Hi birdhouse123,
The thickness of a mattress is really just a side effect of the design and is also only one of many variables that can affect the feel and performance of a mattress and by itself also isn’t particularly meaningful (see post #2 here). In some cases higher weight ranges will sometimes do better with a mattress that is a little thicker than lower weight ranges but even this depends more on the specific design and combination of materials in the mattress and on how well the mattress “as a whole” matches your specific needs and preferences than anything else.
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).
If you decide to take on the challenge 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 (Posture and alignment, Pressure relief, and Personal preferences) as a reference point and try and “match” every layer and component in your reference mattress (including the type and blend of latex, the thickness of each layer, and the firmness of each layer as well as the type of cover as well) as closely as possible or use a “bottom up” approach (see post #2 here).
Latex can oxidize faster with exposure to air and ozone and ultraviolet light along with other substances that can damage it see here and it’s always a good idea for a latex mattress to have a suitable dedicated cover to give it the best possible protection and to help maximize it’s useful lifetime. A mattress cover can also have a significant effect on the feel and performance of a mattress. There is more in post #3 here and post #3 here that will give you some sense of the effect of different types of covers on latex.
ADMIN NOTE:Removed 404 page link | Archived Footprint: primelineindustries.com/natural-rubber-chemcompchart.html
Phoenix