How to store a mattress without ruining it, according to experts

My first bed-in-a-box mattress was one of the best purchases I ever made. So when I suddenly had to put it into storage for six months during an extended trip, I wasn't worried about where I'd sleep — I was worried about ruining an expensive investment . That concern was well-founded: Store a mattress the wrong way and it can come out moldy, sagging or permanently damaged.

Fortunately, protecting a mattress in storage isn't that complicated. After talking to mattress manufacturers, moving professionals and sleep experts, we found that preventing damage mostly comes down to controlling moisture, pressure and temperature. Here's how to store your mattress so it comes out looking — and feeling — just as good as when it went in.

How to store a mattress properly

Your mattress deserves more than to be exiled to a musty basement or garage. Store it the right way once, and your future self will thank you night after night. 

Clean and fully dry your mattress

"If storage is going to be longer than a few weeks, in a warm or humid environment or if the mattress hasn't been properly cleaned in more than six months, it's crucial to clean, sanitize and dry it before storing," says Ken Faherty , founder of Be Green Carpet Cleaning in Denver. Organic stains (think sweat, oils or worse) plus dust, crumbs and other debris can make their way onto — and into — your mattress even if you use a mattress cover. Cleaning will help prevent odors, mold and bacteria.

Faherty suggests starting your storage prep by " vacuuming all sides of the mattress using the upholstery tool. Pay careful attention to the corners and piping where crumbs and dust easily hide." You can also sprinkle up to one pound of baking soda onto your mattress, letting it sit for at least eight hours, before vacuuming, a practice experts at Saatva recommend . 

Next, Faherty suggests spot cleaning with a mix of hydrogen peroxide , Dawn dish soap and water. "Gently blot the mixture with a clean, damp rag." Repeat until the stains are gone. Then press a clean, dry towel onto the area to absorb as much moisture as you can. Allow the mattress to dry completely before storing it to prevent mold and mildew. To speed drying, stand the damp mattress upright in a well-ventilated area and direct fans at it.

Use a breathable mattress bag

Do not send your freshly cleaned mattress into storage naked. It needs a protective layer to shield against dust, pests and moisture — but it shouldn't be plastic. "Fully sealing a mattress in heavy plastic for an extended period can sometimes create condensation, particularly in humid environments," says Drew Miller , spokesperson from Sit 'n Sleep, Southern California's largest mattress retailer. Instead, opt for a "breathable, high-density polyethylene mattress storage bag that's securely sealed," says Byron Golub , vice president of product and merchandising at Saatva. "For added protection, place the wrapped mattress in a sturdy cardboard box to prevent physical damage." It's also smart not to set it and forget it. Experts at Purple recommend peeking inside the storage bag every few weeks, if you have access, to check for moisture, mold or pests.

Choose a climate-controlled space

"Ideally, your mattress needs to be in a cool, dry and climate-controlled environment," says Miller. Over time, too much humidity and heat can erode adhesives, warp exterior fabrics and degrade foam density, one of the mattress's most important structural features. Very low temperatures may even freeze gel-infused memory foam . Once foam density is compromised, so is the mattress's support and lifespan . 

Of course, securing climate-controlled conditions often means paying for a professional storage facility. If that's not in the cards, you can reduce the risk of mold and mildew by keeping indoor humidity below 60%, but ideally between 30 and 50%, according to the Environmental Protection Agency (EPA). To help get there, place a dehumidifier in the storage space — and even use moisture absorbers , notes Golub. "But understand there is still a risk."

Store your mattress flat

"Mattresses are designed to lie horizontally. This helps preserve the integrity of internal layers and support systems," Miller says. But if you tip your mattress upright or on its side for long stretches, that "can lead to sagging, shifting or uneven wear — especially with foam, latex or hybrid constructions." If you are only storing your mattress for a few weeks, however, upright is likely OK.

Keep it off the floor

Even if it's bagged and stored in a climate-controlled space, don't place your mattress directly on the floor. Instead, store it on a clean, flat, elevated surface to reduce the risk of moisture, pests and accidental water damage. Experts at Layla suggest placing plywood on top of other stored furniture to create a flat surface for your mattress. Another reason to shun the floor: If your mattress is still under warranty, improper storage — including storing it directly on the floor — may affect your coverage , depending on the manufacturer's terms.

How long can you store a mattress?

While experts generally recommend limiting storage to about six months, that timeline isn't absolute — under ideal conditions, a high-quality mattress can last longer. "If properly cleaned, dried, wrapped and kept in a stable environment, it can last up to a year without significant issues," Golub says.

The same storage timeline applies to all mattress types , though foam, latex and hybrid mattresses tend to be less forgiving than innerspring models because they're especially sensitive to moisture, heat and prolonged pressure, says Golub. If you're storing your innerspring mattress for an extended period, Mattress Firm suggests flipping it every few months to prevent uneven wear.

Common mattress storage mistakes to avoid

Consider this your cheat sheet of what not to do when storing your mattress.

❌ Don't store damp:Give your mattress a chance to fully dry after spot cleaning. "I can't stress this enough because in a dark, moist environment, mold can start to grow within 24 hours," says Faherty. "By one to two weeks, there will be noticeable spots and a smell. Not only that, but foam breaks down faster when wet and springs can corrode."

❌ Don't wrap it tightly in plastic:Not only can fully sealing your mattress in heavy plastic create condensation, but tight wrapping can compress its layers and put tension on its cover and stitching.

❌ Don't leave it upright:Long-term vertical storage can cause sagging, shifting of internal layers or misshaping, especially in foam mattresses, says Golub. For a short period during a move, though, you're likely A-OK.

❌ Don't keep it in a hot environment:Excess humidity, heat or dramatic temperature swings can impact the structural integrity of your mattress and encourage mold and mildew.

❌ Don't stack items on top:Your bed is not a table. Do not place boxes, furniture or anything else on top of it. They can easily leave deep and permanent impressions in the fabric and foam.

How long can you leave a bed-in-a-box unopened?

As tempting as it may be to store your bed-in-a-box mattress unopened until its permanent spot is ready, experts don't recommend it. Most mattresses can only stay compressed for up to a month from their delivery date; after that, the foam starts to break down, causing your brand new, never-slept-on mattress to sag, lose support and take longer to expand — or never fully expand. Plus, improper storage may void your warranty, and the manufacturer may deny your claim for a mattress replacement.

How to tell if a stored mattress is still safe to use

Before sleeping on a mattress that's been in storage, inspect it carefully for:

• Tears

• Lumps, indentations or deformities

• Damp patches

• Pest damage 

• Mold

• Unusual odors 

Keep in mind that mold can grow for some time before it becomes visible, so damp patches or a musty smell are early warning signs in themselves. If you notice any of the above, it is likely time to discard your mattress and shop for a new one .

Even if everything looks good, vacuum the mattress, then let it air out for several hours in a well-ventilated room before making the bed. If it's a foam mattress that was compressed at any point, allow it to fully expand first.

The bottom line

Mattresses aren't cheap , and replacing one because it was stored improperly is an expensive mistake. Store yours the right way from the start, and you'll protect both your investment and the quality of your sleep.

FAQs

Can I store my mattress in the garage? 

Attics, garages and basements are the least ideal spots for storing mattresses, because they're more vulnerable to moisture, dust and heat fluctuations, says Miller. "A climate-controlled storage unit is usually the safest option." 

Can a mattress get bed bugs in storage?

If you share a wall with an infested unit, your mattress could become infested too — bed bugs can survive 20 to 400 days without feeding , giving them plenty of time to travel. For more on how to spot and how to eradicate these pests, check out our all-things bed bugs guide .

How do I know if my stored mattress has mold?

While mold can start growing within 24 hours, it can take time to become visible. Watch for damp patches, musty or unusual odors or visible spots on the surface. If you notice any of these signs, the mattress is likely compromised and should be discarded. If you decide you need a new bed, follow these tips for picking the best mattress for you .

Is it bad to store a mattress on its side?

For a short move, propping your mattress upright is usually fine. But long-term vertical storage can cause sagging, shifting of internal layers or misshaping — especially in foam mattresses. Mattresses are designed to be supported horizontally, so lying flat is best for anything longer than a few weeks.

Meet our experts

• Ken Faherty , PhD, chemical engineer and founder of Be Green Carpet Cleaning in Denver

• Drew Miller , spokesperson for Sit 'n Sleep , which describes itself as Southern California's largest mattress retailer

• Byron Golub , vice president of product and merchandising at Saatva

Our health content is for informational purposes only and is not intended as professional medical advice. Consult a medical professional on questions about your health.