Wentworth Mercer Deluxe Wool 4000 Pocket Mattress
Mattress
Wentworth Mercer Deluxe Wool 4000 Pocket Mattress
Size
Firmness
Medium Firm
Construction
Depth (cm)
29
Layers
4
Layer Details
- Cover. A viscose cover, a soft breathable fabric, finished to a high standard. It gives the sleeping surface a smooth, cosy feel.
- Wool. A plush layer of wool fibres for a luxuriously cosy feel. Wool also naturally helps with temperature regulation, so it tends to suit warmer sleepers.
- Soft White Fibres. Soft synthetic polyester fillings layered on top of the springs for extra comfort. These add a gentle cushioning between you and the firm support below.
- Pocket Springs. The core is 4,000 pocket springs, made from twice tempered steel, that adapt to your shape and movements. Each spring moves independently, which means personalised support and less motion transfer across the bed.
- .
Layer details from mattressonline.co.uk product page, September 2026.
- Leaves room for everything else: We suggest at least 2.1m x 2.8m of floor space, which means a child's room can still fit a wardrobe, a desk and somewhere to play.
- Firm support for growing teens: The firm spring unit gives a teenager heading into adult weight steady support, which usually suits them better than a soft bed they will sink into.
- Two singles for flexible guests: A pair of UK singles in a spare room lets you host two friends or siblings separately, and the wool filling helps regulate temperature for visitors who run warm.
- Fits a narrow loft footprint: At 3ft wide, the UK single can sit beneath a sloping loft ceiling where a wider mattress would push you out into the headroom.
- Suits a study that doubles as a guest room: A UK single along one wall keeps most of the floor free for a desk, so the room still works as an office most of the week.
This size suits you if...
You sleep alone and like a firm, springy feel in a compact room, or you're kitting out a teenager's bedroom, a student let or a spare room that also serves as a study.
Consider another size if...
You share the bed, or you sleep alone but sprawl across the mattress. We'd recommend the UK double instead, which gives 67.5cm each for two sharing; we suggest at least 2.6m x 2.8m for the UK double.
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Will the Wentworth Mercer Deluxe Wool 4000 UK single fit a bunk bed or cabin bed?
The width and length, 90 x 190cm, match standard UK single frames. The depth is the concern: this mattress is 29cm deep, which is thicker than many raised frames allow. Check the frame maker's maximum mattress depth first, because a deep mattress on a top bunk can reduce how much guard rail sits above the sleeper.
Is the Deluxe Wool 4000 in a UK single too firm for a child?
It can be for a young, light child. The retailer describes it as firm, and lighter bodies press into a firm surface less, so it may feel hard on the hips and shoulders for a small side sleeper. Older children and teenagers nearing adult weight are more likely to find the support comfortable.
What size bedroom do I need for a UK single Deluxe Wool 4000?
We suggest at least 2.1m x 2.8m of floor space for a UK single. That allows room to walk around the bed and open drawers, and in a child's room it leaves space for storage and a desk. For two singles side by side with a walkway between, you will need noticeably more width.
Should one adult choose the UK single or UK small double Deluxe Wool 4000?
If you sleep still and your room is small, the UK single is enough. If you turn often or like to stretch out, the UK small double is 30cm wider at the same length, and we suggest at least 2.4m x 2.8m for the UK small double. Only the width changes; the firm feel does not.
Is the single Wentworth Mercer Deluxe Wool 4000 a good choice for a guest room?
It works well if you tend to host friends, siblings or children who would rather not share a bed, since two UK singles give each guest their own mattress. If your usual guests are couples, one larger bed will suit them better. The firm feel is worth mentioning to guests who prefer softer beds.