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My Memory Foam Mattress Not Expanding: Causes and Solutions

Did you recently purchase a memory foam mattress that just won’t seem to fully expand? Are you feeling frustrated and unsure of what to do next?

Memory foam mattresses have become increasingly popular in recent years due to their ability to provide a comfortable and supportive sleeping surface. However, some consumers have reported issues with their mattresses not expanding to original shape, leaving them with an uncomfortable and lumpy sleeping surface.

If you’re experiencing expansion issue, there are a few potential reasons as to why your memory foam mattress may not be expanding as it should. In this article, we’ll explore the common causes of this problem and provide some helpful solutions to get your mattress back to its intended state of comfort and support.

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Why is my memory foam mattress not expanding?

There are a few possible reasons why your new memory foam mattress is not expanding as expected. 

You were not patient enough

Patience is key when it comes to purchasing a new memory foam mattress. Unfortunately, some people are too eager and end up not giving their mattress enough time to expand properly. If you were one of those people, then you may have found that your mattress isn’t expanding as expected.

Though manufacturers may promise that your mattress will expand in one or two hours, it is advisable to wait for at least 72 hours before the mattress expands fully, especially at the corners. 

2. There may be foam pockets on your mattress

Foam pockets can form on a memory foam mattress for a number of different reasons. This could be due to the mattress being trapped in a box for too long before shipping or it could have been kept in the box after purchase for an extended period of time. The fibers in the mattress can become locked, which prevents it from expanding properly and creating foam pockets. 

Some mattresses are packaged tightly, so when they are released, they may not expand correctly. If this is the case with your mattress, then you may find that there are small areas that remain compacted and form foam pockets.

3. There is not enough heat to warm it up

Many memory foam products are designed to respond to body heat, allowing them to expand and conform to the shape of the sleeper. If your mattress is not expanding properly, this may mean that it’s not receiving enough heat. This can occur if you are using a mattress protector or sheet that prevents your body heat from transferring through.

If there have cold temperatures in the bedroom, then the mattress may not be able to warm up enough for it to expand.

4. Your room is too humid

Humidity can be a major issue when it comes to memory foam mattresses not expanding properly. Memory foam is made of polyurethane, a material that absorbs moisture from the air. If your room has high humidity levels, then this moisture will prevent your mattress from expanding properly.

In order to solve this problem, it’s important to reduce the level of humidity in your bedroom.

5. Thicker or High-density mattresses

Thicker or high-density mattresses are made of denser material than regular foam mattresses, meaning they take a bit longer to expand once you take them out of the box. Because higher density mattresses require more time to expand and fill out their full shape.

To speed up the process, it’s important to follow the manufacturer’s instructions and allow the mattress plenty of time to reach its full size before you try sleeping on it.

What to do if your memory foam mattress is not expanding?

If you’ve just purchased a new memory foam mattress and it isn’t expanding as it should, there are a few things you can do to help the process.

Increase the room temperature

Memory foam is temperature-sensitive, so a warmer room temperature can make it expand faster and reach its full size and firmness levels. We recommend a room temperature of at least 68 degrees Fahrenheit for optimum mattress expansion. Additionally, your body heat during the first night of sleep on your new mattress will also aid in reduce expansion time.

If you don’t have access to air conditioning, then there are other ways to increase the room temperature. Space heaters or fan heaters can provide warm temperatures in your bedroom while also helping to circulate fresh air. You may also want to consider using extra blankets or electric blankets on your bed as this helps retain heat and keep the mattress warm throughout the night.

Increasing the room temperature won’t just help with mattress expansion – it can also improve your sleep quality and comfort level by providing a more restful environment. So, if you’ve been struggling to get comfortable on your new memory foam mattress, try upping the warmth in the room before calling an expert for advice.

Put it on a flat surface (such as the floor)

Flooring your mattress is an important part of getting it to properly expand. We recommend laying your memory foam mattress on a flat surface such as the floor for at least 24 hours after unboxing it. This will ensure that it reaches its full size and firmness levels, giving you the best night’s sleep possible. It’s also important to make sure that there are no obstructions under the mattress, such as furniture or other objects, as this could prevent proper expansion.

When putting your mattress on the floor, you should also consider using a mattress topper or cover beneath it to protect it from dust, dirt, and pet hair. This will help keep your bed clean and hygienic while still allowing air to circulate beneath the mattress so that it can expand properly. When you’ve finished letting the mattress expand on the floor, simply pick it up and place it back onto your bed frame or platform bed – no need for any tools!

Improve air circulation

Improving air circulation around your memory foam mattress is essential for it to expand fully. This can be done easily by opening a window or running a fan in the same room as the bed. The increased airflow will help speed up the expansion process and reduce any off gassing that may occur. You should make sure that there is no furniture blocking off the mattress, as this could inhibit air movement and prevent it from expanding properly.

Placing a breathable sheet or cover beneath the mattress will protect it while still allowing air to circulate. With these simple steps, you can ensure that your memory foam mattress expands fully so you can enjoy its superior levels of comfort and support for many years to come!

Massage the mattress

Massaging your memory foam mattress is a great way to help it expand and reach its full potential. Start by placing your hands on the surface of the mattress and gently kneading it in a circular motion. This helps activate the foam layers so they can start expanding. You should also use your fingers to press down into the mattress and move them around in small circles, which helps distribute air pockets evenly throughout the mattress. This will ensure that all parts of the mattress are able to expand properly for maximum comfort and support.

After massaging for about 10 minutes, turn off any fans or other sources of air circulation in order to allow the foam to cool and settle down for a few hours before you use it. 

Return the mattress for a replacement

If you’ve followed all of the steps above and your memory foam mattress still isn’t expanding, it may be time to consider returning it for a replacement. Most of the best mattress brands offer a free sleep trial period that gives you the ability to return or replace your mattress free of charge. All you have to do is contact the manufacturer and let them know that your new memory foam mattress isn’t expanding. They can then arrange for a replacement or provide you with an appropriate refund.

You need to keep all original packaging and paperwork so it can easily be returned. With a few simple steps, you can be sure that your memory foam mattress will expand fully and provide superior levels of comfort and support for many years to come!


How Long Does It Take for the Corners of a Memory Foam Mattress to Expand?

It typically takes a memory foam mattress 24-48 hours to fully expand and reach its natural shape. However, it’s important to note that the corners of the mattress may take slightly longer to expand than the rest of the mattress. This is because they are more likely to be compressed during shipping and may require additional time to restore their shape.

If you’re still waiting for your new memory foam mattress corners to expand after 48 hours, you can try placing heavy items (such as books) on them in order to speed up the process. Additionally, make sure that you give the mattress plenty of space for air circulation so it can properly expand without any obstructions. With a little bit of patience and some extra help from gravity, your memory foam mattress should be ready for use in no time!

How Long Does It Take a Memory Foam Mattress to Expand Fully?

Depending on the size and type of memory foam mattress you purchased, it could take anywhere from 24-72 hours for the material to reach its full potential.

To ensure your mattress expands properly, be sure to remove it from its packaging and give it plenty of space in a well-ventilated room. Additionally, you can help speed up the process by placing heavy items (like books) around all four corners of the mattress; this will help expedite the expansion process and make sure your bed is ready sooner!

Can You Damage a Memory Foam Mattress by Sleeping on It Too Soon?

Sleeping on your new memory foam mattress too soon can cause a variety of issues and can even damage the mattress over time. Memory foam mattresses need time to fully expand, which typically takes 24-48 hours; if you sleep on it before then, it won’t be able to reach its full potential and may even start to sag in certain spots. Additionally, sleeping on the mattress too soon can prevent the material from settling properly, which could lead to body indentations if you don’t give it enough time to mold around your body.

To avoid damaging your memory foam mattress and ensure you get the best sleep possible, try to wait at least 24 hours after taking it out of the box before using it. This will give the foam time to adjust and form around your body without any disruption or pressure that could potentially cause long-term damage. If you’re too eager to sleep on your new mattress right away, try placing heavy items (such as books) on all sides of the corners for a few hours first; this should help speed up the process!

Can you use a hair dryer to expand memory foam?

No, you cannot use a hair dryer to expand memory foam. Memory foam is made up of a temperature-sensitive material that requires heat to expand. However, applying heat with a hair dryer can create uneven expansion, and you may end up damaging the foam or consuming too much of its lifespan.

If you wish to expand memory foam, you could place it in a well-ventilated area at room temperature and wait for it to expand naturally. Alternatively, some manufacturers suggest rolling and unrolling the foam to expedite the process, but it is always best to follow the manufacturer’s instructions. Applying heat in any form could damage the foam or void the guarantee, so it is essential to take precautions when handling memory foam.

Can you sleep on a memory foam mattress while its expanding?

It is generally not recommended to sleep on a memory foam mattress while it is expanding. The reason for this is that memory foam mattresses typically take anywhere from a few hours to a few days to fully expand and take the shape of the bed frame.

During this time, the mattress may not provide adequate support, causing discomfort and even possible strain on the body. Additionally, sleeping on a partially expanded memory foam mattress may also cause damage to the foam cells, resulting in a less comfortable and less durable mattress overall. It is best to wait until the memory foam mattress has fully expanded before using it for sleep.


If your memory foam mattress is not expanding, there could be a few different reasons why. One common issue is that the mattress may have been compressed for too long, which can cause it to lose some of its ability to expand fully. Additionally, the temperature and humidity in your room can also affect how well the mattress expands.

To ensure that your memory foam mattress expands properly, it’s important to follow the manufacturer’s instructions carefully. In some cases, it may be necessary to allow the mattress to sit for a few days before using it. If you’re still experiencing issues, it may be helpful to contact the manufacturer or seek advice from a mattress expert.

Author: Jessica

Jessica is a lover of both life and gardening. She loves to share his passion for both on social media. He often posts about his latest gardening projects, as well as tips and tricks for others who might be interested in starting their own gardens. She also frequently posts about the different aspects of his life that he enjoys, from spending time with friends and family to exploring new places.