How Long For Memory Foam Mattress To Expand

A memory foam mattress is made up of viscoelastic material that is sensitive to heat. As you lie on a memory foam mattress it molds itself with the shape of your body and when you get up the mattress uses its viscoelasticity to retain its shape. A memory foam mattress is not only known for its comfort but also for its shippability. It is made such that it can be compressed by a manufacturer and this feature allows the memory foam to be deflated, folded and put in a box which is easy to ship. This is the reason why memory foam is also sometimes called bed in a box.

It takes 24-72 hours to expand a memory foam mattress completely but it expands up to 90% in about 4-6 hours, according to mattress manufacturers. It takes 24 hours for memory foam mattress toppers to expand 100%. Memory foam pillows take about 48-72 hours to expand fully because they are denser.

The amount of time for memory foam products to expand may depend on other factors, which will be discussed next.

How long does it take a memory foam mattress (or mattress-in-a-box) to expand?

As stated before, it takes up to 24 hours for a memory foam mattress to expand. The air that is pushed out of the memory foam during compression starts filling the open cell structure again when the memory foam is taken out of the box. As the air starts filling in the open cell structure of the foam the viscoelasticity of the material allows it to expand to its original shape. As mentioned previously, the expansion time of the memory foam can vary based on the product type.

Here are the three factors that can affect the expansion time of the memory foam products:

Temperature: Any memory foam will expand faster in a warmer room. Heat reduces the viscosity of the material and increases its fluidity, which means that it will be easier to mold.

Density: Different manufactures make memory foams of different density. A denser foam will take longer to expand. It does not matter if it’s a topper or a pillow. A foam with more density is also more firm. You may like this article on properly using a tempurpedic pillow.

Thickness: The thickness or depth of the foam also affects the expansion time. Pillows may take longer to expand fully because they are thick. Memory foam toppers which are very thin will expand in less time as compared to the thicker toppers and mattresses. If your memory foam is too thick, you might be interested in cutting your memory foam mattress or topper.

What happens if you don’t wait for 24 hours for the memory foam to expand fully?

Most memory foams come with an instruction to allow 24 hours for expansion. Once the mattress is completely expanded you can see whether or not the product has defects. Some cracks and flaws only show when the product is fully expanded.

However, if you do not follow this instruction and use the memory foam before 24 hours, it will not damage the memory foam in any way. In fact, your body heat will help the memory foam to expand faster. If you cannot wait for 24 hours before using the mattress, we advise you to at least wait for 4-12 hours before you use it.

This initial 4-6 hours’ period after the unboxing of the memory is the period in which most of the expansion occurs and it is called the off-gassing period. Off-gassing is when the mattress lets off chemicals in the form of gas and it is what happens during expansion. Off-gassing is not usually dangerous for healthy people but it can be unpleasant and cause discomfort to people with asthma. You may be interested in this article on offgassing and mattress flammability.

It is important to note however that some manufacturers claim that their memory foam mattress expands fully in 8 hours and some products even claim it takes only minutes. We advise you to contact the manufacturers about all the details you want to know before making a purchase.

How long does it take a gel memory foam mattress to expand?

It takes gel memory foam 24-72 hours to expand. This time may vary with the thickness and density of the foam and the temperature of your room.

A gel memory foam may take a little longer to expand than a regular memory foam due to its increased density but the difference is not much. The main difference between a gel memory foam and a regular memory foam is that the gel foam has been infused with particles of gel.

These particles help to keep this memory foam cooler than the regular memory foam. Due to increased density, a gel memory foam also provides more support to the body.

Here are tips in case your memory foam mattress topper is not expanding (also applies to mattresses).

How to make memory foam mattress expand faster?

We know it is very difficult to wait when you have a brand new mattress. The first thing you want to do is to see how it feels to lie down on it. But with memory foam mattresses, rv mattress toppers and pillow you have to wait for the mattress to expand first.

To make memory foam expand faster, follow these tips:

Unbox the Mattress Right Away
Unfold it and lay your mattress flat
Make sure the room is warm
Provide the mattress air circulation and ventilation

Unbox the Mattress Right Away

If you do not want to wait too long before you can use your memory foam mattress, make sure to unbox it as soon as you receive it. The sooner you unbox it, the sooner you will be able to start the expansion process.

Unfold the mattress and lay it flat

Once the mattress is unboxed, make sure to unfold it and lay it straight. This will increase the surface area that is exposed to the air and make sure that the expansion occurs fast and evenly.

make memory foam mattress expand faster by laying flat

Make sure the room is warm

Keeping the mattress in a warm room is the key step to reducing its expansion time. If your room is not very warm you can make it warmer by switching on a room heater. Warmer temperatures increase the fluidity of the viscoelastic material that the memory foam is made of and allows it to expand faster.

Warm temperature also helps keep the mattress soft even after expansion.

warm room makes memory foam expand faster

Provide proper air circulation and ventilation for the mattress

Another trick used to reduce the expansion time of the memory foam is to create some air flow through the memory foam. One way to do this is to keep it in a well ventilated space (such as on a platform bed with slats) and another way is to provide air circulation artificially by using fans.

Instead of using regular fans, fan heaters may be used to expand the memory foam faster. Please note, if you choose this method, make sure the heat setting is low and check with the manufacturer that this method is safe for their product. This sleep number user guide suggests that you keep the heat source far away from the product.

What’s the mattress topper hack and how does it save money compared to buying a mattress?

takes less time to expand memory foam mattress with good ventilation

Does a warm room help make memory foam expand faster?

A warm room will make a memory foam expand faster. Although memory foam expands just fine at the normal room temperature but if you place it in a warmer room the pace of expanding may speed up.

The effect of heat on memory foam doesn’t end after the expansion is complete; heat helps to keep the memory foam softer over time by reducing the viscosity of the material and increasing its fluidity. So, if your memory foam is placed in a warm room it is likely to stay soft. Please check your manufacturer’s instructions to learn what temperatures the product can be safely exposed to since different products react to heat differently.

How long does it take a memory foam mattress to expand + tips for pillows and mattress toppers