What is the term for bracing that prevents joists from moving side to side?

The term that describes bracing used to prevent joists from moving side to side is known as bridging. This technique involves installing diagonal members between joists to provide lateral support. Bridging serves to stabilize the joists, reducing the risk of twisting or shifting, which can lead to structural issues or sagging in the floor system. It is a critical practice in carpentry and construction that helps maintain the integrity and stiffness of floors and ceilings.

Other terms provided in the choices refer to different practices or components in carpentry. For instance, boxing typically refers to the framing around a structural element, while trimming involves finishing work that includes the installation of moldings or casings. Tailing is not a recognized term in this context and may lead to confusion, as it does not relate specifically to bracing or structural stability. Thus, bridging is correctly identified as the practice necessary for preventing side-to-side movement of joists.