How to Store a Mattress in a Storage Unit

ADMIN
February 27th, 2026

A good mattress is not cheap, and it does not take much to ruin one. Moisture, poor support, and tight plastic wrapping can quietly damage the inside while it sits in storage. By the time you notice, the comfort is gone.Storing a mattress correctly keeps it clean, supportive, and worth using again.

Why mattress storage can go wrong

Mattresses are built from layers of foam, springs, and fabric. Those layers can shift or trap moisture if you lean the mattress the wrong way or seal it too tightly. Over time that leads to sagging, odors, and sometimes mold.The Sleep Foundation notes that mattresses exposed to damp, poorly ventilated spaces have a higher risk of developing mold inside the layers, which is not something you want to sleep on later.

Step 1: Clean before you pack

Vacuum both sides of the mattress. Pay attention to seams and tufted areas where dust collects. Spot clean stains with a cleaner appropriate for your mattress type and let everything dry completely.Do not rush this step. Any moisture that goes into storage stays there.

Step 2: Use a breathable mattress cover

A mattress bag or cover is essential. Look for one that is durable but still allows some airflow. Slide the mattress in carefully and seal the end with tape.Avoid wrapping the mattress tightly in plain plastic sheeting for long term storage. That traps humidity and can encourage mold or mildew.If you want a quick comparison of methods and materials, National Storage has a post specifically on how to store a mattress with simple, step by step guidance.

Step 3: Store the mattress flat

In a storage unit, the safest position for a mattress is flat, not on its side. Standing it up saves floor space, but can cause springs or foam layers to shift if it stays that way for months.Place it on pallets, a platform, or other items that keep it off the bare floor. Avoid stacking heavy boxes or furniture on top of it.

Step 4: Choose the right type of unit

Mattresses prefer stable temperature and low humidity. If you live in an area with humid summers or cold winters, a climate controlled storage unit is worth considering.You can view all National Storage locations and explore which sites offer climate controlled options and unit sizes that match your needs.

Step 5: Plan for long term storage

If this mattress will be in storage for a long stretch, it helps to check on it occasionally. Make sure the cover is intact, nothing has been stacked on top, and there are no signs of moisture.For more big picture guidance, the article on the top tips for storing items for the long term walks through how to think about long duration storage, from packing choices to climate considerations.

Keeping your mattress worth sleeping on

A mattress that has been stored correctly should feel familiar when you bring it back home. Clean it, cover it, keep it flat, and give it a unit that will not fight against it. That is usually all it needs.