mattressunderground logo

Putting the layers together - Zoned construction

 

This third method of construction uses different materials or levels of firmness in different parts or "zones" of a mattress support layer. It is also a way of combining comfort (pressure relief) and support (spinal alignment) in a single layer similar to a progressive construction. While it is often used in more "difficult" circumstances, some zoning schemes are poorly thought out in manufacturing or poorly understood by the person selling them and "suggested" when they are not appropriate. In these cases they they can do more harm than good. Some zoning schemes are also so similar in ILD or firmness between zones that they are not as effective as a higher quality material without zoning. While zoning when done correctly can be very beneficial, it is also the subject of some misinformation and deceptive sales practices which are used to sell mattresses. If you choose a zoned mattress, 2 or 3 zones are generally the most important and more than this can have questionable benefits and can sometimes lead to the purchase of an inappropriate and very uncomfortable mattress.

The reason for zoning is because of the difference in weight, thickness/thinness, and surface area of three main areas of the body that are the most difficult to accommodate. The first of these is the hip/pelvic area which carries the greatest amount of weight and has the greatest density, no matter what type of body you have, and often has a wider profile (especially in women). The second is the waist/lumbar area which is often lighter and thinner and has a lower density. The third is the  shoulder/chest area. The shoulders are narrower and have less surface area (on the side) and will sink in more easily until they reach the torso which is often wider than the hips but lighter and lower density. Dealing with these 3 areas in all the different sleeping positions and differences in body profiles and the difficulties associated with balancing them in terms of pressure relief and alignment is the reason that zoning is sometimes used in more difficult or extreme body weights or profiles. It is appropriate and can be very helpful when a progressive or differential method of construction cannot accommodate the circumstances.

Three zone mattresses with a firmer layer in the middle under the lumbar and pelvis and 2 softer zones above and below this.

This is most commonly used to help correct alignment and is the most common type of zoning you will see. It uses "normal" ILD's in a support layer with the exception of a firmer layer in the middle. It is most useful when everything is fine in terms of pressure relief and support in all areas of the body except the hips are sinking in too deeply. This is usually a body profile with thinner and relatively heavier hips. This can be very beneficial since the hip area is the heaviest of the body and if they are thinner and the support layers are soft enough to allow the wider shoulders to sink down into alignment, then the hips in turn may easily sink down too far for  correct alignment. Men in particular with wider shoulders and chests than hips may do well with this. Those with wider hips but more normal weight will likely not do well with this zoning scheme as their hips need to sink down further in proportion to the shoulder to accommodate their width and help with alignment.

This type of zoning is used to give better support to the lumbar and pelvic area.

Multi zone mattresses with a softer layer under the hips and shoulders and a firmer layer under the lumbar.

This is what we call "reverse zoning because the areas of softness and firmness have been reversed. This type of zoning is most appropriate for those who need to sink in more deeply with their hips and shoulders so that a firmer layer (or zone) underneath the recessed lumbar curve can "move up" and be in firmer contact with the lumbar area which is not getting enough support and tending to "collapse". This can either be because someone is too light and not sinking in deeply enough to their comfort layer leaving "air" or "non resilient foam" under the lumbar or because someone carries a great deal of excess weight around their middle and particularly on their back this weight is tending to collapse the lumbar and cause misalignment.  While in these two cases where other solutions do not work this zoning scheme can be beneficial, it is often sold to someone who will not benefit from it and in these cases it can cause discomfort of the lumbar area.

This type of zoning is used to give better support to the area under the lumbar curve..

Two zone mattresses with a softer upper zone from the lower ribcage upwards and a firmer lower zone from the same point down to the bottom of the mattress.

This type of zoning is perhaps the least used. Because they have a smaller surface area than the hips, the shoulders will often sink in easily until the wider chest area comes in contact with the mattress comfort layer. At this point the chest which has more surface area than the hips and is also lighter will stop sinking if the comfort layer is not soft enough to allow it to sink in. This can lead to either alignment problems if the upper body is being supported in a position that is too high and out of alignment or pressure issues if the upper body and shoulder cradle is not deep enough. This can also lead to the lumbar gap not being filled in firmly enough to support the lumbar, upper back issues if the alignment there is not correct, or neck issues if it is out of alignment from the shoulder area being too high. By using a softer layer from the lower rib cage area to the top of the mattress, these problems can be solved. This would be of particular benefit for those with larger shoulders or chests that are bigger or wider than normal in relation to the hips. This type of zoning is often used in both the comfort layer and/or a middle layer immediately below it unlike the other two which are more commonly, although not always, used in the lower layers.

This type of zoning is used for pressure relief in the upper body and to help with upper body alignment.

 

One other "zoning" option that is sometimes used in a mattress support core are firmer coils or firmer foam around the edges to prevent "roll off" and to make them firmer for those who often sit on the edge of a mattress. In the case of some coil constructions, it is also done to keep the coils together and in also in the case of some specially constructed innersprings which are made to be used on an adjustable bed and do not have a thicker wire (called a border rod) around the edges so they can bend. High quality foam support cores such as latex do not need firmer foam around the edges and it can actually be a disadvantage as the edge foam will wear out long before the latex and can lead to "collapsible" edges and sagging over time. Otherwise this type of "zoning" would be based on preference.

Because zoning can be complex and may not be necessary at all, it should be approached with caution, especially if it is possible to accomplish the pressure relief and alignment you need without it. Zoning schemes that use more than 3 zones may also be less effective in some cases because the zoning differences are sometimes less than the natural differences across the surface of the layer (especially in the case of zoned foam layers) or the zones may not "fit" the specific body type or sleeping style of the person on the mattress. In some cases they can also be a justification for higher prices than necessary. In the end ... how well a mattress provides the pressure relief and neutral alignment you need in all your sleeping positions in your "real life" experience is a more important guideline than any "theoretical" benefits of a zoned design even though a zoned design can certainly be useful in the right circumstances and in a design that "matches" the needs and preferences of the person that would be sleeping on it.

Log in to comment

gardenguy's Avatar
gardenguy replied the topic: #2 26 Feb 2018 16:01
Greetings,
I am looking to add a 2 inch zoned Dunlop topper under my 2 inches talalay and above 6 inches dunlop core. My hope is that this would allow my shoulders to sink in just a touch more and relieve some pressure, which is a problem area for me. I was hoping to get some input on where I could purchase one, and how much seperation of ILD would it take to tell a difference from hip and shoulder?

I found one sold which is advertised as 7 zone, from Lake Mattress, which is a retailer I found on the component list here. There is a 2-3 Ild difference between zones, and I can get this in 2 inch. I am not sure 3 Ild will make much difference. I would prefer just having a 3 zone at most, but aside from Flo-beds and other shredded toppers ( which don't interest me) there seems to be little to no market pushing these types of products into existence, at least in a solid slab form. I know about the 6 inch cores, but this is too thick for me, as I already have my dunlop core. Maybe I could make something from two types of soft foam, say 15 and 20, but this could get expensive, since I will need to purchase two sheets of two different ild foams and throw most of one away.

Will a 7 zone topper cause more problems than it could solve? Maybe this is impossible to answer, but any input would be appreciated.

Thanks!
Phoenix's Avatar
Phoenix replied the topic: #3 27 Feb 2018 15:48
Hi gardenguy.

Welcome to our forum! :)

I was hoping to get some input on where I could purchase one, and how much seperation of ILD would it take to tell a difference from hip and shoulder? I found one sold which is advertised as 7 zone, from Lake Mattress, which is a retailer I found on the component list here. There is a 2-3 Ild difference between zones, and I can get this in 2 inch. I am not sure 3 Ild will make much difference. I would prefer just having a 3 zone at most


I am not very sure what you mean by “separation of ILD… to tell between the hip and shoulder” because the zoned layer itself is usually not made from separate pieces of different ILDs which are laminated together. E.g. zoning in dunlop latex is achieved using different size pins to increase or decrease the amount of material in a section of the foam which in effect alters the amount of material in that particular section which will change its overall density/ILD. Depending of the pin size used, this results in a softer or firmer overall zone feel. One of the concerns with zoning is that people have different body configuration, height, weight, and profile, and a particular zoning configuration might not work for everyone because the zoning does not adjust to the size of the people. Whatever type of zoning you are considering, make sure to verify that the “zone” falls under the areas of your body that needs adjustment

Placing zoned latex as a transition layer under a top layer, can provide more sinking than a layer that has the same ILD without zoning, but as all layers work together, how much you’ll sink depends on your body specifics and also on the overall layer combination, including the encasement and the bedding being used. Adding extra layers (zoned or not) also can help with pressure relief provided that the ILD is soft enough. This may be just the “touch” you need to help with taking the “edge off” the pressure points you are experiencing in the shoulders area. FloBeds site is a good source to see configurations and zoning combinations and as they are an expert of our site you can reach out and discuss your specifics with them.

I would prefer just having a 3 zone at most, but aside from Flo-beds and other shredded toppers ( which don't interest me) there seems to be little to no market pushing these types of products into existence, at least in a solid slab form.


A 3 zone layer is usually softer on ends (shoulders and legs) and firmer in middle (under hips) and could be a good solution for someone with wider shoulders as this would allow the shoulders to sink in past the support that is needed for the lumbar curvature of the of the spine. Five zone tends to give more allowance for shoulder and hip sinkage, but keep in mind that this varies by manufacturer. The 2 zone layer could be working well for someone with a large size differential between shoulders and hips and this is the type of zoning that is usually used in the comfort/transition layers of the mattress, as opposed to the 3, and 5 zoning which is found more in the deeper layers of the mattress.

I found one sold which is advertised as 7 zone, from Lake Mattress, which is a retailer I found on the component list here. There is a 2-3 Ild difference between zones, and I can get this in 2 inch. I am not sure 3 Ild will make much difference.


I don’t keep a record of all outlets selling zone latex in 2” layers and generally speaking zoning is usually applied more to mattress cores, so you’ll have to do some more searching, but you are correct that this is not something that you would easily find as thinner zoned pieces are not as common because the zoning in a thinner piece doesn’t make “as much” of a difference as in a 6” core.

2-3 ILD difference isn’t much, but whether or not it is noticeable depends mainly of each individual and where the zone is located in relationship to the area that needs zoning accommodation, but generally the closer to the top the more potential for the “difference” to more to be noticed. I would also keep in mind that ILDs are not exact numbers but ranges and they may slightly vary throughout the layer.

Will a 7 zone topper cause more problems than it could solve?


There are many interrelated variables when it comes to zoning, which are different for each individual, such as the difference in weight, surface area, thinness/thickness of the part of the body that needs a special zoning accommodation along with the sleeping positions and the differences in body profile of any particular person all of which makes it very difficult to predict whether this zoning will work for you. 7 zone layers IMO adds a level complexity to an already complex situation and I would advise you to approach it with caution as it can do more harm than good and be costly in the process of figuring this out.

You may find it useful to peruse a few more discussions about zoning in post #11 here . Also in post #2 here and post #7 here (latex momzone unique properties).

Best of luck and I'll be interested to learn of your eventual decisions.

Phoenix
jxp10's Avatar
jxp10 replied the topic: #4 21 Jul 2018 17:03
Thank you for your insight and recommendations regarding zoning. I have not found much on this topic and appreciated what you shared. I found your various comments in several of your articles. By any chance, do you have a single article about zoning with all of your advice and wisdom systemtically organized and explained? You are the most knowledgeable zoning expert I have found so far and it would be helpful if you had a single reference to share your wealth of information and explain it to those who may benefit from zoning. Thanks for your helpful website!!
Phoenix's Avatar
Phoenix replied the topic: #5 22 Jul 2018 10:24
Hi jxp10.

Welcome to our forum! :) and thank you for your words of appreciation.

As you well noted ... while the basic information about zoning is summarized in a few articles on the main site many of the in-depth details connected with it and questions & answers can only be found in various threads on the Forum. I agree with you ... consolidating this information in one place is a consumer need that we are in the process of addressing and while we are already working on it ... this time-consuming manifold process and it may not be as fast as we would wish to.... the good news is that for those like you who are inclined to do a bit of homework most of the information is already on main site and forum and also our zoning expert FloBeds here is always ready to answer any zoning related questions :)

Phoenix