Mattress Medic’s Guide to What’s Inside!

Finding the right mattress can transform your sleep quality, improve posture, and support long-term health. That’s why understanding mattress construction matters. Today’s mattresses use three main support systems: open coil springs, individual pocket springs, and foam. Each system offers unique benefits, from enhanced pressure relief to superior motion isolation. In addition, the comfort layer may include polyester fibres, natural fillings, memory foam, or latex foam. As a result, every mattress delivers a different level of comfort, firmness, and breathability.

This in-depth mattress buying guide helps you compare the most popular mattress types available in the UK. More importantly, it explains how materials, support systems, and build quality affect comfort, durability, and spinal alignment. Whether you are searching for a firm mattress for back support, a medium mattress for balanced comfort, or a soft mattress for extra cushioning, this guide makes your decision easier. Furthermore, you’ll discover what to look for when choosing a mattress, including temperature regulation, edge support, motion control, and long-term performance.

At Sleep United, we believe that everyone deserves better sleep. That’s why our experienced and friendly team provides honest, personalised advice to help you find the perfect mattress for your needs. If you prefer to shop locally, visit our showroom and try different mattress styles in person. We’re open seven days a week from 10am to 5pm and always happy to help you compare options, test comfort levels, and make a confident choice.

Ready to upgrade your sleep? Visit our store today, speak to our expert team, or explore our full mattress range online. Take the first step towards deeper sleep, better support, and brighter mornings.

Types of Mattress Support

Open Coil Springs

Open coil mattresses, also known as innerspring, box spring, mira-coil, or bonnell spring mattresses, use a network of interconnected metal springs to create reliable, full-surface support. Because these springs move together, open coil mattresses feel more responsive and bouncier than pocket spring alternatives. As a result, they offer a classic mattress feel that many sleepers still prefer today.

In addition, open coil mattresses often cost less than other mattress types, which makes them an excellent choice for budget-conscious shoppers. However, affordability does not mean sacrificing comfort. These mattresses provide consistent support across the sleeping surface and work well for guest rooms, children’s bedrooms, and everyday use. Furthermore, their open structure allows air to circulate more freely, helping to improve breathability and temperature regulation.

At Sleep United, our open coil mattress collection includes multiple tension options, allowing you to choose the firmness level that best suits your sleeping position and comfort preferences. You can also select from a variety of comfort fillings, including polyester and cotton blends for lightweight cushioning or memory foam layers for enhanced pressure relief and body contouring. Therefore, you can enjoy traditional spring support with modern comfort upgrades.

If you’re looking for a durable, affordable, and supportive mattress, an open coil mattress could be the perfect solution. Visit our showroom to try different firmness levels in person or speak with our expert team for personalised recommendations. We’re here to help you find the right mattress and enjoy better sleep every night.

Pocket Springs

Pocket spring mattresses use individually wrapped springs, each encased in its own fabric pouch. Because every spring moves independently, this design significantly reduces motion transfer. As a result, pocket sprung mattresses are an excellent choice for anyone who shares a bed. You can move freely during the night without disturbing your partner, which helps promote deeper, more restful sleep.

In addition, pocket springs offer one of the most versatile support systems available. Manufacturers can adjust support levels by increasing or decreasing the number of springs inside the mattress. This flexibility allows you to choose a mattress that matches your body weight, sleeping position, and comfort preferences. Therefore, pocket spring mattresses suit a wide range of sleepers, from those who prefer gentle cushioning to those who need firmer spinal support.

At Sleep United, our pocket spring mattresses are available in multiple spring counts, measured using a king size mattress as the standard reference:

• 1000 Pocket Springs – Medium support for balanced comfort and everyday use
• 1500 Pocket Springs – Firm support for enhanced stability and posture support
• 2000 Pocket Springs – Extra firm support for maximum durability and pressure control.  This is the maximum number of springs available in one layer.

However, it’s important to note that spring count refers only to the underlying support system. The overall comfort level of your mattress also depends on the type and quantity of comfort fillings used in the top layers. Materials such as memory foam, natural fibres, and advanced comfort foams play a key role in creating the final feel of the mattress.

For complete transparency, the spring count of each of our pocket sprung mattresses is clearly displayed in the product name. This makes it easier for you to compare models and choose the right level of support with confidence.

If you’re searching for a supportive, long-lasting, and partner-friendly mattress, pocket springs could be the perfect solution for you.

Foam Mattresses

Foam mattresses have grown in popularity in recent years, mainly because they are easy to transport and convenient to set up. Most foam mattresses arrive vacuum packed and rolled into a compact box, which makes delivery simpler and allows you to move them easily into bedrooms, flats, or upstairs spaces. Once unpacked, the mattress expands into its full shape, ready to provide comfortable support.

However, not all foam mattresses feel the same. There are many types of foam available on the market, and each comes with different density levels that directly affect firmness, durability, and overall comfort. Higher-density foams tend to offer better support and longer lifespan, while lower-density foams provide a softer, more cushioned feel. Therefore, choosing the right foam mattress depends on your sleeping position, body weight, and comfort preferences.

Memory foam mattresses remain one of the most popular options because they contour closely to the body and relieve pressure points. That said, traditional memory foam can retain heat, which may cause some sleepers to feel too warm during the night. If temperature regulation is important to you, it’s worth considering modern alternatives. Gel foam mattresses provide a similar body-hugging feel while improving airflow and cooling performance. In addition, latex mattresses and natural fillings offer breathable comfort with a more responsive, supportive surface.

Hybrid mattresses combine the best of both worlds by pairing a spring support system with a foam comfort layer on top. This design delivers strong underlying support alongside enhanced pressure relief. However, most hybrid mattresses feature foam on one side only, which means they cannot be flipped. Instead, they are designed to be rotated regularly to maintain even wear and long-term performance.

If you’re looking for a pressure-relieving, convenient, and modern sleep solution, foam or hybrid mattresses could be the perfect fit. Visit our showroom to compare different foam types in person or speak with our friendly expert team for personalised recommendations.

The Different Types of Foam Available

Memory Foam

Memory foam is ideal for side sleepers as it offers excellent pressure relief for your hips and shoulders.  Available in either full foam (no springs) or combined with open coil or pocket spring support systems.

Ideal For: Side Sleepers that like a little extra pressure relief

Gel Foam

Gel foam is essentially the next generation of memory foam that doesnt hold the heat as much. Like memory foam, gel is excellent for side sleepers and has added breathability for a cooler nights sleep.

Ideal For: Those that like memory foam but don’t like the heat

Latex Foam

Latex foam is a natural product derived from the sap of the rubber tree. In foam form it provides excellent support and a springy but firmer feel. Excellent durability and neutral to heat change unlike more modern memory foam mattresses.

Ideal For: Those looking for a more sustainable material and a cooler nights sleep.

“Edge to Edge” Support

Another important factor to consider when choosing your new mattress is edge support. Strong edge support improves stability, increases usable sleeping space, and makes it easier to sit or get in and out of bed. Without proper reinforcement, the sides of a mattress can weaken over time and reduce overall comfort.

Some mattresses use a basic steel rod edge system. While this option is usually available at a lower price point, it can lose shape if you regularly sit on the edge of the bed. As a result, you may experience sagging, reduced support, or the uncomfortable feeling of rolling towards the edge while sleeping.

To improve durability and performance, higher-quality mattresses use reinforced sidewall construction. Luxury models often feature hand side stitching, which strengthens the mattress border and helps maintain shape over time. In addition, many modern mattresses use foam encapsulated edges, where high-density foam surrounds the spring unit to create strong, consistent support from edge to edge.

Both reinforcement methods offer excellent stability, improve mattress lifespan, and maximise the sleeping surface. Therefore, choosing a mattress with enhanced edge support is especially beneficial for couples, taller sleepers, and anyone who likes to use the full width of the bed.

If you want a mattress that feels secure, supportive, and built to last, edge reinforcement is a feature worth prioritising.

Foam Encapsulation

Our encapsulated range of mattresses gives excellent support on the sides of the mattress using a firm foam bolster to allow edge to edge sleep. Also very useful if you have mobility issues or simply like to sit on the side of the bed regularly.  Available with gel foam, latex foam and natural wool/silk/cashmere toppings.  These types of mattress are usually single sided/no turn.

Hand Side Stitched

The traditional artisan method used in mattress making to re-inforce the sides to give edge to edge support. This method is usually only found in the most luxurious hand crafted mattresses using only high quality natural materials.  This skill has passed down through generations and is still employed today.  Hand side stitched mattresses are usually double sided so require turning regularly as part of your care routine and can be quite heavy

Use our guides below for further help in choosing the right bed and mattress to suit your needs or contact our Mattress Medics for friendly helpful advice!