First bed build using hd36 hq wondering if an 8" pocket coil mattress would be good underneath for some give?

Hello, I have used high density foam in couches, and my current hd36 is comfortable in my couch at 6" but the couch has (very firm) but nonetheless springs, so I’m wondering if putting a mattress underneath like this Signature Sleep Contour 8-Inch Independently Encased Coil Mattress it has pocket coil springs and I was wondering if it would work under 6" hd36 or would I be better off just going with the foam? I want to be able to flip the mattress as I’ve always done that with my couch cushions. I’m new to this so any information would be helpful. Thanks

The mattress you’re considering uses some really low quality foam. Maybe Phoenix can comment on that. You’d be better off getting a better mattress or buying an innerspring from a component supplier.

Hi alpharaplpha.

It sounds like you’re considering making your own mattress with 6" of 36IFd polyfoam as the top layer. 36IFD would certainly be a firm upper layer for a mattress, but based upon your own PPP it may be something you prefer. Here is a chart (section 4.2.2) from the Polyurethane Foam Association that relates different typical IFD values.

If you are attracted to the idea of designing and building your own DIY mattress out of separate components that are purchased from one or several different sources 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 useful as well.

There is more about the pros and cons of different types of innersprings in this article and in post #10 here.

Overall, it’s not possible to tell how a mattress will feel and perform for any specific person based on the specs or density of the materials and it would depend entirely on the person and which mattress design was a better match in terms of comfort, firmness, and PPP. For some people one would be better and for some the other would be better and for some neither one would be a suitable choice. The only way to know would be based on your own careful testing or your own personal experience when you sleep on it.

You are making a risky purchase with your Signature Sleep mattress because the foam layers on either side of the spring are a very low quality/density material (1.25 lb polyfoam) that could compromise the durability and useful life of your mattress/topper combination. A mattress like this doesn’t meet the durability guidelines I would suggest, even though these foam layers would be deeper in the DIY mattress you’re considering creating.


It was just a thought. Mainly I’m using hd36-hq, and like the fact that I can flip/rotate it over the years. But if that’s not important using 2.8 lb density foam, I was thinking of 2" lux on the bottom, 4" hd36 with a 2" topper of hd23; or 6" hd36 and 2" hd23, because though I sleep on my couch with the 6" hd36 it would be nice to have a soft top layer. What do you think of these options, foregoing the spring mattress idea.

Hi alpharalpha.

While I’m still not completely sure what you’re attempting to do (I don’t know if you’re just placing pieces of foam on top of each other on the floor and sleeping on them or attempting to make your own mattress – your posts aren’t clear), having a “core” of 2.8 lb polyfoam with an upper layer of 2.8 lb. softer polyfoam (again, you’re not clear of the densities of all of these foams – ILD is more of a softness scale) would certainly make a more gradual transition from support to comfort layers and having the softer foam on top would “tend” to be more comfortable for most people. And if you wanted to make the product flippable, you could put the softer foam on the top and the bottom of the core and you’d have a flippable mattress.

As far as how this will feel to you, I can’t speak to how any specific mattress combination will “feel” for someone else or whether it will be a good “match” in terms of comfort, firmness, and PPP because this is too subjective and relative to different body types, sleeping positions, and individual preferences, sensitivities, and circumstances and you are the only one that can feel what you feel on a mattress … outside of PPP (which is the most important part of “value”), the next most important part is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t see or “feel” and assessing the durability and useful life of a mattress depends on knowing the specifics of its construction. I would always make sure that you find out information listed here so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress. If you’re putting something together and all of the polyfoam is 2.8 lb. in density, you’d certainly be using some better quality materials.

Good luck!


The frame I currently have is a platform/slats. I can either put extra slats so they’re 2" apart or put a solid piece of plywood in place of the slats?
I have used this hd36-hq (2.8 lb density, ild around 36.) I’m impressed with the product, sleep well on my couch with it, except when it was newer I had wished it had a little more give, so this time I would like to go with a top 2" layer of 2.8 lb density hd23-hq–this foam is new to me but it seems like it would be comfortable. I had considered putting the hd23 on both sides but wondered if it would flatten, indent the bottom? Also it would add an extra $100 as that’s what 2" of full size hd23-hq would run me (does that price seem right?) Considering that this foam is supposed to have an around 15 yr lifespan give or take, Do you think flipping it is necessary or could II have the hd36 & hd23 glued together and not flip it (but rotate it) and not have it sag or indent over that long a period? If not, do you think it’s worth it to put the extra piece of hd23 on the bottom?

Hi alpharalpha,

As long as you had proper center reinforcement of your slats to avoid sagging, I would have you lean toward the slat system, as this would allow for better air circulation around your mattress.

A two sided mattress that is rotated and flipped on a regular basis (see post #2 here) will certainly last longer than a one sided mattress that uses the same comfort layers on only one side of the innerspring (even with very durable materials such as latex) because for half the time the comfort layers on the bottom of the mattress aren’t subject to the same amount of compression forces that soften and break down the materials over time as the upper layers in the mattress. There is more about the pros and cons of one sided vs two sided mattresses in post #3 here and the posts it links to.

I can’t comment upon the pricing but if you want to make the product two-sided and increase your durability it doesn’t seem to me to be too large of an extra price to pay.

I’m interested to hear how your “experiment” turns out.


Yes I agree, the extra $100 would be worth it, but my concern with that is if the hd23 would be adversely affected by the slats–indentations etc?

Hi alpharalpha,

I personally wouldn’t have a concern with properly reinforced slats approximately 2" apart as you described previously.


Don’t know at this point if I should start a new post or continue, please advise.

I have settled on an all foam mattress, and have opened up to other materials. I have read posts that state HR foam to be considerably better quality than HQ, is this the case? If so I’ve found it in 3.0 lb density both 15 ild, 36 ild and 50 ild. And now that I’ve read a bit more would consider latex. I find a 29 ild 4 lb and a 5.6 lb dunlop. I also found both natural and blended talalay 3" from 20 ild to 30 (but no density ratings does talalay have them?)

I want something firm enough to be able to sit up in bed to read etc, but soft enough to side sleep. In a perfect world I’d like to make it double sided. I can either go with just the HR foams, or introduce the latex. And suggestions?

Since I had started out with the intention of using polyfoam and when I ordered some samples from foam order I got a couple of the hr poly foams to check out; a hr44 and hr24, both are 2.8 lbs density. While I’ve moved over to buying a latex mattress (the latex samples I have do feel MUCH better than the poly foams, the hr poly foams would probably make a decent mattress with the firmer 44 core and the 24 comfort layer (especially as the hr24 is 2.8 lbs so should hold it’s shape over time.) The cost is less and there isn’t the concern of exposing the latex and having it breakdown over time. Or the possibility of a latex odor etc. Just thought since I started here and have the samples I’d follow up on it.
3" v44 core $189.24
2x3" v24 (for two sided) 205.83 ea = 411.66
Shipping $74
(Cover just some basic encasement around $50)
Total = $725 (- $205 if I put one 3" v24 in it’s own encasement as a topper) then total closer to $550

This is when I started to consider latex, at the higher density foams they’re pretty close in price to latex. I think the 2 products would probably last about the same, so for a 9" mattress there ends up being a $300 difference between the two.

Hi Alpharalpha,

Thanks for the update.

Just to be clear, as I’m not sure to what you’re referring to (or maybe asking about) here, you’d want to cover up polyfoam or latex to help shield it from UV and oxidation with an appropriate mattress cover. Regarding odor, latex will tend to have what some people describe as “slightly sweet” or “vanilla-ish” smell, which tends to dissipate quickly.