Sofa Bed Mattress Types Explained

The mattress decides whether a sofa bed is pleasant to sleep on. The mechanism gets the attention, but it is the mattress you lie on. Here is what each type is really like, without the marketing language.

Foam

Standard polyurethane foam is the most common sofa bed mattress, because it folds well and keeps the sofa light.

• Feels like — firm and even, with no give in any particular spot.
• Good for — occasional guests, children, and anyone who prefers a firm surface.
• Watch out for — low-density foam, which softens within months. Depth is the usual clue: anything under 8cm is almost always a basic foam.

A good-quality foam at 12cm or more is perfectly comfortable. A thin, cheap foam is where the sofa bed's bad reputation came from.

Memory foam

A layer of temperature-sensitive foam, usually on top of a firmer foam base.

• Feels like — it moulds to your shape and takes pressure off hips and shoulders.
• Good for — side sleepers, and anyone with aches who finds firm surfaces uncomfortable.
• Watch out for — heat. Memory foam holds warmth, which is lovely in January and less so in July. Also check how thick the memory layer actually is; 2cm on top of 6cm of basic foam is a memory foam mattress in name only.

Sprung (open coil)

Traditional springs linked together, with padding above.

• Feels like — bouncier and more like a conventional bed than foam.
• Good for — regular use where you want a familiar mattress feel.
• Watch out for — because the springs are joined, movement travels across the bed. Two people will feel each other turn over.

Pocket sprung

Each spring sits in its own fabric pocket and moves independently.

• Feels like — the closest thing to a real bed. Supportive, and movement stays where it happens.
• Good for — couples, and anyone sleeping on it most nights.
• Watch out for — weight and price. Pocket sprung sofa beds are heavier to open and cost more. They are also less common, because the mattress has to be thick enough to be worth it, which limits how tightly it folds.

Depth: the number that matters most

Whatever the type, depth tells you more than the name does.

• Under 8cm — a few nights a year.
• 10–14cm — regular guests and weekends.
• 15cm and above — suitable for everyday sleeping.

A 15cm basic foam will usually beat a 7cm "memory foam" mattress. If you only check one specification, check this one.

What is underneath also counts

Even the best mattress feels poor over widely spaced metal bars. Ask whether the base is slatted, boarded, or barred, and how far apart the supports sit. This is the most common reason a sofa bed that looked right on paper is uncomfortable in practice.

Which should you choose?

• Guests a few times a year — foam, 10cm or more. Do not overspend.
• Weekly use — foam or memory foam at 12–15cm.
• Someone sleeping on it most nights — 15cm or deeper, pocket sprung if you can, memory foam if not.
• Two adults sharing regularly — pocket sprung, or a deep memory foam.
• A hot sleeper — avoid memory foam; choose sprung or a good foam.

The cheapest upgrade there is

If you already own a sofa bed and it is not quite comfortable, a 5cm mattress topper will usually fix it for a fraction of the cost of replacing the sofa. Roll it up and keep it in the storage box. This is honest advice, not a sales line — if a topper solves your problem, buy the topper.

Ask us for the real numbers

We will give you the actual mattress type, depth and base construction for any piece we sell, before you order. You can browse the range on our sofa beds page, and there is more in our sofa bed buying guide and our guide to everyday sleeping comfort.