Need help with replacing polyfoam in a hybrid spring/poly mattress

[Mike77]

Hello

I currently have a sealy Opal Innocence twin size mattress that i bought about 3 years back. At about the 6 month mark, i noticed (as many others have) that the bed no longer supported my hips as well as they originally did. I soon awoke w/ back pain due to misalignment problems, and as a result i had no option (since i couldn’t return it) than to open it up (cut the top off) and pull out the junk foam (polyfoam low density) to have it replaced. All of this was over a set of springs at the bottom.

Ive tried a couple of 2 inch latex toppers (the current configuration i have now). 1 dunlop at about 30 ILD and one Talalay at about 32 ILD (tried one on top of the other). and while the alignment is not an issue, the problem im having is with hip pain and constant waking during the night to switch positions.

I weigh about 200 LBS and am heaviest at the hips. The spring core seem to support alignment OK as ive laid directly on them and had no issues with back alignment. So how would a differential build work with a comfort layering scheme given the spring core underneath? I assume the comfort layers would “sink” into the “hole” that my hips create underneath me. Is this a problem in terms of the “pressure relief” id get from the comfort layers.

Im certainly looking for HR quality foam w/ densities above 2 if i can get them. But the ILD is a little tricky to nail down. What values would you recommend for me (200 lbs male)? Ive been toying with 40-50 ILD since my hips are pretty heavy. If i can get a sag factor of >2 would 40 ILD be ok? How much do typical hips weigh in terms of proportional bodyweight? Considering ill all ready be sinking into the springs about 1-2 inches, would a thinner comfort layer be better than a thicker? Or a thicker w/ a higher ILD?

As for the thicknes, should i get at least 3-4 inches? Maybe 5 considering any compression tolerances that occur from me sleeping on it? So if the layer sinks a bit, I wont bottom out or be pushed into alignment issues.

Is polyfoam generally considered adequate for being “bed ridden” or would you recommend a pure spring coil mattress for low budget (maybe marshal coil based)?

I would also like to purchase a new polyfoam online and have seen you recommend foamonline.com. Are they reputable as fare as you know? I live in Vermont , so might you know of any closer distributes that i could either contact or visit (online or offline)? Maybe even in the new england area. I haven’t been able to find any close by.

Any answers to these questions will be greatly appreciated.

Thank you for your time.

[phoenix]

Hi Mike77,

Ive tried a couple of 2 inch latex toppers (the current configuration i have now). 1 dunlop at about 30 ILD and one Talalay at about 32 ILD (tried one on top of the other). and while the alignment is not an issue, the problem im having is with hip pain and constant waking during the night to switch positions.

I weigh about 200 LBS and am heaviest at the hips. The spring core seem to support alignment OK as ive laid directly on them and had no issues with back alignment. So how would a differential build work with a comfort layering scheme given the spring core underneath? I assume the comfort layers would “sink” into the “hole” that my hips create underneath me. Is this a problem in terms of the “pressure relief” id get from the comfort layers.

I don’t have any specific suggestions because the first “rule” of mattress shopping (or mattress surgery) is to always remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort” or PPP (Posture and alignment, Pressure relief, and your Personal preferences) or how a mattress will “feel” to you or compare to another mattress based on specs (either yours or a mattress), sleeping positions, health conditions, or “theory at a distance” that can possibly be more accurate than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).

I also wouldn’t focus on whether a mattress uses a “differential” or a “progressive” construction because these are only very general and broad descriptive terms for how a mattress is layered and there is no inherent reason that either one would be better or worse in terms of PPP and either one could certainly make a good choice depending on the specifics of the materials and components and the overall mattress design and layering.

If you are attracted to the idea of designing and building your own DIY mattress out of separate components and a separate cover (which in effect is what you are doing if you are doing “mattress surgery”) then the first place I would start is by reading option 3 in post #15 here and the posts it links to (and option #1 and #2 as well) so that you have more realistic expectations and that you are comfortable with the learning curve, uncertainty, trial and error, or in some cases the higher costs that may be involved in the DIY process. While it can certainly be a rewarding project … the best approach to a DIY mattress is a “spirit of adventure” where what you learn and the satisfaction that comes from the process itself is more important than any cost savings you may realize (which may or may not happen).

There is also more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel” that may be helpful as well.

There is also more about mattress surgery in post #2 here and the posts it links to that may also helpful.

Is polyfoam generally considered adequate for being “bed ridden” or would you recommend a pure spring coil mattress for low budget (maybe marshal coil based)?

Every layer and component in a mattress (including the cover and quilting) will affect the feel and performance of every other layer above and below it and the mattress “as a whole” so it would really depend on the body type and sleeping style of the person and the overall design of the mattress.

Assuming that the materials in a mattress you are considering are durable enough for your body type and meet the quality/durability guidelines here relative to your weight range … the choice between different types and combinations of materials and components or different types of mattresses are more of a preference and a budget choice than a “better/worse” choice (see this article).

I would also like to purchase a new polyfoam online and have seen you recommend foamonline.com. Are they reputable as fare as you know? I live in Vermont , so might you know of any closer distributes that i could either contact or visit (online or offline)? Maybe even in the new england area. I haven’t been able to find any close by.

The component list here includes the better online sources for polyfoam that I’m aware of (and includes foamonline) and there are also some comments and comparisons in post #4 here and post #6 here that may be helpful as well.

I don’t know of any local polyfoam suppliers in Vermont off the top of my head but New England foam is one of the suppliers on the list and they are in Connecticut although they have a minimum order of $200 and you would need to check their prices for the specific foam layers you are interested in.

Phoenix

[Mike77]

Thanks for the response. I like the info.

I think one of the problems im having more specifically is finding good layers to fit over the springs, which i couldn’t sleep on alone. I have the shoulders about right, but the waist is what sunk in early on, which is where the material depressed the most. I think im going to try and look for a nice polyfoam just for my trunk section (not for the entire length of the mattress). I think a big stumbling block for me is getting the ILD right. Since i weight about 200 LBS, is there any way to know how much your hips weigh and how that relates to ILD? Would i be correct in thinking that a 32-40 would be a good range for me given that sag factor of about 2.0 (means it would be about 80 ILD further down)? So maybe a 3-4 inch piece of polyfoam, w/ maybe a 2 inch soft memory foam or soft talalay on top?

I would like a cut that doesn’t sag over possible long periods in bed. What density should i be getting for polyfoam? I realize that layers can be “weak links”, so i want to be sure that polyfoam can last. How long does it typically withstand long bouts of lying down? could it last weeks of being bed ridden for example?

I appreciate the help

[phoenix]

Hi Mike77,

I think a big stumbling block for me is getting the ILD right. Since i weight about 200 LBS, is there any way to know how much your hips weigh and how that relates to ILD? Would i be correct in thinking that a 32-40 would be a good range for me given that sag factor of about 2.0 (means it would be about 80 ILD further down)? So maybe a 3-4 inch piece of polyfoam, w/ maybe a 2 inch soft memory foam or soft talalay on top?

Unfortunately there are too many variables involved so there isn’t a formula that can predict which combination of layers or which design will work best for any specific person so your own trial and error and personal experience will really be the only way to know whether any specific design will be a good “match” for you in terms of PPP.

Unless you have a great deal of knowledge and experience with different types of mattress materials and specs and different layering combinations and how they combine together and can translate them into your own “real life” experience that can be unique to you (which would only be a very small percentage of people) … I would avoid using individual specs such as layer thicknesses or ILD numbers or compression modulus or other complex combinations of information or specifications to try and predict how a mattress will feel or perform for you or how it will compare to another mattress and focus more on your own actual testing and/or personal experience and if this isn’t possible then on more detailed conversations with a knowledgeable manufacturer or retailer.

I would also keep in mind that every layer and component in a mattress (including the cover) will have an effect on the feel and performance of every other layer and component above and below it and specs such as ILD are only one of several variables or “specs” that will determine how soft or firm an individual layer or a mattress “as a whole” will feel to different people (see post #4 here). In addition to this the ILD of different materials or different types and blends of latex also aren’t always directly comparable to each other (see post #6 here) so using the ILD of a particular layer or combination of layers as a reliable indication of how any mattress will “feel” or how firm will feel to you compared to another mattress with a different combination of layers can be more misleading than helpful.

While knowing the specs that can affect the quality and durability of the layers and components in a mattress is always important … when you try and choose specific layers or components based on complex combinations of “comfort” specs that you may not fully understand then the most common outcome can often be “information overload” and “paralysis by analysis”. Even the best mattress designers in the industry are often surprised at what a mattress they design “should have felt like” when they design it and what it “actually feels like” when they test out their new design.

I would tend to take a “one step at a time” or “bottom up” approach and purchase layers and components one at a time and then you can base your choice of each new layer using your experience on the previous combination as a reference point until you reach a final design that is “good enough”.

I would like a cut that doesn’t sag over possible long periods in bed. What density should i be getting for polyfoam?

While there is no way to quantify how long any mattress will last for a specific person or predict exactly when you will decide to replace it because it is no longer suitable or comfortable for you (because this is the only real measure of durability or the useful life of a mattress that really matters) because there are too many unknowns and variables involved that are unique to each person … if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new (see post #2 here) and you have confirmed that it meets the minimum quality/durability specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or even longer and the chances that you would have additional “bonus time” would be higher as well.

There is also more detailed information about the many variables that can affect the durability and useful life of a mattress in post #4 here.

If you are spending unusual amounts of time in bed (or if you are in a higher than average weight range) then I would tend to use higher density and more durable materials than the minimums in the guidelines and would probably use 2.0 lbs as a minimum density for polyfoam (and higher would be better yet) and 5 lb as a minimum density for memory foam or any type or blend of latex which are all among the more durable foam materials.

Phoenix