MattressNextDay Super Firm Foam Mattress
Mattress
MattressNextDay Super Firm Foam Mattress
Size
Firmness
Firm
Construction
Depth (cm)
20
Layers
Layer Details
- Deep Reflex Foam. Deep reflex foam gently contours your body without compromising the extra firm feel, which means you get personalised pressure relief across your entire body while the surface stays supportive. Reflex foam is denser and springier than standard memory foam, so you won't feel stuck in one position.
Layer details from mattressnextday.co.uk product page, September 2026.
- Fits raised frames: At 20cm deep with no springs, it sits comfortably within the safety rail limits most bunk, cabin and mid sleeper frames specify.
- Firm support for growing sleepers: The extra firm reflex foam gives children and teens a flat, supportive surface rather than a soft one they sink into.
- Room to live around it: At 90cm wide, a UK single leaves floor space for a desk, wardrobe and toy storage in even a small child's bedroom.
- Light enough to move: An all-foam single is the easiest build to carry upstairs, useful for lofts, student rooms and first flats where you supply your own mattress.
- Cheap, easy bedding: Standard single sheets and a 135 x 200cm duvet fit, and they're the most widely stocked bedding of any UK size.
- Guest room friendly: Two singles fit a spare room where one bigger bed wouldn't, and the firm surface suits occasional guests of most sleep styles.
This size suits you if...
You're buying for a child or teenager who needs a firm, flat surface, especially on a bunk or mid sleeper where a 20cm all-foam build fits safely. It also suits solo adults who sleep on their back or front and want real resistance, or a spare room, study or loft conversion where 90cm of width is all the space allows.
Consider another size if...
You're an adult who shares the bed, or you spread out in your sleep and find 90cm restrictive. We'd recommend the UK double instead: it's 45cm wider at the same length, giving 67.5cm each for two, and needs a room of at least 2.6m x 2.8m.
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Will the MattressNextDay Super Firm fit a bunk bed in a UK single?
Yes, in most cases. The UK single measures 90 x 190cm, the standard bunk size, and at 20cm deep this all-foam mattress usually sits below the safety rail height that bunk and mid sleeper frames require. Check your frame's stated maximum depth before ordering, as a few children's frames specify less.
Is the UK single of this mattress suitable for a child?
For older children and teens, yes. The extra firm reflex foam gives a flat, supportive surface without the soft sink that can encourage poor sleeping posture, and it's hypoallergenic, which helps if your child has allergies. Very light children may find the surface a little hard at first, so bear their weight in mind.
How much room does a UK single mattress need?
We suggest allowing at least 2.1m x 2.8m of floor space, which gives you walking room alongside the bed. That makes the UK single the easiest size to fit under a loft slope, into a box room, or into a spare room alongside a desk. Two singles will fit where one double often can't.
Can an adult sleep comfortably on this mattress in a single?
A solo adult who sleeps on their back or front and likes a hard surface can, and at 190cm long it suits most heights. If you change position a lot in the night, 90cm of width is limiting, so consider the UK double, which is 45cm wider at the same length.
Where can I buy this mattress in a UK single?
Compare the retailers listed on this page. The prices shown here are live and updated as retailers change them, so it's worth checking back if you're not buying today. Stock and pricing for the UK single can differ from the UK double and UK king, so check the size you want specifically.