The topping-out ceremony is held when the last beam or equivalent is put in place within the structure. Alternatives can include a ceremonial pour of the last section of concrete or laying the last block or brick. Essentially it signals the frame of the new building reaching its maximum height and while at this stage, much of the rest of the construction is still unfinished, an important milestone in the project has been attained.
The origins of the ceremony can be traced back many centuries across multiple cultures, including ancient Egypt and the Americas. However, most sources reference the Scandinavian practice of placing an evergreen tree atop a new building, in a bid to rehouse any tree spirits displaced when the required timber was lumbered. The tradition then migrated across Northern Europe and then the Americas.
Today the practice provides a great PR opportunity for the client, contractor, subcontractors and design team, as well as celebrating the achievement of reaching the highest point of a new building. Given that buildings seem to be getting ever taller, this is no mean feat.