Sealy Advantage Classic Mattress
Mattress
Sealy Advantage Classic Mattress
Size
Firmness
Construction
Depth (cm)
24
Layers
4
Layer Details
- Quilted Cover. The cover and fillings are stitched together into a patterned comfort quilt, which means the soft top layer stays put rather than shifting over time. It gives that traditional, gently cushioned surface feel.
- Zoned Foam. This layer targets key areas of your body and applies support where you need it most. In practice that means firmer backing under heavier zones like your hips, with a little more give elsewhere.
- Reflex Foam. Reflex foam is a firmer, springier foam used here between the comfort layers and the springs. It adds a stable, comfortably supportive middle so you don't feel the coils directly.
- PostureTech CS Springs. These open coil springs are weight responsive, getting firmer as pressure increases, which means deeper support under the parts of you that need it. Sealy describes this as deep down support that's designed to last.
Layer details from mattressnextday.co.uk product page, September 2026.
- Real stretching room for one: At 120cm wide, a solo adult can roll over, starfish and shift position freely, which a UK single simply doesn't allow.
- Fits rooms a double crowds out: The UK small double is 15cm narrower than the UK double, and in a box room or loft conversion that can be the walkway beside your bed.
- Zoned support at a modest footprint: The zoned foam and PostureTech CS springs firm up under your hips and give a little at your shoulders, the same build as the bigger sizes.
- A sensible guest room choice: A visiting couple can share it for a night or two, and the open coil movement transfer matters far less for occasional stays than nightly use.
- Easy bedding and frames: 4ft is a standard UK size, so small double fitted sheets and frames are simple to find on the high street.
This size suits you if...
You sleep alone and want space to spread out without giving your bedroom over to a double, your teenager has outgrown a single but the room can't spare more floor space, or you're furnishing a guest room or small second bedroom in a rental where couples stay occasionally rather than every night. Allow at least 2.4m x 2.8m of floor space and the room will still breathe.
Consider another size if...
You share the bed every night, because this mattress uses an open coil system and 120cm leaves a couple noticing each other's movement. We'd recommend the UK double instead; allow at least 2.6m x 2.8m for it.
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Is a small double big enough for the Sealy Advantage Classic to support two people?
For occasional nights, yes. A couple can share the UK small double comfortably enough for a guest room stay. For nightly sharing it's tight: 120cm of width combined with the open coil springs, which transfer movement more than pocket springs, means you'll feel each other. Regular couples should look at the UK double, which is 15cm wider.
What room size do I need for a small double Sealy Advantage Classic?
We suggest allowing at least 2.4m x 2.8m. That's our guidance rather than Sealy's, and it leaves enough clearance to open the door, walk round the bed and fit a wardrobe. If your room is smaller than that, the UK single may be the wiser buy; we suggest at least 2.1m x 2.8m for that size.
How much wider is the small double than the single for this mattress?
The UK small double is 30cm wider than the UK single, and the two are exactly the same length at 190cm. That extra width is the whole point of the size: it turns a bed you fit on into a bed you can actually move around in, without stepping up to a full double footprint.
Is the small double a good size for a teenager?
Often, yes. A teenager who has outgrown a single gets meaningful extra width, and the medium feel with zoned foam suits a growing sleeper. The trade-off is floor space, so measure first: if the room can't absorb a bed 120cm wide, the UK single keeps more of the floor usable and shares the same 190cm length.
Will normal double bedding fit this size?
A standard double duvet works fine, and slightly overhangs the 120cm width, which most people rather like. Fitted sheets are the exception: you need small double (4ft) sheets specifically, because double sheets will bag and single sheets won't stretch. It's a standard UK size, so they're easy to find.