The base of the bed on which the mattress is placed is called the foundation. It is a box made of wood and many wooden panels on the side to provide a flat surface for the mattress. It is very much like the box spring but differs in its function.It is structured to support the mattress unlike the box spring which acts as a shock absorber and adds more spring to the mattress.

The supporting role

In earlier days the box spring was used to provide support but, it

it only carried the body weight and acted as a shock absorber. With the evolving trends, the box spring gave way to the foundation which actually provided the support for the mattress by evenly distributing the weight of the body and reducing the pressure on the spine. They do not have any springs but, they provide thicker and stronger support for the mattress.

Suitability

The foundation is not suitable for all mattresses. For example, it is not suitable forfor memory foam mattress and flip- pillow top mattresses. They are more suited for coir mattress and even inner spring mattresses. It is advantageous for those who require a firm or rigid surface to sleep on.

Structure

The foundation which evolved from the box spring is often structured like a grid which holds the mattress firmly. It lets the mattress feel soft and pliant without giving it much flexibility. They are made of V shaped steel segments that make up the grid. These not only provide support, they also enhance the longevity of the mattress. Not all foundations follow the grid structure. Some of them are made of wood, especially when zero flexibility is called for.

Type of mattress

Most of the time, foundation accompany the mattress that you purchase. Memory foam mattresses without springs require a firm and rigid base or foundation like those made of wood. Mattresses with inner springs require foundation with a little flexibility like the grid structured ones. The innerspring mattresses feel comfortable with a foundation since most of the weight is absorbed by the foundation and this influences the way the mattress yields to the body contours.

Longevity

The foundations are generally built to last very long, however, it is always better to change them if they are over years, as they might have developed cracks or loosened up a bit which would affect the behavior of the mattress.