Mattress Online Rock Hard Mega Firm 1500 Pocket Mattress
Mattress
Mattress Online Rock Hard Mega Firm 1500 Pocket Mattress
Size
Firmness
Firm
Construction
Depth (cm)
25
Layers
2
Layer Details
- Comfort Layer. Soft white fibre fillings, finely filled with high density compressed polyester. This gives a thin layer of cushioning over the springs, which means you'll feel comfort at the surface but firmness underneath rather than a plush, sink-in feel.
- Support System. 1500 pocket springs that gently contour around your body for personalised support. Because each spring moves independently, you get support matched to your shape and less motion transfer if you share the bed.
Layer details from mattressonline.co.uk product page, September 2026.
- Fits a crowded small room: At 90 x 190cm, the UK single leaves floor space for a desk, wardrobe or toy storage, and we suggest allowing at least 2.1m x 2.8m.
- Firm support for one: All 1500 pocket springs sit beneath a single sleeper, which means firm, independent pushback under heavier areas like the hips without anyone else's movement to feel.
- Two singles for a guest room: A pair of UK singles lets two friends or siblings each have their own firm surface, although you'll need space for a walkway between them.
- Steady edges on a narrow bed: Steel piping around the border helps the sides hold their shape, which matters a little more on a 3ft wide bed where you're closer to the edge.
- Suits a study that doubles as a spare room: A UK single keeps the bed compact, so a home office can take an overnight guest without the bed taking over the room.
This size suits you if...
you sleep alone on your back or front and want a properly solid surface, or you're furnishing a teenager's room, a student room or a spare room where floor space is tight and a 3ft wide bed is all that fits.
Consider another size if...
you're an adult who sprawls, or you often share the bed with a partner or child. The UK small double would suit you better; we suggest at least 2.4m x 2.8m for it.
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Is the Rock Hard Mega Firm UK single too firm for a child?
It may be. Mattress Online describes it as extra firm, and lightweight side sleepers are likely to find it hard at the shoulder and hip. Children are usually light, so this UK single is better matched to an older child or teenager who sleeps on their back or front.
Will a Rock Hard Mega Firm UK single fit a cabin bed or mid sleeper?
The UK single's 90 x 190cm footprint matches standard single frames, but the mattress is 25cm deep. Raised frames often set a maximum mattress depth to keep the safety rail effective, so check your frame maker's guidance before buying.
How much room do I need for a Rock Hard Mega Firm UK single?
We suggest allowing at least 2.1m x 2.8m of floor space for a UK single. That leaves room to get in and out comfortably, with space left over for a desk or wardrobe in a small bedroom.
Is a UK single big enough for an adult on a firm mattress?
For one adult who sleeps fairly still, yes, at 3ft x 6ft 3in. A firm surface means you won't sink in, so you'll feel the edges clearly. If you want more width, the UK single is 30cm narrower than the UK small double.
Can a single Rock Hard Mega Firm go under a sloping loft ceiling?
A 90cm wide UK single is one of the easier sizes to fit under a slope, because you can tuck the long side against the low wall. Measure the usable headroom where you'll sit up, since the firm surface won't compress much beneath you.