Hi buttercupbetty,
There are some factors involved with this that you may want to take into account. If you buy a mattress with very thin comfort layers then it will almost certainly include polyfoam in the mattress which may or may not be an issue for some people. Almost all mattresses like this will have more than “around an inch or so” in the comfort and quilting layers combined which means that you would need to make sure that the polyfoam density was high enough to prevent softening and impression issues in the mattress. Wool won’t soften over time although it does “nest” which is a normal part of how it performs as opposed to polyfoam where softening and impressions can be a sign of the material breaking down.
Tufting can also play a role and as you mentioned tufting a mattress can not only change how it feels and performs significantly but it will also help the mattress materials maintain their loft vs a mattress where the layers are quilted or just layered without pre-compressing the materials. A separate topper wouldn’t act in the same way.
A two sided mattress with wool comfort layers will also help the wool to compress and settle more evenly but of course a wool topper also has more flexible options vs a mattress that has wool in the cover which doesn’t have the ability to put it out in the sun to refresh it as easily and take advantage of the self cleansing nature of wool or to clean it or even replace it without having to replace the entire mattress.
Having said that … one of our members here does sell a “basic” innerspring mattress that also uses a 460 coil innerspring with GOTS certified organic cotton and wool and has no polyfoam or latex at a very reasonable price that may be a good “candidate” for a wool topper (it would be quite firm by itself) and they may be well worth talking to.
They are right about this (not surprisingly). A Lura Flex is an open ended offset design that has helical coils that connect each spring together so each coil is linked to the ones beside it so there are more coils that share the load. A pocket spring doesn’t have helicals that join the coils together (the fabfic pockets are connected together in the middle) so they are more “point elastic” or contouring. A pocket coil generally needs thinner comfort layers because they provide some of the contouring and pressure relief while an offset coil may need thicker comfort layers to provide similar pressure relief and contouring. In most cases the support of an innerspring with helicals is more even and they are often good options for heavier people or those with more weight under the hips because they are stronger and more “resistive” to help prevent the heavier parts of the body from sinking in as far. Pocket coils … particularly with thinner comfort layers or in lower gauges … will compress more individually so each coil will have more wear.
In spite of the differences between the different types and the fact that a pocket coil would be less durable “in theory” in an apples to apples comparison but not always in practice … an innerspring is not usually the weak link of a mattress with some exceptions depending on the gauge, type, design and number of coils, the layers above the coils, and the total amount of steel in each innerspring which affects how much the coils are compressed on a regular basis.
If you are confident in your experiences with wool toppers and aren’t too much towards the “princess and the pea” end of the range then this would reduce the risk of an online purchase … especially if you have tested a fairly similar combination in person.
Phoenix