Firmness
Firm
Type
Open Coil Spring
Depth (cm)
Number of Layers
2
Trial Period (nights)
60
Warranty (years)
Price Range
£1,129 to £1,815
Best Sleeping Position(s)
Certifications
Assessed from the specification published by Mattress Man, captured September 2026, and from regular price comparison across our UK retail partners.
Choose the Serenity if you want a traditional firm mattress from an established name. The AlignSupport® open-coil spring system, which is exclusive to Sealy, provides the core support, which means a stable, evenly sprung feel rather than the contouring hug of an all-foam bed. The foam layers above soften the surface without undermining that firmness. From £1,129.65 it sits at the pricier end for an open-coil design, but you are paying for Sealy's engineering and a build intended to hold its shape. If you sleep on your back or front and like a bed that pushes back, this is a sensible shortlist candidate.
Key Features & what's inside
- Foam layers. Foam comfort layers sit above the springs, which means a slightly cushioned surface feel over the firm support beneath. They complement rather than mask the spring system below.
- AlignSupport® spring system. An open-coil spring system exclusive to Sealy that forms the mattress's supportive core. Open coils give a springy, connected feel across the whole surface, keeping you supported rather than cradled.
Layer details from mattressman.co.uk product page, September 2026.
Who's it NOT for?
This is a firm mattress, so lightweight side sleepers may find it too hard on the shoulders and hips. If you prefer a plush, enveloping feel, or you want the motion isolation of pocket springs or memory foam, an open-coil design like this is unlikely to suit you.
Sealy Serenity Mattress
How firm is the Sealy Serenity mattress?
It is rated firm. That means a supportive surface with minimal sink, which tends to suit back and front sleepers, or anyone who finds softer mattresses leave them feeling stuck. Lighter side sleepers may want something with more give.
What is the Sealy Serenity mattress made of?
It combines foam comfort layers with Sealy's AlignSupport® spring system, an open-coil design exclusive to the brand. The springs provide the firm support while the foam adds a little surface comfort.
Does the Sealy Serenity come with a sleep trial?
Mattressman lists a 60-night trial with this mattress. That is the retailer's own offer rather than a Sealy guarantee, so check the terms if you plan to buy elsewhere.
What sizes does the Sealy Serenity come in?
It is available in UK Single, Double, King and Super King, with prices ranging from £1,129 to £1,815 depending on the size you choose.
How quickly can the Sealy Serenity be delivered?
Mattressman offers free next day delivery on this mattress, with a handling time of 0 to 1 day and transit of 1 to 3 days. These are the retailer's delivery terms, so timings may differ if you buy from another shop.
Couldn't find an answer to your question? Send us a message