Memory Foam Myths

The truth about Visco-Elastic Memory Foam When it comes to memory foam there is a lot of confusion. There are dozens of people all telling you different things. Well we want to set the record strait.

First of all, I just want to say that memory foam is not a product for everyone. There are those long infomercials telling you what a wonderful miracle foam it is. While it is a truly unique foam, it is not made for everyone.

Memory foam responds to your body heat differently than regular foams. It is a thermo-sensitive foam. When shopping for a memory foam mattress the most important thing is to lay on it for awhile. Get comfortable. Then after you have laid on it for a few minutes try turning on your side or back in a different position. With memory foam’s slow recovery this is a crucial test.

Mattress Myths vs. Facts

1. Tempurpedic is the only real memory foam. They have the patent on it.

This is completely false. NASA designed the foam. They hold the patents. Tempurpedic may say that it is patented but that does not mean they hold the patent. NASA released the rights for memory foam to the public in the early 80s and Tempurpedic was one of the first companies to really push it in their product lines.

2. All memory foam is the same.

All memory foam has the same basic chemical composition but that does not make it the same. The most important thing to keep in mind is the density of the foam. A 3.8lb density is completely different from a 5.3lb density. When it comes to density the higher the density the slower the recovery rate. But on the other end of the scale, the lower the density the more it will feel like a regular foam. Lower density memory foam will be softer. Higher density foam will be firmer. But that is not the only thing that determines firmness (See the section about layering for more). We have always found that there was a good median with a 4.5lb - 5.0lb density.

Lower density foams are still memory foam but they will feel like a regular foam. The price is usually cheaper because the quality is cheaper. We don’t really consider anything under a 4.0lb density to be considered memory foam.

But higher doesn’t always mean better. We’ve tested higher density foams such as the 5.3lb density foam used by Tempurpedic. We have found that at this high of a density it is almost too high. The recovery time is long. It may sound like it isn’t a problem but consider this, when you first lay down in bed at night most people start on their backs and move to their sides or stomach. In a high density memory foam when you go to move to your side it will take so long to remold to your new body shape that some people feel like they are being pulled back into a hole.

Ten pound density is a myth. If 5.3lb density foam is almost too dense, 10.0lb density would take days to recover. So when you see someone selling you 10lb density they may have just forgot the decimal point and confused the 1.0lb with 10lb.

3. Any thickness of memory foam will due.

When it comes to memory foam the height of the mattress or topper and the amount of actual memory foam is very important. The more memory foam you have the further you will sink into it.

While there are places that sell 1” toppers you would be wasting your money. Anything under 2” of memory foam will do little more than make your sheets a bit tighter. But once again, don’t be fooled into thinking that more is better. There is a point when more just becomes too much. Remember, however much memory foam you have is how far you will sink into the mattress or topper. When it comes to toppers, they should be no thinner than 2” but no thicker than 4”. In truth, 4” is too much. A 4” piece of foam is on the borderline between a topper and a mattress. And depending on your state may be required to be covered and sold as a mattress. In truth, if a 3” or 3½” memory foam topper isn’t enough then you need to look at a new mattress and not just a topper.

When it comes to mattresses pay attention to the layering as well as the overall amount of memory foam. Once again, if you are getting just an inch or so of memory foam and the rest is filler foam then why are you paying so much? A memory foam mattress should have at least 2” of memory foam. The most important thing is to stretch out on it. Everyone’s needs are different. Find the amount of memory foam that fits you. It is like trying on a pair of shoes. You have to find the perfect fit. Our research has led us to feel that 6” of memory foam in one solid block may be too much. While we have customers who sleep on that much, more people than not find that it is too soft, too dense, and they sink into it too much. Just as important as the amount of memory foam is the layering of memory foam versus base foam (See layering for more).

4. The more layers the mattress has the better.

This is the most preposterous thing we have ever heard. A little known fact, the only way to attach different pieces of foam together is by laminating it. And laminating is a fancy word for glue. Let’s be honest here, we’ve all glued two pieces of paper together and noticed how much harder the paper is where the glue is. When a customer came to me one day and said that they saw a mattress that was 8” thick with 7 different layers I couldn’t help but wonder if it was more glue than foam. Besides, to make an 8” mattress with 7 layers would require that each layer was 1” or less. And it was. In fact some of the layers were only ¾” and as we have already noted, you aren’t getting much out of ¾” of memory foam.

The most common misconception regarding memory foam is when a customer tells me they laid on a mattress that was “All memory foam”. I don’t think there is a mattress manufacturer in the world that would be crazy enough to make a mattress out of only memory foam. Going back to question number 3, I repeat… However much memory foam you have is how far you can sink into the mattress. So if you have an 8” mattress and it was “All Memory foam” you would sink all the way through the 8” and bottom out on the boxspring. And no one wants to sleep on the boxspring.

Memory foam MUST have some sort of base foam to support it. Now, there are about a thousand different regular foams out there so pay attention. You want a high density foam to support your memory foam. High density gives you a better quality and firmness. After all, you don’t want to bottom out on the memory foam only to bottom out on the base foam and still end up feeling the boxspring. You want a substantial amount of base foam, at least 2” of a high density base foam. You want the base foam or filler foam to be firmer than you would normally sleep on but not really brick hard.

Another thing that always gets me laughing is the people that make those mattress cores that have their super special top secret air flow system. This is just fancy lingo for egg-crate style cut foam or even worse those places that cut lines into the top surface of the foam and charge you more. Quite frankly, I find it laughable. When it comes to memory foam you want a solid, uniform piece of memory foam. Regular foams are different when you cut egg-crate designs in them because they make them softer so you get loft and plush feel. But memory foam already has the plush feel. Cutting into it only defeats the purpose of memory foam. The manufacturer does it because they can tell you that they have this fancy, special, oh-so-secret method that no one else does and then charge you ten times more. We frown upon those kind of practices. Besides, when you lay on the mattress the so-called air channels will compress closed and that defeats the entire purpose.

5. Rubber Memory Foam.

Perhaps the most common error is that people believe that Memory Foam is a rubber foam. There is a HUGE difference between Latex foam (which is made from the sap of the rubber tree) and Memory foam. While Latex foam and Memory foam are both amazingly unique foams they are NOT the same thing. Memory foam is NOT a rubber foam. Memory foam is a polyurethane foam. Some also refer to it as polyfilex. But it is made the same as your polyurethane foams with only a few slight modifications in the mixing process. The only foam that can truly be called a “Rubber Foam” is Latex. Latex is made from the rubber tree. Both products are hypo-allergenic, dust mite resistant, and anti-microbial. I can get into a long speech about the differences between Memory foam and Latex foam but I will try to keep it simple…

While Memory Foam and Latex foam both contour and mold to the shape of your body there are 3 main differences.

First, Memory foam is a slow recover foam while Latex foam is a quick recovery foam. So if you lay down on your back on a Memory foam mattress for a few minutes then turn to your side you will see the memory foam slowly recover and smooth back out while it forms a new mold to your side. Whereas, if you do the same on the Latex foam mattress it will spring back almost instantly. Latex foam is not a dense foam. Many people who like the contouring effect of memory foam but don’t like that “sinking” feeling will probably love Latex foam.

Secondly, while memory foam MUST have some sort of base foam to support it (or you will sink all the way through - as we discussed in the layering section), Latex foam gives you the best support and feel when you use just Latex foam. There are a lot of imitations out there that call their mattress a Latex mattress. Most of the time their “Latex” mattress uses mostly a regular foam with just 1”-3” of Latex foam.

Third, the pin holes in a Latex core are extremely important. The pin hole size on Latex helps to determine the firmness. It isn’t the only factor but it is important. I feel that I should point out that these are “pin holes” and not drilled into the foam. They are made when the foam is first poured into the mold and will be a part of the foam forever. A smaller pinhole will typically feel firmer than a larger pinhole. Many manufacturers will Tri-Zone a core. This is also called multi-zoning. This means that different portions of the mattress core or topper will have different pin hole sizes. Usually, you use a smaller pin hole size in the center third of the mattress, where your hip area lies, for firmness.

6. Special covers such as knit fabrics, zipper covers, cool top fabrics, down mattress pads, and wet-proof or vinyl mattress covers should be used on Memory Foam mattresses.

This is where a lot of the sales reps can confuse and deceive buyers. When it comes to Memory Foam the most important thing to remember is that it MUST breathe. Memory foam needs air flow to properly function. Using vinyl or wet-proof mattress covers are good to keep a normal mattress clean but on memory foam it can actually suffocate the foam causing it to be very uncomfortable, lumpy, warm, and can even damage the foam. Many down mattress covers and mattress pads can do the same thing.

Knit fabrics are commonly associated with memory foam because with that super thin fabric you are so close to the memory foam that you feel every contour. Knit fabrics give it a wonderful feeling when you are feeling the foam in the showroom. HOWEVER, I am not a fan of the knit fabrics whatsoever. Sure, you get that super smooth and oh-so-soft feel but you put sheets on top of that anyway. Also, because there is nothing but a thin little knit or terry-cloth fabric between you and the memory foam your body heat buildup nearly doubles and you find yourself sinking more and more. Not to mention that those fancy zipper covers that everyone raves about can only be washed a handful of times before they shrink up so much that they won’t fit on the mattress anymore. The whole reason we use fitted sheets on our mattress is so that we can wash them. Washing the mattress cover may be a nice perk but having it shrink up and needing to buy a new cover all the time gets costly, which is the way the guy who sells the mattress covers likes it.

Cool Top fabrics and Aloe Vera fabrics have their place. They can make the mattress feel quite nice. But as far as making the mattress cooler… the jury is still out on that one. As I have mentioned time and time again, the more you sink into the mattress the warmer you will be. I don’t care what cover they have on the mattress, if you are sleeping in it versus on it then you will get hot at night. I have heard just as many complaints about body heat buildup on the supposedly “Cool Max” fabrics as I have had with the regular knit/terrycloth fabrics. And don’t let the sales rep fool you into thinking that their mattress is the only one with that special fabric. That fabric is sold all over the world. Like Tempurpedic, they may have the trademark on the name but the patent on any product is held by the manufacturer of the fabric, not the mattress manufacturer. Any mattress manufacturer can get the fabric and put it on their mattress.

7. Shredded memory foam is still as good as solid memory foam.

Once again, they have used whistles and bells to sell you a lemon. Sure shredded memory foam may feel nice in a throw pillow but once it is out of it’s solid state you might as well save your money and pay for a regular foam, shredded or not. Shredded memory foam isn’t shredded for the great feel and superior quality. It is shredded because it is scrap, left-over foam that the foam manufacturer thought they could make some money off of. You hear memory foam and everyone remembers those amazing Tempurpedic commercials where everything is wonderful and the wine glass doesn’t spill… well, shredded memory foam is not the same. Don’t be fooled to think that shredded memory foam will give you anything near the feel, support, or durability of a solid piece of memory foam. For small throw pillows they may be okay, or if you like down pillows they might feel nice, but if you are looking for that contouring, flexible, motion-free support of memory foam, don’t expect it from shredded memory foam.

8. Memory foam pillow top mattresses.

First of all, I always need to clarify, a pillow top mattress is a mattress that has an additional pad attached to it. This pad is a separate piece from the main portion of the mattress but is still attached.

Now if you are looking at a memory foam mattress and the sales associate is telling you that their solid foam mattress has a memory foam pillow top stop right there. Got back to the section about layering and re-read it. Because, chances are that the only memory foam you are getting is in the pillow top. This means you are paying a lot of money for memory foam and you aren’t getting much memory foam. Be sure to ask how much of the mattress is actually memory foam. Keep in mind that everyone needs different support. Maybe it will work for you but chances are that the base foam or whatever regular foam they have in the main portion of the mattress will sag, dip and soften so don’t expect a miracle.

9. You can put memory foam on any old boxspring or foundation.

The portion under the mattress is called a boxspring or a foundation. To make things simple I will call it a foundation. Okay, I am going to put this the best way I know how… putting a new mattress on an old foundation or a foundation not intended for it is like building a house on sand. You never know what you are going to get or how it will hold up.

There are many different foundations out there. Most of them fall into one of four categories: formed wire or firm wire foundations, soft coil or spiked coil foundations, foam foundations, and wood box foundations.

Memory foam needs a firm surface to support it. If the foundation has dips or bumps in it then when you put the contouring memory foam on it, then it will contour right along with the dippy-bumpy foundation. The best thing is to buy the matching foundation that the manufacturer intended the mattress to be used with. You can tell this by the law tag on the mattress. All mattresses sold in the US must bear a tag stating that the mattress should be used with a specific boxspring/foundation. If you look at the tag on the mattress and find out which boxspring it should be pared with you can match it to the tag on the foundation to make sure you are getting the correct support.

10. Because Memory foam molds to the shape of your body it is the perfect mattress for everyone.

Okay, if you believed that statement then you haven’t been paying attention to anything I’ve said. Memory foam is different from manufacturer to manufacturer. Even if you stick with the same manufacturer they can have from one to one hundred different ways of making a memory foam mattress. So to answer this one NO! MEMORY FOAM IS NOT FOR EVERYONE. It is like trying on a pair of shoes. They may be the right size but when you put them on your feet they could be too big, too small, or just plain uncomfortable.

Additionally, I NEVER recommend memory foam for infants, toddlers, or small children. Never leave a child unattended on a memory foam mattress, mattress pad, or topper. As we have already established memory foam creates a mold to your body shape and so you have to do all the work to turn and move. A baby or child may not be able to move and could suffocate.

We have also found that those of us that have difficulty moving, such as disabled, or elderly people, have an extremely difficult time moving or getting out of the bed. That may vary from person to person and from mattress to mattress. I’m going to sound like a broken record here… However much memory foam you have is how much you can sink into the mattress.


The best advice I can give anyone shopping for memory foam is… stretch out on the mattress and get comfortable. You aren’t afraid to try on shoes in the shoe store so don’t be afraid to try out a mattress in the mattress store. If the sales rep won’t let you lie down on the mattress then why do they have them there. And don’t be afraid to ask the sales rep questions. After all, that is their job.

For more great shopping tips check out our shopping and sleep tips. Remember, the average person spends 1/3rd of their life in bed. That is a long time to be uncomfortable.