When purchasing a bed what size box spring should be used? Remember, when purchasing a bed the slats are not enough to support the mattress. You will always need to use a M.O.O.D. base or appropriate foundation to support the mattress and avoid sagging of the mattress.
A standard box spring is going to be 9" thick and suitable for most all bed purchases. The only times you do not use this is on the following.
When purchasing a bed with storage drawers under the rails.
When a platform bed is purchased.
When using a M.O.O.D. base.
A bunkie board is going to be a thin foundation that is 1" thick and used in the cases below.
When a bunk-bed is using a standard mattress and not a bunkie mattress.
Used on a storage or platform bed.
Used on low profile beds with a thick mattress.
A low profile box spring is thicker version of the bunkie board at 4" thick and is used in the same scenarios as a bunkie board.