I am not a fan of Memory Foam on Reflex Foam combi mattresses. I cannot understand how some people can spend considerable sums of money on what is essentially a foam mattress. Albeit a high quality foam mattress. The sums of money spent could get you, at the very least, a top of range pocket sprung mattress with a decent memory foam comfort layer.
Memory foam in itself is an excellent material as a comfort layer, coming second to latex and far exceeding polyester. It is comforting and cradling and more importantly, rather durable. It does take a week or so to get used to the completely different sensation memory foam offers as a comfort layer, but when you do you, you will realise why it has become so popular.
First of all, understand that there are only two usual methods of using memory foam in a mattress.
1. As a comfort layer on top of a traditional spring system such as pocket springs.
2. As a comfort layer on top of a foam mattress.
I must admit to the fact that in the past I too was on the Memory Foam bandwagon! I have tried and sampled most models from most manufacturers and can assure you that all memory foam mattresses are NOT created equal. Even some expensive models are not as comfortable as a cheaper model. To understand the differences between models and ultimately the pricing anomalies of what seems to be identical products, you really have to understand the basics as well as the hype and jargon.
What is the make up of a Memory Foam mattress?
The basic structure of a memory foam mattress is quite simple. A layer of memory foam is laminated (glued) to a layer of High Density base foam – also commonly known as Reflex® Foam although there are several foam converters other than British Vita making a similar high density foam product. This ‘mattress’ is then wrapped in a removable fabric covering.
The memory foam layer is the important part of this construction.
It can come in various depths, usually:
2.5cm / 5cm / 7cm / 10cm / 12cm
In this case – More is not necessarily better. The agreed optimum depths are 5-7cm.
Memory Foam is manufactured in various densities, usually measured by kilograms per square meter (kg/m3). The most popular densities are:
58 – 65kg/m3 up to 85 kg/m3. A description should at the very least tell you this information. It can also be identified by a V Rating; such as V60 for a 60kgm3 density. Same for V55, V40 or whatever.
Some MF mattresses utilise a combination layer system. For example, 1″ of Supersoft (Low Density – usually V40) MF laminated to an underlying 1″ or so, of a firmer MF and so forth. The combinations on offer at present have now reached ridiculous levels. Any wonder the confusion exists.
There is also the Summer / Winter (or Dual Season) mattress either on a pocket spring unit or cage sprung unit. A memory foam layer on one side and (usually) Polyester wadding on the other. This combination is not overly expensive and offers a compromise to people who find memory foam too warm for use in the summer months. If the asking price is comparable to a one sided memory foam mattress then it may be a viable consideration.
How do you decide what density is best?
The density of memory foam causes the most unnecessary confusion and is the subject of much hype and mis-selling. I always say ‘aim for the best – pay the least’. There is no argument that 85kgm3 is superior in quality to 65kgm3, it’s common sense. An 85kgsm has more raw ingredients in the material – hence it being heavier, but, a 65kgm3 is just as good.
A good rule of thumb is that:
The higher the density the firmer it will be. The lower the density, the softer it will be.
The higher the density – the longer the response (rebound) time will be.
The higher the density [may] mean the more heat it retains.
As a comfort layer on foam 58-65kgm3 is the most common combination from nearly all manufacturers. Somewhat softer than a 85kgm3, but if you are getting it at a good price you wont be regretting it.
So what is that in money terms?
An 85 memory foam layer is about 30% higher quality than a 65. So when doing comparisons you can reasonably expect to pay 30% more in price. Why would you want to pay more than this?
What are the density cons?
It’s simple really. Unless you know what to look for there is no foolproof way for a consumer to tell what the actual density is. Therefore, a salesman could tell you that the mattress contains a 85kgm3 memory foam layer when in actual fact is a standard 58 – 65. bear in mind that Memory Foam can come in as low as 40kgm3 – often described as supersoft. I have also seen mattresses described as Memory Foam but contain nothing more than differing densities of standard Reflex foam. Be careful out there!
In reality, the selling price of the mattress will be the best determining factor. A 1000 pocket sprung double mattress with an acceptable 2″ memory foam layer (60kgm3) should not be costing you much more than £350. If you are asked to pay more than this then shop around a bit more.
The longevity of Memory Foam was once described as in excess of ten years. Back then, the price commanded for Memory Foam was in the several hundreds and so it made commercial sense to advertise the product as long lasting and so on. In my view it turns out that Memory Foam starts to lose its recovery properties after about two years or so, and you will see on most warranties for Memory Foam/Combi mattresses that a disclaimer is written in that a permanent indent of three quarters of an inch or less WILL NOT warrant replacement .
What depth of memory Foam should you look for?
On a sprung mattress the depth is usually 2″. This is generally regarded as the optimum depth and it is unusual to find a layer with a higher depth than this. It is also unusual to find a mattress with dual sided memory foam – although they are on the market. Obviously, a dual sided mattress is better – being able to last a lot longer by regular turning, but always weigh up the cost implications. Is it better to replace sooner and pay less? or keep your mattress longer and pay more?
As a point of interest, I often read of retailers saying there is no such thing as a completely 100% slab of memory foam. Well, back in 2008 or 9, I was at a furniture trade show and spoke to an agent of Relaxsan (Vac packed mattresses) he showed me such a mattress [Note: I can only go by what he told me as I didn't do any checks or such like] and obviously I tried it. I always thought with Memory Foam you would ’sink through’ or bottom out, but No. It was quite supportive. Based on the theory that as it’s your body heat that softens the foam – only so much bodyheat can penetrate the mattress. Now he did say that the market did not embrace such a mattress and so I think it may now have been removed from product list. Footnote: General Traders Ltd (exclusive distributor for Relaxan products [Magniflex, Italy] are currently in administration (March 2010) Update: Magniflex (Italy) are now marketing the Relaxsan branded products direct.
On a Memory Foam / Reflex Foam combination mattress the depth of MF should again be at least two to three inches. Depths less than this on a high density foam base are deemed to be budget or economy levels. As a comfort layer on a sprung mattress it is usually 1″ with another layer of foam or 2″ in isolation or even 2″ laminated to a 1″ layer of Reflex Foam. As with Memory Foam on foam, the combinations and detail that can be utilised are enormous.
Your weight should be an important influence on the depth you choose. How so?
When your body heat softens the MF you sink down into the material. If you are light you sink in a little. If you are heavy – you sink in a lot. What you have to decide on is how far do you want to sink? Remember, If you sink in too much you will be sleeping in a hollow or dip that wont recover until it has cooled down and so makes it difficult to move once your body heat has made the impression.
Why the vast variations on price?
When looking at memory foam mattresses you really do have to compare ‘like for like’. I admit this is easier said than done which you will probably soon find out. The three most important aspects of comparison are:
* The depth of memory foam in the mattress
* The density of the memory foam.
* The price for just these two measures
Anything more than this are only add-ons that make the mattress more suitable to you.
The price differences you will see reflects all the bells and whistles that have been added on to the mattress basics. For example;
* It may have a high tech moisture control fabric such as Outlast / Climasmart / Coolmax /
* The foam support layer(s) may be vented / zoned / convoluted etc, to channel air
* The memory foam layer(s) may be layered in varying densities
Summary
I personally do not like memory foam on foam combi mattresses which is why there are none on this site, but mainly for the reason that manufacturer/retailer prices are in the main kept artificially high for what is essentially a foam mattress. When the prices come down to what should be a realistic level I will reconsider them as a viable product.
When Memory Foam is used as a comfort layer on pocket springs it is exceptionally comfortable and more importantly, far durable than a mattress with a polyester comfort layer. It does not really make a bit of difference about density as long as the mattress is comfortable. The price will/should always reflect the quality of the foam anyway.
The heat properties associated with memory foam on foam combi mattresses is not as great (but is there) when used on any sprung mattress as there is plenty of natural ventilation through the springs. However, some people really are overly sensitive to night heat – if this is you then avoid any memory foam mattress.
Memory foam on foam does have a much reported reputation for being ‘too’ warm for the reason that there is no practical ventilation through foam. It is a heat retentive mix and that can be a downside to some people. However, there are equally as many people who do not seem to notice this as a problem. For example, those of you who need an electric blanket in the midst of Summer.
Finally..
There is plenty of information on the technical aspects of memory foam on the internet which is why I don’t need to explain the actual manufacturing process. There is also plenty of rubbish.
I am not here to discredit the product, I just want you to be aware that in my opinion (and remember I deal in beds everyday) a budget of £300 or more is better spent on a well constructed traditional pocket sprung mattress with a memory foam or latex comfort layer than ‘any’ memory foam on foam combi mattress. Even ‘that one’ that sells at over £1000. Ridiculous!
