Last seen for £699 at Mattress Man on 8th November 2026
Sealy Alston Advantage Double Mattress
The Sealy Alston Advantage comes in UK Single, Double, King and Super King.
- Soft, plush euro-top feel
- Gel layer for a cooler feel
- Twice-tempered springs for support
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
More available sizes
Last seen for £706.50 at Mattress Man on 31st October 2026
Last seen for £699 at Mattress Man on 8th November 2026
Last seen for £589 at Mattress Man on 9th October 2026
Mattress details
Mattress
Sealy Alston Advantage Mattress
Size
Firmness
Medium Soft
Construction
Open Coil Spring
Depth (cm)
Layers
3
Layer Details
Plush pillowtop (euro top)
A generous euro top gives the Alston a very soft, plush surface. If you like to sink into a cushioned feel, you'll notice it straight away.
Geltex comfort layer
A gel-infused comfort layer that is designed to relieve pressure in the areas of your body that need it most. That means softer cushioning where you press into the bed, with a cooler feel than you'd expect from a plush top.
PostureTech spring system
Sealy's own PostureTech springs, twice tempered, sit at the heart of the mattress and are designed to give lasting, deep support. Underneath the soft layers, they give your body a steady base to rest on.
Layer details from mattressman.co.uk and hafrenfurnishers.co.uk product pages, October 2026.
Key benefits
- Made for the average UK bedroom: At 135 x 190cm it sits well in most rooms; we suggest allowing at least 2.6m x 2.8m so you can still open drawers and doors.
- Room for bedside tables on both sides: In a typical double bedroom this footprint usually leaves space for a table each side, something a UK king often rules out.
- A workable width for two: You get 67.5cm each for two people sharing, which is fine for settled couples, a little snug if one of you sprawls.
- Easy to dress cheaply: Double sheets and duvets are sold everywhere at every price point, useful if you're kitting out a whole home on a stretched budget.
- Simpler to get upstairs: A double is easier to manoeuvre round the turning stairs of an older terrace or a tight new build landing than the larger sizes.
This size suits you if...
You're a couple in a typical UK bedroom and want a bed you can share without it dominating the room, you're furnishing a first flat or guest room where visiting pairs need to fit alongside a wardrobe and drawers, or you sleep alone but want space to spread out, with room to spare for a dog or cat that claims a corner.
Consider another size if...
You both wake when the other turns, and 67.5cm each for two people sharing isn't enough. The Sealy Alston Advantage in a UK king gives you 15cm more width and 10cm more length; allow at least 2.7m x 2.9m for it.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
FAQ's
Is the Sealy Alston Advantage UK double big enough for a couple?
For most couples, yes. The UK double is the traditional shared size, giving 67.5cm each for two people sharing. If either of you is broad-shouldered or a restless sleeper, the UK king adds 15cm of width and 10cm of length, provided your room can take it.
What room size do I need for the Sealy Alston Advantage in a UK double?
We suggest allowing at least 2.6m x 2.8m, with around 3m x 3m the comfortable norm. That leaves room to walk round the bed and open wardrobe doors. In a typical double bedroom you should still fit bedside tables on both sides, which is one of this size's quiet advantages over a UK king.
Should I get the Sealy Alston Advantage in a double or a king?
It comes down to your room. The UK double is 15cm narrower and 10cm shorter than the UK king, so it suits rooms where a king would dominate. If you can allow at least 2.7m x 2.9m and you both like space, size up; if not, the UK double is the safer buy.
Will a UK double fit up a narrow staircase?
Usually, yes. At 135cm wide the UK double is one of the easier sizes to carry up the turning stairs of older terraces or the tight landings of new builds. Measure your narrowest pinch point before ordering, and check the mattress can flex round it, as Sealy doesn't publish handling guidance for this model.
Is the UK double a good size for a guest room?
It's the classic choice. At 4ft 6in x 6ft 3in it sleeps visiting couples properly rather than making one of them take the sofa, and double bedding is cheap and easy to find. In a smaller spare room shared with a wardrobe and drawers, just check the 2.6m x 2.8m minimum we suggest still works.