How To Store a Mattress In a Storage Unit: Simple Steps to Keep It in Good Shape

If you’re wondering How To Store a Mattress In a Storage Unit without ruining it, you’re not alone. Mattresses can be bulky, heavy, and surprisingly delicate when stored the wrong way. This FAQ-style guide walks through what to do (and what to avoid) so your mattress stays as clean and comfortable as possible.

Why does it matter how I store a mattress?

Mattresses are made from layers of foam, coils, and fabric that can be damaged by moisture, pressure, and improper positioning. Poor storage can lead to:

  • Sagging or misshapen support layers
  • Mold, mildew, or musty odors
  • Stains, dust, and pest damage

Learning How To Store a Mattress In a Storage Unit correctly helps maintain its structure and feel, so it’s still usable when you’re ready to sleep on it again.

What should I do before putting my mattress into storage?

1. Clean and dry the mattress

Always store a mattress clean and completely dry.

  • Lightly vacuum the surface to remove dust and debris.
  • Spot clean any visible stains with a small amount of mild soap and water, then let it dry fully.
  • Allow extra drying time if you’ve used any moisture, so you don’t trap dampness inside plastic or covers.

A dry mattress is far less likely to grow odors or mildew in storage.

2. Use a protective cover

A cover is one of the most important steps in How To Store a Mattress In a Storage Unit.

  • Use a breathable mattress bag or fabric cover rather than airtight plastic if possible.
  • If you only have plastic, avoid sealing it completely for long-term storage; leave small openings for airflow.

Key idea: Your goal is to protect the mattress from dust, dirt, and pests while allowing some air circulation.

Should I store the mattress flat or on its side?

Best practice: Store it flat

For most mattresses, flat is best. This keeps the internal layers in their natural position and reduces the risk of:

  • Bending or warping
  • Coils shifting
  • Foam compressing unevenly

If possible, lay it flat on a raised surface (like pallets or clean boards) rather than directly on the floor. This adds some airflow under the mattress and keeps it away from any moisture that might accumulate.

What if I don’t have room to store it flat?

Some people stand a mattress on its side to save space. This is not ideal, especially for longer storage periods, because:

  • The weight can cause the mattress to slump over time.
  • Foam and coils may shift, affecting long-term comfort.

If you must store it on its side:

  • Only do so for a short period.
  • Make sure it is fully supported along the entire length, not just at one end.
  • Avoid leaning it sharply against corners or edges that could create dents.

Can I put heavy items on top of the mattress?

In general, avoid placing heavy objects on your mattress in storage.

  • Heavy boxes or furniture can compress the materials.
  • Long-term pressure may leave permanent impressions or damage springs.

If you need to stack items, stick to very light, soft items (like empty bedding bags or pillows), and keep them evenly distributed. But when in doubt, leave the mattress clear.

Is a climate-controlled storage unit necessary?

A climate-controlled unit can be helpful, especially if:

  • You live in an area with high humidity.
  • Temperatures in your region are very hot or very cold.

Extreme temperature swings and excess moisture can contribute to mold growth, odors, and material breakdown over time. While not always required, a more stable environment generally supports better mattress preservation.

How long can I keep a mattress in storage?

There’s no strict limit, but the longer it stays stored, the higher the risk of:

  • Gradual sagging or compression
  • Dust and odor buildup
  • Minor changes in feel when you use it again

If you know the mattress will be stored for many months or longer, paying attention to proper cleaning, covering, positioning, and climate becomes even more important.

What should I do when I take the mattress out of storage?

When you remove your mattress from the storage unit:

  1. Uncover it and inspect all sides for visible damage, stains, or odors.
  2. Let it air out in a clean, dry room for several hours or a full day if possible.
  3. Lightly vacuum the surface again before making the bed.

Some mattresses may feel slightly different after being stored. Giving them time to “settle” on a flat bed base can help them regain their usual feel.

✅ Quick Mattress Takeaways

Key points to remember about How To Store a Mattress In a Storage Unit

  • Clean and dry first: Never store a dirty or damp mattress.
  • Use a protective cover: Prefer breathable covers to reduce dust and moisture buildup.
  • Store flat when possible: Flat storage helps maintain structure and comfort.
  • Keep it off the floor: Use pallets or a platform to add airflow and avoid moisture.
  • Avoid heavy weight on top: Heavy items can cause permanent impressions.
  • Consider climate conditions: Stable temperature and humidity are better for long-term storage.
  • Air it out when you’re done: Let the mattress breathe and inspect it before using again.

Understanding How To Store a Mattress In a Storage Unit comes down to protecting it from moisture, pressure, and dirt. With a bit of preparation and the right positioning, you can help your mattress stay supportive and ready for many more nights of comfortable sleep.