A be frame or bedstead is the part of a bed used to position a mattress or foundation set off of the floor. Bed frames are typically made of wood or metal. A bed frame is made up of head, foot, and side rails. Most double (full) sized beds, along with all queen and king size beds require some type of center support rail, typically also with extra feet extending down to the floor. Warranties can become invalid if the proper bed frame is not used, and it is suggested that you read your warranty card to confirm whether or not your bed frame is adequate.