Rest Assured Kelbrook Super King Mattress
The Rest Assured Kelbrook is an extra firm pocket spring mattress built around 1400 pocket springs, which means each spring moves independently, so you get support that follows your shape rather than one solid push-back.
- Extra-firm for back & front sleepers
- Wool fillings help you stay cool
- Minimises partner disturbance
£733.50
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Rest Assured Kelbrook Mattress
More available sizes
Mattress details
Mattress
Rest Assured Kelbrook Mattress
Size
Firmness
Extra Firm
Construction
Pocket Spring
Depth (cm)
Layers
2
Layer Details
Pocket springs
A core of 1400 pocket springs, each sewn into its own fabric pocket so it compresses independently. In practice this means support that adjusts to where you place weight, and less motion transferring across the bed.
Wool fillings
Wool fillings sit above the spring unit, softening the surface slightly without undermining the extra firm feel. Wool also wicks moisture and breathes well, which helps if you tend to overheat at night.
Layer details from mattressman.co.uk product page, September 2026.
Key benefits
- A full 90cm each: Two adults each get 90cm of width, so a partner who kicks or turns all night is further away before the springs even come into play.
- Springs that keep movement local: The 1400 pocket springs move independently, which means a restless sleeper's shifting is less likely to travel across such a wide surface to you.
- Room when the children wander in: A small visitor can squeeze into the middle without either adult ending up clinging to the edge, although lightweight children may find the extra firm feel a little hard.
- Space for a large dog: If a big dog sleeps on the bed as routine, the extra width means sharing no longer costs you your own sleeping space.
- Wool helps a crowded bed stay cooler: More bodies means more heat, and the wool fillings breathe better than synthetic alternatives, so a full bed should feel slightly less stuffy.
- Suits a generous room: In a large master bedroom or period property, a UK king can look undersized, while the UK super king fills the wall in proportion.
This size suits you if...
You share the bed with a genuinely restless partner, or children and pets regularly join you in the night, and you both like a firm surface on your back or front. It also suits you if your bedroom comfortably clears our suggested 3m x 2.9m minimum.
Consider another size if...
Your bedroom falls short of 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 a UK king.
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FAQ's
Kelbrook super king vs king: how much more space do you get?
The UK super king is 30cm wider than the UK king, and both are the same length. For two people sharing, that works out at 15cm more each, taking you from 75cm each on the UK king to 90cm each on the UK super king. You gain width only, so taller sleepers won't notice any difference at the foot.
Is the Rest Assured Kelbrook super king big enough for two adults and a child?
For occasional visits, yes. With 90cm each for two adults, a small child can fit between you without anyone being pushed to the edge. Bear in mind the Kelbrook is extra firm, and a lightweight child is likely to sit on top of it rather than sink in, so it may feel harder to them than it does to you.
Will a restless partner disturb me less on a super king Kelbrook?
Probably, yes. Distance is the simplest fix for a fidgety partner, and the UK super king gives you 90cm each. The 1400 pocket springs also compress independently, so movement tends to stay on your partner's side. Neither removes disturbance entirely, but together they should make it much easier to ignore.
Does a UK super king mattress fit in a loft conversion bedroom?
It can, but the sloping ceiling usually decides where it goes. Place the headboard against the tallest wall so neither of you sits up into the slope, and measure the full-height floor area rather than the whole room. We suggest at least 3m x 2.9m, with around 3.5m x 3.2m feeling more comfortable.
Is the Kelbrook super king a good choice if my dog sleeps on the bed?
If a large dog joins you every night, the UK super king's 180cm width means the dog's spot doesn't come out of your share. The extra firm surface also stays fairly level under paws rather than sagging where the dog lies. Keep in mind a heavy dog shifting about will still be felt a little.