Types of Mattress Construction

Water Beds

• There are several types of water beds, each constructed differently. WaterBeds.com lists six types of water beds: free flow, semi-waveless, waveless, shallowfill, midfill and deepfill. All use durable vinyl and seaming to ensure longevity and avoid leakage. A free flow mattress is filled with water and has no other layers. The semi-waveless mattress combines a water filled-core with a fabric layer to stop movement after a few minutes. Shallowfill water beds are constructed by placing vinyl tubes between a foam and fiber frame and have a depth of 3 1/2 to 4 1/2 inches. In a midfill water bed, 5 to 6 inches of water depth controls the firmness of the pillowtop mattress. In the deepfill mattress, fiber and foam cover a core capable of holding 7 to 8 inches of water.

Futon Mattresses

• Most futon mattresses are constructed from compressed foam covered by cotton, wool or synthetic fibers in different combinations for comfort and flexibility, as they are used for both sleeping and sitting.

Air Beds

• Air beds have an air-filled core that supports the mattress and can be adjusted to suit individual sleepers. Luxury models cover the air chambers with several inches of foam and a quilted top cover. The air serves to harden or soften the surface of the mattress.

Innerspring

• Innerspring mattresses are encased in layers of upholstery which insulate steel springs and protect the sleeper's body. This the the common type of mattress.

Foam

• Foam mattresses can be made from a solid core or from several layers of various types of foam, says The Better Sleep Council. Memory foam, or visco-elastic foam, has "billions of small, open cells (bubbles with holes in them), tightly packed together," according to MyFoamMattress.net. The air compresses, allowing the the foam to conform to the sleeper's body and distribute the weight evenly.