Updated at: 15-01-2023 - By: Jane

It has been a staple of bedding for than a century, and is utilized in both comfort and support layers of most common mattress types. Technology has grown at an unparalleled rate in the previous few decades, and one of the seemingly inconsequential outcomes has been the development of new and improved sleeping products.

Although it was originally designed to protect astronauts in space, memory (or viscoelastic) foam has found its true vocation as a therapeutic and conforming mattress comfort material.

A wide variety of products are now available on the market, and it is necessary to know the features of both materials, specifically how they complement and contrast each other.

With that in mind, here is an explanation of foam vs. memory foam to help you compare mattresses that use these components.

Basics of Polyurethane Foam

Foam made of polyurethane foam is the most commonly used mattress material (as well as a whole host of other applications). As a first impression, low density polyurethane (LDPE) is selected by many manufacturers because it has an initial feel that is soft but does not endure long.

Support cores made of high-density polyurethane (i.e., polyurethane with a higher density) are used to keep the most pressing elements of your body from sinking through the soft comfort layer.

While low-density polyurethane will exhibit evidence of deterioration after a few years, high-density polyurethane will continue to perform for years without any noticeable change in performance.

The Pros and Cons


  • Generally speaking, it’s a bargain.
  • You can pick from a variety of different firmness levels.
  • Differentiating between densities and firmnesses is a simple way to provide durable support while also relieving pressure.
  • It’s easy to keep up with.
  • Cooler.


  • Memory foam is more durable.
  • No compliant support is provided.
  • Motion transfer is not totally eliminated.

Comfort and Pressure Relief

Unless the mattress is going to be used sparingly, even low density polyurethane can provide adequate spring support. However, this material won’t last very long. Polyurethane in HD or HR grade can give years of comfortable use if the maker does not overdo the thickness for short-term gains in reputation.

If you’re looking for a mattress that bounces back when you put pressure on it, you’ll want to look for a mattress with a high degree of firmness. As an example, the softer forms of high density polyurethane foam may be able to alleviate your pain locations by simply being more compressible, but they’ll be less bouncy as a result.


Heat Retention and Breathability

In spite of its open cell structure, polyfoam is more effective at transferring heat away from your body than most other materials.


Density plays a big role in the durability of both viscoelastic and polyurethane.

After a few years, low density polyurethane foam begins to sag, but high quality, high density foam (density north of 2 lb./cu.ft.) can be expected to endure much longer. It will, however, not age as elegantly as viscoelastic does.

Motion Transfer

Polyurethane isn’t bad at decreasing motion, but it isn’t as highly elastic as viscoelastic foam and does transfer some of the pressure to the bed’s edges.

Basics of Memory Foam

When a body is placed on memory foam, it is capable of absorbing and redistributing the pressure, allowing it to form a conforming cuddler that matches your sleeping style. This results in pressure being taken away from the hard points, like the hips and shoulders of a side sleeper, so that the spine can be in its natural position.

The primary function of viscoelastic foam is to relieve pressure, not offer comprehensive support. The base of a mattress must be made of a tougher, more resilient substance like HD polyfoam in order to provide both support and relief.

Compared to conventional polyurethane, viscoelastic foam employs extra chemicals in order to achieve its viscoelastic properties. Viscoelastic foams having densities of more than 4 pounds per cubic foot tend to keep their capacity to conform for a longer period of time than other types of foam.

The Pros and Cons


  • Adapts to your body’s contours.
  • Provides customized relief from stress.
  • Motion isolation is a strong feature of his.
  • When paired with a solid base, can give cradling support.


  • Pricey.
  • Hot.
  • Temperature sensitivity.
  • The first whiff of chemicals.


Memory Foam Vs Low Density Foam

‘Dead’ support can be found in Viscoelastic foam, which absorbs most of your body’s impact and reflects it very little, resulting in a lack of springiness or’resilience’

More than a few inches of viscoelastic in a comfort layer can induce spinal misalignment, especially for heavier folks (unless the support layer is harder, like the standard with current mattresses).

While memory foam lacks viscoelastic properties, low density polyurethane (under 1.5 lb./cu. ft.) provides the same soft support but with a bit more spring. In order to adequately support your body, however, you will need additional support elements beneath the mattress.

Memory Foam Vs High Density Foam

There is no rigid support to be found in viscoelastic foam. It is possible, however, to create foams with both high density and high resilience (2.5 lb/cu.ft. density and 2.4 support factor), so that they provide both gentle and deep support.

HD and HR foams can be utilized in any support role, whereas viscoelastic can only be employed in comfort layers because of their stiffness and quality. In reality, prominent local producers blend high density viscoelastic foam / high density foam mattress hybrids that provide both soft surface conformance and deep support concurrently.

Comfort and Pressure Relief

Using viscoelastic foam, you can target the portions of your body that protrude and cause back pain by cradling them in the foam. It conforms to the contours of certain areas and relieves pressure on them, resulting in increased comfort.

That being said, a viscoelastic mattress will give you the sensation of sleeping “in” the mattress rather than “on,” so don’t go for it if you’re looking for something with a little more oomph.

Heat Retention and Breathability

Viscoelastic foam, with its closed-cell structure, has a tendency to run hot, which is compounded by its intrinsic response to heat, which leads it to sink further into the cradle, making it even hotter.

To address this problem, open-cell memory foam was created, and it has proved successful to varied degrees. After a few years, producers began to incorporate gel beads into the open cell structure in order to improve heat transfer and breathability even more significantly.

In the end, viscoelastic is still the hottest form of bedding material, and it is not suggested for tropical climates, especially when there is no active air-conditioning present.


For this reason, it’s essential that memory foam be extremely supple and thick enough (about 3″ thick) in order to sink in and form the cradle that it is so well known for. Polyurethane, on the other hand, comes in a variety of stiffness levels, from extremely soft to quite firm.

The Indentation Load-Deflection (or Indentation Force-Deflection) value of a material, as determined by a common physical test, is a good indicator of firmness. The higher the ILD rating, the firmer the mattress will feel to the user.

The average ILD range for viscoelastic foam mattresses is 10 to 14 (semi-rigid), whereas the range for polyurethane mattresses is 6 to 45 ILD. It is clear, then, which of the two materials has the most variety in stiffness.


Density plays a big role in the durability of both viscoelastic and polyurethane.

As long as the density is greater than 4 pounds per cubic foot, viscoelastic mattresses will survive for several years and preserve their properties without any noticeable change. Viscoelastic foam begins to degrade, but instead of becoming a hard lump, it softens and begins to feel like you’re sleeping in a fluid. When this happens, it’s time to get a new mattress.

Motion Transfer

To ensure that the person on the opposite side of the bed isn’t awakened by your nightly movements, memory foam is a viscoelastic substance, which has a high point elasticity, allowing it to respond to pressure extremely locally.


Once every three months or so is a good time to rotate polyurethane foam and memory foam mattresses so that the materials can rest and regain their shape.

I would also recommend that you utilize viscoelastic foam in a moderately regulated environment (with respect to humidity and temperature). When the viscoelastic material is too cold or hot, the cell structure of the material may begin to distort, making it more susceptible to wear and tear.


The cost of viscoelastic foam is more than ordinary polyurethane because of the additional processes and materials needed in its production. This is reflected in the large price difference between mattresses that utilize viscoelastic and those that only use polyurethane.


Memory Foam vs Reflex Foam

Reflex foam is a specific kind of polyurethane foam that offers higher physical conformance than standard polyurethane if you like viscoelastic foam but lack the funds to purchase it.

Instead of holes like viscoelastic foam, reflex foam is made of HD polyurethane with a medium hardness and uses bubbles to accomplish its contouring properties. Pressing on the bubbles causes them to collapse due to the weight difference, while releasing pressure causes them to expand back to their original size.

Open-cell Versus Closed Cell

These are a few additional terms you might come across when looking for a mattress, and knowing what they imply will come in handy.

When it comes to comparing these substances, it’s all about the term. The cell walls of open-celled goods have been damaged. Cooling sleepers on mattresses can benefit from this characteristic because these materials allow air to fill the cells.

This is something to keep in mind while you shop, as it might alter the hardness and durability of the product over time.

For closed foams, the walls are closed and the construction is more substantial, hence they should be denser than open cells. Traditional versions of these materials tend to sleep hot since they are more robust and serve as an insulator.

Gels and other elements that assist diffuse heat more evenly across the foam are typically included in modern iterations of closed-cell goods.

Memory Versus All-foam Mattresses

“All-foam” refers to a mattress that is made entirely of viscoelastic materials, whereas “memory bed” refers to a mattress that is made entirely of viscoelastic materials, such as memory foam.

Memory mattresses differ greatly from ordinary poly mattresses in terms of how they feel. It’s commonly associated with excellent pressure relief (particularly for side sleepers), and it’s also more resilient than other mattresses. In certain typical memory beds, it might be difficult to get out of the impression your body creates in the bed, which can make you feel like you’re stuck.

Increasingly, manufacturers are incorporating gel additives and cooling technology into their sleep goods (known as a hybrid bed) as they become more aware of their advantages. Mattresses that combine different materials can be perfect since they offer flexibility in movement and temperature management, as well as comfort.

Polyurethane Foam vs Memory Foam Comparison Table

Polyurethane FoamMemory Foam
Generally cheap.Generally expensive.
Tends to run cooler than viscoelastic foam.Tends to run hot.
Provides resilient, non-localized support and pressure relief, depending on firmness and density.Provides soft, conforming support and pressure relief.
Available in a range of firmness values.Generally soft.
Deteriorates relatively quickly.Longer lasting than polyurethane in general.
Tends to be used in the support layers of a mattress.Sensitive to temperature and humidity.
Works well for back and stomach sleepers.Works well for side sleepers and those who suffer from chronic back pain.


I’m not going to make a blanket statement about which of the two materials is superior to the other because, in the end, your personal preferences for sleep will play a significant impact in your decision: When it comes to finding a mattress that provides adequate pressure relief and support, a high-density medium-firm polyurethane mattress is the best option for the average back and stomach sleeper.

Because of the way their shoulders and hips cut into the sleeping surface, side sleepers tend to put a lot of stress on their spine, which requires soft, conforming support from memory foam mattresses. The same is true for those who suffer from persistent back discomfort.

I’ve already covered motion transfer, heat retention, and maintenance, so perhaps you have a better understanding of the difference between the two materials now that you’ve read this far.

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