Hi tpsmith82,
[quote]1st let me say thanks to everyone on this site for all the amaing articles, feedback, tips and information about mattresses. It has been fun and very informative!!!
After lots of reading I decided to order our DIY mattress. It is my wife and myself. I am 5’ 9" and 160 lbs. My wife 5’ 7" and 150 lbs. This is what we have so far:
Comfort Layer: 3" Ultimate Dreams Talalay Blended Latex by Dreamfoam Bedding. ILD 19 (amazon $354)
“Transition” Layer: 3" Pure Green Natural Dunlop Latex by Sleep on Latex. ILD 30 (sleeponlatex $303.05)
Support Layer: 3" Lux High Quality Foam by Foam Factory. Density 2.8 / ILD 50 (Foam Factory $97.99)[/quote]
Welcome to the Mattress Forum! 
If you are attracted to the idea of designing and building your own DIY mattress out of separate components and a separate cover 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.
For those who decide to take on the challenge (which you already have) then I would either use the specs (if they are available) of a mattress that you have tested and confirmed is a good match for you in terms of PPP as a reference point or blueprint and try and “match” every layer and component in your reference mattress as closely as possible or use a “bottom up” approach (see post #2 here).
[quote]So, this seems like a good set up and feels almost perfect. But I was wondering if I added maybe 2" of super soft foam by Foam Factory ( Density 1.2 / ILD 12) In between the support layer and the transition layer if it would add just a touch more “soft” or “bounce” to the mattress. Seems When I sit down on mattress or roll/bounce around that it is a bit firm.
or
If I would be better with adding some type of mattress topper/pad on the very top to add a bit more to the comfort layer.
Would love any thoughts or ideas to finish up the job. Thanks again. [/quote]
If your mattress is “almost perfect” then I would hesitate to make any changes … at least until you have been sleeping on it for at least a month or so. There will be a break in and adjustment period for any new mattress or sleeping system as the mattress loses any of it’s “false firmness” and the cover stretches and loosens a little and the materials settle and your body gets used to a sleeping surface that is different from what it is used to (see post #3 here). This would typically be a few weeks but it can be shorter or longer depending on the specifics of the person and the mattress (higher density materials can take longer) and it can be surprising to many people how much their sleeping experience can change over the course of the first month or so.
If you are considering ordering from Foambymail (AKA FBM or Foam Factory and other names as well) then I would also read this post and this post and this topic (about their polyfoam and sources) and this post (presumably from a past employee) before buying anything or considering them as a reliable supplier that provides accurate information about their foam products.
As you can see in the foam quality/durability guidelines here … I also wouldn’t use 1.2 lb polyfoam in a mattress.
Once you have slept on your mattress for a month or so … which layers to change and how to change them (make them firmer or softer) or whether to add any additional layers would depend on what the specific “symptoms” you are experiencing when you sleep on the mattress are pointing to.
While it’s not possible to “diagnose” mattress comfort issues on a forum with any certainty because there are too many unique unknowns, variables, and complexities involved that can affect how each person sleeps on a mattress in terms of “comfort” and PPP (Posture and alignment, Pressure relief, and your Personal preferences) or any “symptoms” they experience … there is more about the most common symptoms that people may experience when they sleep on a mattress and the most likely (although not the only) reasons for them in post #2 here that may be helpful as well.
Phoenix