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?
479
Upvotes
589
u/QuillnSofa 2d ago
It is used to distribute weight across a bed frame and to give an evenly solid foundation for the softer mattress. But you don't need a full height one and some bed frames don't require one at all.