Learn all about general memory foam pros and the cons, then check out Serene Foam and what makes it different.

Memory Foam Pros

Visco elastic foam or “memory foam” is different than the many other materials used in mattresses. There is a lot of misinformation on the material “disguised as fact.” Not all memory foams are created equal. They have many different formulas and compositions depending on who manufactures it. There is also a lot of marketing hype out there that borders on misinformation.

There are two basic ways that a material in a mattress reacts to weight and pressure.

1. Viscous materials flow away from pressure like a liquid or honey. They distribute and absorb energy.

2. Elastic materials tend to store energy under pressure and to different degrees push back against compression

Materials like Water and Air, are viscous

While these materials do feel like they “push back” it is actually the combination with the elasticity and resilience of the enclosure or from other materials in the enclosure that allows these materials to push back. Viscous materials can be very hard initially with sudden pressure but feel much softer under more gradual pressure (try leaping onto an airbed or waterbed core). This is because viscous materials take time to “give way” to pressure. When they do give way, they give way in any available direction, dictated by their enclosures, and spread the pressure out through the layer.

Springs and non memory foams (like “normal” polyurethane and latex) are elastic

Elastic materials recover quickly and with different amounts of “force” behind them (based on how quickly they spring back) to their original shape or length. Both are breathable enough that air just goes in and out with little to no resistance in all directions (compression and recovery) so the response from both of these are mainly because of the material itself not from what encloses them (although this will also have some effect). Of course foam has some resistance to airflow in both in and out directions so airflow plays a small part in its qualities while innersprings are not at all affected by air. Compression of an elastic material works in real time so it would initially feel much softer than a viscous material if you leaped on it but it only gives way in one direction (underneath you) so it will store energy underneath you (and push back) and may feel softer initially but firmer than a viscous material after a matter of some seconds. They have “bounce” and this bounce is known as resiliency.

Natural fibers are elastic and resilient to much lesser degrees but not viscous

Natural fibers are very breathable so air easily flows through them as they compress under pressure but the fibers are not nearly as elastic or resilient as non-memory foam or springs and they don’t “recover” as easily. Natural fibers are also not created equally. horsehair is the most resilient of the commonly used fibers, it recovers more strongly than wool which recovers more strongly than cotton. These fibers are so breathable that there is very little resistance to air flow under compression but since most fibers don’t have the resiliency to recover with as much force as springs or most foams and are less elastic, they will become more “permanently” compressed to differing degrees over time. They tend to need a resilient support layer underneath them.

Memory foam has a combination of viscosity and elasticity

This is why it is often called “visco-elastic.” This characteristic is what sets memory foam apart from other materials. It is made to recover over a matter of seconds and is strong enough to “refill” the air but it is not so resilient as to absorb the energy of compression to return with a “springy” feeling. It is less breathable than other materials and under compression the air both leaves and returns against more resistance than most other foams. This plays a part in why it is slower than other materials to compress and return. Memory softens in response to heat and humidity from your body or room temperature as it changes from a more elastic material into a more viscous material. The length of time it is continuously compressed can also affect how much the memory foam softens as well. This change or “melting” also takes time when you lie on it and it also takes time to change back to elasticity and return to its shape when you get up.

Memory foam is great for pressure point relief, but it must have a quality core, or support layer beneath it.

Layers that store energy and push back can be good at pressure relief in softer versions, but are usually considered better for support. This also depends to some degree on the point elasticity of the material and its ability to form a conforming cradle that mirrors the shape of the body. All viscous materials are good at this. Some elastic and more resilient materials are better at this than others. The different layers in a mattress are usually designed in such a way that the complete mattress will have both supportive qualities and pressure relieving qualities. The core of the mattress which is the middle and bottom parts, usually innersprings, latex, or higher quality polyfoam, is the part that is primarily responsible for supporting the heavier parts of your body and keeping them from sinking in too far. The comfort layers which is the few inches (usually polyfoam, latex, memory foam, natural wool, horsehair, or synthetic fibres) are responsible for redistributing pressure so you don’t get “pressure points” when you sleep. They are responsible for supporting the inner or more recessed parts of your body like the small of your back, waist, upper thighs etc. so that gravity doesn’t pull them down against the natural position or curvature of your spine. The lighter parts of your body don’t usually sink in enough for the deeper support layers to play much of a part in supporting them.

What does all this mean in mattress terms?

Memory foam’s greatest advantage is its ability to distribute and relieve pressure. This does not mean however that it is dramatically better than the best of other materials as there are other types of foam like latex or high quality polyfoam that in their softer versions through compression alone are very close to memory foam in their ability to distribute pressure to levels below personal detection for most people. Even natural fibers that have broken in and formed a “cradle” to your body can distribute pressure very well and are often used in high quality mattresses. If a mattress relieves pressure below levels that you personally can detect, then knowing exactly which material is used in the comfort layers to do this is not so relevant except for other reasons such as its ability to support, its breathability, and its durability. In hospital applications (such as the relief of pressure sores) or with highly sensitive people, this slight difference in pressure relief can be very important. However, in most applications the difference is not as critical or even noticeable and the difference in materials used for pressure relief is more about how they feel and personal preference.

Memory foam requires body heat (in differing degrees with different formulations) to become viscous enough to “flow”

Depending on the individual memory foam’s characteristic sensitivity to heat, the “un-melted” areas of foam that are further away from your body will be firmer and resist pressure without “flowing away” from that pressure. This means that you are enclosed in a “stable cradle” of material that is “softer” close to you while it remains “firmer” further away from you. This combination of softness and firmness feels very good to people who like to sleep “in” a mattress that also feels “stable.” Without this ability and the difference in viscosity and elasticity in different parts of the mattress, you would be sleeping “in” a viscous material which felt more like water or jelly without the feeling of “stable softness” that comes from a good memory foam layer. Other more elastic foams and natural materials to greater or lesser degrees can combine a feeling of softness with stability as well but memory foam is the leader in this respect.

Motion Isolation in Memory Foam

This is especially noticeable when more than one person is sleeping on a mattress. ESPECIALLY if one person likes to toss and turn at night while the other is a light sleeper! Memory foam’s ability to absorb energy and isolate movement is better than most other materials because of its ability to both absorb energy and respond locally to movement. Latex in a comfort layer is also excellent at motion isolation because of its ability to “localize” compression better than other materials but it doesn’t absorb energy nearly as much as memory foam. Latex, certain high quality polyfoams, and certain innersprings (like pocket coils) in the support layers also contribute to a mattress’ ability to isolate movement and what is under your memory foam is very important if motion isolation is important to you.

Quality memory foams are more durable, will keep its qualities, and last longer than many other polyfoams

This is especially true in the upper comfort layers. It is not unreasonable to expect the best quality memory foams to last 8 – 12 years depending on use. That said, it is true that some very high quality polyfoams, latex foams, better quality innersprings, or natural fibers used in “upper end” mattresses can last longer without breaking down.

Memory Foam Cons

Because of its low resilience, memory foam is not suited to be a support layer

It is so important to pay attention to the layers underneath the memory foam in a mattress as this is where the deep support (ability to keep your spine aligned) comes from. Treating memory foam as “supportive” as opposed to “pressure relieving” will usually lead to a potential purchaser paying less attention to underlying parts of the mattress and their resilience and other qualities, and possibly choosing a mattress with a poor ability to provide good alignment for a their body, weight distribution and/or different sleeping positions. Because a lot of the more heat-sensitive memory foam on the market can allow you to keep sinking in further over the course of the night as it softens, the underlying parts of the mattress that will prevent your heavier parts from sinking in so far that your spine is out of alignment are also important and some mattresses that have thicker layers of memory foam may keep you in good alignment when you first go to sleep at night but you may be out of alignment when you wake up in the morning.

Some side effects of memory foam’s greater sensitivity to heat can also lead to sleeping issues for some people

The deeper in a mattress someone sleeps, the more likely they are to have issues with “sleeping hot.” This of course is a quality of all foams where you “sink in” to some degree but it is compounded by the makeup of memory foams in general which allow a greater degree of sinking in and are typically less breathable (allow for less evaporation) than other foams. Even the newer generation memory foams which are more breathable, are not as breathable as other foams that are readily available. The greater breathability of other foams which have a more “open” cell structure (like latex or other polyfoams) tend to lessen the heat issues even for those who like to sleep more “in” a mattress using softer “non memory” foams. Natural fibers breathe best of all and tend to be cooler than any foam … especially memory foam.

This same sensitivity to heat can also lead in some cases to a mattress becoming “too soft” or “too hard” depending on the external temperature

The temperature in your bedroom can change its feel from season to season or from what you experienced in the store depending on environmental conditions. Different types of memory foam can be more or less sensitive to this but it can be more important to control the temperature of your bedroom with some memory foams than it is with others or with other materials.

Another potential issue of memory foams is that they take more time to adjust to different positions.

This can be an issue for those who change positions often or are sensitive to the time it takes for the memory foam to conform to their new position as it can create short term “pressure” while it forms a new “cradle”. Again different types of memory foams will take shorter or longer to conform to a new position. This “time to compress” or “rebound” that changes with temperature is both part of memory foam’s strength for some (creates a “stable cradle”) and its weakness for others (doesn’t conform to new positions quickly enough or feels too firm). Some people may also be sensitive to a lack of resiliency or “pushback” which allows them to change positions more easily with a little “help” from the mattress and helps to support the lumbar area. This same lack of resiliency or “springiness” is also why it is often rated lower than other materials for the “other activities that take place on a mattress”.

Finally there are the “offgassing issues” of some of the poorer quality foams that are common in the market today.

While all memory foams and polyurethane foams in general (including the “green” ones) use some “nasty” materials in their manufacture, some of them have more of this material left in them by the time you sleep on them than others. For those that are sensitive to this offgassing, this can lead to issues ranging from a reaction to the unpleasant smell itself all the way to respiratory issues caused by the vapors. Your best protection against this is to make sure you know who manufactures the memory foam used in a mattress and not just accept the “re-branded name” that has been given to it (and to you). If the foam in your mattress has been certified by Certiur (or a similar organization), you can be reasonably sure that at least any smell or offgassing that you may notice has been tested for any potential harm it may cause you (within the limits of the test). More natural materials used in mattresses such as different fibers and good quality latex foam (which may also have a less unpleasant odor for a short time and is usually tested as well) are usually considered to be superior in this area. In the case of CertiPur certification, the foam will also have been tested to some degree for durability and so is less likely to lose its beneficial qualities in a few months after purchase but the density of the memory foam would still be much more important durability factor than any limited durability testing done by CertiPur.

Without knowing what specifications and certifications the memory foam in your mattress has, I would not buy it. 

While it’s not directly connected to the quality of memory foam itself because higher heat and humidity levels can speed up the softening and break down of any foam material … with more temperature sensitive materials like memory foam this can happen faster and so I would tend to avoid using memory foam with heated mattress pads or blankets or at the very least use them at the lowest setting and only for short periods of time.

Serene Foam found in our Gel Tech line is different

Our line of Gel Tech mattresses uses a new and highly advanced type of memory foam that takes all the best qualities of older generations of memory foam while reducing the the price and breeding out the qualities of older memory foams that many people do not enjoy.

Serene foam is the newest iteration of memory foam on the market. By combining elements of high density foam and Supportive Air Technology, Serene Foam increases support without compromising comfort. It is ideal for alleviating pressure on the hip and back which reduces readjustment in the night, leading to more restful sleep. Serene foam also decreases motion transfer so you and your partner won’t be disturbed during sleep.

Unlike traditional memory foam, Serene Foam isn’t temperature sensitive. Gel infusion and immediate responsiveness help to mitigate and release body heat so that you can stay at a more consistent temperature all night long.

What is the purpose of Gel in Memory Foam mattresses?

Gel memory foam is made by infusing gel micro beads into memory foam with an open cell structure that helps to mitigate heat trapped by memory foam.