History

• Joseph P. Leggett, co-founder of Leggett & Platt in Carthage, Missouri, invented the first commercially-viable, spiral-steel coiled bedspring in 1883. Each spring was a cone-shaped coil formed from interlaced wire. Coils were mounted on a base made of wood. He continued to perfect his springs and received 12 patents by 1901.
  
  In the 1800s, mattresses were constructed from feathers, cotton or horsehair and placed on a cast-iron bed to reduce insect and vermin infestation. Bedsprings provided support and a base for the mattress. It was the precursor for today's boxsprings.
  
  

Function

• The boxspring raises the height of the mattress so it's easier to get in or out of bed and provides a firm structure to keep the mattress from sagging.
  
  Boxsprings also act like a shock absorber on a motor vehicle. It absorbs some of the shock caused when you sit or lay down on the bed. This dissipation of energy prolongs the life of the mattress.
  
  

Engineering

• Manufacturers use technological advances to continually improve mattresses. Many boxsprings are custom-engineered for use with specific mattress models to obtain the best performance and life from the mattress.
  
  

Types

• The least expensive of the boxsprings, a foundation is simply a platform made of wood and covered with fabric. It has no shock-absorbing capabilities, can crack or break, and will eventually squeak.
  
  The semi-flex boxspring is composed of a rigid-steel in the upper structure and a 2-ply wooden base. It is stronger than a foundation boxspring, has more shock-absorbing properties, and is less apt to squeak.
  
  Traditionally used as a boxspring, the coil boxspring has a 2- ply wooden base with wooden cross beams. The top is a steel grid used to stabilize the coils that attach to the cross beams on the base. It offers more protection for your mattress.
  
  A torsion bar boxspring reduces side-to-side motion and creates a solid edge. It constructed with a 2- or 3-ply wooden base. The base has specially-designed steel modules that have engineered twists that provide better resistance and strength.
  
  The steel boxspring is designed to protect your mattress from sagging due to breaks.
  
  

Benefits from Use

• As technology improves the quality and performance of mattresses, prices rise accordingly. Bedsprings preserve your investment.
  
  According to the Better Sleep Council, the foundation absorbs a lot of the wear and tear resulting from use. It also "contributes to the bed's overall comfort and support." The Council's website advises against using an old foundation, pairing your mattress with another boxspring, or adding a board between the mattress and boxspring.
  
  When a mattress is placed on the floor or on a waterbed foundation, there is no dissipation of energy. As a result, a mattress lasts 20 to 50 percent less when used in this fashion.