Ever wondered why some mattresses last for years while others sag within a few months? The secret often lies in foam density. It might sound like a technical term, but it’s actually one of the biggest factors that determine how supportive, comfortable, and durable your mattress will be.
At Sloom, we believe that when you rest better, you become a better version of yourself. That’s why we build our mattresses with premium, pure foams that stay comfortable and supportive for years.
What Is Foam Density, Really?
Foam density is a measurement of how much raw material goes into a specific volume of foam, usually expressed in kilograms per cubic metre (kg/m³).
Think of it like baking bread. A dense loaf feels heavy and satisfying, while a light loaf is airy but doesn’t last as long. Foam works the same way - the denser it is, the more supportive and durable it will be.
It’s important to remember that density is not the same as firmness. You can have a high-density foam that feels soft, or a low-density foam that feels firm. Density is about quality and durability, not just how the mattress feels on the surface.
The Confusion: Fillers and Marketing Trick
In South Africa, most foams contain fillers to artificially bulk up the density. This tricks buyers into thinking they’re getting quality, when in reality the foam won’t last.
If a manufacturer doesn’t specify 100% pure foam, it almost certainly contains fillers. That’s why Sloom only uses pure foams. You get genuine density and durability, with no compromise on comfort.
Types of Foam and Their Densities
1. Polyfoam (Polyurethane Foam)
- Common and affordable, but quality varies widely.
- In South Africa, many brands call 23–28kg/m³ “high density,” but globally, true high density starts around 30–35kg/m³ and above.
- At Sloom, we use 33kg/m³ pure polyfoam as the supportive core and 35kg/m³ pure polyfoam for our firm comfort layer, giving you real, long-lasting performance.
2. Rebond Foam
- Made from recycled waste foam, pressed into a block.
- Very firm, with densities between 40–100kg/m³.
- Cheaper but not premium, and often uncomfortably hard for most sleepers.
- You’ll never find rebond foam in a Sloom mattress.
3. Latex Foam
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Can be natural (from rubber trees) or synthetic.
Natural latex is premium but expensive in South Africa. - Synthetic latex offers similar elasticity at a better value.
4. HR Foam (High Resilience Foam)
- A premium polyurethane foam with excellent elasticity.
- Distributes pressure evenly and absorbs motion for less partner disturbance.
- Breathable and cooler than standard foams.
- Sloom uses a 55 density HR Foam, designed to combine the best of latex and premium support.
5. Memory Foam (Viscoelastic Foam)
- Contours to your body and relieves pressure points.
- Much denser than polyfoam, typically ranging from 30–100kg/m³.
- Good quality memory foam should be at least 50kg/m³ for durability.
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In the Sloom Original Mattress, we use 55kg/m³ memory foam for the perfect balance of contouring and support.
Why Foam Density Matters for You
A mattress made with high-density, pure foam will:
- Last longer without sagging
- Provide consistent spinal support
- Reduce pressure points on shoulders and hips
- Resist flattening, so you don’t feel like you’re “sleeping in a ditch"
According to the Sloom Sleep Survey, South Africans rate comfort and support as the most important factors when it comes to sleep. Foam density directly impacts both - which is why choosing the right mattress makes such a difference.
The Sloom Difference
We designed the Sloom Original Mattress to solve South Africans’ biggest frustrations: sagging, discomfort, and the inability to adjust your comfort once you’ve bought a mattress.
That’s why it’s modular, giving you three comfort options (soft, medium, firm) in one mattress. Combined with premium, high-density foams, it’s built to give you better sleep for years to come.
Foam density might sound technical, but it comes down to one simple truth: the denser and purer the foam, the better your sleep will be. At Sloom, we don’t just build mattresses - we build solutions for better rest, because when you rest better, you really do live better.
Ready to experience the difference? Explore the Sloom Original Mattress today.