I recently purchased a Serta iComfort Insight. I chose this firmer model knowing that it had the potential to soften over time and taking your wisdom that it’s always easier to make a bed softer than the other way around.
I am 5’2", 130 pounds and strictly a side sleeper.
I slept on it the first night without any added topper and while it wasn’t the firmest bed I’d ever slept on, the next morning I added a 2" memory foam topper that I had used with a previous bed. (I’m sure it is a low quality foam) My comfort level improved greatly, although I could probably go a bit softer with this added comfort layer. Oh, I forgot to mention it’s a twin topper on a queen bed! So, my need to upgrade the topper is obvious
I want to get a latex topper. Locally, Jamestown Mattress Co. sells a 3" (I assume Talalay) with a cover. Unfortunately, they don’t have one in their showroom to lay on and even if they did it would feel different on one of their mattresses. I once slept on too many memory foam toppers at once and developed terrible hip pain that took months to resolve. I’m concerned about going overboard when adding my comfort layer on top of Serta’s comfort layer.
Online I see 2" or 3" latex toppers in Talalay, 100% Natural Talalay, Blended Latex - Talalay Process, and 100% Natural Latex-Dunlop Process. I believe I need the Soft 22-24 ILD, but wonder the difference between all of these?
Toppers aren’t returnable and I’d welcome any insight (pun intended) you may be able to share with me.
I would suggest the thinnest topper that you believe you can get away with (depending on how much you need to change the softness of the mattress). The reason for this is that the iComfort insight already has 2.75" of soft gel memory foam on top (the firmness comes from “going through” this to the polyfoam underneath) and if you add a soft topper that is too thick … then you may be too far away from the support layers and the soft memory foam would become part of your deeper support layers instead of the comfort layers of the mattress and you could risk misalignment of both the spine and hips (as you mentioned). I wouldn’t go any thicker than 2" because of this. If the memory foam topper you used was soft and very low density or had softened considerably … it would likely also allow you to “go through it” so the firmness of the deeper layers would come through more than if your topper was a more resilient or slightly firmer material which could actually feel softer for you (isolate you more from the firmness of the support layers).
You are also light which usually indicates a preference for softer foam … in this case perhaps in the lower end of the “typical comfort range” of 19 - 24 ILD and some may prefer even lower depending on the amount of changes needed in the mattress, their sensitivity, and what they are used to.
I believe that the Jamestown toppers are 14 ILD talalay latex (they would tell you) which would be a lot of soft thick material on a mattress that already has almost 3" of softer materials in it. While latex is more forgiving of thicker softer layers or “mistakes” because it has a higher resilience and compression modulus (gets firmer faster and is more supportive) … this would still be quite risky IMO. The firmness level would be closer to a “typical” memory foam so it may also work well in terms of softness but I would tend to use a thinner layer.
This article will explain more about the different types of latex. The most popular choice for a comfort layer for those who prefer softer versions of latex would probably be blended Talalay which is generally softer than the same ILD of Dunlop (it doesn’t get as firm as quickly) and is less expensive, more durable, and more pressure relieving than 100% natural Talalay in softer ILD’s.
While there are probably dozens of companies that offer blended Talalay latex toppers … some of the best value sources are listed in post #4 here.
Bear in mind too that Dunlop and Talalay are quite different in their performance and feel and that there are many Dunlop toppers that are “listed” as having a softness level that may not be accurate. There is more about this in post #4 and #6 here. If a topper is Talalay … it will usually say so. if it doesn’t specifically say this … it is quite likely Dunlop.
IFD means “Indentation Force Deflection” and for practical purposes means the same as the older term that is still more commonly used which is ILD or “Indentation Load Deflection”. The difference between the two testing protocols (the older ILD and the newer IFD) are very small and have to do with using a 1 lb pre-compression as a base line and a longer delay time between initial compression and the time when the compression force is measured.
Layer thickness and the layers that are both above and below any other layer will also make a big difference in how a topper feels and performs. Local mattress manufacturers (such as Jamestown) and local foam suppliers are other sources that may often sell toppers in various materials including latex. Jamestown’s Talalay toppers are in the lower end of the firmness scale (in the range of 14 - 15 ILD blended Talalay) as far as I know.
Sleep Like a Bear has the widest range of talalay latex available both in terms of material, thickness, and ILD (they carry every type and ILD that is made by Latex International) but as you mentioned they are more expensive than other sources that may not have the same range of choices.
Out of the sources you listed … I would definitely avoid using Foam by Mail (FBM) who IMO are not a reliable supplier. There is more about this in post #2 here along with post #2 here (as well as many other places around the forum).