hello all, and thank you in advance for your suggestions! 
My very expensive, 3 year old European Sleepworks mattress has become uncomfortable - aching hips in the morning, and numb fingers (due to not supporting my neck which has some minor degeneration). I’ve been sleeping on my son’s mattress, and find that it’s very comfortable, and want to duplicate what he has.
His mattress was purchased new on Craigslist from a guy who resells mattresses from defunct companies (or so he claimed). There’s no label, of course, and a very soft quilted bamboo cover (doesn’t feel “organic” or wool filled, but not sure) and there was a synthetic egg crate layer on top that I removed. The base latex layer is 6 inches and was too firm alone, so I added 2 inches of N5 latex which I think has a 18 ILD rating.
Can anyone please advise me on how I can figure out what ILD the base layer is? It’s not stamped, I looked. And there’s no manufacturer or brand name tags on the mattress. Is there a “field test” to determine ILD I can do at home? If I can figure out his base layer ILD, I can get a similar base/core for my mattress, since I have the same top 2 inches of N5/18 ILD. (my current mattress has a 6 inch core of N8/39 ILD; in retrospect, way too firm)
Thanks all!
I’m sorry to hear that your mattress is no longer working well for you.
While it’s not possible to “diagnose” mattress comfort issues on a forum with any certainty because they can be very complex and there are too many unique unknowns, variables, and complexities involved that can affect how each person sleeps on a mattress in terms of “comfort”, firmness, and PPP (Posture and alignment, Pressure relief, and your own 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.
Your neck and finger issues could also be a pillow issue rather than a mattress issue and changing the thickness, shape, or firmness of your pillow could also make a difference.
If the only issue with a mattress is that it is too firm and there are no soft spots or sagging in the mattress then a good quality topper can be an effective way to add some additional softness, “comfort” and pressure relief to your sleeping system (and would be less costly than replacing the support core) but the only way to know for certain whether a specific mattress/topper combination is a good “match” for you in terms of comfort, firmness, and PPP is based on your own careful testing or personal experience on the combination. If you can’t test the combination in person then there will always be always some risk and uncertainty involved in adding a topper because the specifics of the mattress itself along with your own body type, sleeping position, and preferences can affect which specific topper would be a suitable choice on any specific mattress.
There is more information about choosing a topper and a link to the better online sources I’m aware of in post #2 here and the topper guidelines it links to which along with a conversation with a reliable and knowledgeable supplier (that can provide you with good information about how their toppers compare to each other or to other toppers they are familiar with that are available on the market) can help you use your sleeping experience as a reference point and guideline to help you choose the type, thickness, and firmness for a topper that has the least possible risk and the best chance for success. A good exchange/return policy can also reduce the risk of an online topper purchase so I would make sure you are comfortable with the options you have available after a purchase just in case the topper you choose doesn’t turn out as well as you hoped for.
Every layer and component in a mattress (including the cover) will have an effect on the feel and performance of every other layer and component above and below it and ILD is only one of several variables or “specs” that will determine how soft or firm an individual layer or a mattress “as a whole” will feel to different people (see post #4 here). In addition to this the ILD of different materials or different types and blends of latex also aren’t always directly comparable to each other (see post #6 here) so using the ILD of a particular layer or combination of layers as a reliable indication of how any mattress will “feel” or how firm will feel to you compared to another mattress with a different combination of layers can sometimes be more misleading than helpful.
In order to “duplicate” a mattress you would need to use the same type and blend of latex layers with the same thickness and the same firmness and a functionally similar cover but unfortunately there is no way to test the specific ILD/IFD of a foam material at home because it requires specialized testing equipment.
Phoenix