I hate saggy shelves, and so does my last client who wanted her TV shelf (originally made by some other carpenter) replaced due to excess sagging.This project was a simple replacement of existing elements with the addition of a little “guaranteed-not-to-sag” built in. This illustrates why I like the traditional style of cabinetry over the “european” style. The original shelves were built in the european style (ie, no face frame) and a bit shoddily as well. As a result, the TV shelf bowed badly which presented both aesthetic and safety issues.
I used a face frame glued to the front face of the shelves which not only added beam strength to the shelf, but added visual weight as well. Additionally, I added a frame to the back edge of the unit (both above the main shelf and below it) to add even more stiffness and to add architectural detail to the large space of the main rectangle.
If it can hold me without sagging, it will hold a TV, no problem.