Topping out

In building construction, topping out (sometimes referred to as topping off) is a builders' rite traditionally held when the last beam (or its equivalent) is placed atop a structure during its construction. Nowadays, the ceremony is often parlayed into a media event for public relations purposes. It has since come to mean more generally finishing the structure of the building, whether there is a ceremony or not. It is also commonly used to determine the amount of wind on the top of the structure.