Sealy Advantage Quartz Memory Mattress
The Sealy Advantage Quartz Memory Mattress combines a MemorySense foam layer with PostureTech CS springs, which means you get that slow, cradling memory foam feel on top with proper spring support underneath rather than an all-foam base.
- Memory foam eases pressure points
- Stable edges, no roll-off feeling
- Twice-tempered springs hold their shape
£429
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Sealy rates the Advantage Quartz Memory Mattress Medium Firm, a balance that suits most sleepers, although those who like a very soft, sink-in surface may find it a little too supportive. It's 27cm deep and sits at the accessible end of the market for a hybrid of this kind. Sealy is an NBF-Approved Manufacturer and the mattress is made in the UK, which offers some reassurance about what's actually inside it.
Mattress specifications
Firmness
Medium Firm
Type
Memory Foam
Depth (cm)
27
Number of Layers
4
Trial Period (nights)
Warranty (years)
5
Price Range
£429 to £749
Best Sleeping Position(s)
Back Sleeping
Stomach Sleeping
Combination Sleeping
Certifications
Assessed from the specification published by MattressNextDay, captured September 2026, and from regular price comparison across our UK retail partners.
Why should you choose this mattress?
If you like the pressure-relieving hug of memory foam but worry about sleeping hot or feeling stuck, the spring core here helps, allowing more airflow and bounce than a solid foam slab. The PostureTech springs are twice tempered, which means the steel is heat-treated twice so the springs keep their shape and support for longer. EdgeGuard reinforcement around the springs also firms up the sides, so you can sit or sleep near the edge without that roll-off feeling. Available in five UK sizes from Single to Super King, it's a sensible choice for a family home where different rooms need different sizes.
Key features & layer details
Quilted Cover
The cover is stitched together with the fillings to create a patterned comfort quilt, which means the surface has a soft, cushioned feel built in rather than a flat top. It's the first thing you'll notice when you lie down.
MemorySense Foam
This memory foam layer adapts to your body position, cocooning you and easing pressure at the shoulders and hips. In practice, that means less tossing and turning to get comfortable.
PostureTech CS Springs
These springs respond to your body weight to give deep-down support, so heavier areas get more pushback than lighter ones. They're twice tempered, meaning the steel is heat-treated twice to stay resilient over years of use.
EdgeGuard
A high-density foam strip reinforces the springs around the perimeter, extending their lifespan. You'll feel this as a firmer, more supportive edge, useful if you sit on the bed or share it and need the full width.
Layer details from mattressnextday.co.uk product page, September 2026.
Best suited for?
Side sleepers
The MemorySense foam layer adapts to your body and eases pressure at the shoulders and hips, which suits the curves of side sleeping.
Couples
EdgeGuard reinforcement firms up the sides of the mattress, which means you can both use the full width without feeling a roll-off at the edge.
Combination sleepers
The spring core gives more bounce than a solid foam slab, which makes it easier to change position without feeling stuck in the surface.
Back sleepers
A Medium Firm rating and PostureTech springs that respond to your body weight give deep-down support, so heavier areas get more pushback than lighter ones.
Guest rooms
Five UK sizes from Single to Super King mean you can match it to whichever room needs a bed, and the medium firm feel suits most people.
If you prefer a plush, sink-right-in surface, the Medium Firm rating here may feel a touch too solid. Committed hot sleepers should also think carefully: the springs help with airflow, but memory foam does hold more warmth than latex or open coil designs. And if you want a lengthy home trial, none is mentioned on this listing.
Save on an earlier or ex-display model
Some retailers still sell the earlier version of this mattress, or ex-display and returned stock at a lower price. These are the sizes where it costs less than the current model's best price.
Sealy Advantage Quartz Memory Mattress
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FAQ's
How firm is the Sealy Advantage Quartz Memory Mattress?
It's rated Medium Firm. That means a supportive feel with a softer, quilted memory foam surface on top, a balance that suits most back and side sleepers, although lightweight side sleepers may find it slightly firm.
Does the Sealy Advantage Quartz come with a guarantee?
The MattressNextDay listing states a 5-year guarantee on this mattress. There's no trial period mentioned on that page, so check the terms with your retailer before buying if a sleep trial matters to you.
How deep is the Sealy Advantage Quartz mattress?
It's 27cm deep, which fits standard UK fitted sheets comfortably. That depth comes from the quilted cover, memory foam layer and spring unit combined.
What sizes does the Sealy Advantage Quartz come in?
Five UK sizes: Single, Small Double, Double, King and Super King.
Is the Sealy Advantage Quartz made in the UK?
Yes. It's made in the UK and Sealy is an NBF-Approved Manufacturer, which means the National Bed Federation has audited what goes into the mattress and how it's made.
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