Building own mattress topper

Hi there,

Looking to build a mattress topper as the newly bought firm mattress from Ikea is too firm and I can feel the top of the coil.

I’m thinking about a 4" combo mattress topper : 2" 4-lb density memory foam on top of 2" HR conventional foam so it won’t be too heavy for me to set up.

I’d think I’d want a soft top so I’d select a soft memory foam.

The main questions are then for the 2" HR foam:

  • Would I want to get a firm instead of soft/med for the HR foam since it serves as the ‘base’ under the memory foam? The main thing is I don’t want to feel the ‘bottom’ when I sleep – which means I’d feel the coil again.
  • Is 2.5lb density good enough, or I’d need to get a 3lb density HR foam?

Which would be some good online stores for HR foam?


Hi joebk,

The layer of polyfoam will also have a lot to do with how soft the topper feels because with 2" of 4 lb memory foam you will “go through” it and feel the material underneath it. You may not have a choice of how “soft” the memory foam feels because memory foam is not generally sold in different firmness/softness levels even though different types of memory foam are softer or firmer than others. In general though … any 2" layer of memory foam would be fairly soft when it was warm.

Based on “averages” and not on your own personal testing or on your body type or sleeping style … I’d tend towards a memory foam with a medium/soft layer below it so that you have a more gradual transition between layers. Don’t forget though that you are looking at a combination that you haven’t personally tested and combinations of materials are less “predictable” in terms of how they will feel for a specific person than single layers so your own experience may be different from any “theory”. Both of these would be part of your comfort layer so the combination as well as the top part of your current mattress would need to provide you with the pressure relief you need and “fill in the gaps” of your spinal curves … especially in the lumbar area. If the comfort layers are too firm (as a combination) … they won’t provide the pressure relief you may want. If the topper layers in combination with the current soft layers in your mattress are too thick … you may be too far away from the support layers and could compromise alignment.

Both 2.5 lb and 3.0 lb polyfoam can be HR foam and would both be good quality. In choosing between these … the specs and “performance” of the foam would be more important to me than the density (which is good in both cases here). If the 2.5 lb foam is HR foam and it comes in the ILD you want … then it would be fine. If it is just a higher density of HD foam (it doesn’t use the specific combination of chemicals that produces HR foam) … then I would go with the 3.0 lb.

HR foam has a higher resilience and a higher compression modulus (sag factor) than HD foam and both of these make it a higher performance choice in a mattress outside of just durability issues. Some lower density foams can be “high performance” (similar to HR but lower density) and some higher density foams can be “conventional” foams (similar density to HR in density but not the same performance).

Some polyfoam sources (outside of any local foam shops that may be close to you) are in post #4 here.


Thx for the v. informative answers. It seems to me you’d prefer recommending one-piece memory foam over 2 separate pieces together.

I wonder about a general life span of a memory foam – is it like 10 years (for a 4lb density high quality memory foam)? Would a HR Polyfoam last longer (like 15 years)?

I kind of like the cloud-like feeling of a memory foam, although I wonder if a 2" memory foam is thick enough to create such sleep experience (w/ a 2" HR foam below), or I’d need at least a 3" memory foam? I am a back sleeper.

Also, I wonder if I would be able to find HR polyfoams in local fabric stores (I am figuring at least I can try a sample of it)?

I am also thinking if I just get a one-piece HR polyfoam, would a 3" thick HR form be good enough (won’t bottom out) or it’d be safer to get a 4". Also, I wonder if there’d be heat issue w/ the HR polyfoam? I won’t prefer the convoluted kind as there’d be a lot less foam material. You’d have a suggestion how the heat issue be taken care of?

Thx much.

Hi joebk,

this would really depend on the “feel” and performance you are looking for and what the topper is being added to. A topper that has a combination of polyfoam and memory foam will have a feel that is more in between a fast response (latex or polyfoam) and slow response (memory foam or gel memory foam) material. Regardless though … I would look for high quality materials rather than just the generic material itself. All materials can be high or low quality. For those that are looking for more of the slow response memory foam feel … then a 3" layer of memory foam will feel more like what they are looking for than say a topper which has 2" of memory foam and 2" of polyfoam. I personally like the feel of a combination of slow and fast response materials but it would be important to know how a combination like this felt to you because each person’s needs and preferences can be very different.

There are many factors involved in how long a mattress or a topper will last for any particular person. Some of the many variables are in post #2 here. Because of all the variables … there is really no way to know for sure how long it will last for any particular person except to say that 4 lb memory foam will soften more and is less durable than 5 lb memory foam. As a topper though … and also depending on all the many factors including your own weight, how thick it was, what is over and under it, and how much “room” you have for the foams in your sleeping system to soften and still provide you with good pressure relief and support … I would be surprised if a 4 lb topper lasted for 10 years and probably half or that or a little more would be a reasonable expectation. For some people who have little room for a mattress to get softer and still have good support, it may last a few months (even the initial break in period may be more softening than they can tolerate for their spinal alignment) while for others who can tolerate much more foam softening because of the other factors involved … it may last 10 years (although this would also not be the norm).

Again depending on all the other factors involved … a good “true” HR polyfoam will generally last longer than a 4 lb memory foam yes and will begin to approach latex in its durability.

The “cloud like” feeling is not unique to memory foam (it’s usually a result of good alignment and even pressure distribution which can happen with any material) but the memory foam version of a “cloud like feeling” would probably need 3-4" of memory foam. Of course this would also depend on the type of memory foam not just the density (there are hundreds of different formulations) and on what is over or under the memory foam as well. All the materials interact together and each layer will affect every other layer to greater or lesser degrees. If you have a mattress that already has several inches or more of softer materials in the upper layers … then adding enough memory foam to get the “feel” you want may also compromise alignment. Generally thinner soft toppers are less “risky” in terms of alignment and it’s always a tradeoff between the feel you want and the alignment/support you need.

Comfort is what you feel when you first get into bed at night (and this is what people usually pay the most attention to). Alignment is what you feel when you wake up in the morning (people generally pay less attention to this because spinal alignment is not as “obvious” or as easily tested as “comfort”) and durability/quality is what people will feel a year or more down the road when the foam softens (and to know the relative durability of a topper or a mattress compared to other materials or quality levels you need to know the “quality” specs because you can’t “feel” quality).

Most local foam shops would carry various versions of polyfoam and fabric shops that were doing upholstery would probably have some as well but you would need to ask if they carried HR quality because some will and some won’t. Some may not even know what you are talking about :slight_smile:

Again this depends entirely on the body type, sleeping style, the mattress it is being added to, and the many other variables involved. Each person can be different. Heat issues also have many different factors involved in them. One of these is the breathability of the foam, one is how much you sink into the mattress, and one is the layers that are over or under the mattress. As a general rule … polyfoam is more breathable than memory foam but each material has a range of properties depending on the formulation of the foam. Lower density foams are often more breathable than higher density foams as well (they contain more air and less materials). Convoluted foams have a different compression curve than non convoluted foams but they will also generally be less durable than a non convoluted layer of the same type (they will be more subject to repeated deeper compression and mechanical wear).

There is more about the factors involved in the sleeping temperature of a mattress in post #2 here and information about temperature regulation that is more specific to memory foam in post #6 here.

One of the things that can be most frustrating (or an interesting challenge for some) about building a mattress or choosing materials based on “specs” is that there are really no simple or black and white answers to most of the questions people ask because the usually involve multiple interacting factors or layers. This is where the experience and knowledge of a manufacturer or better retailer and their knowledge of a specific mattress and all it’s components can be helpful.


Want to clarify – does the end of the life span of a memory foam imply the experience of ‘bottoming out’ – toward the end of that 10 years?

If that is true, I think this relatively short life span of a memory foam would cause me to think of the HR foam (or latex foam) instead, as I sure don’t want to repeat this relatively tricky process of finding a suitable topper too often.

I looked up the references you mentioned on HR foam for a 3-inch Queen size HR foam, and here are my findings and some questions.

My very basic requirement is ‘no bottom-out’ until at least end of 10 years span.

    Ultra Foam Medium: : Is this HR foam?
    2.6lb density, 35lb compression

  2. (Custom-cut foam): Are these HR foams?
    1520-soft : $134 + $22 S/H
    2030-medium-soft $134 + $22 S/H

  3. Not sure if these are HR foams (not mentioned).
    EverFlex™ V34 Med-Firm:
    Density: 2.6 lb/ft3, ILD: 34

DuraFlex™ D34 Med-Form: Mid-grade : Is this good enough as HR foam? Is it soft enough as a topper?
2.5 lb/ft3, ILD: 34

  1. : Custom shapes
    Soft (18) High Resilience Foam (3.0lb) 80.000"L x 60.000"W x 3.000"T Queen Mattress 252.05
    Soft (18) Evlon Foam (2.2lb) in 80.000"L x 60.000"W x 3.000"H rectangles 221.66

Seems higher priced.

Is the Evlon foam considered HR foam, and durable enough and won’t bottom out until after 10 years?


HR foam, firmness = 21 Price = $160
(no lb density rating)

Seems I’m not able to locate ‘soft’ foams from these vendors (except a1foamandfabrics but lb density is not specified) for anything close to 2.5lb rating or higher. You might know why? You might have references of some other vendors where I can locate ‘soft’ HR foams for use as toppers?

Thx for help.

Hi joebk,

This is not as simple a question as you may think because all the layers of a mattress are affected by the layers both above and below them and the thickness of the topper also plays as big a role as its softness. The two things that will be affected by foam softening are comfort (pressure relief) and alignment (support). It is the loss of either comfort or support that is the biggest reason that a topper or a mattress needs to be replaced.

No matter what materials is used in the top layers of a sleeping system (whether it’s a topper, a pillowtop, or the comfort layers) … they will degrade faster than the lower layers. If they are a foam … they will soften. If they are a fiber, they will compact and become firmer. the deeper in a mattress a layer is … the more slowly it will lose it’s original properties.

So if you have a topper that softens and it is fairly thin … then it would allow you to “go through” it more easily and you would feel more of the layers below it. If the deeper layers were firm … you would feel more firmness and if they were very firm … it would feel more like “bottoming out” (sleeping on a layer that wasn’t providing the pressure relief you need). In this case … foam softening would result in a mattress that felt firmer. If the topper was thicker … then as it softens it may still “hold up” the lighter parts of your body without reaching the firmer layers below them but the parts of the thicker layer under the heavier hips and pelvis would soften more rapidly and sink in more so you would end up with an alignment issue (the hips/pelvis was sinking in too deeply relative to other areas of your body) even though the pressure relief may still be fine.

Foam of all types will go through 3 stages of softening. The first stage is the initial break in period where the softening is more rapid (first 90 days or so). For some people this initial softening period can lead to a degree of softening where they lose comfort or alignment (especially if they made a choice which was close to the limit of softness that was suitable for them when they first purchased the mattress). This initial softening is followed by a more gradual softening over a much longer period of time. The final stage is where the foam loses it’s resilience and breaks down and begins to show impressions that don’t come back when there is no weight on the mattress.

High quality memory foam (such as 5 lbs or more) is in the same general range of durability as HR polyfoam and latex is more durable yet. This is assuming an apples to apples comparison because softer foam on top will also break down faster than firmer foam because it is subject to more mechanical compression.

The other challenge with memory foam though is that there are so many different types (as you can see in post #9 here and post #8 here which talk about the many different properties of different memory foams). Memory foam also has a quality called “creep” which means that like any material with viscoelastic properties you will continue to sink in deeper over time as the foam relaxes. HR polyfoam and latex is more consistent between different manufacturers with similar specs and has much less creep (the compression that you start with will be similar to how you wake up). It is easier and less “tricky” to make the most appropriate choices with more elastic foams (polyfoam and latex) than choosing viscoelastic foams in other words. Of course being a little more “tricky” to make a good choice doesn’t mean that it is a bad choice either … there are just more things to take into account.

So just to re-affirm the earlier part of this post … memory foam as a material doesn’t have a shorter or longer life than polyfoam because it depends on the density/quality of each you are comparing and on the rest of the layers in the sleeping system. Good quality memory foam will be roughly equivalent in durability to good quality polyfoam and both will be less than good quality latex.

Again … this will depend on the layering in the sleeping system as a whole, the thickness of the topper, the quality of the topper, and what is under the topper more than just the topper by itself. Different combinations can lead to either the loss of comfort and support even with high quality more durable materials if the combination of materials you use has little “room” for foam softening. In an appropriate combination of layers that is more in the “middle” of your range or is even on the firm side … the sleeping system as a whole will last much longer. The advantage of a topper as well is that once you make a choice that “works” for you … then it’s easy to replace the topper with a similar one because you already know what type of topper works for you and the topper will extend the life of the materials below it.

In looking through your choices I would ask the manufacturers about the quality of the specific foam they offer. The “accurate” definition of HR foam (which has both a higher density and better performance properties than conventional foam) is that it is 2.5 lbs or higher, has a compression modulus (also called sag factor) of 2.4 or higher and has a resiliency rating of 60%. There are many foams that are labelled as HR which don’t have all these specs. There are also foams that are “high performance” foams that have a higher sag factor or higher resilience that don’t meet the density requirements of HR foam (they are often called “high comfort” foams or “high performance” foams).

In addition to this … ILD (or the term which replaced it called IFD) is a measure of the softness/firmness of the foam which has little to do with its density. Both higher density foams and lower density foams can be made in a wide range of firmness choices. The choice of firmness would be part of making a suitable choice for your needs and preferences and would be based on the overall design of your sleeping system. Generally the top few inches would be softer, the middle layers would be a “transition” zone which would be partly for comfort and partly for support and then the lower layers would be much firmer to “stop” the heavieer parts of the body from sinking in too far and causing misalignment. The different combinations of softness/firmness levels of these three vertical sections of a mattress and how they interact together is the “art and science” of mattress construction and fitting a mattress to the different body types, sleeping positions, and preferences of different people. Most people who have been making mattresses for decades will tell you they are still learning as new materials emerge and new ideas about how to design a mattress become more popular.

The Albany Foam choice has the density of HR foam (and probably is) but the ILD (35 lb) is on the firm side for a comfort layer.

Neither of the Foam Products choices are HR foam. The 1520 means it is 1.5 lbs density and has an ILD of 20 lbs. The 2030 means it has a density of 2.0 and an ILD of 30 (which is also on the firm side for a comfort layer depending on body type and sleeping position).

The Foam Order foam descriptions are here and you can see that the Everflex V 34 is 2.6 lb (HR range) and has an ILD of 34 as you mentioned. They consider this to be a very high quality foam that will last 15 years (but it will depend on the factors that I mentioned earlier whether it will last 15 years for you). The Duraflex is what they call “mid grade” (this is relative to their other foams) but some foam suppliers would consider this high quality compared to other lower density foams they supply. For most people … 34 ILD is on the firm side but this is personal preference and depends on thickness as well. To know whether it worked for you would require a personal reference point of testing a mattress where the ILD of the foam layers were known. Without this reference point … a conversation with a more knowledgeable foam supplier that included the layers that the topper was being used on would provide your best guidance. They know the properties of the foams they sell better than anyone (hopefully).

Foam Online has the HR foam and the Evlon which is a higher density version of HD foam. Both of these are more in the range of “soft” that most people would prefer.

With a1foam and fabrics I would confirm the density of the foam because many foam suppliers call a foam HR when it’s not and they mean it in a more “relative” way (higher density than other foams they carry) instead of meeting the specs of actual HR foam. It is also in the “soft” range that most (but not all people) would prefer but again this depends on what is over and under it and on the thickness of the topper.

The bottom line is that without a reference point of foams that you have tried and know the specs of the layer … the guidance of the people selling the foam would likely be the most accurate means of making a choice rather than trying to decide by “specs” that have little meaning to you without the personal experience of actually lying on a mattress with specs that are known.

I would tend to keep it simple and go with a “soft, medium, or firm” rating which is likely to be close enough for what you need, stick with the thinnest layers that you believe would do the job, and buy the best quality that you can reasonably afford whether it is memory foam, polyfoam, or latex (or even other choices such as wool).

After knowing all of these more “complex” more technical factors that are in the first part of this post … I would tend to take a different less “spec” oriented approach to your topper and first try to describe as accurately as possible what you are feeling on the mattress now (in terms of alignment and pressure relief) and how you would like it to feel.

The first step would be to identify what you are looking to achieve in the overall feel and performance of the mattress and topper as a whole. I would try to describe this in more specific terms such as are you looking for better pressure relief, how is the support and alignment, and which specific areas of the body are you having issues and what are the actual “symptoms” involved. I would try to identify and quantify as much as possible how much of a change you need (are you close or far away from your ideal).

The next step is to decide between your preference of slow response or fast response materials. This is a personal preference and should be based on testing both in stores to see which you prefer.

The next step is to identify what is in the mattress you have (which of the Ikeas did you buy) so that you can make less “risky” choices in terms of how much soft foam will be in the upper layers of the sleeping system.

Once you have done these three steps … then you will be in a better position to talk with the suppliers of the topper you are adding and make the choice of the softness and the thickness of the topper in the type of material you prefer based on your body type, sleeping style, personal preferences, and the layering of the mattress it will be used on.


Thx so much for the detailed explanation. I am marveled at your patience in explaining the various details and ways of approaching this topic.

So to respond to your suggested steps of approaching this,

  1. The Ikea model I got is the SULTAN HANESTAD, the lowest model coil mattress with active-coil (individual coils) system.

The reasons I chose this model are the following:

  • the 25 year mattress warranty Ikea offers does not cover the foam. To me this implies that Ikea’s foam could well be low quality foam. So I just wanted to get a good coil mattress and build the topper myself instead.

  • the coil gauge according to the sales rep is 13 3/4 gauge, which is the strongest among all the Ikea’s coil mattresses. I look for a mattress with a firm core so can provide me a good support. This mattress fits my need in this regard.

I checked, and I think the Ikea mattress has about 2.5 inch of top soft foam. From Ikea’s product description density is (Polyurethane foam) 1.5 lb/cu.ft.

  1. My current experience with the Ikea mattress.

The active coil response system works well and when I sit on the mattress I feel it is responsive and there is enough support yet not to hard. However, the top foam layer is so weak that within 1 week I can start sensing the top of the coil if I push my hand hard on the mattress (i.e., the top foam has bottomed out).

Pressure Relief
I am finding I often sleep on my side. And with that the top foam bottoms out fairly quickly and I am having pain on the side of my hip already.

This is the one single area that I really need to take care of – within a short amount of time, as I had a back injury working in the backyard a year ago, and this ‘bottoming out’ of the top foam is only causing more pain in the hip area. I am waking up in pain pretty much every morning at this point. If I sleep on my back I have the same back pain around my hip.

I have put in 2.5 inch soft generic brand convoluted foam as a starter to just see what it can do to help out w/ the lack of pressure relief/hip pain issue. I feel the mattress has become somewhat more comfortable in most areas but along the hip it is of no help – it bottoms out right away. This tells me the convoluted foam is of really low-density and perhaps way too soft plus there really is not enough foam to help out.

My temporary solution is to have a long King size pillow to lean on to when I sleep on my side as I tilt 45 degrees toward the pillow (I’d be half sleeping on my stomach – on the pillow that way), so there is less pressure on my side where it contacts the mattress. I am finding this greatly relieves the pain issue on my hip as I wake up in the morning.

Alignment issue
I don’t know if there’s any alignment issue perhaps if you can provide some examples so I can tell if I do have this situation, but the ‘bottom-out’ issue is definitely what causing my hip a lot of pain (my back injury obviously make it more sensitive of course).

I notice that if I sit on the bed I don’t feel my hip hitting the top coil. I wonder if it is because of the amount of weight is concentrated the coil is compressed. When I sleep on my back/side, the coil is strong enough that it’s not compressed yet to form the right alignment, but the top foam already bottoms out–and hence my hip is hitting the top of the coil. At that point the alignment isn’t right (as the coil isn’t compressed). As a result, the pressure isn’t evenly distributed along my side/back and my hip gets more pressure than it should be and hence the hip pain.

My goal:

  • As you can see, my primary goal at this point is to look for a topper that won’t ‘bottom’ out as I sleep on my side/back.

  • For personal preference, I like the cloud-like feeling of a memory foam but regular foam is ok w/ me. I also tried the latex top while I was @ Ikea which I sensed was of higher density (compared to regular foam) and that also help quite well from hitting the coil.

Let me know if you’d have some input at this point.

Looking at these online foam stores, many of them only offer medium firmness HR foams.

An important question is:
Are medium firmness foams not suitable for my current situation? (Obviously I don’t want more ‘firmness’ that’d cause me more hip pain)

If only soft HR foam would work for me, currently only foamonline has the soft HR foam, but at their $250 price I can find 2" latex foams from like (although I don’t know if those are reliable latex foams) and I’m tempted to try out the latex foam, as my impression @ Ikea on the latex was that latex is much denser foam and would save me from the ‘bottom-out’ pain.

I also read your post here, and this gets me concerned in whether the topper solution I’m considering would last – as if the top foam in this mattress wears out say in 4 years or so. Perhaps I should have considered building a foam mattress altogether instead so I won’t need to tackle the issue of low-quality top foams inside mattresses from the mattress manufacturers.

Hi joebk,

The Hanestad is a lower coil count pocket coil which means that the coils in the mattress act independently and are not connected to the coils beside them with helical wires. Even though it is towards lower end of the gauge scale (13.75) … because they are independent and a relatively low count they will not be as “supportive” as a similar gauge coil that has helicals where each coil can “share the weight” that is being applied to it (such as a Bonnell innerspring). Hopefully it also has a good insulator which will help the soft foam on top from compressing into the gaps in the coils but at this price the insulator may also not be great or could be missing completely. A good insulator will also even out the pressure on the coils and will add to it’s support qualities.

The 1.5 lb density polyfoam is low/mid grade foam but the density has nothing to do with the firmness or softness of the foam. Any density foam can be made either firm or soft and the reason you are going through the foam onto the coils is the firmness of the foam not the density. Because there is already 2.5" of soft lower density foam in the mattress … it would be a good idea to use a topper that is as thin as possible because the soft foam underneath it will still compress even with firmer foam on top and the top part of the pocket coil innersprings will compress as well.

The softness of the foam and the thickness of the layer that is most suitable will also depend on your weight and body type. Lighter people can use softer foams and thinner layers than heavier people without feeling the coils underneath the foam.

I would tend towards a 2" layer of higher quality foam which is suitable for your weight and body type. This would give you 4.5" of foam in your comfort layer which in addition to any compression of the innersprings should be OK for pressure relief. If you add foam that is too firm … then it may cause some pressure issues (although with soft foam underneath this is less likely) and if it is too soft … regardless of the quality or density … then you may still feel the springs underneath (again depending on your weight). If it is too thick … it may provide you with the pressure relief you need and isolate you from the feel of the coil but your heavier parts may sink in too far and you may be trading pressure issues for spinal alignment issues. In other words the thinnest/firmest layer that would provide you with the pressure relief you need would give you the best odds of good alignment as well.

While I don’t know the firmness (ILD) of the latex topper that Ikea sells … the fact that a 1 5/8 thick Dunlop latex topper seemed to work well indicates that 2" is a reasonable target range for thickness that would probably work in the right firmness. If you do choose to go with memory foam … a little thicker may be OK if you want more of the memory foam “feel” (memory foam is soft and less supportive than latex so you will probably sink into it more evenly) but again it should be good quality or you may go through it too easily and still feel the springs underneath you and I would still tend towards thinner rather than thicker.

So while this is not a particularly good base for a mattress/topper combination (because of the type of innerspring and because of the 2.5" of soft and lower density foam) … I think that with a higher quality topper that is the right firmness (depending again on your weight) … then you would have the best odds of getting to the best possible combination with the mattress you have.


Just want to post an update.

I bought a Serta 4" 4lb density memory foam mattress topper from as I was still concerned about ‘bottomed out’ on a thinner topper.

The good news is that the back pain that was caused by my back hitting the super firm Ikea spring mattress before went away as this soft topper cushioned my back from the hard mattress.

A con is that 4" thick memory foam topper feels very soft.

If I sit on top of the bed, the topper almost ‘bottomed out’ (compressed to about 1/4" think).

If I sleep on the side, it’s compressed to about 1/2" around the hip area.

If I sleep on my back, there’s definitely enough cushion (the topper perhaps compressed to 3/4" to 1"). Although I am finding I’d need a very thin pillow or just remove it from under my head then I’d feel more comfortable – perhaps related to better alignment along my back.

I’m around 180 pound and around 6’ tall.

So in a sense, this memory foam topper is thick enough (and perhaps barely dense enough) that it doesn’t 't bottom out when I sleep.

I am still a bit concerned that the memory foam topper is a bit too soft and there isn’t enough back support.

I still have some pain around my waist although this originally came from an injury while bending too much when working in the backyard.

Is the 4" 4-lb density memory foam topper too soft for me? Or a 3" topper would have given a better support? Perhaps someone can help provide a good answer on these answers.

Hi joebk,

IMO … not only is this “thick enough” but in combination with your pre-existing comfort layers you have 6" of soft foam in the comfort layers which is likely to be “too thick”. This would be especially true when the lower density foam softens under the greater compression of the heavier areas of your body and there would be significant risk of alignment issues with this combination. Of course each person is different and your actual experience may not reflect this but it certainly seems to me … for the reasons that I mentioned in the earlier posts and in post #8 here … that you may be too far away from the firmer support layers in your sleeping system to provide good primary support (the support that “stops” the heavier areas from sinking down too far).

With a 4 lb softer memory foam topper … I think that the bigger issue would be that it may be too thick rather than just too soft. I would hesitate to use a topper this thick in almost any circumstances when a mattress already had 2" of soft foam in the comfort layers. It may be “OK” in the shorter term but the risk is much higher that it won’t be in the longer term or even over the course of the whole night (memory foam can “creep” or keep on sinking over the course of the night) after the initial and ongoing softening that is more likely with 4 lb memory foam.

I should also mention that your experience with sitting on the mattress will have little to do with its suitability for sleeping because sitting concentrates more weight in a much smaller area and this is not what you will experience when you are actually sleeping on the mattress.

The bottom line is that if it works for you then there is no arguing with success or personal experience but it would certainly be a much more risky choice both in the short and long term for the majority of people IMO.


I think I should have read your previous post on the recommendations of the foam thickness.

I recently bought a zippered mattress encasement, and it seems to cause the mattress to be less ‘stretchable’, making the mattress feel a bit ‘firmer’ now.

So things are now working a bit better for my back–just about the right softness (and not too soft).

Hi Joebk,

This type of “fine tuning” such as different types of mattress protectors or mattress pads can certainly make a difference for “fine tuning” and the depth that you sink in as long as your initial configuration is “close enough”.

Thanks for letting us know … that’s great news :slight_smile:

I would also flip and rotate the topper from time to time so that it softens more evenly.