From sentimental newspaper clippings to your kiddo’s artwork to your marriage certificate, paper documents hold up surprisingly well with proper storage in a conditioned space. In a damp basement, paper is essentially a sponge. As your documents soak up excess humidity, mold and mildew can begin to take hold. Plus, any writing or printing on the paper will degrade over time.

Just like paper documents, storing photos in a basement is a bad idea. Photos are naturally sentimental items, and you want to take utmost care to preserve them. While the photo paper may seem tougher than standard paper, it will degrade in the same way.

Even if an item is deemed safe for basement storage, you should still use a proper storage bin rather than a cardboard box. Cardboard simply will not last in a basement environment, as it will trap ambient moisture, leading to mold and mildew growth and eventual decay. Oh, and did we mention pests love cardboard?

Fabrics and textiles (like pillows, baby clothes, bedding, stuffed animals, gowns and the like) should never be stored in a basement, as they’re a magnet for mold and mildew. This goes for seasonal clothing storage, too, as damage can occur more quickly than you think.

Storing your old VHS or DVD player from yesteryear so you can rewatch classic movies and family videos that are no longer compatible with modern devices isn’t a bad idea, but putting it in the basement is no better than putting it in the trash. Temperature and humidity fluctuations can damage delicate circuits and wiring, rendering these devices inoperable.

Wood furniture seems solid and strong, and it is — but only in a stable environment. You see, even in your home’s living space, wood expands and contracts in response to subtle temperature and humidity changes. An uncontrolled basement environment turns this expansion and contraction up to 10, causing permanent damage to wood furniture and decor, like warping and cracking. Our preferred solution: Pull your wood furniture out of storage and style it in your home with our tips below.

Old paint cans, gas cans, propane tanks and any other flammable or hazardous materials should never be stored in a basement. Placing these items near an open flame from a gas furnace or water heater (two things often located in a basement). Storing any of these items there can have disastrous consequences, as the flammable components and fumes could ignite.

Batteries shouldn't be stored in a basement, as the higher humidity can lead to corrosion and degradation. Plus, an unregulated temperature can wreak havoc on batteries, accelerating self-discharge and reducing their lifespan.

While you may not play granddad's guitar much, it deserves a spot beneath the bed rather than the basement. A basement's uncontrolled atmosphere is a delicate musical instrument's worst nightmare. Suddenly, that priceless vintage guitar or heirloom piano is totally worthless. If you have several instruments, it may be worth designating a room for storage and enjoyment.

We've established that a basement's humidity and temperature fluctuations, along with stagnant air, are the perfect recipe for mold and mildew. For this reason, plus the dangers of unexpected flooding or pest infestations, we recommend you never store keepsakes and mementos in a basement. Even if they are made from seemingly durable materials like leather or metal, a basement can cause lasting damage to these irreplaceable and cherished items.