Wentworth Mercer Deluxe Wool 4000 Pocket Super King Mattress
The Wentworth Mercer Deluxe Wool 4000 Pocket Mattress is a firm pocket spring mattress with wool and soft synthetic fillings beneath a viscose cover.
- Suits back & front sleepers
- Wool helps regulate temperature
- Minimises partner disturbance
£1,199
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Wentworth Mercer Deluxe Wool 4000 Pocket Mattress
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Mattress details
Mattress
Wentworth Mercer Deluxe Wool 4000 Pocket Mattress
Size
Firmness
Medium Firm
Construction
Pocket Spring
Wool
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.
Key benefits
- Real distance from a restless partner: With 90cm each and independent pocket springs, a partner who tosses and turns is further away and their movement travels less, which means fewer 3am wake-ups for you.
- Room for small visitors: At 6ft x 6ft 6in, the surface can take a child who wanders in at night without anyone ending up clinging to the edge.
- Wool helps with a full bed: More bodies mean more heat, and the wool layer above the springs helps regulate temperature, so a crowded super king should feel a little less stuffy.
- Proportioned for a large bedroom: In a generous master or a high-ceilinged period room, a UK super king fills the space properly where a UK king can look slightly lost.
- More width, same length as a UK king: The UK super king is 30cm wider than the UK king but the same length, giving each sleeper 15cm more without taking extra floor at the foot.
This size suits you if...
You share the bed with someone who fidgets, snores or keeps different hours and you want genuine distance, or children and a large dog regularly join you overnight, and your bedroom comfortably clears our suggested minimum of 3m x 2.9m.
Consider another size if...
Your bedroom is smaller than 3m x 2.9m, or door swing and walking space are already tight. We'd recommend the UK king instead, which needs at least 2.7m x 2.9m.
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FAQ's
Is the Deluxe Wool 4000 UK super king worth it over the UK king?
If space between you matters, yes. The UK super king is 30cm wider than the UK king and the same length, so each of you gains 15cm. The trade-off is floor space: we suggest at least 3m x 2.9m for the UK super king, against 2.7m x 2.9m for the UK king.
Will a UK super king Deluxe Wool 4000 stop my restless partner waking me?
It should help considerably. You each get 90cm, and the 4,000 pocket springs move independently, so a partner turning over disturbs a smaller area of the bed. Distance does most of the work at this size. It won't silence snoring, but it gives light sleepers the best chance this mattress offers.
Is a UK super king big enough for two adults and a child or dog?
For occasional or regular visitors, usually yes. At 180 x 200cm (6ft x 6ft 6in), there is room for a small child or a dog between two adults without anyone losing their side entirely. A large dog that sprawls every night will still take a noticeable share, so expect some compromise.
How much more room each do we get in a UK super king than a UK double?
Quite a lot. A UK double gives 67.5cm each for two sharing, while the UK super king gives 90cm each, which is 22.5cm more per person. The UK super king is also 10cm longer, helpful if either of you is tall.
Will a UK super king fit in a loft conversion bedroom?
Check the full floor area first: we suggest at least 3m x 2.9m. In a loft conversion the sloping ceiling usually decides which wall the headboard goes against, so measure the usable floor with full headroom rather than the total footprint. Allow for landing turns and door swing too, since the mattress has to reach the room.