What is a pocket spring mattress?

How is a pocket spring mattress constructed?
A pocket spring mattress always consists of a core of metal springs. These springs are individually wrapped in a fabric bag, hence the name "pocket spring." On top of the springs, there's usually a pressure distributor and a top layer. These determine the sleeping comfort and transfer the support of the springs to the body. The pocket springs are usually held in place by a cold foam edge. However, some mattresses have a different support base for the pocket springs, such as a border of small pocket springs or a thin metal frame around the core. This has the advantage that the mattress can be slept on along its entire length, unlike a cold foam edge, which doesn't support the sides of the core. Finally, there's a cover around the mattress. This mattress cover is also called a ticking. A good pocket spring mattress has a stretchy cover with a high percentage of cotton and some polyester for elasticity, filled with natural materials like wool and wild silk.

What is a good pocket spring mattress?
A good pocket spring mattress provides optimal back support. This means your spine can maintain its natural curvature whether you're sleeping on your side or on your back. It's also important that a pocket mattress provides a pleasant sleeping environment through proper ventilation. This is primarily influenced by the top layer and the cover.

The following points are important to know whether a spring mattress is good:

• Number of springs. Pocket mattresses come with 150, 200, 250, 300, and 500 springs/m². The more springs, the more easily your body weight is distributed across the entire mattress. This reduces pressure, which most people find very comfortable. You'll also disturb your partner less if you move in your sleep. The higher number of springs absorbs movement better. Besides the number of springs, the mattress's construction can also vary. The springs can be arranged in rows or nested like a honeycomb. The arrangement doesn't really matter, as long as your body receives the proper support.
• Spring quality. The firmness of the springs is determined by the number of coils and the thickness of the metal wire within the spring. These significantly impact the mattress's lifespan. It's also important that the pocket spring is hardened by heating the metal coil (thermohardening) and/or passing electricity through it (electrohardening). This allows the spring to retain its elasticity and shape longer. By varying the firmness of the springs, you can create zones. The firmness of the mattress and the number of zones are best chosen based on the user's body type.
• Quality of the top layers. Directly on top of the springs lies a pressure-distributing layer, usually made of jute or felt. On top of that is a comfort layer, and around that is the mattress cover. A good pocket spring mattress has a natural and flexible comfort layer on top of the spring core; we prefer natural latex. This is comfortable and effectively distributes the support of the pocket springs. Due to its antibacterial and antifungal properties, latex is also better for sleep hygiene. However, synthetic top layers such as cold foam or memory foam are also often used. These often make the mattress firmer and less ventilated. In addition, these foams don't distribute the support of the springs as effectively because they are less elastic than natural latex. This negatively impacts the spinal position. The advantage is that it often makes the mattress more affordable. Another option is a hybrid comfort layer, which combines different materials.
• Quality of the cover. Even the cover, also called the mattress ticking, significantly influences the quality of a pocket spring mattress. A tight synthetic cover often makes the mattress too firm and provides insufficient ventilation, causing you to sweat more easily. A cover with a combination of natural materials is often best. This applies to both the top of the cover and the interior. We prefer a cover with a high percentage of cotton, blended with polyester for elasticity, and filled with wool. For even more ventilation, the wool can be blended with wild silk, which reduces heat retention.
• Reversibility. A mattress will last longer if it's turned regularly, at least once every three months, for example, at the change of seasons. A reversible mattress requires two things: a comfort layer that isn't too thick (maximum four cm) and symmetrical zoning. For more comfort, you can still choose a thicker top layer, but in that case, it's best to choose one that can be turned.

Zones in a pocket spring mattress
As described above, a pocket spring mattress ideally consists of springs with varying wire thicknesses so that the mattress has multiple zones. The number of coils determines the spring's height and how much resistance it provides. On average, the number of coils is between 7 and 9. With the same number of coils, the wire thickness determines the firmness. The thicker the wire, the firmer the spring feels. At Sit & Sleep, we offer 3-zone and 7-zone mattresses. We also have a personal pocket mattress where you can choose the number of zones based on your body type. The zones determine the support for your body. A 3-zone mattress has the same firmness at the pelvis and waist, making it often more suitable for an average male body with a narrow pelvis. A 7-zone mattress has a separate pelvic zone with softer springs and is better for an average female body with a narrower waist compared to the pelvis.

The cover layers of a pocket mattress
The core of a pocket spring mattress is finished with a comfort layer. Lying directly on the spring doesn't feel very comfortable. Various materials can be used for this comfort layer. Natural materials like natural latex or talalay latex are best. These are highly breathable and feel soft. Even within the natural top layers, you can vary the number of zones and the patterns or profiles in the top layer itself. The more textured a latex layer is, the softer it feels. Synthetic top layers negatively impact ventilation and also feel slightly harder. A PU layer, which stands for polyurethane, is often used. This is one of the cheapest materials, but it is very stiff and not very breathable. A variant is cold foam; this foam is made from the same raw material as PU foam, but has an open-cell structure for better ventilation. However, it is still a synthetic and not very elastic material, making it feel slightly harder than natural latex. Hybrid top layers are also used these days. This is a combination of natural and synthetic latex. The thickness of the top layer can also make a significant difference in sleeping comfort. With a top layer of, for example, 7cm, the springs carry less weight and can therefore last longer. However, it remains important that the top layer allows the springs to do their job to ensure proper support. A top layer that is too thick and hard will work against the springs, making it harder for your back to lie comfortably.

The bed base for a pocket spring
A pocket spring mattress works best on a smooth surface. This can be a coil spring base, a box spring, or a simple slatted base with a pressure-distributing mat. A coil spring base is the most suitable. It's easier to clean. People with allergies will have less trouble with dust or dust mites. With a simple slatted base, the mattress may feel slightly firmer because wooden slats are harder than metal springs.

Lifespan of a pocket spring mattress
Pocket spring mattresses typically last 8 to 10 years. If a pocket spring mattress is symmetrically made, you can rotate it in all four directions. Doing this every season can extend the mattress's lifespan. Some mattresses have a thicker top layer (from 7 cm thick) which puts less strain on the springs. With these mattresses, simply rotating the top layer is often sufficient. The springs in this mattress can often last longer than ten years, meaning the topper often needs replacing.

The hygiene of a pocket mattress
A mattress's sleep hygiene depends on its ventilation and absorption capabilities, and possibly the washability of the cover. The better the mattress ventilates, the better. Due to the open cell structure inside a pocket mattress, the ventilation capacity of these mattresses is generally already relatively high, but the effect of the finishing on top of the springs on sleep hygiene should not be underestimated. Generally, natural materials like wool and/or wild silk are better than synthetic materials, as they absorb more moisture and also release it back into the air. Cotton is also a natural material, but releases moisture less quickly than wool. Therefore, it's best to look for a pocket spring mattress with natural materials in the cover. Since wool is self-cleaning, most covers do not need to be washed, and it's even unwise to wash them. If it does get dirty, have it professionally cleaned by a dry cleaner. If you would like a washable cover, you can choose an anti-allergy cover, which is machine washable.

The disadvantages of a pocket spring mattress

• A pocket mattress that can only be slept on on both sides will not last as long as a mattress that is completely symmetrical (the top and bottom are the same, and the head and foot end are the same).
• The mattress's finish can also be a drawback. A synthetic finish often feels firmer, providing less shoulder room and less ventilation.
• With most pocket mattresses, it's not possible to adjust the spring support. This makes finding a good sleep solution for pain or discomfort after purchase more difficult. A personal pocket mattress can offer a solution. This type of pocket spring can be custom-made, and if necessary, the springs can easily be replaced later.
  
• A pocket spring mattress is often combined with a box spring. However, a box spring isn't ideal for people with dust mite allergies. There's much less ventilation, which makes the box spring a favorite habitat for dust mites.
• Pocket spring mattresses are often made too firm, and there are so many differences in finish and number of zones that it's often hard to see the forest for the trees.
• Another disadvantage can be that it's harder to sleep in the middle of the bed. Usually, two different mattresses are needed for two different body types. This creates a gap between the two mattresses in the middle, resulting in less support. There are mattresses with continuous springs or in which you can combine two different cores without much loss of support in the middle.

Why choose a pocket spring mattress?
A pocket spring mattress is often chosen if you already have a frame and/or base that you'd like to keep. If the base offers little to no support, a pocket spring mattress is the best and only option. Moreover, the right pocket spring mattress can be a valuable addition for people who get warm easily at night and sweat a lot. They ventilate very well. However, make sure the cover is finished with wool or Tencel, and the top layer is also a natural material. For optimal ventilation, it's best to choose a coil spring base.

Why not pocket springs?
A pocket mattress is often a fixed feature. That's why it's harder to guarantee after-sales service. At Sit & Sleep, we call this the "good-sleep guarantee." Most pocket spring mattresses are completely glued in place, making it impossible to adjust anything. People with severe back or pain issues are best off switching to an alternative sleep system where the settings can be adjusted afterward. Pocket spring mattresses are evolving, however. These days, some pocket springs offer the option of making adjustments afterward.

Another reason not to choose a pocket bed has to do with the surface. If you have a very flexible slatted base with large gaps between the slats, a pocket bed won't be able to provide sufficient support for your back. The springs won't get enough support from the flexible slats, or they'll fall between the slats.