How Do I Make My Mattress Harder?

Place a bed board or a piece of plywood between the mattress and the box spring. This will help add support to the mattress without feeling the effects of the rigid materials. Wooden or plastic bed boards can be purchased at many mattress stores.

Flip the mattress. Many times a mattress will wear unevenly and will be much firmer on one side than the other. Flipping a mattress once a month will also ensure the mattress wears evenly, which will make it last several years longer.

Remove the mattress from the bed, drag it outside or into the basement and hit it repeatedly with a blunt object, such as a baseball mat. This will help realign any springs that have been warped or damaged and it will help disperse any filling inside the mattress. This method will also help remove dust mites or allergens from the mattress, which will help allergy sufferers.

Replace the box spring under the mattress. Many times the mattress itself is firm and the box spring is causing the sagging issue.