("Tempurpedic mattress" will henceforth be abbreviated "TPM".)
The most basic TPM consists of two, simple layers: a lower, "support layer" of firm polyurethane foam and an upper "comfort layer" of memory foam. On 90% of their mattress models, the only differences between Tempurpedic's most basic bed and the top of their product line are the quantities, qualities and juxtapositions of these two basic "support" and "comfort" layers. But making high-end Tempurpedics from separate components can get a little complicated, so let's start by making our own version of "The Original Bed" by Tempurpedic. See this link for a useful glossary and an illustration of this two-layered construction: http://www.tempurpedic.com/sleep_system ... /features/
1 - The Support Layer:
This is the backbone of your mattress; without it, your bed would sag like a deflated balloon. It consists of high-density polyurethane foam (HDPF), similar to what's in your sofa cushions only a LOT firmer and much denser (high-density = durability.) You want to use HDPF with a density between 2.4lb/ft3 and 2.8lb/ft3 and a "compression" (a firmness rating) between 35lbs and 50lbs. I like a decidedly firm core to my mattress, so I chose the firmer foam, with a "compression" (firmness rating) of 50lbs.
How thick should this supportive base layer be?
THE REQUISITE THICKNESS OF THE BASE LAYER DEPENDS ON THE WEIGHT OF THE SLEEPER.
One of the neat things about assembling your own mattress is that you can customize according to YOUR needs (often saving money). If you're making a child's bed, you don't need a 5" thick base. Likewise, if you are a heavyweight, you're gonna need a much thicker 6" or even an 8" support layer, to keep from "bottoming out" the mattress. I suggest the following thicknesses for the mattress base.
under 70lbs ------- 3"
70lbs - 100lbs ---- 4"
100lbs - 150lbs --- 5"
150lbs - 300lbs --- 6"
over 300lbs --------8"
Here's what I used as my 6" base layer: http://www.foamdistributing.com/products/lux-hqM.html
This stuff is so firm and resilient, I was able to do jumping jacks on it without bumping into the floor!
If you prefer a less firm mattress core use this: http://www.foamdistributing.com/products/hd36-hqM.html
Notice; the density of each of these HDPF products is the same (2.8lb/ft3) but the compression (firmness) is 50lbs and 35lbs respectively. Density refers to the weight of foam given a certain volume; the higher the density, the longer the foam will last; high-density foam like this should last 10-15 years as a mattress core. Compression refers to the firmness of foam.
PS: This is a good company with a good reputation. They offer free shipping to the 48 states and Canada. For those of you in the rest of the world, I don't have any reliable links yet. If you know of any, please share.
2 - The "Comfort" Layer, Memory Foam
Well, now you've got a thick, stable, supportive base-layer of high-density polyurethane foam lying on your bedroom floor. (Not so sure, but I think you might want a little cushioning on that thing.) Memory-Foam to the rescue! For our purposes we'll use 3" of Sensus brand 5lb/ft3 density foam, it's great stuff, from here: http://www.foamsource.com/shop/product/9
. Just take the memory foam layer and stack it on top of the base. Voila! You just made the Tempurpedic Original bed!
Or add an extra layer of memory foam like I did from this site. http://www.healthyfoundations.com/toppers.html
NEXT TIME, I'LL DISSECT AND REBUILD THE TEMPURPEDIC CLASSIC BED!
Questions? I have answers.