Describe step by step how the joints between sheets of gypsum board are made invisible. List the potential range of functions of a finish ceiling and of a finish floor. What are the advantages and disadvantages of a suspended ceiling compared to those of a tightly attached ceiling? When designing a building with its structure and mechanical equipment left exposed at the ceiling, what precautions should you take to ensure a satisfactory appearance? What does underlayment do? How should it be laid? List several different approaches to the problem of running electrical and communications wiring beneath a floor of a building framed with steel or concrete.