Firmness
Medium Firm
Type
Memory Foam
Depth (cm)
30
Number of Layers
5
Trial Period (nights)
100
Warranty (years)
7
Price Range
£1,134 to £1,979
Best Sleeping Position(s)
Certifications
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
This mattress suits sleepers who want memory foam comfort without the sunken, slow-moving feel some all-foam beds have. The MemorySense ComfortCore layer targets support around the back and hips, while the twice tempered coil springs respond to your body weight to keep the spine aligned. If you sleep warm, the knitted cover uses SmarTex fibres to draw heat and moisture away, a genuine help since memory foam has a reputation for trapping warmth. Allergy sufferers get a ProShield treatment and Allergy UK approval. It's also been approved by the Good Housekeeping Institute for 2023. At £1,134 upwards it's a considered purchase, but the 7 year guarantee offers reasonable long-term reassurance.
Key Features & what's inside
- Knitted cover. A soft knitted cover treated with SmarTex fibres, which draw heat and moisture away while regulating body temperature. It also carries a ProShield treatment to fight allergens, useful if dust or dander tends to set you off.
- InfiniLux foam. A high density foam layer designed for long-lasting comfort, which means it should resist softening and sagging over time. It cushions your body while staying responsive rather than letting you sink.
- MemorySense ComfortCore. A memory foam layer that gives extra support around the curve of your back. In practice, this is where the pressure relief for your back and hips comes from.
- Reflex foam. A soft, flexible foam that supports spinal alignment. It acts as a transition between the memory foam above and the springs below, so you feel supported rather than perched.
- AlignSupport coil springs. Sealy's Posturepedic spring system senses and responds to your body weight to keep the spine aligned. The springs are twice tempered, which means they're heat-treated to hold their responsiveness for longer.
Layer details from mattressonline.co.uk product page, September 2026.
Who's it NOT for?
If you're on a tight budget, the £1,134 starting price will feel steep. Sleepers who share a bed and wake easily should note that some owners report motion transfer between partners. And if you prefer a genuinely soft, sink-in feel, this medium tension may read as firmer than you'd like; one reviewer found it too hard.
Sealy Posturepedic Elevate Ultra Arden Memory Mattress
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How firm is the Sealy Posturepedic Elevate Ultra Arden?
Sealy's own description rates it as medium, although the retailer listing says medium firm. Owner feedback suggests firmness perception varies by individual, and one reviewer found it too hard. If you're a lightweight sleeper who likes a soft surface, treat it as firmer than the label suggests.
Does the Sealy Arden mattress come with a trial period?
Mattress Online lists a 100-night trial, although their customer service replies have mentioned 60 nights, so confirm the current terms before ordering. The trial also requires you to buy a mattress protector from Mattress Online. This is the retailer's own offer, so it won't apply if you buy elsewhere.
How long is the guarantee on the Sealy Elevate Ultra Arden?
The mattress comes with a 7 year guarantee, as listed by the retailer. That covers a reasonable stretch of the mattress's working life, though as always, check the terms for what counts as a manufacturing fault versus normal wear.
Is the Sealy Arden mattress good for allergy sufferers?
It's a strong option. The mattress is Approved by Allergy UK, and the knitted cover carries a ProShield treatment that fights against allergens. That's a reassuring combination if dust mites or similar triggers disturb your sleep.
How deep is the Sealy Posturepedic Elevate Ultra Arden?
It's 30cm deep, which is on the generous side. Do check your fitted sheets before it arrives, as standard sheets can struggle with deeper mattresses.
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