Pocket Springs, Open Coils or Memory Foam: Mattress Constructions Compared

Walk into any bed shop or browse online and you will quickly meet a wall of jargon. Pocket springs, open coils, Bonnell units, memory foam, hybrids, spring counts and comfort layers all compete for your attention. It is easy to come away more confused than when you started.

The good news is that most mattresses sold in the UK fall into a handful of construction types. Once you know how each one works and what it tends to feel like, choosing between them becomes much more straightforward.

Open coil: the traditional workhorse

Open coil mattresses, sometimes called continuous coil or Bonnell spring mattresses, use a single network of springs joined together by wire. When you press down on one area, the springs around it move too, because they are all connected.

This construction has been around for a long time, and it has some real strengths. Open coil mattresses are usually the most affordable option, tend to be lighter and easier to turn, and allow plenty of air to circulate, which helps them stay cool. They are a common choice for guest rooms, children’s beds and rental properties.

The trade-off is that they offer less targeted support. Because the springs move as a unit, they do not contour as closely to your body, and you are more likely to feel a partner moving around during the night. Cheaper versions can also develop dips sooner than better-made alternatives.

Pocket springs: individual support

Pocket sprung mattresses take a different approach. Each spring sits in its own fabric pocket and moves largely independently of its neighbours. When your shoulder presses down, the springs beneath it compress, while those under your waist stay more upright to support the curve of your spine.

This tends to give more responsive, body-following support than open coil, and it reduces motion transfer, so couples often notice they disturb each other less. Pocket springs also keep the airflow benefits of a sprung mattress, which many people who run warm appreciate.

You will often see spring counts quoted, such as 1000, 1500 or 2000 springs. A higher count can mean finer, more detailed support, but it is not the only measure of quality. The gauge of the wire, the comfort layers on top and the overall build matter just as much. Pocket sprung mattresses are usually heavier and cost more than open coil, and some need regular turning.

Many well-known British brands build their ranges around their own spring systems, so it is worth reading up on how a specific manufacturer approaches it. If you are weighing up one of the bigger names, our in-depth Silentnight review is a useful example of how a mainstream brand’s spring technology and comfort layers compare across its range.

Memory foam: close contouring

Memory foam responds to heat and pressure, softening and moulding around the shape of your body. Lie down and you sink in gradually; get up and the impression slowly fades. Many people describe it as being cradled rather than lying on top of the mattress.

Its main strength is pressure relief. Because it spreads your weight over a larger area, it can ease pressure on the hips and shoulders, which is why side sleepers often like it. Memory foam also absorbs movement very well, so a restless partner is less likely to wake you. Most foam mattresses never need turning, and many arrive rolled in a box.

On the downside, traditional memory foam can trap heat, and some sleepers feel stuck or find it harder to change position. Newer foams often include cooling gels or more open structures to address this, with varying success. New foam mattresses can also have a slight smell for the first few days, which generally fades once aired.

Hybrids: a bit of both

Hybrid mattresses combine a pocket spring core with substantial foam comfort layers on top. The idea is to get the support, bounce and airflow of springs with the pressure relief of foam.

For many people, hybrids are a sensible middle ground. They feel less enveloping than pure memory foam but more cushioned than a traditional sprung mattress. They do tend to be heavy and are often priced towards the middle or upper end of the market, though there are good value options available.

Which construction suits you?

There is no single best construction, only the one that suits your body, sleeping position and budget. As a starting point:

• Open coil suits occasional use, tighter budgets and anyone who wants a light, cool mattress.
• Pocket springs suit couples, warm sleepers and people who want responsive support that adapts to their shape.
• Memory foam suits side sleepers, those with pressure point discomfort and light sleepers bothered by a partner’s movement.
• Hybrids suit people who cannot decide, or who want contouring without feeling stuck.

Firmness is a separate question from construction. You can find soft pocket sprung mattresses and firm memory foam ones. Generally, heavier people and back or front sleepers lean towards firmer options, while lighter people and side sleepers often prefer something softer. If possible, try a mattress for at least several minutes in your usual sleeping position, or choose a retailer with a reasonable home trial.

Conclusion

Open coil, pocket springs, memory foam and hybrids each have clear strengths and weaknesses. Rather than chasing the highest spring count or the newest foam, think about how you sleep, whether you share the bed and how warm you tend to get. Match the construction to those needs, choose a sensible firmness, and you are far more likely to end up with a mattress you are happy with for years.