5 Things You Should Never (Ever) Store on Your Balcony, According to Experts

There’s something truly special about stepping outside, feeling the breeze on your skin, and enjoying the outdoors without leaving the comfort of your home. And since balconies can feel like extra space, it’s tempting to treat them like a storage spot. But, and we hate to break it to you, it's not.

Here's what you should never store on your balcony to best protect your home, belongings, and yourself.

Electronic Appliances

Since electronics are particularly vulnerable to the elements, they don't belong on your balcony, says home organizational expert Andrew Pope. "Say you’ve gotten a new washing machine and parked the old one on the balcony while you decide what to do with it," Pope says. But exposed to the elements, "heat warps plastic housings, moisture seeps into seams, and metal parts corrode," he warns, "which can lead to shorts that spark and potentially start a fire."

Instead of leaving appliances exposed, consider short-term indoor storage or a storage unit until you can properly recycle, sell, or donate the item.

Flammable Items

Things like propane tanks and gas cans can quickly become a fire hazard on a balcony. “Even a forgotten stack of old newspapers could ignite,” professional inspector Tim Dadourian says. To stay safe, keep flammable items stored indoors and in approved outdoor storage containers designed to prevent leaks and minimize fire risk. Never leave them exposed to sunlight or heat, and avoid stacking combustible items in ways that could trap air or accelerate burning.

Upholstered Furniture Pieces

Even furniture approved for outdoor use has its limits, especially if you leave it out year-round, Pope says. Cushions fade with sun exposure and, if you live in a particularly damp climate, mold and mildew growth can run rampant. “If you have outdoor furniture that isn't properly treated, it’ll will likely soak up moisture and eventually crumble when someone goes to sit on it,” Dadourian says. “If the items aren’t stainless or galvanized, they will rust from the inside out, leading to weak joints that fail without any warning.”

This warning extends tenfold when it comes to indoor furniture (think mattresses and other upholstered pieces not designed for the outdoors), even for short-term shortage. Besides trapping moisture and attracting pests, Pope says that indoor furniture items are particularly flammable. “They add a lot of combustible material right outside your home, which can make any fire spread faster,” he explains. “If a fire does start, these items burn hot and fast, and that’s why many buildings explicitly ask residents to keep them indoors.” 

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Extra Heavy or Bulky Items

Balconies are designed for people (and a light side table or two)—not massive gym equipment or other super-heavy items. “It’s a huge misconception that balconies are as strong as your interior floors,” Dadourian says. “They actually have much lower weight limits. Over time, the constant stress creates tiny cracks in the concrete or, even worse, starts pulling the balcony away from the ledger board of the house.”

To stay safe, Pope recommends spreading weight evenly across the balcony, keeping the heaviest items near the wall, and checking building load limits if you’re ever unsure. Only everyday outdoor pieces should stay outside, and anything unusually heavy should be stored indoors on the ground floor.

Items With Lithium Batteries

E-bikes, hoverboards, scooters, and rechargeable tools pose serious fire risks if left exposed to the elements. According to Pope, extreme heat or sunlight can trigger dangerous reactions inside lithium batteries, potentially causing them to overheat or catch fire. Even if a device looks fine on the outside, heat and UV exposure can damage the internal cells, which reduces battery life and increases the chance of failure the next time you use it. “These devices are safest stored and charged in well‑ventilated, shaded areas, never packed tightly among other combustibles,” Pope says.

If you have to store them outdoors temporarily, keep them in insulated, well-ventilated containers and away from anything flammable. Always follow the manufacturer’s instructions for charging and storage, and never leave batteries unattended while charging.