Which of the following is NOT a method for tying scaffolds to buildings?

In the context of scaffold construction, tying scaffolds to buildings is essential for ensuring stability and safety during their use. The methods for tying scaffolds typically focus on securely anchoring the scaffold to the structure to prevent movement or collapse.

The box tie method involves securing the scaffold to the corners of a building, providing enhanced stability at critical points. The column tie method connects the scaffold to vertical elements of the building, such as columns or wall supports, ensuring that the scaffold remains rigid and stable. The U tie method is employed to anchor the scaffold to the structure in a way that resembles a 'U' shape, which allows for secure connection while accommodating some building features.

In contrast, the arch tie is not recognized as a formal method for tying scaffolds to buildings. While arch structures exist in construction, the term "arch tie" does not correspond to a standard practice for securing scaffolding. This distinction highlights the primary focus on methods that directly relate to enhancing scaffold stability by leveraging existing building structures. Thus, identifying the arch tie as not being a method associated with tying scaffolds makes it the correct choice in this context.