I say hybrid because I artfully combined 4 different materials with VERY different properties. Traditional poly foam, egg-crate poly foam, memory foam and wool. After months of trial and error, I found my dream mattress.---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Set DIRECTLY on the floor (for extra stability), I made an extra long twin mattress composed of the following: 12" thick poly foam with an IFD of 50 (very firm), topped by 4" of poly foam with an IFD of 35 (moderately firm) covered with 2" of 5.3lb/ft3 Sensus foam with an IFD of 15 (soft) topped off with 2" of egg-crate poly foam with an IFD of 35 (I found that by putting the traditional poly egg-crate OVER the memory foam undid that "squishy" feeling and and gave the mattress a nicely balanced responsiveness. I covered all that with a HEAVY weight (I think it weighs 60 lbs!) wool comforter (which gave it even more textural evenness), sealed it up with a clothed-vinyl mattress cover, added a fitted cotton mattress pad over THAT, added sheets and AHHHHHHHH. My perfect mattress.

Did I mention this whole mattress was about $700! Even if it only lasted for three years it would be worth it. Most beds you get at your basic furniture store give five years at best. And I bet for a whole lot more than $700!

sandman wrote:

Yes it's a cloth coated vinyl, as if cotton were sprayed onto it. The mattress doesn't breathe at all. (internally that is) That's by design, it prevents oxidation of the poly foam, a major contributing factor to poly foam degradation. I want it hermetically sealed and it just about is. The very top layers, (which are in reality not parts of the mattress) the thick cotton mattress pad and sheets provide all the "breathe-ability I need. It's extremely comfortable.

Good night.

Pete wrote:
Pete, I"m very happy for you; if it works for you that's all that matters.

My only caution to others is that poly foam tends to die much quicker than latex. It appears your base layer is lasting and I am surprised and happy to hear that. And you're right, having it in layers makes it so you don't have to replace the whole thing at once.

My experience with HR foam - which is supposed to be rated for 10 years - is this: the 1" layer I was using seemed to have given out on me. I can't prove it and I admit I could even be wrong, but it sure seems that when I replaced that layer, all is good with my mattress again. And I only had that layer in use for about 2 years.

As for Sensus, some like it but to me, that also seems to give no support. (Could be too that my Sensus from Overstock.com is not really Sensus! )

I'm not knocking your accomplishment, nor your foam, I'm just saying to others, "your mileage may vary" with the poly foam.

Thanks for reporting this, though; if I ever do a pure foam mattress again I will consider some of your info in this post, in my configuration!
p.s. Are you serious?! A 60lb wool topper? Where the heck did you get that?! And how much did you pay for it! Wow, that's a lotta wool! (Or does it have lead sewn into it?!)

HAHA, the wool "topper"is a dinosaur. It's a super thick wool comforter that was made just after 1950, my grandmother gave it to me. she'd kept it in a cedar chest practically covered in naphtha. I don't think "they make 'em like like that anymore"

About overstock and Sensus, I have a positive opinion. My sister ordered the 2" king topper and it weighed 36lbs, yielding a density of exactly 5.3lb/ft3. It has the trademark pink color and super smooth texture. It's for real. I may even (either the height of hypocrisy, irony or some dysfunctional combination of both) order one for myself.

Jim is right about latex lasting longer than most, heck ALL foam products, there's just one problem; I HATE LATEX! But if you do go the foam route make sure you get something with a density of 2.8lb/ft3 or greater, light weight stuff wears out FAST! Jim, it's also of note that the thinner a layer of foam, that faster it wears out. (I need a physics major to tell me why) For example, a few years ago I put a 1" slice of HD36-HQ foam from foam distributing.com on my bed; it was totally shot inside of six months! BUT the 4" thick layer of the exact same foam within my mattress seems to be holding up very well after 6 years of use, the 12" thick base layer is ageless and seems brand new. But I take great pains to seal my mattress from the air, oxidation is the main cause of poly foam degradation.

It ma also be notable that none of the foam on my mattress has discolored. The white HD36-HQ is still snow white, the Sensus is still pristine pink and the Lux-HQ is still baby blue. I'm tellin' ya if you can seal up a foam mattress against the atmosphere, it preserves the foam greatly. (Tempurpedic mattresses come with such an air tight cover, I think)

Jim, about sensus not giving support, Of course it CAN'T give support, no memory foam can, only the firm understructure can do that. It's got an IFD of 12, I believe, I just use it to take a bit of the bounce out of all that poly foam. IMO, the less the better 2" is perfect for me 1" might be better for some. I "trialled and errored" an awful lot to find find what works for me. While i suspect that most people would find my bed very comfy, some might be put off by it's firmness. (Remember the sensus is buried under several layers including that monster wool comforter!) lol So anyone looking to imitate me be warned; figuring out exactly what you like isn't so easy!

Has anyone else assembled their own mattress? I'd like to hear your story.