Why is a rolled-up mattress uneven on the surface after being unpacked?

Rolled-up mattresses can be uneven initially due to compression, material memory, and improper expansion—here’s a clear breakdown:

Core Reasons for Unevenness

1. Compression Memory: Mattresses are tightly rolled/packed for shipping, compressing layers (foam, coils, padding) for weeks/months. Materials retain this compressed shape temporarily after unpacking.
2. Layer Shifting: Foam or padding layers may shift slightly during rolling/transport, creating small lumps or gaps that appear as unevenness.
3. Incomplete Expansion: Most mattresses need 24–72 hours to fully expand (called “off-gassing” period). Jumping on or using it too soon interrupts this process.
4. Coil Settling (Hybrid Mattresses): Pocketed coils in hybrid models may be compressed unevenly during packing, requiring time to spring back to their original position.

How to Fix It

• Let it rest: Leave the mattress uncovered in a well-ventilated room for 24–72 hours (follow the brand’s guidelines).
• Avoid pressure: Don’t sleep on, sit heavily on, or move the mattress during expansion.
• Flatten gently: If small lumps remain, press down lightly on uneven areas to encourage layers to settle.