Jay-Be Flex Ultra Firm Mattress
Mattress
Jay-Be Flex Ultra Firm Mattress
Size
Firmness
Firm
Construction
Depth (cm)
21
Layers
4
Layer Details
- Advance e-Fibre. A breathable filling layer at the top of the mattress. It lets air move through the surface, which means less heat building up around you overnight.
- Rebound e-Fibre. A second breathable filling layer beneath the surface. It sits between you and the springs, adding a little resilience without softening the extra firm feel.
- High Density e-Fibre. A denser breathable filling layer above the spring core. This is where much of the firmness comes from, giving the surface its solid, supportive character.
- Open coil spring core. A sprung core providing reliable support across the mattress, with 325 springs in the king size. Open coil systems move as one unit, which means a firmer, more traditional feel than pocket springs.
Layer details from furniturevillage.co.uk product page, September 2026.
- The classic shared footprint: At 135 x 190cm, the UK double fits comfortably in rooms where a UK king would crowd the walkways and the wardrobe doors.
- 67.5cm each for two people sharing: Two sleepers get 67.5cm each, workable for couples who sleep still, which back and front sleepers on a firm surface tend to do.
- Slim 21cm depth eases delivery: At 21cm deep this is slimmer than many hybrids, which helps on the turning stairs of older terraces and tight new build landings.
- Breathable where two bodies share: The e-Fibre filling layers let air move through the surface, useful when two people are warming the same 135cm of mattress.
- Firm support for both sleepers: The open coil core keeps the surface consistently hard across the full width, so neither sleeper rolls towards a soft middle.
This size suits you if...
You share the bed every night and both want a properly hard surface, or you sleep alone and want spreading-out room without giving a whole wall to the bed. It also makes sense for a guest room that hosts visiting couples, since a firm, breathable mattress used occasionally stays fresh, and the UK double fits alongside a wardrobe and drawers in a modest second bedroom.
Consider another size if...
You're a couple who wake each other up, since open coils transfer more movement than pocket springs and 67.5cm each leaves little distance between you. We'd recommend the UK king instead, which is 15cm wider and 10cm longer; allow at least 2.7m x 2.9m for it.
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Is the Jay-Be Flex Ultra Firm UK double big enough for a couple?
For most couples, yes, with a condition attached. The UK double gives 67.5cm each for two people sharing, which is comfortable if you both sleep fairly still. The open coil core does pass movement across the bed more than pocket springs would, so restless pairs may prefer the UK king, which is 15cm wider and 10cm longer.
What size room do I need for the Jay-Be Flex Ultra Firm double?
We suggest allowing at least 2.6m x 2.8m, with around 3m x 3m the more comfortable norm. That gives you space to walk around the bed and open drawers, and in most rooms of that size you can still fit bedside tables on both sides of the 135cm-wide mattress.
Will the Jay-Be Flex Ultra Firm double fit up narrow stairs?
It should be easier than most. At 21cm deep it's slimmer than many hybrid mattresses, and the 135 x 190cm footprint is more forgiving on a turning staircase or a tight landing than a UK king would be. Measure any awkward corners on the route before ordering, as with any sprung mattress.
What are the dimensions of the Jay-Be Flex Ultra Firm in a double?
The UK double measures 135 x 190cm, which is 4ft 6in x 6ft 3in. It takes standard double sheets and a 200 x 200cm double duvet, both stocked everywhere at every price, so dressing the bed is straightforward. The mattress itself is 21cm deep, so shallower fitted sheets will still tuck in properly.
Should I get this mattress in a double or size down for a spare room?
If the room mainly hosts visiting couples, stay with the UK double; the firm surface and breathable e-Fibre fillings cope well with occasional use, and two guests get 67.5cm each. If guests are usually solo and the room is tight, the UK single is 45cm narrower and the same length, needing just 2.1m x 2.8m.