What should be done first on an exterior plaster wall?

Placing jambs and windows is the appropriate first step on an exterior plaster wall. This is critical because these elements need to be installed before applying any finishes to the wall, such as the brown coat. Jambs and windows define the structural openings in the wall, and ensuring they are correctly positioned allows for a seamless integration of the plaster layer around them. If the plaster is applied first, it could lead to complications with fitting the jambs and windows, resulting in improper sealing or additional work needed to accommodate these openings later.

Once the jambs and windows are in position, the brown coat can be applied effectively, as it will provide the necessary base for the finish coat of plaster. The sequence of construction activities is crucial to ensure high-quality results and avoid revisits that could cause delays or increase costs.