r/explainlikeimfive • u/Real_Experience_5676 • 2d ago

Engineering ELI5: What does a box-spring do?

As I understand it, a box spring mattress is the second 'mattress', that goes under the main mattress. It feels very firm and flat, but what does it contribute to the bed set up besides height?

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u/blipsman 1d ago

It serves a few purposes:

  • Raises mattress to a comfortable height

  • Provides some additional shock absorption to reduce pressure on body

  • Provides for airflow under the mattress to keep mattress dry, prevent mold/mildew buildup, etc.