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6 Ways to Fix a New Mattress That Sinks in the Middle

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A new mattress arrives at your doorstep wrapped in plastic inside a box or hand-delivered in a truck. You hire professionals to go to the bedroom, unwrap it, and place the new mattress on the bed.

But, after sleeping on it for a week, the middle sinks. Confused, you read the warranty or contact customer support about the issue. If this scenario, or a similar one, has happened to you, we’re here to help.

A new mattress that sinks in the middle is an unusual dilemma, but is it normal? We’ll show you how to solve this problem and help you determine whether you should return the mattress or keep it.

Young woman lying in the middle of a bed

What Causes a New Mattress to Sink in the Middle? Is It Normal?

New mattresses come straight from the factory, so you are the first one to sleep on them. The chosen firmness level will make sleeping comfortable and relaxing.

But, you can never expect to get a good night’s sleep with a sinking middle. While it’s normal for mattresses to sink in the middle towards the end of their warranty, it’s not normal for a brand new mattress. That sinking could be the result of:

  • The box spring base is not new. It came with the last bed and you kept it for the new bed.
  • The factory construction was poor. Low-grade materials, incorrect assembly, and defects are making the bed sag.
  • The bed frame foundation, wires, or bed slats are sagging or unstable.
  • The soft-to-firm ratio for your comfort level is incorrect.
  • The mattress was never new and the company you bought the mattress from scammed you.
  • The bed cannot support your weight.

Can You Fix a New Mattress That Sinks in the Middle?

There are two ways to look at the word fix.

If fix means taking these solutions and eliminating the sag forever, these tips won’t help. Nothing listed in the next section will make the sinking mattress flat again. Therefore, if that’s what you want, your only option is to return the mattress and exchange it for a new one.

However, if fix means accepting the sinking middle, these tips will help. While they won’t return your mattress to normal, they will stop the sag from sinking deeper. You will still get years out of this mattress before having to replace it.

Close up of corner of a mattress

New Mattress That Sinks in the Middle: 6 Ways to Stop It

1. Rotate the Mattress

The best way to rotate any mattress is to turn it from end-to-end 180 degrees. The foot of the bed will now be near the headboard, and the headboard part will be at the foot. 

This strategy distributes the weight across every part of the bed and evens the bed out. It will also even out any wear and tear. In addition, it stops sagging beds from deepening and prevents new dips from forming. For best results, rotate the mattress often between three and six months.

If you have a two-sided bed, you can also flip the mattress from front to back. This idea keeps consumers from buying beds as often. Manufacturers make comfortable beds on only one side of the mattress now so you can’t flip them.

2. Stuff Plywood Under the Mattress

A simple solution is stuffing plywood under the sinking mattress area. It props up the sagging area to reduce the sinking appearance. You also won’t feel the mattress swallowing you up at night because it adds firmness to sagging spots. You can start with plywood that’s an inch or less to start, but go thicker if the mattress dents are noticeable.

If there is a box spring base, stuff the plywood between the mattress and box base. The plywood relieves pressure from the box spring while propping up the bed.

3. Add or Replace the Box Spring

If your bed is sitting on a bed frame, the stress is on the bed frame. A box spring offers the in-between needed to prevent mattresses from sagging. If there is no box spring base, buy one. If you have a box spring base, you should always replace it whenever you buy a new mattress to prevent sagging.

4. Replace the Bed Frame

While you’re at it, a new mattress and a new box spring deserve a new bed frame. Older bed frames are weaker because the frame supported the previous mattress. A new bed frame will be more durable.

The best bed frame to buy to prevent sagging is a frame with six legs. Six-legged bed frames support the front, back, and center of the mattress. Bed frames with four legs cause dips in the middle because nothing holds the middle part up. Frames with slats cause sagging between the slats.

5. Add Pillows

A solution to prop up sagging mattresses is adding pillows. Since pillows provide temporary support, you should pair it with another idea on the list. Place pillows between the bed and the bedsheets to keep the bed level. Placing them anywhere else deteriorates the bed faster.

The best places to stuff pillows are the back, the hips, and the legs. They help with neck and back pain. Also, choose pillows that don’t need fluffing often.

6. Mattress Topper or Mattress Pad

A mattress pad is a thin and soft layer that adds comfort and support for tiny dents. It is suitable for all beds except memory foam. A mattress topper is a thick cushion that adds height, comfort, and support to memory foam and other bed types. Toppers and pads help more with sleep than with sagging mattresses.  

Therefore, this suggestion is the last resort rather than a first choice option. Pair this suggestion with one of the other five options for the best results. The installation consists of placing the topper or pad on a bare mattress. Then, add sheets, pillows, and a comforter on top.

New Memory Foam Mattress Sinking in the Middle

Since a memory foam mattress conforms to your body, a sinking middle will form. However, it is not normal to see dents in a new memory foam mattress. The causes are:

  • Poor protection
  • No box base
  • Too much heat
  • Too much moisture
  • Negligence due to children and pets

All the above solutions work on memory foam mattresses except mattress pads and pillows.

White mattress bed in the middle of a room

Should You Return Your New Mattress That Sinks in the Middle or Keep It?

Return a Mattress

Most mattress companies will accept returns after a trial period— usually 30 or 60 days. The details are on the receipt, warranty, website, online chat, or a customer service call. That goes for both brick and mortar establishments and online-based companies.

You should send it back if your new mattress sinks in the middle and none of the techniques work. You can choose to get your money back or exchange it for a similarly priced mattress. A representative will pick up the mattress and send it back to their facility.

Depending on the warranty and company, the manufacturers will repair the sagging area. Learn about any costs incurred to avoid sticker shock before agreeing to repairs. There may be fees for repairs or postage.

Keep a Mattress

No one should pay a high cost to settle with a new mattress that’s sinking in the middle. A common reason people do this is that sending it back to turn around and buy a new one is a hassle. However, this is not a good reason to keep it as you will resent the mattress.

One reason to keep it is if you like the mattress. If the mattress is the right soft-to-firm feel and your body gets a restful sleep, then you should keep it. A second reason is if the suggestions above helped the middle sink in less. 


A sagging middle is common for mattresses deep into their lifespan or warranty. A sagging mattress is a sign that it is not working like new. The sag will expand, and so will the discomfort and the pain that come with it. Pain and discomfort in sleep lead to poor sleep patterns or restless sleep.

After testing out our solutions, you have a choice to make. Will you keep the mattress or will you send it back after the trial period for an exchange? Just keep in mind that no solution will reverse the sinking middle.

Did you try these suggestions? Did you keep your mattress after trying them? Our readers want to hear from you. Leave a comment about the article in the box below.

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