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How to Restore and Fix a Sagging Memory Foam Mattress
Top 10 | Best and Worst Mattresses

How to Restore and Fix a Sagging Memory Foam Mattress

Mattress Resources
Read Time: 7 minutes

What do you do when the mattress you tried out in the store starts to sag beyond repair? Or what if your mattress is outside the sleep trial and you’ve noticed a bit of dipping in the material? It can be frustrating to spend thousands of dollars on what you thought was a quality mattress, only to discover after using it for a while it starts to fall apart.

Most company warranties repair or replace mattresses with a 1-inch sag or deeper, but if you’re dealing with sags or divots smaller than that, the warranty doesn’t apply and you’re out of luck. Thankfully, there are some things you can do to restore or fix that sag in your memory foam, at least temporarily.

Buying a new bed might seem like the easiest (although not the cheapest solution), but you might not be in the market for one yet because of other pressing budget concerns. Read our guide for ways to rehabilitate your mattress and get a better night’s rest without neck or back pain. After all, losing out on sleep isn’t something to ignore!

Use a Mattress Topper or Mattress Pad

mattress topper for a saggy bed
One of the most common and cheapest ways to cover up pesky sags is to buy a mattress topper. Yes, it’s a temporary fix, but so are most of the suggestions on our list, and some users find their sleep is elevated to a whole new level when they start using a topper.

Many toppers are made using memory or latex foam— both popular materials in high-end mattresses thanks to their close-conforming ability and pressure relief. You can find good-quality toppers on Amazon, and some mattress companies sell their own toppers via their website.

Mattress topper materials vary, but memory foam mattress toppers usually cost between $100-250. On the other hand, toppers made with egg-crate foam or polyester fibers are quite cheap, with a price range of $10-60.

If a mattress topper doesn’t seem right for your situation, you can try a mattress pad. These are typically made with down or polyester sewn into the top for plush cushioning. They do not provide as much support as a topper, but they can still give you the comfort your saggy mattress may not be providing anymore.

Time for an upgrade? Read our guide on finding the best mattress.

Try Additional Mattress Supports

Sometimes the solution doesn’t involve fixing the top layers of your mattress, but the core support layers instead. You can try bolstering the underside of your bed using a few different products. Some of them may be items you already have laying around the house, while others require you to invest some extra money to get that good night of rest.

If you search for “sagging mattress supports” on Google or Amazon, some products will come up that amplify the support under your mattress.

These support systems work to lift your foam mattress a few inches off the slats or to completely fill gaps between the slats. Essentially, they act as an extra support core for your mattress, lifting the sagging portions upward and keeping the mattress surface even. These supports are usually made with high-density foam or a sheet of plywood.

You can also reinforce your bed using metal support bars, also sold on Amazon or other online retailers.

One of the cheapest ways to reinforce your mattress only requires a few old pillows you’ve got sitting around the house. Simply slip them under your mattress where you’ve noticed the most sagging, or, if you’ve got lots of old pillows, you can cover the entire foundation with them.

To get the most comfortable sleep and wake up every morning pain-free, read our guide on finding the best mattress for back pain.

Flip or Rotate Your Mattress

Rotating your mattress on a regular basis will keep the surface even and prevent sagging from building up in the same place. However, this solution doesn’t always last, and some users resort to flipping their mattress over entirely just to get a decent night of sleep.

Flipping your mattress will only work if 1) your mattress is dual-sided, meaning it was made so you can sleep on both sides or 2) you prefer sleeping on the much firmer side with the support cores on top. Sleep Junkie doesn’t recommend this option for most traditional mattresses because the support core is meant to be the foundation. If you flip the comfort layer to the bottom, your mattress may start to sag even more. In short, you should really only flip your mattress if it’s dual-sided.

Keep in mind that flippable mattresses may sound convenient, but they don’t always have the same hefty core construction that non-flippable beds do. They are built with comfort foam layers on both sides, so they may cause problems for you later.

Why Do Mattresses Sag?

Sometimes knowing what causes foam mattresses to sag can help you prevent it from happening. Of course, some of these factors aren’t really preventable, and if they apply to you, you may be better off sleeping on a different type of mattress like a hybrid or latex bed.

Extra Weight on the Mattress

Most mattresses should be around 10-12 inches thick, with more luxurious models boasting even taller heights. In general, a mattress thinner than this will sag much quicker, meaning the more pressure you put on it, the shorter its lifespan will be.

If you share your bed with a partner, a pet, or even if you just move around a lot while you sleep, you’ll need a mattress with sturdy support cores. Many foam mattresses are made using high-density foam layers in the base and convoluted foams throughout to deter sag. If you’re not sure a foam mattress will be supportive enough for you, you can always look to a hybrid or a latex bed, which have a different makeup but offer support and comfort similar to memory foam.

Lack of Core Support

All high-quality mattresses should come with some kind of support core in the base layer. Hybrid mattresses will usually use a combination of steel coils and wrapped coils, while foam and latex mattresses use high-density foam in the base. Spring mattresses use coils as the main foundation layer, but customers often report this mattress type sagging after only a few years.

A poor support core can lead to an uneven surface, so that’s where bolstering the foundation comes in handy. The most common sagging areas appear where your body normally rests. Many companies use transition foams to provide further contouring and support to these areas. If you need support for your lower back, consider your pillow as well as your mattress.

Wrong Foundation

It doesn’t matter if you bought an expensive or a cheap mattress— using it on an incompatible foundation or a weak bed frame will make for a very uncomfortable night. Foam mattresses are especially susceptible to indents and sagging if they are used on the wrong foundation. Memory foam conforms and cushions easily, which is one of its major benefits. However, it can also sink easily through large gaps in your foundation, so be sure to use your mattress on slats with gaps 3 inches or smaller.

While bolsters and foundation supports exist to “remake” your foundation, we caution against any DIY methods, since these can damage your mattress further. For the best support, buy a compatible, supportive foundation for your new bed from the get-go.

While a good foundation can help your mattress last, they offer only a fraction of the benefits best adjustable beds can provide. Read our guide to learn more.

Preventing Sag

Maybe after reading all of this, you’re wondering how to keep the top of the mattress from sagging in the first place! Whether you’re a stomach sleeper, side sleeper, back sleeper, or something in between, your mattress should offer even support, keep your posture neutral, and let you sleep pain-free. When one side of the mattress starts to dip, it can be nearly impossible to sleep well.

The best way to prevent sagging is to regularly rotate your mattress— even every month if you want to! Some memory foam beds are quite heavy, so you might need more than one person to do the job.

You can place a memory foam topper on your mattress as soon as you get it to add extra cushioning and create a “buffer” between you and the mattress, potentially alleviating risk of future sagging.

Sometimes, if you know your bed will need to support a lot of weight, it helps to invest in a firm mattress. Firmer foam mattresses use fewer cushioning layers— these are made with low-density foam, which can sag faster than high-density foam.

Other Questions to Consider

  1. How old is your mattress? If it’s around 7-10 years old, it might be time to replace it. Invest the money you would’ve spent on a topper or reinforcements in a new mattress instead.
  2. Are you using the right foundation? Innerspring mattresses often need a box spring to work properly. Memory and latex foam mattresses should not be used with box springs, but instead placed on a flat surface or a platform bed with slats. Many companies will specify in their warranty the exact type of foundation you should use with the mattress— going against this recommendation can void your warranty, which you might need when your mattress starts sagging.
  3. Do you need extra support? Sleeping on a sagging mattress can lead to backaches, neck pain, and other issues. At this point, you might be beyond a temporary fix. Look for a new mattress with built-in back support in the form of transition foams, pocketed coils (often found in hybrid mattresses), or gel foams.
  4. How much are you willing to maintain it? Extending the life of your mattress can save you money, but it might cause more problems down the road. Consider how much you want to maintain your sagging bed— will you have to keep flipping it and rotating it to get comfortable? Will you have to replace the reinforcements you installed every few years? Sometimes buying a new mattress is worth more than the time and money you save trying to restore an old one.
  5. Does your warranty cover the sagging? Mattress sag is a common issue mattress companies address in their warranties. The average sagging depth they will cover is 1 inch, although some like you to have an even deeper sag before you can cash in on the warranty. If the foam has begun to dip below the warranty’s specified measurement without any weight pressed down on it, contact the company for further instructions. They will probably let you exchange your mattress for a new one.

Interested in the benefits of memory foam? Read our other guide on finding the best memory foam mattress for your sleep needs.

Are You Ready to Fix Your Mattress?

A good mattress should maintain an even, smooth surface for at least seven years, give or take depending on the mattress type. When the top of your mattress starts to dip along with your sleep quality, it’s time to re-evaluate your sleeping situation.

Are you in the market for a completely new mattress, or can you patch things up with one of the ideas we’ve presented here? Whichever route you choose, be sure it doesn’t further damage the bed or your back. For more tips on choosing a good mattress, check out our article here.

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Comments (2) Leave a reply

  • My Select Comfort mattress sunk in the middle where the inner foam had split vertically allowing a large indention. I’ve added a 2.5” topper and a center twin to king connection. This resolved the sagging. However, the increase in height makes me feel like I’m falling off. I’m looking for two firm side supports and one for bottom. Can anyone help?

    • Hi Sandra,

      Thanks for reaching out! We’re glad to hear you were able to find a solution for the sagging of your mattress. We don’t know of any firm side or bottom supports compatible with your mattress that we could recommend. However, we believe the Select Comfort mattresses do come with a warranty that covers premature sagging. We would recommend reaching out to your local Sleep Number retailer (or the retailer you bought the mattress from) and asking their advice; they may be able to file a warranty claim for a new mattress or steer you towards the best side supports for your mattress.

      We hope this helps!

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