SleepSoul Space 4000 Orthopaedic CoolGel Mattress
Mattress
SleepSoul Space 4000 Orthopaedic CoolGel Mattress
Size
Firmness
Construction
Depth (cm)
38
Layers
4
Layer Details
- Pillow Top. A generous layer of plush comfort filling that moulds to your body, which means the firm mattress beneath feels a little more forgiving on shoulders and hips. It's sewn on top, so you get pressure relief without losing the supportive base.
- CoolGel™ Foam. A thick layer of CoolGel foam that prevents heat build-up within the mattress while cradling your body. If you're a hot sleeper who's been put off memory foam before, this layer is doing the cooling work.
- Mini Springs. A layer of smaller springs that contours more closely to your body shape than full-size springs can. This helps relieve tension at each point of contact rather than supporting you in broad zones.
- Pocket Springs. Individually pocketed springs with a firm feel that work independently, targeting support where your body presses down most and helping keep your spine aligned. Because each spring moves on its own, a restless partner is less likely to disturb you.
Layer details from mattressnextday.co.uk product page, September 2026.
- 90cm each for two sleepers: At 180 x 200cm, or 6ft x 6ft 6in, the UK super king gives each of you 90cm, which means you can change position without drifting into your partner's half.
- Distance for restless partners: Individually pocketed springs limit how far movement travels, and the UK super king adds 15cm each over the UK king, putting more mattress between you and a fidgety sleeper.
- Space when children climb in: The UK super king is 30cm wider than the UK king, so a child arriving after a bad dream is less likely to push either adult towards the edge.
- Cooling with a fuller bed: The CoolGel foam layer is designed to prevent heat build-up, which helps when two adults plus a child or a dog would otherwise warm the bed up quickly.
- In proportion in a large room: In a period property or a spacious master bedroom, the UK super king fills the room sensibly where a UK king can look slightly undersized.
This size suits you if...
You share the bed with a restless partner and a UK king still feels crowded, or children and a large dog regularly end up sleeping with you, and your bedroom comfortably clears our suggested 3m x 2.9m.
Consider another size if...
Your bedroom is smaller than our suggested 3m x 2.9m, or you mostly sleep alone. We'd recommend the UK king instead, and we suggest at least 2.7m x 2.9m for it.
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Is the SleepSoul Space 4000 UK super king big enough for two adults and a child?
It's the most comfortable size of this mattress for that. The UK super king gives two adults 90cm each, so a small child in the middle has room without anyone perching on the edge. Because the pocket springs move independently, a wriggling child is also less likely to jolt you awake.
Will I feel my partner move on the SleepSoul Space 4000 super king?
Less than on the smaller sizes. The pocketed springs work independently, which limits how far movement travels, and on the UK super king you each have 90cm. That's 15cm more each than the UK king, and that extra distance helps more than any comfort layer with a genuinely restless sleeper.
SleepSoul Space 4000 UK king or UK super king: which should I buy?
The two are the same length, so the choice is about width. The UK super king is 30cm wider and gives 15cm more each. Pick the UK super king if you share with a restless partner, children or pets and have at least 3m x 2.9m. Otherwise the UK king needs at least 2.7m x 2.9m.
Is the SleepSoul Space 4000 super king good if my dog sleeps on the bed?
The width is what helps most. With 90cm each on the UK super king, a large dog curled at the foot or between you is far less likely to squeeze either sleeper out. The firm pocket spring base also gives a steady surface, and the CoolGel layer is designed to stop the extra body heat building up.
Will a UK super king Space 4000 work in a loft conversion bedroom?
Only if the floor space clears our suggested 3m x 2.9m, ideally nearer 3.5m x 3.2m. In a loft the roof slope usually decides which wall the headboard goes against. At 38cm deep, this mattress sits fairly high once it's on a frame, so check you'll have headroom on your side of the bed as well.