Kaymed Heavy Sleeper 1200 Pocket Hybrid Mattress
Mattress
Kaymed Heavy Sleeper 1200 Pocket Hybrid Mattress
Size
Firmness
Firm
Construction
Depth (cm)
33
Layers
3
Layer Details
- Knitted cover. A soft knitted finish that adds a touch of cosiness and warmth on the surface. It's designed to help with airflow and breathability too, which matters on a firmer mattress where you sleep more on top than in it.
- Reflex Foam. A layer of high density reflex foam that supports spinal alignment, which means your back stays in a healthier position through the night. It's firm and durable rather than plush, so expect a solid feel from the first night.
- Pocket Springs. 1,200 individual springs, each encased in its own cloth pocket, adapt to your movement independently. That gives personalised support to different parts of your body and helps limit motion transfer from a partner.
Layer details from mattressonline.co.uk product page, September 2026.
- Room to share without dominating the bedroom: At 135 x 190cm, the UK double leaves space for wardrobes and drawers in a typical room, which matters more with a firm mattress you sleep on top of.
- 67.5cm each for two people sharing: Two sharers get 67.5cm of width apiece, and the 1,200 pocket springs respond to each of you separately, so one partner's movement is less likely to wake the other.
- Bedside tables on both sides, usually: We suggest a room of at least 2.6m x 2.8m for a UK double, which in most bedrooms still leaves room for a table each side.
- A substantial presence on the frame: The 33cm depth gives the double a hotel-style profile on a standard 4ft 6in frame, so it looks and feels more solid than the size name suggests.
- Easy to dress: Double sheets and a 200 x 200cm duvet are stocked everywhere at every price, useful if you're furnishing a whole home and the budget is stretched thin.
- Live prices on this page: The prices shown here update as retailers change them, so compare the listings before you buy rather than relying on a figure you saw last week.
This size suits you if...
You share the bed every night and your room sits around the 2.6m x 2.8m minimum we suggest, so a UK king would feel cramped. It also suits a solo sleeper who likes to spread out, or who shares with a dog or cat that has claimed a corner, since the firm surface stays stable however the space gets divided.
Consider another size if...
You and your partner both like space and your room comfortably clears 2.7m x 2.9m. We'd recommend the UK king instead: it's 15cm wider and 10cm longer than the UK double, which taller sleepers will notice at the foot end.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
Is the Kaymed Heavy Sleeper 1200 double big enough for a couple?
Yes, for most couples. You each get 67.5cm of width, and because this is a firm mattress with 1,200 individual pocket springs, you sleep on top of the surface rather than rolling towards the middle. Larger-framed sharers, the very sleepers this mattress is built for, may prefer the extra 15cm of width the UK king offers.
What room size do I need for the Kaymed Heavy Sleeper 1200 in a UK double?
We suggest at least 2.6m x 2.8m, with around 3m x 3m the comfortable norm. That's our guidance rather than Kaymed's, and it allows for walking space and bedside tables on both sides. In a first flat or second bedroom with a wardrobe and drawers to fit in, the UK double usually works where a UK king wouldn't.
Should I choose the UK double or the UK king in this mattress?
It mostly comes down to your room. The UK double is 15cm narrower and 10cm shorter than the UK king, and we suggest at least 2.7m x 2.9m for the UK king. If you're tall, that extra 10cm of length is the bigger difference. If your room is average-sized or you're buying solo, the UK double is the better balance.
Will the double size fit up narrow stairs?
It's the easiest of the shared sizes to manoeuvre, but at 33cm deep with a full spring unit it won't fold or squash the way an all-foam mattress does. Measure any turning stairs or tight landings before ordering, especially in older terraces. Kaymed doesn't publish a weight for this mattress, so plan for two people to carry it.
How much bigger is the double than the small double?
The UK double is 15cm wider than the UK small double, and both are the same length at 190cm. For two people sharing a firm mattress like this one, that extra width is meaningful: you sleep on the surface rather than sinking in, so shoulder room matters more than it would on a softer bed.