What is an open coil mattress?

Open coil springs are commonly used in low to mid-end mattresses because they are durable and can be mass-produced cost-effectively. Coil springs are shaped like an hourglass, narrower in the middle and wider at the top and bottom. The design allows the springs to easily compress under pressure while providing enough resistance to remain supportive.

Each spring is made from a single steel wire twisted into an hourglass shape. The springs are then arranged in rows and connected with thinner helical wires to form the spring unit.

Also known as Bonnell springs, coil springs typically feel firmer and bouncier than other mattresses.

What are the pros and cons of an open coil mattress?

Coil springs are popular because they are affordable, relatively durable, and provide a firmer sleeping surface. However, they also have some drawbacks. Knowing the pros and cons of an open coil mattress will help you decide if it’s right for you.

Pros

Support

Coil springs are designed to be supportive. Their hourglass shape allows the springs to compress under pressure whilst remaining responsive. Since coil springs are interconnected, they distribute weight evenly, ensuring consistent support across the sleeping surface.  

Open coil mattresses offer different levels of support, depending on factors such as spring count, wire thickness, construction quality, and the shape and height of the springs.

Open coil mattresses usually contain between 300 and 800 springs. Typically, the more springs there are in the mattress, the more supportive it should be. However, some manufacturers use mini springs to achieve a higher spring count, but that doesn’t necessarily mean they will provide more support.

The wire thickness (gauge) can be adjusted to provide different firmness levels, allowing sleepers to choose a mattress that suits their weight and comfort preferences. Generally, the heavier you are, the firmer the mattress you need. Therefore, choosing the correct mattress firmness should ensure the spine is aligned and supported.

Affordable

Open coil mattresses are inexpensive to manufacture because they can be mass-produced primarily by machines. Most of the process is automated, making it more cost-effective than other mattresses.

This makes open coil mattresses a good option for those on a budget. They are suitable for children or teenagers and can work well as occasional mattresses in guest bedrooms.

Changing sleeping positions

Open coil mattresses typically feel firmer and bouncier than other mattresses, making it easier to turn over in bed. The springs provide some pushback and resistance, preventing you from feeling ‘stuck’ in the mattress, a common issue with softer mattresses. The bouncier feel benefits heavier individuals or those with mobility issues who often find it difficult to turn in bed.

Lightweight

Open coil mattresses tend to be lighter than other mattresses, making them easier to turn and manoeuvre.

Widely available

Coil springs are commonly used in mattresses and are widely available. Many are in stock and available for immediate delivery. This is ideal for those needing a mattress quickly, such as replacing a damaged or worn-out mattress or accommodating overnight guests.

Cooler sleeping surface

Open coil mattresses have an open structure that allows air to circulate more freely between the springs, which can help create a cooler sleeping surface.

Cons

Lack of contouring

A mattress should conform to the body and support the spine. A mattress that is too firm will not allow the body to sink into it, resulting in aches, pains, and painful pressure points. On the other hand, a mattress that is too soft allows the body to sink too far into it, creating an unnatural arc.

While supportive, coil springs are less effective at body-conforming than other mattress materials like memory foam and latex. Coil springs are interconnected and work as a unit rather than independently, making it difficult for them to conform and adapt to the body. When weight and pressure are applied to a specific area, the surrounding springs are also affected and compress.

Lack of pressure relief

Open coil mattresses are not as effective at relieving pressure as other mattresses. There are several reasons for this. First, the springs are interconnected and work as a unit, which means they cannot provide targeted support to specific areas of the body.

Second, coil springs tend to push back against the body, especially the heavier areas like the shoulders and hips. This can create discomfort and pressure points and may cause you to toss and turn during the night as you try to find a comfortable position.

Finally, open coil mattresses often have thinner comfort layers, which lack proper cushioning and adequate pressure relief.

Partner disturbances

Since open coil mattresses are bouncier and transfer movement across the entire sleeping surface, couples are more likely to disturb each other when they move in bed. In contrast, pocket springs, latex, and memory foam mattresses are better at isolating movement and reducing partner disturbances.

Poor edge support

Basic coil spring mattresses tend to have poor edge support. They typically have weak edges, which may sag or collapse under pressure. This can make you feel like you’re rolling out of bed if you sleep close to the edge.

Shorter lifespan

An open coil mattress typically lasts between 6 and 8 years. Its lifespan can vary depending on usage, construction quality, care and maintenance. While coil springs are generally durable, they do have some limitations.

Open coil mattresses are predominantly made by machines and are often constructed to meet a specific price. The construction quality is not as good as that of hand-made mattresses or those containing latex or high-quality foam.

Open coil mattresses typically have thinner comfort layers made from synthetic materials such as foam, polyester and fibre pads, which wear out sooner than other materials.

Another issue with coil springs is that they are interconnected. If a spring breaks it impacts the entire unit, affecting the overall support.

Limited options

Although open coil mattresses are widely available, they usually have limited options and cannot be tailored to suit your needs or preferences. They often come in a standard firmness and may not be suitable for couples with different weights or comfort preferences, resulting in one partner having to compromise. Furthermore, open coil mattresses are generally only available in standard sizes and come with standard covers or ticking, with no option to choose an alternative design.

In contrast, higher-quality mattresses offer more flexibility, including options for custom mattress sizes, firmness levels, and covers, allowing you to tailor them to your specific requirements.

What are the alternatives to coil springs?

Several other options are available if you’re unsure whether a coil spring mattress is suitable.

Pocket springs

Pocket springs are a good alternative for those who prefer a traditional sprung mattress. Unlike coil springs, which are interconnected, pocket springs are encased in fabric and work independently. This allows the mattress to better conform to body shape and distribute weight evenly. Pocket springs also absorb movement. When one spring compresses under pressure, the others are unaffected. As a result, sleeping partners are less likely to disturb one another in bed.

For more information, see our detailed comparison between coil springs and pocket springs.

Memory foam

Memory foam is a popular mattress material that closely conforms to the body. It can feel quite firm initially but softens with body heat. Memory foam offers excellent pressure relief from sensitive areas like the shoulders and hips. It can also help alleviate aches and pains and improve circulation. Memory foam absorbs movement, so sleeping partners are less likely to disturb one another when they move.

Latex

Latex conforms to the body and has a slightly bouncier feel. Like memory foam, it offers excellent pressure relief. However, while memory foam recovers slowly, latex responds immediately, making it easier to turn over in bed.

Natural latex is exceptionally durable and often outlasts other mattress materials, but it is typically more expensive than coil springs. Latex has a pin-hole structure allowing better airflow and can feel cooler than other materials.

Hybrid

A hybrid mattress combines the pressure-relieving benefits of foam with the responsiveness of springs. It offers the best of both worlds for those who are undecided about whether to buy a sprung or foam mattress.

The top comfort layer is typically made of memory foam or latex. Some mattresses have tiny coils on top for extra comfort. The support layer usually consists of an open coil or pocket spring unit.

Final thoughts

A well-constructed open coil mattress can be a good option for those looking for a mattress on a budget. However, it is important to compare different options carefully, as quality can vary. While open coil mattresses are affordable and lightweight, they may not feel as comfortable as pocket springs, latex, and memory foam mattresses.