps reduce that risk from the start.

Long-term storage is often treated as “set it and forget it.” Once items are inside the unit, months can pass without a single visit.

But without periodic check-ins, moisture buildup, shifting boxes or pest activity can go unnoticed. Even a quick visit to make minor adjustments — like re-stacking a leaning pile or replacing a moisture absorber — can prevent long-term damage if caught early.

To keep your unit in good shape over time:

• Schedule brief check-ins every few months, even if you don’t need anything.

• Look for signs of moisture, odors or box collapse.

• Reposition items that have shifted or are pressing against walls.

• Refresh moisture absorbers and confirm locks and access are secure.

Think of storage visits as maintenance, not retrieval. A quick five-minute walkthrough can extend the life of your belongings and preserve the organization you set up on day one.

Insurance is easy to overlook when everything feels secure and well-packed. Even though insurance is required at most storage facilities, many people assume their homeowner’s or renter’s policy will automatically cover items in storage, or they choose minimal coverage without fully understanding what it protects.

The risk is that damage or loss may not be covered at all — or only partially — depending on the policy. Events like water damage, theft and unexpected incidents can leave you responsible for replacing valuable items out of pocket.

One important detail many renters miss: insurance coverage often varies by cause, not just value. Reviewing coverage terms and ensuring stored belongings are properly protected can prevent major financial surprises later, especially for long-term storage situations.

When storage is intended to be long-term, monthly payments can easily slip out of mind. Over time, unpaid balances can lead to late fees, restricted access or even auctioned belongings.

This mistake tends to happen when storage accounts are set up during a hectic period and never revisited. Without autopay, it’s easy for a single missed month to snowball into a serious issue.

A simple safeguard is setting up automatic payments and confirming your contact information is up to date. Many people don’t realize that storage facilities are legally required to follow lien processes once accounts fall behind, making autopay one of the easiest ways to protect your belongings long-term.

It’s natural to pack storage units based on size and weight, not how often items will be needed. As a result, frequently accessed boxes or seasonal items often end up buried behind furniture or stacked at the back of the unit.

This can be a hassle when you visit your storage unit, requiring you to clear out half of it or shuffle heavy boxes just to reach the back. 

A helpful strategy is to think of your unit as a working space (like your kitchen counter) rather than just a holding area. In the same way that you would keep your most-used knives and seasonings close at hand on your kitchen counter rather than tucked away in the pantry, items you expect to access regularly should live near the front of your storage unit, while long-term or rarely used belongings can be stored deeper inside.

Ready to store your belongings the right way from the start? Use our Storage Locator to find a SmartStop facility near you, and explore the SmartStop blog for more expert tips on long-term storage and organization.