Building a Mattress: Have a few questions

Hi everyone,

I’ve been reading this forum for a long time, but this is my first post.

I’m in the process of designing and building a new mattress, and also trying to improve a formerly built DIY mattress. We are both back and (sometimes) side sleepers.

Let’s start with the previously built one, which was a Queen mattress for a guest room. Everything was from Foam Factory. The layers are, from bottom to top, 5 inches of https://www.foambymail.com/LR_2/lux-r-foam-mattress.htmlLUX-R poly foam as a support layer. This foam has a 1.8-pound density and has an ILD of 50. Next up was a layer of 5lb https://www.foambymail.com/V_5/5lb-memory-foam-topper.htmlViscoMax Memory foam, 3 inches. This combo didn’t work because although the 5-pound memory foam is very nice, we would bottom out against the very firm poly foam support layer. We then added a 2 inch soft Talalay latex memory topper underneath the memory foam which improved things but still we ended up bottoming out. After discussing this with the Foam Factory, they pointed out that we probably made a mistake by starting with the Lux R foam, and suggested we buy a 5" piece of their https://www.foambymail.com/HDHQ_2/hd36-hq-foam-mattress.htmlHD 36 HQ foam, which has a softer feel with an ILD of 35 And a density of 2.8.

Here’s my question: although I am sure that buying the softer support foam would hopefully fix the feeling of a hard bottom to the mattress, it means tossing out a perfectly good piece of support foam and spending more money. I’m curious if anyone has any good ideas about an intermediate layer of foam which would sit between the 3" 5-pound memory foam on top and the very firm support foam on the bottom. Options might include a two or 3 inch https://www.foambymail.com/LTX_T/dunlop-latex-foam-topper.htmlDunlop latex layer, or perhaps a medium firmness regular poly foam in a two or 3-inch layer. Obviously, the poly foam would be much less expensive. Or should I just toss the firm support foam and start with the medium support foam?

The main bed build will also source most of the components from the Foam Factory. It would start with a 5 inch layer of medium firm poly support foam, the HD 36 HQ foam with an ILD of 35.

The challenge for this mattress is that it needs to work for a 205 pound 5 foot nine man as well as 115 lb. 5 foot three woman. So it might involve some split layers.

The transition layer might be 1 or 2 inches of medium firm Dunlop latex, with an ILD Of 29. This should allow the heavier one of us not to bottom out against the support foam. Input as to whether one or 2 inches would be preferable would be great. I’m not sure that 1 inch would be enough of an intermediate layer to stop me from bottoming out.

The top comfort layer could either be a simple 3-inch layer of 5 pound Visco memory foam, or could be two individual 2" layers of 5lb and 4lb Visco memory foam. The advantage I see of splitting the comfort layer into two layers is that they could be swapped from up and down to change the firmness slightly.

All of this will go into a mattress case with the zipper. Initially I would build this as a single, un-split mattress, but if necessary would cut some of the layers longitudinally to allow some customization for each sleeper.

Any input would be great. I know this is a little bit complicated, but I like to fiddle, and having tried a variety of other bed in the box memory foam mattresses that friends have purchased, I haven’t been impressed with most of them. I also like the option of replacing foam layers, especially in the comfort layer zone, as they wear out, rather than having to toss an entire mattress.

Hi androiddd,

Welcome to the Mattress Forum! :slight_smile: I’m glad you’ve found us and have taken the time to contribute.

I’m not sure if you’ve found it yet, but some of the better comments and links I have for designing a DIY mattress are listed after Option #3 in this post. Even if you were extremely knowledgeable about foams and mattress design, there is quite a bit or trial and error that can go into designing your own mattress, but some people (such as yourself) enjoy “tinkering” and derive satisfaction from your own personal creation.

I wouldn’t be able to tell what material might work best for you, but it does make sense that you are “feeling through” the 3" of memory foam and then the 2" of “soft” (you didn’t mention the ILD) Talalay latex to the firm polyfoam core. I would expect that in this combination you’re going to “feel through” to just about anything placed underneath, as memory foam itself isn’t a very supportive material nor does it show much resilience (rebound). Keeping the firmer polyfoam core and then the upper 3" of memory foam, a more progressive construction using a more “medium” latex (such as the Dunlop you mentioned) or a good density (1.8 lb minimum) polyfoam in the “medium” range could work as a better transition layer, better matching the compressed feel of the memory foam on top instead of being closer to it in feel than the plush Talalay latex was. There’s more detail about typical “progressive” construction you should read in this article. There’s certainly no reason that using the firmer polyfoam support core wouldn’t work for you, but I think that even if you chose the softer polyfoam core that you’d still want to consider a more “medium” transition layer as you described, so logically you may wish to begin with this and then perhaps decide if you wish to change to a different support core.

If the “main bed” is also a queen like the guest bed, why wouldn’t you buy this polyfoam core at the same time as the transition foam for the guest bed and then have all of that to play with? Just a thought.

That’s easy enough to do with an electric meat carving knife after the fact, should you desire to customize the transition and uppermost foam layers within the mattress. That’s one of the nice things about an all-foam DIY project.

While I understand what you “mean” by “bottom out”, I want to comment that you won’t be compressing the foam to it’s minimum thickness. All of the foam layers of a mattress work together, not individually or sequentially, so you’re desiring something in the transition layer that matches better with the “compressed ILD” of the uppermost layer so that this transition from the comfort layers to the base foam isn’t so abrupt, if I understand this correctly. You’re correct that only 1" of latex probably won’t have as much impact as at least 2" of the “medium” Dunlop that you are considering in this case, and something like this is certainly a common choice used by many mattress manufacturers.

I think in these scenarios, if splitting, I would consider splitting the memory foam layer(s) as well as the Dunlop latex “transition” layer. This could give you options for moving the latex up or down in the order of comfort layers, as well as allowing you to place different ILDs of latex on each side.

In the scenario using two different 2" memory foam layers over the latex transition layer, this of course would allow for more comfort “tinkering” by moving the latex layer up within the ordering. But rearranging the two memory foam layers (4 lb and 5 lb) on top of each other in the #1 and #2 positions won’t have as much of a noticeable difference in comfort, especially once your body temperature has impacted the viscous nature of the memory foam after 10-15 minutes. All memory foam is relatively soft (in the low to mid-teens for ILD), and while there are subtle differences in feel, responsiveness to heat, rebound and speed of viscosity change, it would be minor in perception as compared to different ILDs in latex or poly foam.

As I think you’re already aware, I can’t predict what might feel “best” to you, but only comment upon the ideas you’re considering. In the end, as I think you’ve already discovered, only your own personal testing will be able to determine if what you’ve constructed will meet with your personal comfort preferences, so hopefully some of my comments here have bene helpful.

And while I know you’ve been dealing with Foam Factory (aka Foambymail or FBM and other names as well) you may still want to read this post and this post and this topic (about their polyfoam and sources) and this post (presumably from a past employee) if considering anything else from them and some of the information and sources of their foam products.

Phoenix

I have a Ph.D. in psychology but I think Phoenix, you should be awarded an honorary Ph.D. in Mattressology! What a thoughtful and deep reply.

I have a few questions.

  1. What is high resilience foam and where does one buy it?

  2. I read your other article about progressive layers, and it sounds like since we are both side sleepers at least part of the time, we would need a comfort layer on top of 2 inches, and then an intermediate layer of 2 to 3 inches. Perhaps a 2 inch 5 pound memory foam on top, followed by a 3 inch layer of Dunlop latex in a medium firmness. The memory foam tends to have an ILD of 14 or so so I’m wondering if the Dunlop should be 20 or more like 29 ILD as the progressive layer?

  3. If I don’t want to spend the money on the Dunlop latex, which costs about $100 per inch and a queen size, what kind of poly foam would you recommend for that intermediate layer? Should be flat foam or convoluted foam? Should it be high resilience foam? Particularly on the guest bed that I’m rebuilding, I want to keep the price down.

3.5 I see what you mean about not splitting the comfort layer between 5 pound and 4 pound memory foam as they probably both feel pretty similar. I do wonder if it would make sense to split the bottom support layer into ILD 29 and ILD 50 pieces, perhaps 3 inches thick for each? I would assume the 29 firmness should go on top. But they could be swapped later if necessary. I may be overthinking this :slight_smile:

  1. Not a question just a comment. I have used Foam by Mail before and other than slow shipping I haven’t had problems. As far as I can tell their prices for memory foam are much lower than anywhere else, but if there’s another vendor that has similar prices but better quality I would certainly be interested in knowing their name. For latex they seem to be more in the same ballpark as other vendors, with costs for Dunlop being about $100 per inch of thickness and the queen size. (Of course there are very high-priced latex vendors too, which almost double those prices.)

Most of the complaints that I read on your site seem to be about confusion between Dunlop and Talalay latex, but FBM no longer even sells any Talalay latex.

Anyway, I want to thank you from the bottom of my heart for such a smart response and this will greatly help me in planning this bed build. I’ll be ordering the components over the next few days, and building the bed in about two weeks. I’ll update on success or failure.

Hi androiddd,

Thank you for the kind words!

High resilience polyfoam is technically polyfoam with a density of 2.5 lb or above, with a compression modulus of 2.4 or above. It’s discussed in more detail here in this article. Some better sources of which I am aware for polyfoam are listed in the component supplier post here.

A 2" + 2" or 2" + 3" combination certainly could work well. The 20 ILD Dunlop would be closer in plushness to the memory foam, but might be more of an abrupt transition to the polyfoam base (depending upon which you choose). The 29 ILD Dunlop might “bend into” either polyfoam core better, but it could be a bit more of an “abrupt” transition between that and the upper memory foam layer. It all depends upon your personal preference. Remember that all of the layers work together to provide overall comfort, but the uppermost layers will have the greatest impact upon comfort perception.

If you want to keep the price down for the guest room mattress, for the transition you may want to consider 1.8-2.0 lb polyfoam. I personally would choose a solid sheet versus convoluted.

You certainly could do this, and yes normally the 50 ILD would be on the bottom with the 29 ILD on top. This would provide a more “gradual transition” to the deepest support layer. And if you do this, it would impact what you would choose for your upper transition layer. I always recommend a “bottom up” approach when analyzing these scenarios.

If you read through all of the comments on the forum about them, you’ll see that there was more than what you mentioned. What I believe to be Dunlop represented as Talalay, evasiveness with specifications, uncertainty about sources, repetitiveness of support factor numbers (questionable specifications)…(from one of my previous posts) There is more but I think you catch my drift. I won’t support a business which I believe follows less than ethical (by my standards) business practices and they have a long way to go and a lost reputation to make up for before I would consider buying any of the latex foam they sell or suggesting anyone else does. There are many who “love” them … but I believe that is only because they don’t really know what they actually purchased. There are also many more who don’t … and with good reason. If you choose to deal with them that’s certainly your prerogative, but I’ve been pretty clear regarding my position for the reasons stated here and elsewhere on the forum.

And to repeat what I posted earlier, some better sources of which I am aware for latex and polyfoam are listed in the component supplier post here.

I’ll look forward to your updates. And there are no failures…just steps along the learning curve.

Phoenix

Hi Phoenix,

Quick question on adding a layer to a mattress build that Almost Works.

The build is this, from bottom to top layer.

Bottom: A very firm latex mattress, probably about 10 years old, in good shape and not sagging at all but way too firm. Not a pillowtop.

Next Layer: 3 inches of new 5 pound density memory foam.

Next and top layer: 2 inches of a fairly soft talalay latex topper. It’s one of those dual layer toppers with 1 inch of slightly firmer foam and 1 inch of softer foam. The softer side is up.

Here’s the problem. The current configuration feels very supportive, but needs a little additional pressure relief. Both my partner ( 115 pound woman) and I (205 man) find that we toss and turn quite a bit on the current set up. My experience of it is that I’ll be on my back for a while, then I’ll turn on one side, then my shoulder will start hurting so I will turn back on my back and so on. Both of us wake up feeling a little bit beat up.

We’ve tried having the memory foam on top of the latex layer but then we tend to sink into much, so the support is not adequate.

What you think might help? Ideally if I could add a single layer of something to get a little additional pressure relief, that would be great. Alternatively, I’m not that invested in continuing to use the 2 inch latex topper (it could go elsewhere) so if there’s a alternative that would get us both pressure relief and not bottoming out onto the way too firm latex mattress underneath, that would be great.

Options might include some soft poly foam on top, or perhaps 1 inch of memory foam. Open to other suggestions as well.

Also, here’s what I have access to stealing from other beds in the house.

2 inch memory foam, probably three or 4 pound density

3 inch soft Dunlop latex topper

Thanks for your help with this it’s been vexing me every morning. The bed is so close to being perfect. But oh so far!

Not Phoenix here, but based on your described issue and what you have available on hand I’d suggest trying the 3" soft Dunlop topper in place of the 2" soft Talalay topper. The additional inch added to your comfort layer may give you the pressure relief you’re seeking and it should be relatively easy to try. Once you see how that feels even if it isn’t your ultimate solution it may help determine how to better achieve your desired feel. Good luck with your project!

Hi adroiddd,

I would try combinations with what you have available to you first. Sweet Dreams had a good thought up using the plush Dunlop topper in place of the thinner Talalay topper. Another thought would be try the firm mattress, then place on top of that the memory foam, then place on top of that the Dunlop topper, then the new plush Talalay topper on top of that.

I’d be interested to learn your results trying out those two different configurations.

Phoenix

Hi guys,

Couldn’t figure out how to post a new post so am posting in my old post.

Sadly enough, after several years, much of the memory foam failed in my DIY bed. Some of it was older, some of it was 3 pound memory foam, but it got too mushy. Part of the problem was that I weigh 200 and my girlfriend weighs 110, and we never rotated any of the foam so it failed on my side. Note to self, rotate every few months.

I need help tuning up both beds.

Bed One: from bottom to top, 5 inches of HD 36 support foam, 3 inches of a soft to medium Dunlop Sleep on Latex topper, and currently 2 inches of a high density 5 pound but older memory foam, and a 1 inch piece of blue gel convoluted foam on the very top.

The memory foam layers feel too soft, and I sink through them and then hit the latex layer, which pushes back. So simultaneously it feels a little bit too soft and too firm. It’s not terrible, but not as supportive as I would ideally like. And since the foam is pretty old it’s probably time to replace the 2 inch memory foam layer.

What could I replace the older 2 inch 5 pound memory foam with? Ideally it would be a little bit stiffer foam, and ideally also a gel based foam so it would sleep a little bit cooler. I’ve only bought foam online from Foam by Mail, so would be curious if there are other sources for a good quality four or 5 pound memory foam with gel. FBM sells a 4 pound blue memory foam and a 5 pound pink memory foam but neither has gel.

A source on Amazon that has two day shipping would be great, since I’d like to get this fixed as soon as possible and FBM takes two weeks.

Also, would it make sense to perhaps split the comfort layer, with a slightly stiffer 4 pound memory foam on my side (200 pounds) and a softer 5 pound memory foam on her side (hundred and 10 pounds)?

BED TWO: the other bed has a rock hard very firm latex mattress as the base, and then the same 3 inch latex topper which is a soft to medium Dunlop latex, and then the 5 pound pink memory foam from FBM. That memory foam has gotten pretty mushy and on top of 3 inches of latex really feels mushy. Although my girlfriend who weighs under 120 doesn’t mind it, I sink so far in that it hurts my low back.

Again recommendations for replacing that top layer of 5 pound memory foam would be great. Should we reduce it to 2 inches, and with what? Or consider using two foams of different stiffness and splitting them so that my side is stiffer and her side is softer.?

Thank you in advance for all of the help!

Hi androiddd,

Thanks for the post, … this is the best place for your post as it is easy to follow your previous history and experience with rebuilding your beds.

Good point about rotating these the foams especially for couples that have a larger weight differential (See post #2 here ~ which also has more information about this)

Your first question is one of the most common questions on the forum (ie. which material type or firmness level would be better for me?) Sometimes getting the right mattress/topper combo could be as difficult as getting a new mattress. As you probably know from your previous readings …while it’s not really possible to make specific suggestions because of all the many variables involved that are unique to each person and your own experience is the only way to know for certain whether any mattress/topper combination will be a good “match” for you in terms of PPP, replacing the memory foam with soft latex which is still supportive could take care of your issue. While being supportive because of the push back it would also give the extra cushioning needed and provide the air flow for a more temperature neutral environment.

There is more information about choosing a topper in post #2 here and the topper guidelines it links to which along with a conversation with a reliable and knowledgeable supplier (that can provide you with good information about how their toppers compare to each other or to other toppers they are familiar with that are available on the market) can help you use your sleeping experience as a reference point and guideline to help you choose the type, thickness, and firmness for a topper that has the least possible risk and the best chance for success.

Regarding the “gel memory foam” typically this type of gel foam conducts heat from the body (like putting your hand on a marble countertop) and is “thermally conductive”. It transports heat directly away from the body and releases it into the surrounding atmosphere (as long as it is cooler than the gel) without needing something to “carry” the heat away.

FYI, this type of gel memory foam will cool at first for a while until the temperatures equalize and then the foam would once again become an insulator and trap heat. It may provide an extra cooling effect when you are first going to sleep and the foam will feel cooler to the touch but neither of the gel technologies provides as long-lasting cooling benefits as moisture wicking, storage, and ventilation. The higher the percentage of gel the more effective and longer lasting the effects of the gel will be.

Aside from the “not rotating” the comfort layer, your memory foam toppers only lasted 2 to 3 years. This is one of the issues with recommendations from Amazon or FBM and one of the reasons why we wholeheartedly recommend our trusted members who meet a set of rigorous criteria for their products, and services before we include them on our site. Many times when buying from unknown sources, you’re never really given all the specs that would allow for an informed decision. In this case, you don’t know the ILD (firmness), only the density. Many of our members use a soft/firm choice for each side of the bed, but most of the time this is done with latex foam, primarily with Talalay latex, as Talalay has more firmness ranges than memory foam and other latex foams. If you like the feel of latex, of course, you have many options that are much more durable and have better temperature regulating qualities than gel or any of "temperature enhanced "memory foams.

While at first glance this may not be quite the answer you’re looking for I’d first make sure that you do not end up with a top foam layer that will break down rather quickly as you can easily find yourself in the same place 2 to 3 years later.

Once you have a chance to read through the links I provided let us know if that generates any new approach to your bed rebuilt and questions.

Phoenix

A few more questions:

I have a 5 inch base of HD 36 poly foam. I’m starting to wonder if that’s too thin. It’s not quite as stiff as it was when I purchased it several years ago. I may try swapping another similar piece from a bed that never gets used. Or I could throw both pieces on, and have a 10 inch base. What you think about that?

The other issue is that I looked up the ILD on my 3 inch piece of Dunlop latex. It is 20. I’m wondering if using this as the intermediate layer between the HD 36 and memory foam is actually part of the problem. Last night I tried sleeping on 4 inches combined of relatively low quality memory foam without the latex layer, just on top of the HD 36 piece, with a polyester mattress pad on top. That felt quite a bit stiffer, maybe a tiny bit too hard, but reasonably comfortable.

Although I have a $300 investment in the latex piece, I’m wondering if I should consider replacing it with a firmer piece, or a thinner 2 inch piece, or eliminating it entirely? Again would love your opinion.

If I replaced it with a firmer piece, what would be the appropriate ILD?

One thing I did discover in all this experimentation is that putting a mattress pad on top of memory foam totally changes the firmness of it. Previously I had just a thin sheet like cover, and that meant we sunk into the memory foam. A relatively cheap mattress pad means that you sink less into it.

Another issue is temperature. I find that memory foam sleeps hot. Would buying and using a wool mattress pad lower the temperature? Or should I consider another solution such as a 1 inch layer of latex on top of the memory foam?

Now I see why people just buy a mattress online or in a store. Tweaking mattress, especially as the layers wear out, is tricky.

Finally, as I consider replacing the memory foam, I’m debating whether or not to use 5 pound memory foam or 4 pound memory foam? From what I understand, the higher density memory foam will be more enveloping, whereas the lower density may be more resilient, and perhaps the higher density will last longer. I do know that my last experiment using 3 pound memory foam lasted a very short time.

One thing I learned from that experiment, is that if you either have disparate weights and to people using the bed, or one person using the bed on one side primarily, it’s important to rotate foam layers regularly otherwise they fail prematurely. I never really thought about that before.

I need to pull the trigger on a decision in the next couple of days, so would really appreciate all the input possible from this forum.

My goal is to have a port of but not too hard mattress, that works for myself (185 pounds) and my partner (115 pounds). I would even consider splitting foam to make a differential firmness on either side.

I don’t want to spend a fortune on foam , and looking at some of the sources it seems like some people are charging $400 for memory foam which seems excessive.

Thanks for your help! This is the only forum that has any intelligence about beds and mattresses.

Hi androiddd,

You can certainly use another piece of 5" HD polyfoam. I would put the lesser used foam on the bottom as the one you were sleeping on now is probably a little softer than when you first purchased it. Not sure it will make a tremendous amount of difference in feel except for a height that you may be more comfortable with.

Generally speaking, latex is more breathable than memory foam and many people use the latex above the memory foam because it is much more temperature neutral than memory foam which tends to sleep hot. It’s difficult to compare as each individual has different preferences…Dunlop has a different “feel” and performance than Talalay and is less lively or springy. You can see a comparison between them in post #7 here but your own experience is really the only way to know which one you prefer with any certainty. Some people would notice more of a difference than others with transition or support layers that used each material if the top layers were the same type of latex because you will “feel” more of the upper layers than the deeper layers … at least when you first lie on a mattress. Dunlop always has a bit firmer feel than Talalay latex.

If you replace the Dunlop topper with a firmer feel you may want to try a 28-32 ILD. The latex will give you longer durability than most memory foam toppers. Especially a 3-pound memory foam topper. As you have correctly pointed out … low-quality memory foam will breakdown quite quickly, thus after a short time your mattress will feel completely different than when you first purchased it.

You are making a good point! It is always interesting to see how the smallest change can alter the feel of the sleeping system because every layer and component in a mattress can affect the feel and performance of every other layer and the mattress “as a whole” … the most reliable way to know if this is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) is of course based on your own careful testing of how much the mattress pad itself can change the firmness of the mattress. This is also another reason why people can’t do DIY layers and then try to match up the mattress with the comfort layers one got used to as it always feels completely different when a manufacturer finishes a mattress.

The wool will help with wicking away moisture but It’s not really possible to quantify the sleeping temperature of a mattress for any particular person with any real accuracy because there are so many variables involved including the type of mattress protector and the sheets and bedding that you use (which in many cases can have just as significant an effect on sleeping temperature as the type of foam in a mattress) and on where you are in the “oven to iceberg” range and because there is no standardized testing for temperature regulation with different combinations of materials … there is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system inpost #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range.

I think you put it very simply but the DIY is ok for some people, of course even mattresses not DIY, and made with mediocre materials, and lower densities will wear out quickly also, so the same issue can exist with the traditional mattress purchasing.

I think you are on the right track with the 4lb and 5lb in terms of durability. I am not sure if you have read the durability guidelines as this article points out some o the issues with lower density memory foam, and also discusses regular polyfoam. While you are correct that the higher density will last longer it is the IFD of the memory foam that will give it the “enveloping” feel that you are describing regardless of the density of the memory foam.

If anything, memory foam is better described as a “dead feeling” foam as it absorbs energy that is applied to it and it has little to no “resilience” as opposed to latex, polyurethane, inner springs, or even many natural fibers so … it is not nearly as springy or lively. It responds very slowly to new and changing positions like “sleeping in the sand”

I hope this helps and let us know if you have any other questions.

Phoenix