Daybeds are a type of mattress frame with three panels -- two on the ends of the bed and one going down the length. Daybeds are designed to be used as sofas during the day and slept on overnight. Daybed construction can vary, and a box-spring foundation is rarely, if ever, necessary.
Why a Box Spring Isn't Used
The daybed construction does not require a box spring, the reason being that the box spring would raise the height of the mattress too much and make it difficult to use it as a sofa. The space beneath the daybed frame is often used for storage with drawers. A trundle is common beneath the frame as well. A trundle stores an extra mattress beneath the frame and hides it inside the construction with paneling matching the frame design.
In lieu of a box spring, the daybed uses a special spring design foundation. The link spring on a daybed is a mechanism that attaches to both end panels to provide the necessary foundation. Link springs look like an interwoven metal grid that can provide the space for storage or a trundle beneath the frame while providing adequate support to the mattress. Most daybeds are designed for a twin-size mattress and are constructed with this frame type.
An alternative on some daybed designs is the use of slats. Some metal daybeds may have slats welded into the frame instead of the link springs, and some designs may be open to allow the use of your choice of slats. An open-framed daybed can theoretically utilize a box-spring, but it will make the bed high and uncomfortable to use as a sofa. The slats are sold in a degree of quality woods, ranging from cost-effective pine to more durable and flexible woods such as birch.
Daybeds don't usually come in sizes bigger than a twin because it will add too much depth to the bed when it's used as a sofa. Daybeds can be constructed in wood, metal or a combination of both materials. For those who prefer a firm bed base, slats may provide a better alternative. Slats allow you to alter the firmness of your base depending on how far the slats are spread apart and by the type of wood you use.